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+*** START OF THE PROJECT GUTENBERG EBOOK 78966 ***
+
+
+
+
+[Illustration: HIPPOCRATES
+
+Ἢν γὰρ παρῇ φιλανθρωπίη πάρεστι καὶ φιλοτεχνίη.
+
+Where the love of man is, there also is love of this Art.
+
+Παραγγελίαι, i.e. _Precepts_ (Hippocratic Collection), § 6
+
+]
+
+
+
+
+                                 A SHORT
+                           HISTORY OF MEDICINE
+
+                    INTRODUCING MEDICAL PRINCIPLES TO
+                    STUDENTS AND NON-MEDICAL READERS
+
+                                   BY
+
+                             CHARLES SINGER
+                       M.A., M.D., D.LITT., OXFORD
+
+           FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS OF LONDON
+                   LECTURER ON THE HISTORY OF MEDICINE
+                       IN THE UNIVERSITY OF LONDON
+
+                Scire potestates herbarum usumque medendi
+                 Maluit et mutas agitare inglorius artes
+
+           _It was his part to learn of the power of Medicine
+              and of the manner of healing and, heedless of
+                   glory, to exercise that quiet art._
+                       Virgil, _Aeneid_ xii, 396-7
+
+                                NEW YORK
+                         OXFORD UNIVERSITY PRESS
+                             AMERICAN BRANCH
+                                  1928
+
+
+
+
+                             COPYRIGHT, 1928
+                       BY OXFORD UNIVERSITY PRESS
+                             AMERICAN BRANCH
+
+
+                 PRINTED IN THE UNITED STATES OF AMERICA
+
+
+
+
+PREFACE
+
+
+The position that Medical Science has now assumed in the social polity
+demands that all educated men and women should have some knowledge
+of the subject, whether they have had a medical training or no. In
+these pages the author seeks to place before the reader, who is
+without special knowledge, some account of Medicine as a Science. For
+this purpose the historical method is peculiarly suited, since it
+recapitulates, in some measure, the actual stages through which each
+learner must pass. Though the story told here opens with Greek times,
+the narrative of the earlier period is so condensed that more than
+half the book is devoted to modern Medicine, which is presented as a
+natural outgrowth of an ancient tradition. An attempt has been made to
+keep the account as simple and as elementary as possible and to make
+the smallest demands on the scientific equipment of the reader. The
+slight divergence, in some matters, of the interests of American and of
+English readers, has been held in mind, so that, it is hoped, the book
+may be useful to both classes.
+
+Throughout the work two particular aims have been steadily kept in
+view: first, to stress the principles of Medicine rather than the
+details of practice; second, to treat of those principles in as small a
+space as may be. For ‘principles’ the author has substituted at times
+the word ‘Philosophy.’ He would, however, beseech the timid reader
+to take no alarm at a word, for he employs the term ‘Philosophy’ in a
+time-honored fashion, and he undertakes not to plunge deep into the
+labyrinth of Metaphysic. The Philosophy of Medicine stands here for the
+disinterested study of the theory of the subject, without reference to
+its application to particular instances.
+
+Certain omissions in the book are justified by the author’s forthcoming
+publication of a history of the biological sciences treated along
+somewhat similar lines. It has thus, for example, seemed superfluous to
+include here any but casual references to such highly important topics
+as the study of hereditary characters or the experimental investigation
+of developmental defects. It is, however, the duty of the author
+to direct attention to certain other omissions necessitated by the
+compression of the work into a small compass. The history of Medicine,
+as here treated, is essentially a history of ideas. The personal
+element has been kept wholly in the background and very little space
+has been allotted to biographical matter. Nor do the limits of the book
+permit any discussion of the status of medical men, and very little
+even of their training. On this account many who in their day were
+remarkable rather for the influence they exerted than for the advances
+in knowledge which they initiated find no commemoration here. This line
+of treatment has involved omission of reference to those teachers to
+whom the author himself owes most, Sir William Osler and Sir Clifford
+Allbutt.
+
+A work on Medicine must be colored, in some degree, by its author’s
+conception of the nature of Life. On this theme there are divers views,
+for the full discussion of which there is here no place. The author
+professes himself, however, an adherent of a school of thought that is
+not, at present, greatly in fashion. He ranges himself as a vitalist
+under the banner of Aristotle and as a follower in the goodly company
+of Harvey, Hunter and Virchow, of Claude Bernard and Johannes Müller.
+He believes that there is a principle in living things that cannot
+be expressed in chemical or physical terms. He believes that this
+principle works to an intelligible end, that it is an _Entelechy_, an
+indwelling purposiveness, and that it is as real a thing as anything
+that is.
+
+_They are right who hold ‘soul’ to be not independent of body and yet
+not a kind of body. ‘Soul’ is not body but something pertaining to the
+body and dwelling therein, and, what is more, specific to each body.
+Our forebears erred in seeking to fit the ‘soul’ into a body without
+regard to the nature and qualities of the body, for the association
+of ‘soul’ and body is by no means thus at random. And so indeed we
+might expect, for the ‘Entelechy’ of each being comes naturally to be
+developed in the potentiality of each being, that is to say in the
+matter proper to it. Whence is manifest that the ‘soul’ is a certain
+‘Entelechy’, a notion or form of that which has capacity to be endowed
+with ‘soul’._ Aristotle, Περὶ Ψυχῆς, _II_, § 2.
+
+The author is well aware that this conception is neither useful
+nor helpful for physiological research in the present state of our
+knowledge. That is a very good reason for excluding it, as the vitalist
+Claude Bernard excluded it, from the physiological laboratory. But
+it is not a good reason for abandoning a point of view which does
+something to make existence intelligible. On the contrary, turning from
+the physiological laboratory to the living being as a whole, it is just
+the indwelling purposiveness that is, before all things, most worthy of
+consideration. Every function, every structure, every instinct, habit,
+or reflex, every mental activity that is related to health--and which
+is not?--may throw some light thereon. It appears to the author that
+the scientific method is by far the mightiest weapon that has as yet
+come within man’s grasp, for the illumination of these multitudinous
+entities. The searching accuracy and power of that superb instrument,
+wielded by human reason in the quest of human health, is the theme of
+this volume. And yet, notwithstanding its triumphs, the experimental
+method, as applied in the separate sciences, has, of its nature,
+certain limitations with reference to living beings in general and
+living human beings in particular.
+
+It is the business of each of the sciences--it is indeed an essential
+part of the method of Science--to separate a circumscribed part of
+the Universe for consideration in and for itself. Men of Science must
+thus perforce become Chemists, Physicists, Astronomers, Botanists,
+Cytologists, Statisticians, and the like. In this respect modern
+_Science_ differs most profoundly from medieval _Scientia_ and from
+ancient _Philosophia_. ‘Specialization’ follows modern _Science_ as
+shadow follows substance. The new method has triumphed wonderfully in
+these last centuries and it is mere folly and obscurantism to seek
+to place intellectual stumbling-blocks in its path. Nor must we be
+afraid of shadows. The author does plead, however, that, while the
+Man of Science must, from the very nature of his method, cut off part
+of his universe of experience from all other parts, he should bear in
+mind, when not employed on his special task, that he has so cut off
+and isolated his special experience, of deliberate and set intent. To
+bear this fact in mind should not mean and must not mean that Science
+fails to influence our view of the world as a whole, but it should
+mean and must mean the basing of our view of the world as a whole on
+experience as a whole, and not on an artificially separated fragment
+of experience. For Man is neither a walking test-tube, nor a living
+anatomy, nor a colony of cells, nor a self-repairing machine that
+carries its own spare parts, nor a mere summation of the factors of
+heredity and environment, nor, for that matter, is he a disembodied
+spirit. But he is a being with a purpose. Of that purpose he, of his
+nature, can know very little, since it is a part of that through which
+he knows. Yet some glimpse of that purpose, though seen through a mist
+and ever so dimly, we may perhaps gain from the view-point on which the
+stony tracks of the separate sciences do ultimately converge. If the
+separate sciences did not so conspire to one end, why should we ever
+bother our heads or weary our limbs over their steep ascents? Are there
+not rosier paths that we might tread?
+
+Throughout this book, then, the ideal kept in view is the description
+of Medicine as a Rational Discipline involving many and perhaps all the
+sciences. Medicine is not now and never has been followed wholly in the
+scientific spirit. But it is the story of the scientific elements in
+Medicine which is here to be told, and other aspects are passed over
+with a silence which must not be interpreted as the silence of contempt.
+
+No two men undertaking the task here outlined would make quite the
+same selections or allot emphasis in quite the same manner. Doubtless
+the author has erred by omission and by commission, through ignorance
+and through misconception, but he hopes that he has never erred
+through prejudice. The ideas that he recounts are those that present
+themselves to him as the most important and fruitful within the range
+of scientific Medicine, and he is prepared to revise his opinions both
+on matters of fact and on matters of stress. He will therefore be very
+grateful for any corrections or suggestions.
+
+The number of names mentioned in the book has been reduced to the
+utmost limit that has seemed feasible. In recounting many episodes
+one name has often been taken as an example or type, and thus perhaps
+sometimes an injustice has been done to other workers, no less
+important but perhaps less typical. When modern times and living
+persons are reached the selection becomes not only difficult but also
+delicate, but the reader must remember that the names are not always
+chosen for their eminence but sometimes rather as typifying the various
+movements that have to be discussed. There is a further complication in
+that an attempt is here made to bring history right up to date. Very
+few names of living men are mentioned, though the work of many living
+men is discussed. Though the author has sought to refrain from passing
+any judgment on such latter-day conclusions the value of which does not
+seem to him clearly and firmly established, yet even this course in
+itself implies a judgment, and one in which he is even more likely to
+err than in other topics of which the book treats. Nevertheless, some
+such judgment seems necessary to make the book a coherent whole.
+
+There are several from whom the author has had help in the writing
+of this book. Mrs. Singer has criticized every detail, and has
+considerably modified its form. No English writer on the History of
+Medicine can fail to refer to the great work of Lt.-Col. Fielding H.
+Garrison of the United States Army and of the Library of Congress at
+Washington. The author of this book owes much to Lt.-Col. Garrison’s
+splendid bibliography, but even more to constant correspondence,
+carried on now through a good many years, with the man who made it.
+He owes a similar debt to a very old-standing friendship with Dr. E.
+T. Withington of Oxford, to whom he takes the liberty of dedicating
+this book. Professor Graham Wallas, Emeritus Professor of Sociology
+in the University of London, and Professor J. C. Drummond, Professor
+of Biochemistry in the University of London, have both read the book
+in proof, and have made a number of suggestions and corrections.
+Help on special points has been given by Dr. Clark-Kennedy of Corpus
+Christi College, Cambridge, Dr. Raymond Crawfurd, Registrar of the
+Royal College of Physicians of London, Dr. J. W. Eyre, Professor
+of Bacteriology in the University of London, the Rev. Father J. R.
+Fletcher, who has the unusual distinction of being both a Priest and
+a Physician, Dr. K. Franklin of the Pharmacological Laboratory in the
+University of Oxford, and Dr. William Robson, Lecturer in Law in the
+University of London, as well as by the author’s pupils Dr. Ivor Hart,
+Dr. J. F. Prendergast, Dr. Dorothy M. Turner and Mr. F. Prescott, M.Sc.
+To all of these the author would tender his grateful thanks.
+
+                                                     CHARLES SINGER.
+
+    UNIVERSITY COLLEGE, LONDON. _January_, 1928.
+
+
+
+
+CONTENTS
+
+
+  PREFACE                                                        vii-xiv
+
+  LIST OF ILLUSTRATIONS                                         xix-xxiv
+
+  I. ANCIENT GREECE, to about 300 B.C.
+
+    § 1. Origins of Greek Medicine                                     1
+
+    § 2. The Hippocratic Physician                                    13
+
+    § 3. Hippocratic Practice                                         18
+
+    § 4. Aristotle                                                    27
+
+  II. THE HEIRS OF GREECE, from about 300 B.C. to about A.D. 200
+
+    § 1. The Alexandrian School                                       36
+
+    § 2. Medical Teaching in the Roman Empire                         41
+
+    § 3. Medical Services of the Roman Empire                         45
+
+    § 4. Roman Hospitals                                              48
+
+    § 5. Galen                                                        50
+
+    § 6. The Final Medical Synthesis of Antiquity                     53
+
+  III. THE MIDDLE AGES, from about A.D. 200 to about A.D. 1500
+
+    § 1. The Period of Depression in Europe                           61
+
+    § 2. Arabic Medicine                                              66
+
+    § 3. The Medieval Awakening                                       68
+
+    § 4. The Universities                                             70
+
+    § 5. Medieval Anatomy, Surgery, and Internal Medicine             72
+
+    § 6. Medieval Hospitals and Hygiene                               77
+
+  IV. THE REBIRTH OF SCIENCE, from about 1500 to about 1700.
+
+    § 1. The Anatomical Awakening                                     82
+
+    § 2. The Anatomical Reaction on Surgery                           92
+
+    § 3. The Renaissance of Internal Medicine                         95
+
+    § 4. The First Physical Synthesis                                102
+
+    § 5. The Revival of Physiology                                   108
+
+    § 6. Microscopic Analysis of the Animal Body                     115
+
+    § 7. From Alchemy to Chemistry                                   122
+
+    § 8. The Medical Theorists                                       126
+
+  V. THE PERIOD OF CONSOLIDATION, from about 1700 to about 1825.
+
+    § 1. The Reign of Law                                            135
+
+    § 2. The Rise of Clinical Teaching                               138
+
+    § 3. Physiology passes to the Modern Stage                       142
+
+    § 4. Some Physiological Advances                                 145
+
+    § 5. Discovery of the Nature of the Air                          151
+
+    § 6. Morbid Anatomy becomes a Science                            156
+
+    § 7. Clinical Methods and Instruments                            159
+
+    § 8. Surgery and Obstetrics                                      161
+
+    § 9. The Beginnings of the Science of Vital Statistics           166
+
+    § 10. Military, Naval, and Prison Medicine                       169
+
+    § 11. The Industrial Revolution                                  172
+
+    § 12. Control and Recognition of Epidemic Diseases               182
+
+  VI. PERIOD OF SCIENTIFIC SUBDIVISION, from about 1825 onwards.
+
+    § 1. Origins and Implications of Scientific Specialization       186
+
+    § 2. The Revolution in Preventive Medicine                       192
+
+      (_a_) Preventive Medicine in Britain                           193
+
+      (_b_) Preventive Medicine in U. S. A.                          197
+
+    § 3. The Transition to a Physiological Synthesis                 203
+
+      (_a_) Anatomy and Embryology in the Earlier Nineteenth Century 204
+
+      (_b_) Chemical Physiology in the Earlier Nineteenth Century    205
+
+      (_c_) Nervous Physiology in the Earlier Nineteenth Century     207
+
+    § 4. The Experimental Foundations of Modern Medicine             211
+
+      (_a_) The Work of Johannes Müller                              211
+
+      (_b_) The Work of Claude Bernard                               213
+
+      (_c_) The Work of Karl Ludwig                                  215
+
+    § 5. The Cell Theory and Cellular Pathology                      219
+
+    § 6. Establishment of the Doctrine of the Germ Origin of Disease 224
+
+    § 7. Anaesthesia                                                 235
+
+    § 8. The Revolution in Surgery                                   237
+
+    § 9. Some Modern Surgical Advances                               243
+
+    § 10. Bacteriology becomes a Special Science                     249
+
+    § 11. Some Important Bacteriological Results                     253
+
+    § 12. The Study of Immunity                                      259
+
+    § 13. Some Practical Applications of Immunity                    263
+
+    § 14. The Conquest of the Tropics                                271
+
+      (_a_) Yellow Fever                                             273
+
+      (_b_) Malaria                                                  280
+
+    § 15. The Changed View of Insanity                               286
+
+    § 16. The New Movement in Psychology                             293
+
+    § 17. The Revolution in Nursing                                  295
+
+    § 18. Some Modern Physiological Concepts of Clinical Import      301
+
+      (_a_) Ductless Glands and Internal Secretions                  302
+
+      (_b_) Nervous Integration                                      308
+
+      (_c_) Vitamins                                                 311
+
+    § 19. Knowledge of the Eye and its Disorders                     313
+
+    § 20. Investigation of the Nature and Action of Drugs            322
+
+      (_a_) Entry of Vegetable Drugs into the Pharmacopoeia          322
+
+      (_b_) Active Principles                                        323
+
+      (_c_) The Alkaloids                                            325
+
+      (_d_) The Glucosides                                           327
+
+      (_e_) The Study of Pharmacology                                328
+
+      (_f_) Chemotherapy                                             329
+
+    § 21. Interpretation of Collective Medical Data                  333
+
+  EPILOGUE                                                           351
+
+  INDEX                                                              364
+
+
+
+
+LIST OF ILLUSTRATIONS
+
+
+  1. Hippocrates. British Museum, second or third
+        century B.C.                                      _Frontispiece_
+
+  2. Ivory and gold Minoan statuette of a votaress in a
+        state of ecstasy. By kind permission of the Museum
+        of Fine Arts, Boston, U.S.A.                                   5
+
+  3. Surgical instruments recovered from Babylonian
+        sites. Reproduced by kind permission of Professor
+        Meyer-Steineg of Jena                                          5
+
+  4. Clay model of sheep’s liver used for instruction in
+        divination in a Babylonian temple school. Drawn
+        from the object in the British Museum                          6
+
+  5. Imhotep. From a statuette in the British Museum                   8
+
+  6. Aesculapius. Photograph Anderson                                  8
+
+  7. Scheme illustrating some of the sources of
+        Hippocratic Medicine                                           9
+
+  8. A Greek clinic of about 400 B.C. From a vase
+        painting                                                      17
+
+  9. Instruments used by Greek surgeons                               20
+
+  10. The _Ladder of Nature_ according to Aristotle                   28
+
+  11. The womb with the names of its parts as given by
+        Aristotle                                                     29
+
+  12. Embryo dogfish, _Mustelus laevis_, after Johannes
+        Müller                                                        29
+
+  13. The four _Elements_ in association with the four
+        _Humours_ and the four _Qualities_                            34
+
+  14. Inscribed tablet of about 100 B.C. from the wall of
+        the temple of Kom-Ombos in Upper Egypt                        40
+
+  15. Roman surgical instruments of the first century
+        A.D. found at Pompeii                                         44
+
+  16. Aqueduct of Nero from an engraving by Piranesi                  47
+
+  17. Roman advanced dressing-station. From Trajan’s
+        column                                                        48
+
+  18. Island of St. Bartholomew in the Tiber at Rome.
+        From an engraving by Piranesi                                 51
+
+  19. Dissection of the hand of a man                                 57
+
+  20. Dissection of the hand of a Barbary ape                         57
+
+  21. Galen’s Physiological System                                    59
+
+  22. The earliest known representation of St. Luke as a
+        Physician                                                     63
+
+  23. Picture of Trephining, from a thirteenth-century
+        manuscript                                                    63
+
+  24. Illustrating the mode of action of the trephining
+        instrument used by the surgeon in Fig. 23                     64
+
+  25. Scene at a siege of Salerno, from a manuscript
+        prepared in South Italy early in the thirteenth
+        century                                                       65
+
+  26. A Jewish translator receiving an Arabic medical
+        volume from an Eastern potentate (right) and
+        handing it, translated into Latin, to a Western
+        monarch (left)                                                69
+
+  27. Medieval Bologna, from a mural painting of about
+        1500 in the town-hall of the city                             73
+
+  28. An anatomical lecture at Padua in the fifteenth
+        century, from a contemporary Italian woodcut                  75
+
+  29. A ward in a hospital at Paris in the sixteenth
+        century. Reproduced, by kind permission of M.
+        Édouard Champion, from D. L. MacKay, _Les hôpitaux
+        et la Charité à Paris au XIII^e siècle_                       79
+
+  30. Drawing of Dissection of the Heart by Leonardo da
+        Vinci                                                         85
+
+  31. Title-page of the work _On the Fabric of the Human
+        Body_, by Vesalius, published in 1543                         87
+
+  32. Skeleton from the anatomical work of Vesalius                   91
+
+  33. Artificial arms and hands, designed and figured by
+        Ambroise Paré                                                 93
+
+  34. The ‘Four Temperaments’, from the Guild Book of the
+        Barber-Surgeons of York                                       97
+
+  35. Earliest picture showing the use of Tobacco                     99
+
+  36. Allegorical picture illustrating the venereal
+        plague                                                       101
+
+  37. Sanctorius in his balance                                      107
+
+  38. The principle of Galileo’s thermometer                         109
+
+  39. The application of the system shown in Fig. 38 by
+        Sanctorius, who used a curved tube                           109
+
+  40. The adaptation of the instrument, shown in Fig. 39,
+        as a clinical thermometer                                    109
+
+  41. Galileo’s ‘pulsimeter’                                         109
+
+  42. Dissection of a vein in the thigh and leg, from
+        Fabricius                                                    111
+
+  43. The circulation of the blood                                   113
+
+  44. The superficial veins, from William Harvey                     114
+
+  45. Lungs of a frog, showing the capillary vessels,
+        from Malpighi                                                116
+
+  46-9. Stages in the formation of the chick, from Malpighi
+                                                                     117
+
+  49a. One of Leeuwenhoek’s microscopes. Reproduced, by
+        the permission of Mrs. George Martin, from _The
+        Asclepiad_, II                                               118
+
+  50-3. Illustrating the blood corpuscles and circulation
+        after Leeuwenhoek                                            119
+
+  54. The first representation of Bacteria                           120
+
+  55-56a. Drawings by Leeuwenhoek of the structure of
+        muscle                                                       121
+
+  57-60. Experiments by Swammerdam                                   123
+
+  61. Boyle’s Air-pump                                               125
+
+  62. Descartes’ conception of the relation of a sensory
+        impression and a motor impulse                               128
+
+  63. Diagram of Descartes, to illustrate nervous action
+                                                                     129
+
+  64. Diagrams from Borelli, to illustrate movements of
+        muscles                                                      130
+
+  65. Diagram of muscular action                                     131
+
+  66. Two Plates from Bernard Siegfried Albinus’
+        _Anatomical Plates of the Muscles of Man_, Leyden, 1747      141
+
+  67. Windmill ventilator designed by the Rev. Stephen
+        Hales. From a print in the British Museum                    147
+
+  68-70. Experiments illustrating the effects of metallic
+        contacts on the nerves and muscles of frogs’ legs.
+        From A. Galvani, _On Electric Forces_, 1792                  149
+
+  71-3. Volta’s figures of the electric pile and crown of
+        cups                                                         150
+
+  74-5. Illustrating the chemistry of burning and
+        breathing, from a work issued by Mayow in 1674               152
+
+  76. Apparatus from Joseph Priestley’s _Experiments and
+        Observations on different Kinds of Air_, 1774                154
+
+  77. Lavoisier in his laboratory making experiments on
+        breathing. From a contemporary sketch                        155
+
+  78. Part of the lung of Dr. Samuel Johnson, from a
+        drawing published by Matthew Baillie                         158
+
+  79-82. Laënnec’s wooden stethoscope, from the first
+        edition of his work _On Instrumental Auscultation_
+                                                                     161
+
+  83. Lying-in scene in the sixteenth century, from a
+        contemporary work on Midwifery                               163
+
+  84-6. Early obstetric instruments                                  164
+
+  87. John Hunter’s country house at Earl’s Court,
+        Kensington, before its demolition in 1886.
+        Reproduced, by the kind permission of Mrs. George
+        Martin, from _The Asclepiad_, VIII                           165
+
+  88. An eighteenth-century Quarantine station (Naples)
+                                                                     173
+
+  89-90. Illustrating the textile trade from home industry
+        to factory work with the consequent break-up of the
+        family as the labour unit. The upper picture from a
+        drawing by George Walker, the lower from _Economic
+        Botany: The Cotton Manufacture_                              175
+
+  91. Graph showing approximate growth of population in
+        England and Wales 1670-1830                                  176
+
+  91a. Tables illustrating vital conditions in the
+        eighteenth century                                           177
+
+  92. St. Bartholomew’s Hospital at Smithfield, London,
+        in 1720. From Strype’s edition of Stow’s _Survey_
+                                                                     179
+
+  93. The Pest House in Tothill Fields, London, in 1796.
+        From a print in the British Museum                           181
+
+  94. Hand of Dairymaid infected with cow-pox, from
+        figure by Jenner                                             184
+
+  95. A cartoon by Robert Cruikshank                                 191
+
+  96. Annual death-rate in London per thousand living
+        over 85 years                                                196
+
+  97. The Old _Dreadnought_ Hospital Ship                            199
+
+  98. Diagram of Transverse section of the Spinal Cord,
+        &c.                                                          208
+
+  99. Diagram to illustrate Reflex                                   209
+
+  100. Diagram to illustrate Cerebral localization                   210
+
+  101. Thomas Young’s Kymograph                                      217
+
+  102-5. Drawings by Theodor Schwann to illustrate cells
+                                                                     221
+
+  106. Organisms of Fermentation, from Pasteur                       226
+
+  107. Pasteur’s experiment to prove that fermentation is
+        the result of air-borne organisms                            228
+
+  108. Bacilli of Anthrax                                            231
+
+  108a. Screw used in the eighteenth and the early
+        nineteenth century to secure analgesia. Reproduced,
+        by the kind permission of Mrs. George Martin, from
+        _The Asclepiad_, VII                                         236
+
+  109. The ‘Donkey Engine’ designed by Lord Lister. Now in
+        the Royal College of Surgeons of England                     241
+
+  109a. Operating table used by Lord Lister in the Glasgow
+        Royal Infirmary. Reproduced, by kind permission of
+        Messrs. Jackson, Wylie & Co., from _Lister and the
+        Lister Ward in the Royal Infirmary of Glasgow_               242
+
+  110. ‘Spencer Wells Forceps’                                       244
+
+  111. Spencer Wells performing an abdominal operation
+                                                                     245
+
+  112. An operation in the sixteenth century                         246
+
+  113. An abdominal operation under modern conditions.
+        Reproduced, by kind permission of W. B. Saunders’
+        Company, Philadelphia, from _The Operating Room,
+        St. Mary’s Hospital, Rochester, Minnesota_                   247
+
+  114. Bacilli of Diphtheria                                         254
+
+  115. Bacilli of Plague                                             255
+
+  116. Diagram showing the Incidence of Malta fever                  256
+
+  117. Bacilli of Tetanus                                            257
+
+  118. Bacilli of Typhoid Fever                                      258
+
+  119. Death-rate of cases of Laryngeal Diphtheria                   263
+
+  120-1. A common Malaria-carrying mosquito and a Yellow
+        Fever-carrying mosquito. Reproduced, by kind
+        permission of the British Museum (Natural History),
+        from Edwards, _Mosquitoes and their Relation to
+        Disease_                                                     272
+
+  122. Distribution of Malaria in England and Wales                  281
+
+  123. The Life-History of the Parasite of Malaria.
+        Reproduced, by kind permission of Messrs.
+        Baillière, Tindall & Cox, from C. M. Wenyon’s
+        _Protozoology_, vol. II                                      285
+
+  124-5. A Malaria-carrying mosquito and a common gnat.
+        Reproduced, by kind permission of the British
+        Museum (Natural History), from Edwards, _Mosquitoes
+        and their Relation to Disease_                               287
+
+  126. Chart of cases of Malaria reported in Italy in
+        recent years                                                 287
+
+  127. ‘The Retreat’ near York. Reproduced, by permission
+        of Messrs. Kegan Paul, Trench, Trubner & Co., from
+        Tuke, _Chapters in the History of the Insane in the
+        British Isles_, 1882                                         289
+
+  128. Florence Nightingale at Scutari. Photograph,
+        Rischgitz Collection                                         299
+
+  129-30. Cretinous infant before and after thyroid
+        treatment. Reproduced by kind permission of the
+        Royal College of Surgeons                                    305
+
+  131. Diagram to show the structure of the eye                      314
+
+  132. Diagram to show the nature of accommodation of the
+        eye                                                          317
+
+  133. The Organisms of Syphilis in a smear from the Local
+        Infection                                                    331
+
+  134. Diagram illustrating alteration in Age-distribution
+        of the population of England and Wales. Reproduced,
+        by kind permission of the authors, from
+        Carr-Saunders & Caradog Jones, _Social Structure of
+        England and Wales_ (Clarendon Press)                         335
+
+  135. Death-rate from Cancer of the Tongue. Reproduced,
+        by kind permission of the Editors, from _The
+        Quarterly journal of Medicine_, vol. v, No. 5                337
+
+  136. Death-rate from Cancer of the Lip. Reproduced, by
+        kind permission of the Editors, from _The Quarterly
+        Journal of Medicine_, vol. v, No. 5                          338
+
+  137. Death-rate from Cerebral Haemorrhage. Reproduced,
+        by kind permission of the Editors, from _The
+        Quarterly Journal of Medicine_, vol. v, No. 5                340
+
+  138. Curve showing percentage of deaths from Phthisis to
+        total deaths                                                 343
+
+  139. The normal curve of error                                     345
+
+  140. Curve of monthly number of deaths from Small-pox
+        during an epidemic at Warrington, Lancashire, in 1743        346
+
+  141. Curve of weekly number of cases of Scarlet Fever
+        during an epidemic at Glasgow in 1892                        346
+
+  142. Analysis of curve representing death-rates from
+        Summer Diarrhoea in London over a long period of
+        years                                                        347
+
+
+
+
+I
+
+ANCIENT GREECE
+
+(TO ABOUT 300 B.C.)
+
+
+§ 1. _Origins of Greek Medicine._
+
+Scientific Medicine began with the Greeks. The Greeks not only started
+scientific Medicine upon its course, but also provided the substantial
+basic elements of our anatomy, physiology and pathology, and above
+all, perhaps, our conception of the bodily ‘constitution’, ‘habit’ or
+‘temperament’. It is from the Greeks that we derive almost all our
+medical nomenclature. When to this we add that our medical traditions
+are inherited through a direct and continuous chain from the Greek
+practitioners, it becomes evident that the debt that Medicine owes to
+this marvellous people is great indeed.
+
+Now this debt has become associated with two or three great figures.
+The names Hippocrates, Aristotle, Galen, are familiar to all. Yet it is
+not always recognized that these men were but the representatives of a
+widely extended and long-lasting system. Greek Medicine was, in fact,
+like modern Medicine, the result of centuries of carefully recorded,
+collated and progressive research. Greek Medicine first assumed a
+scientific aspect with the Ionian and Italo-Greek philosophers at the
+very beginning of the sixth century B.C. It continued to make important
+advances until the death of Galen at the very end of the second century
+of the Christian era. Thus the life-span of progressive and scientific
+Medicine among the Greeks was no less than eight hundred years. With
+the most tolerant use of the words ‘scientific’ and ‘progressive’,
+we can hardly place the beginnings of modern Medicine in Europe
+before the end of the fifteenth century. Thus our own system has only
+been developing its characteristic features for some four and a half
+centuries, which is but little more than half the course that Greek
+science ran.
+
+It is evident, therefore, that we may have much to learn from the
+Greeks, not indeed in matters of actual fact or observation--for nearly
+all that is _directly_ useful in their writings has been absorbed long
+ago into our medical literature--but in spirit and method. From a
+study of the character and course of Greek medical science we can gain
+hints of the snares and pitfalls and catastrophes into which the Art
+of Medicine may at times be led. Further, by study of the practice of
+Medicine under conditions so different from ours, we learn something
+of what is truly permanent in the Art of Healing. Lastly, by tracing
+the growth of the Science of Medicine, as it arose among the Greeks and
+as it died in the hands of their less worthy descendants, we may take
+alike example and warning. We may learn to distinguish the healthy and
+vigorous growth of a science from the stunted and deformed products
+that are often acclaimed, even in our own times, as Wisdom’s final word
+to Man.
+
+It has been said that, ‘save the blind forces of Nature, nothing lives
+or moves which is not Greek in origin’. The saying needs modification,
+for there is a thing which still lives and moves that is not Greek in
+origin, a blind force which is not a blind force of Nature. It is the
+force of Superstition, of that age-old belief that Nature will give
+us something for nothing, which is expressed by the word ‘Magic’.
+The Greeks were no more free from that contemptible fallacy than
+are the men of our own days. But the greatest of the Greeks stood
+wholly above such folly, and we can watch the Greek mind gradually
+lifting itself from that primeval mental attitude which is older than
+any known culture, older perhaps than any known race, the attitude
+of Nature-Worship, or ‘Animism’. To give an idea of how the ‘sweet
+reasonableness’ of the Greek mind gradually dissipated the animistic
+fog, a few words must be said about the history of the Greeks. Without
+that amount of history it would seem a miracle that Man ever became
+reasonable at all.
+
+The Medicine we call Greek might be described as the system which
+prevailed in ancient times in that half of the Mediterranean area which
+lies east and south of the Italian Peninsula.
+
+Up to about 1000 B.C. most of the coast-lands of this Mediterranean
+area were inhabited by that very remarkable people, the Minoans.
+These have left some extraordinary remains, the full significance
+of which has not yet been revealed. The general development of the
+Minoan civilization has, however, been clearly outlined by modern
+archaeological investigation. This has resulted in an entirely new
+interpretation of the story which Homer tells in the _Iliad_. The siege
+of Troy represents an attack by the invading Greeks on one of the last
+Minoan strongholds. About 1000 B.C. the whole Eastern Mediterranean
+basin was being overrun by the Greek tribes coming in from the north.
+These Greeks were no pure race, but a mixed multitude of invaders
+who came along several lines of advance. As always happens in such
+invasions, the conquered were not exterminated, but mingled with the
+invaders. Thus the Greeks, as they advanced, absorbed much of the
+culture and outlook of the civilization that they submerged.
+
+In considering the history of Rational Medicine we are concerned
+chiefly with two main invading streams of Greek tribes: that of the
+Dorians, who passed towards Crete and towards the Island of Cos and the
+opposite peninsula of Cnidus, and that of the Ionians, who colonized
+most of the remaining part of western Asia Minor. These two peoples
+were, between them, responsible for the main intellectual output of the
+Greeks of those early days. The medical system which they initiated
+first took shape in western Asia Minor, and thence became diffused over
+the whole of the Greek world. The Greek system of Medicine which thus
+arose in Asia Minor had various roots, as indeed the Medicine of a
+mixed people, living under very complex social conditions, was bound to
+have.
+
+Firstly, there was the submerged civilization of the conquered Minoan
+folk. It is probable that the cult of the serpent--so constantly
+associated with Aesculapius and still used as a medical emblem--was of
+Minoan origin, for the serpent was a symbol much used in the Minoan
+religion (Fig. 2). It is probable too that some of the hygienic ideas
+of the Greeks were derived from the same source, for the Minoans had an
+excellent system of drainage. We can, however, say little on this head
+because the interpretation of the Minoan records is still hidden from
+us.
+
+[Illustration:
+
+FIG. 2. IVORY AND GOLD MINOAN STATUETTE of a votaress in a state
+of ecstasy. In either hand she holds a serpent, illustrating the
+importance attached to this animal in the Minoan cult. From the Museum
+of Fine Arts, Boston, U.S.A.
+
+FIG. 3. SURGICAL INSTRUMENTS recovered from Babylonian sites. There are
+here represented three knives, a saw and a trephine. These instruments,
+which illustrate the state of surgery in the ancient Mesopotamian
+civilization, are in the possession of Professor Meyer-Steineg of Jena,
+by whose permission they are here reproduced.
+
+]
+
+Secondly, we have to remember that the shores of Asia Minor lie on the
+outskirts of the great civilization which had grown up in the valley
+of the Tigris and the Euphrates. The Greeks drew from that source much
+of their more superstitious beliefs, as well as some, at least, of
+their scientific method. On the one hand, the demoniac theories that
+bulk so largely in later Greek medicine doubtless came from Assyria
+and Babylonia. The Medicine of the New Testament, for instance, with
+its casting out of devils, is of Mesopotamian origin. But, on the
+other hand, the Mesopotamian peoples had for long ages laid up a great
+treasury of observation, notably of astronomical data which were
+often applied to astrological ends. There was also some knowledge of
+anatomy derived from the entrails of animals used in divination (Fig.
+4). Working on the basis of these records, the Greeks were able to
+erect a scientific method which appears as a prominent feature in
+their intellectual life in later centuries. Moreover, there was in
+Mesopotamia a standardization of both medical and surgical procedure
+which the nimble-witted Greeks were quick to adopt (Fig. 3). On its
+lower and less intelligent side, however, the Mesopotamian material was
+made to minister to Greek superstition and especially to astrological
+belief.
+
+[Illustration:
+
+FIG. 4. CLAY MODEL OF SHEEP’S LIVER used for instruction in divination
+in a Babylonian temple school. The object is now in the British Museum.
+It is covered with cuneiform writing, the nature and contents of which
+fix its date as about 2000 B.C. The writing is here omitted for the
+sake of simplicity.
+
+Various parts of the liver have their Babylonian technical terms and
+can be identified with parts recognized by modern anatomists. Some of
+these modern terms are written on our drawing.
+
+To each hole in the original model an inscription containing a forecast
+is assigned. The diviner made his forecast by comparing an actual
+liver with this clay model at each point corresponding to a hole. His
+forecast was elaborated according to the state of the liver at all
+these points.
+
+]
+
+Thirdly, to the Egyptian civilization the Greek debt was also
+considerable. Many drugs were derived from Egypt and others were
+suggested by Egyptian practice. The basis of Greek medical ethics,
+too, can be traced to Egypt. Some of the practical devices of Greek
+Medicine, such as the forms of the surgical instruments, were of
+Egyptian origin. Nor can we neglect the statement made by the Greeks
+themselves, that mathematical knowledge--the test and index of all
+scientific growth--came to them first from Egypt. Lastly, we note that
+the Egyptians deified a physician, Imhotep (Fig. 5), in exactly the
+way that the Greeks deified their physician Aesculapius (Fig. 6). Both
+Imhotep and Aesculapius were, in fact, historic personages, and their
+evolution into gods presents many interesting parallels.
+
+[Illustration:
+
+FIG. 5. IMHOTEP, originally a physician, subsequently deified as an
+Egyptian god of Medicine. From a statuette in the British Museum.
+
+FIG. 6. AESCULAPIUS, originally a physician, subsequently deified as a
+Greek god of Medicine. He holds a staff, around which a serpent twines.
+From a statue in the Capitoline Museum at Rome.
+
+]
+
+The Greeks of western Asia Minor, thus drawing material from many
+sources, came to develop, towards the end of the seventh century B.C.,
+a philosophical system from which the whole of their Science may be
+said to be a natural growth. Factors in this development were the
+medical schools of Cos, where Hippocrates was born, and of the opposite
+peninsula, Cnidus. These schools were in active operation by the sixth
+century B.C. By the middle of the fifth century they were important
+elements in the growing complexity of Greek life. Much of the so-called
+_Hippocratic Collection_, which contains the earliest Greek medical
+writings that have survived, must have been put together somewhere in
+the fourth century B.C., though its final recension is certainly later
+(Fig. 7). In that final recension Persian and Indian elements were also
+included, though to what degree is still very uncertain.
+
+[Illustration: FIG. 7. SCHEME ILLUSTRATING SOME OF THE SOURCES OF
+HIPPOCRATIC MEDICINE]
+
+But the picture of the development of Greek Medicine is not yet
+complete. Although we inherit the scientific spirit from the Greeks,
+and although they set a standard for all time of the purest and
+most disinterested type of medical practice, they are also in part
+responsible for some of the basest forms of medical jugglery that have
+afflicted and still afflict mankind. The medicine of the physicians was
+only one of their medical systems. There was a far lower form which
+gradually passed into the hands of the priests. The temple jugglery of
+Greece is ancestor, both by imitation and by direct tradition, of much
+medieval and modern medical miracle-mongering.
+
+Furthermore, in ancient as in modern times, all medical men were not
+equally pure in aim or scientific in method. The practice of some Greek
+physicians was more than flavored with magic. In justice, also, it
+must be said that not all priests were mere charlatans, and that there
+are traces of scientific method in the treatment of patients in the
+temples. There was, indeed, a relation between the practice of some
+of the physicians among the Greeks and that of some of their priestly
+magicians. We shall not attempt to determine the actual extent and
+nature of this relationship. For our purpose it is enough that the two
+systems were quite distinct in their most typical developments.
+
+The temple system of Greek Medicine was associated from an early date
+with a deity, Asklepios, or, to give him his better-known Latin name,
+Aesculapius. Numerous representations of him have come down to us, and
+in them we see him gradually molded to a particular type. He becomes at
+last an aged man of noble, benevolent and dreamy aspect, holding in
+his hand a staff around which a serpent twines (Fig. 6). The cult of
+the god Aesculapius was carried on at numerous sites. The best known,
+both from literature and excavation, is Epidaurus. The conditions there
+are typical of those in other Aesculapian centers.
+
+Epidaurus is about thirty miles from Athens. It lies between two
+considerable ranges of hills, and the country bears still, in its
+customs and place-names, some remnants of the ancient cult. One
+tradition tells that a certain maiden, Koronis, being with child by
+Apollo, brought forth the infant Aesculapius on the mountain above
+Epidaurus. There is still a village named Koroni hard by. She fled
+to conceal her shame and left the child on the mountain, where it
+was tended by a goat and watched over by a dog. The infant performed
+various miracles which we need not pursue, though the temple arose on
+the site where he is said to have wrought them. One of his miracles,
+however, has a wider interest and is worth recounting. A certain
+Hippolytus, falsely accused of impure relations with his stepmother,
+was slain by the gods in answer to the curses of his father, Theseus.
+Raised from the dead by the wonder-working Aesculapius, he reappears in
+legend at the Arician grove in Italy. ‘There’, says a Greek chronicler
+of the second century A.D., ‘he became a king and devoted a precinct
+to Artemis, where, down to my time, the prize for the victor in single
+combat was the priesthood of the goddess. The contest was open to no
+freeman, but only to runaway slaves.’
+
+The son slain by his father and then rising from the dead; the runaway
+slave seeking sanctuary with Artemis in her grove, allowed his liberty
+and elevated to the priesthood there; the priesthood held only so long
+as the priest can guard it in mortal combat against the next runaway
+slave; this succession of slave kings and priestly murders has touched
+the imagination of the poets and artists in ancient and in modern
+times. The sacred grove of Artemis stood by the side of the lake of
+Nemi:
+
+    The still glassy lake that sleeps
+    Beneath Aricia’s trees--
+    Those trees in whose dim shadow
+    The ghastly priest doth reign,
+    The priest who slew the slayer
+    And shall himself be slain.
+
+It is a picture utterly out of accord with the general trend of
+classical mythology. Long ago scholars saw therein a remnant of a
+submerged faith, that ancient ‘Nature worship’ which survived among the
+Greeks, and survives with us. From this incident is named the great
+classical work of Anthropology, _The Golden Bough_. By this story and
+by all that it implies, by all that learning has drawn out of it and
+associated with it, the history of Medicine comes into contact with the
+brooding spirit of savage man. Into that dark realm we shall not enter
+in this volume.
+
+History is the tale of the spirit of Man unfolding itself. This process
+is always slow, often imperceptible, sometimes retrograde, yet over
+long periods of time it is sure. Where no evolution of the spirit can
+be traced true history cannot be written, wherefore no man can write a
+history of human folly. Irrational man, driven by disease and fear of
+death, exhibits the same follies in all ages. The medical follies and
+superstitions of our own days are as in those when Aesculapius claimed
+men’s allegiance. His garments and his names are changed, his temples
+are transformed, his priests assume other titles, but his face is the
+same, and he works the same wonders with about the same frequency. It
+is of Rational Medicine that we have henceforth to speak.
+
+
+§ 2. _The Hippocratic Physician._
+
+We turn to the other side of the picture. Nothing could be in greater
+contrast to the orgies of the savage, the dark ways of the magician,
+or the charlatanry of the priests, than the serene spirit of wisdom
+which pervades the best Greek Medicine. The finest presentation of that
+system is to be found in a group of about a hundred works that have
+been associated together since antiquity under the name of Hippocrates.
+It is known as the _Hippocratic Collection_.
+
+It will naturally be asked, ‘Which of these works is by the man whose
+name they bear?’ To that question, alas, no definite answer can be
+given. There is no single work which we can state with certainty to
+be the composition of the Father of Medicine. The books of which the
+_Collection_ is composed are the work of a number of authors, belonging
+to different schools, holding various and often contradictory views,
+living in widely separated parts of the Greek world and writing at
+dates divided from each other, in the most extreme cases, by perhaps
+five or six centuries. Of the finest books of this collection we can
+but say that they contain nothing inconsistent with a Hippocratic
+origin, that their ethical standpoint is in accord with the Hippocratic
+ideal, and that they are the work of physicians of great intellectual
+power and experience.
+
+If we ask what is known about Hippocrates himself, and if we seek
+information rather than entertainment, our answer will be almost as
+meager. Hippocrates is no mythical figure, for he is mentioned with
+high respect by his younger contemporary, Plato. He was the son of a
+physician, and was born at Cos about 460 B.C. The most active period
+of his life thus began about 420 B.C. His death is placed between 377
+and 359--the latter would make him 101, an appropriate age for a great
+physician. He led a wandering life, and is heard of at Cos, Thasos,
+Athens, in Thrace and elsewhere, and lastly in Thessaly, where his
+grave was long shown. Among his pupils were his two sons, and his
+son-in-law. Of the work of the latter we have a fragment preserved both
+by Aristotle and in the _Hippocratic Collection_ itself.
+
+That is all that is known about the Father of Medicine. We have not
+even his portrait. Yet we have something far better; we have an
+idealized representation of what the Greek would wish his physician
+to be. It is a noble bust to which the name of Hippocrates was early
+attached. Many copies exist (see Frontispiece). The calm, righteous
+and dignified presence which it portrays has stamped itself on the
+consciousness and conscience of those who follow the Art of Healing. To
+that gracious figure the medical man will continue to pay homage.
+
+If critical examination has dealt thus hardly with the Hippocratic
+writings and with Hippocrates himself, what has been left which we
+may surely derive from the Greek medical system? The answer is that
+Medicine has from the Greeks two great things: the picture of a man and
+the institution of a method.
+
+The man is Hippocrates himself. His figure, gaining in dignity what it
+loses in clearness, stands for all time as that of the ideal physician,
+for the ideal is there and is clearly set forth in these great
+writings, whether we discern the details of his earthly features or no.
+Calm and effective, humane and observant, prompt and cautious, at once
+learned and willing to learn, eager alike to get and give knowledge,
+unmoved save by the fear lest his knowledge may fail to benefit
+others--both the sick and their servants the physicians,--incorruptible
+and pure in mind and body, the figure of the greatest of physicians has
+gained, not lost, by time. In all ages he has been held by medical men
+in a reverence comparable only to that which has been felt towards the
+founders of the great religions by their followers. The figure of the
+Hippocratic physician has been of incalculable spiritual value to the
+medical profession in the twenty-three centuries that have passed since
+his death.
+
+So much for the man. We turn now to the method.
+
+The _method_ of Hippocratic medicine is that known to-day as the
+_experimental_ or better _experiential_. It was employed among the
+Greeks for centuries after the death of Hippocrates. Then came a
+time when a social and philosophical upheaval prevented its further
+prosecution. For the thousand years that followed the break-up of the
+Roman Empire the medical practice of Europe was at best a corrupted
+imitation and misunderstanding of the Hippocratic teaching; at worst
+it descended to a low level of Animism and Magic. Then there was a
+rally. Slowly--very slowly at first--the foundations of Modern Science
+were laboriously laid. Among the first elements in this scientific
+Renaissance was the recovery of the Hippocratic works.
+
+In the centuries that followed this Renaissance the very words of the
+_Hippocratic Collection_ were taught in the medical schools in a spirit
+that was anything but that of Hippocrates. Gradually, however, a better
+understanding crept into men’s minds. The spirit of those writings and
+their methods and observations came now rightly to be exalted above
+the works themselves. The works themselves were wisely dropped from
+the medical curriculum. They are no longer used in any medical school.
+But if we turn again to contemplate the Hippocratic treatises, we may
+recognize in them the modern process of careful record of data and
+cautious inference from them--that collation of experience from various
+sources obtained by various methods with which we are now so familiar.
+We may even see in full force the actual process of case-taking, bed
+side instruction and clinical lecture. These methods are practised
+much in the way in which we know them, and are set forth with a
+conciseness and beauty of language and a loftiness of ethical tone
+which have not since been surpassed. To such a collection medical men
+must always return. No part of it is more impressive than the so-called
+_Hippocratic Oath_.
+
+[Illustration: FIG. 8. A GREEK CLINIC OF ABOUT 400 B.C., when
+Hippocrates was in his prime. From a vase painting.
+
+The physician sits in the center. He holds a lancet in his right
+hand, seizes the patient’s right arm with his left and is bleeding
+him from a vein at the bend of the elbow. The blood falls into a
+large basin on the floor. Above the physician’s head are suspended
+three cupping vessels, shaped thus:
+
+[Illustration]
+
+To the right sits a patient awaiting his turn to interview the
+physician. His left arm is bandaged. Behind this patient stands a
+figure smelling a flower as a preventive against infection. Behind the
+physician stands a man wounded in the left leg, which is bandaged.
+Back to back to this last figure is a dwarf with a disproportionately
+large head. His body exhibits deformities typical of the developmental
+disease now known as _Achondroplasia_. In addition to his other
+deformities, we note that his muscular body is hairy, and that the
+bridge of his nose is sunken. On his back he carries a hare which is
+almost as tall as himself. Talking to the dwarf is a man leaning on a
+long staff, who has the remains of a bandage round his chest.]
+
+The _Hippocratic Oath_, in its present form, is of very much later date
+than Hippocrates. Yet parts of it may be even earlier than he, and
+some suggestion of the Oath is, perhaps, to be seen in the contents of
+Egyptian papyri of the second millennium B.C. It need hardly be said
+that the late date of the _Oath_ by no means removes the interest of
+this grand ethical monument. No passage better reflects the spirit of
+the Hippocratic physicians. The oath is clearly designed for a youth
+entering on his apprenticeship to such a one.
+
+    ‘I swear by Apollo the healer, invoking all the gods and
+    goddesses to be my witnesses, that I will fulfil this Oath and
+    this written Covenant to the best of my ability and judgement.
+
+    ‘I will look upon him who shall have taught me this Art even as
+    one of my own parents. I will share my substance with him, and
+    I will supply his necessities, if he be in need. I will regard
+    his offspring even as my own brethren, and I will teach them
+    this Art, if they would learn it, without fee or covenant. I
+    will impart this Art by precept, by lecture and by every mode
+    of teaching, not only to my own sons but to the sons of him who
+    has taught me, and to disciples bound by covenant and oath,
+    according to the Law of Medicine.
+
+    ‘The regimen I adopt shall be for the benefit of the patients
+    according to my ability and judgement, and not for their hurt
+    or for any wrong. I will give no deadly drug to any, though
+    it be asked of me, nor will I counsel such, and especially I
+    will not aid a woman to procure abortion. Whatsoever house I
+    enter, there will I go for the benefit of the sick, refraining
+    from all wrongdoing or corruption, and especially from any act
+    of seduction, of male or female, of bond or free. Whatsoever
+    things I see or hear concerning the life of men, in my
+    attendance on the sick or even apart therefrom, which ought not
+    to be noised abroad, I will keep silence thereon, counting such
+    things to be as sacred secrets. Pure and holy will I keep my
+    Life and my Art.
+
+    ‘If I fulfil this Oath and confound it not, be it mine to enjoy
+    Life and Art alike, with good repute among all men at all
+    times. If I transgress and violate my oath, may the reverse be
+    my lot.’
+
+
+§ 3. _Hippocratic Practice._
+
+Among the most remarkable features of the _Hippocratic Collection_ is
+the feeling of contact with the patient which most of its works convey.
+This is naturally a special characteristic of the surgical works. One
+treatise, which bears the title _On wounds of the head_, has always
+drawn attention as bespeaking especial ingenuity and experience. The
+description of trephining is of peculiar interest, because the practice
+was known in prehistoric times and is still employed by savage and
+semi-civilized peoples. The process recommended for cases of fracture
+of the skull and injury to the underlying structures resembles, in
+many details, the modern surgical procedure.
+
+    ‘When it is necessary to trephine a patient, make up your
+    mind and judge as follows. If you have had charge of the case
+    from the first, do not trephine the bone down to the membrane
+    at once, for it is not desirable that the membrane be long
+    exposed, lest it end by becoming rotten and fungous. There is
+    also another danger, to wit that you wound the membrane with
+    the saw during the operation, if you try to remove the bone by
+    trephining immediately down to the membrane. Therefore, when
+    the bone is almost sawn through and is already loose, cease
+    trephining and allow the bone to come away of itself. While
+    trephining, often remove the instrument and dip it in cold
+    water. If you do not do this, the trephine, becoming heated by
+    the circular motion and heating and drying the bone, may burn
+    it and cause an unduly large piece of the bone round the sawing
+    to come away.’
+
+[Illustration: FIG. 9. INSTRUMENTS USED BY GREEK SURGEONS.
+
+_a_ Simplest form of trephine. It has central pin and serrated edge.
+The point is held against the skull and the staff twirled between
+the hands. (Cf. Fig. 112.) It could also be rotated by a crosspiece
+and thong, as in Fig. 22. _b_ Case of scalpels from a bas-relief in
+the temple of Aesculapius on the Acropolis at Athens. _c_ Trephining
+instrument of type still in use. The carpenter’s ‘center bit’ was known
+in antiquity, and was probably adapted to the trephine. _a_ and _c_
+represent sixteenth-century instruments of ancient type. No ancient
+trephines of Greek origin are known, though a specimen has come down to
+us from Mesopotamia, see Fig. 3.
+
+]
+
+So much for a normal case which comes to the physician’s hands directly
+after the accident. But in less fortunate cases he is not called in so
+early, and the wound suppurates before he can bring his Art to bear
+upon it. In such a case he is advised:
+
+    ‘Saw the bone immediately to the membrane with a serrated
+    trephine (Fig. 9, _a_ and _c_), frequently removing the
+    trephine and testing with the probe all round along the track,
+    for the bone is sawn through much more quickly if it is already
+    suppurating and penetrated by the pus. The bone, however, often
+    happens to be thin in places. Therefore be on your guard not to
+    apply the trephine at random, but fix it in the bone where it
+    appears thickest, frequently making an examination and trying
+    to raise the bone by moving it. And after removing it, continue
+    such treatment as may appear advantageous to the wound,
+    according to circumstances.’
+
+Among the works of the _Hippocratic Collection_ is a lecture note-book
+known by the title _Concerning the things in the Surgery_. It is
+written in very abbreviated style and consists of mere headings.
+Nevertheless, our attention is arrested by its startling modernness,
+when we read such a category as this:
+
+    ‘Operative requisites in the surgery: the patient; the
+    operator; assistants; instruments; the light, where and how
+    placed; the patient’s person and apparatus. The operator,
+    whether seated or standing, should be placed conveniently to
+    the part being operated upon and to the light. Each of the two
+    kinds of light, ordinary or artificial, may be used in two
+    ways, direct or oblique.’
+
+Or again, such details as:
+
+    ‘The nails [of the operator] neither to exceed nor come short
+    of the finger-tips. Practise using the finger-ends. Practise
+    all operations with each hand and with both together, your
+    object being to attain ability, speed, painlessness, elegance
+    and readiness. Let those who look after the patient present the
+    part for operation as you want it, and hold fast the rest of
+    the body so as to be all steady, keeping silence and obeying
+    their superior.’
+
+Are we not here reminded of an up-to-date operator and operating
+theater?
+
+In the _Hippocratic Collection_ the physician attends cases of every
+type, and does not refuse to do his best for a case because the use
+of an instrument is demanded. He is thus no ‘specialist’. But the
+mass of his practice lay with cases to which instrumental treatment
+was inapplicable. In cases in which surgical intervention was not
+justified the Hippocratic physician adopted for the most part what is
+called an ‘expectant’ line of treatment. Realizing that, in general,
+the tendency of the body is to recover, he contented himself with
+‘waiting on Nature’. This does not by any means imply that he was
+helpless, for much could be done by nursing, regimen and diet to aid
+the patient in that conflict which he alone must fight out. For the
+conduct of that great battle wise and useful directions are recorded.
+But believing in _the healing power of Nature_--the famous phrase is
+used in the Hippocratic writings--the physician was none too eager to
+administer drugs. In the state of knowledge of the day this reluctance
+was well-judged. Nevertheless the Hippocratic drugs, though neither
+numerous nor complex, were some of them very efficient, and their
+judicious if reluctant use at the right juncture saved many a life.
+
+_The Aphorisms_ is the most famous book with which the name of
+Hippocrates is associated, and is as likely as any of the Collection
+to be by Hippocrates himself. It consists of a series of very brief
+generalizations. Many of these have been confirmed by the clinical
+experience of later ages. Some have passed into medical commonplaces,
+others have become popular proverbs. The style of the work suggests an
+aged physician reflecting on the experience of a lifetime. Among modern
+medical writings its closest analogue is perhaps the _Commentaries_ of
+the great English physician, William Heberden the elder (1710-1801),
+which was commenced by him after the age of seventy, occupied the last
+twenty years of his life, contained a summary of the whole of his
+vast experience, and was published by his son after his death. If the
+_Aphorisms_ is similarly a work of the old age of Hippocrates it may be
+dated about 380 B.C. A few extracts give a good idea of the nature of
+the book.
+
+    ‘Life is short and Art is long; the Crisis is fleeting,
+    Experiment risky, Decision difficult. Not only must the
+    physician be ready to do his duty, but the patient, the
+    attendants, the external circumstances must conduce to the
+    cure.’
+
+    ‘Old persons bear fasting most readily, next adults, and young
+    people yet less; least of all children, and of these least
+    again those who are particularly lively.’
+
+    ‘If in any illness sleep does harm, it is a symptom of deadly
+    import.’
+
+    ‘When sleep puts an end to delirium, it is a good sign.’
+
+    ‘Weariness without cause indicates disease.’
+
+    ‘If there be a painful affection in any part of the body, and
+    yet no suffering, there is mental disorder.’
+
+    ‘To eat heartily after a long illness without putting on flesh
+    is a bad portent.’
+
+    ‘Food or drink slightly inferior in itself, but more pleasant,
+    should be preferred to that better itself, but less pleasant.’
+
+    ‘The old have fewer illnesses than the young, but if any become
+    chronic with them they generally carry it with them to the
+    grave.’
+
+    ‘Those naturally very fat are more liable to sudden death than
+    the thin.’
+
+    ‘The dry seasons are more healthy than the rainy, and attended
+    by less mortality.’
+
+    ‘Cold sweats in conjunction with an acute fever indicate death,
+    but with a milder fever only prolonged sickness.’
+
+    ‘Convulsions supervening on a wound are deadly.’ (Tetanus, cp.
+    p. 267.)
+
+    ‘Those attacked by tetanus either die within four days, or if
+    they get through these they recover’ (compare pp. 257 and 267).
+
+    ‘Phthisis comes on mostly from eighteen to thirty-five years of
+    age.’
+
+    ‘It is fatal for a woman in pregnancy to be attacked by one of
+    the acute diseases.’
+
+    ‘In cases of jaundice, hardening of the liver is a bad sign.’
+
+    ‘We should observe the appearance of the eyes in sleep. If any
+    of the white show through the eyelids when closing, this is a
+    bad sign and very dangerous, unless it be due to diarrhoea or
+    taking a purgative.’
+
+    ‘An attack of delirium with laughter is less dangerous than
+    with despondency.’
+
+    ‘Apoplexy is commonest between the ages of forty and sixty.’
+
+    ‘If you give the same nutriment to a patient in a fever and to
+    a person in health, the patient’s disease is aggravated by what
+    adds strength to the healthy man.’
+
+The chief clinical achievement of the _Hippocratic Collection_ lies
+in the descriptions of actual cases. These descriptions are not only
+without parallel during nearly 2,000 years, but they are models of
+what succinct clinical records should be. They are clear and short,
+they give all the leading features and yet they show no attempt to
+prejudge the importance of any particular feature. The records of
+these cases illustrate the Greek genius for seizing the essential. The
+writer does not betray the least wish to exalt his own skill. He seeks
+merely to put the data before the reader for his guidance under like
+circumstances. It is a reflex of the spirit of honesty in which these
+men worked that in the great majority of the cases they record death
+ensued. Two of these remarkable descriptions may be given:
+
+    ‘The woman with quinsy, who lodged with Aristion; her
+    complaint began in the tongue; voice inarticulate; tongue
+    red and parched. _First day_, shivered, then became heated.
+    _Third day_, rigor, acute fever; reddish and hard swelling
+    on both sides of neck and chest; extremities cold and livid;
+    respiration elevated; drink returned by the nose; she could
+    not swallow; alvine and urinary discharges suppressed. _Fourth
+    day_, all symptoms exacerbated. _Fifth day_, died.’
+
+This was a case of Diphtheria. The quinsy, the paralysis of the palate
+leading to return of the food through the nose, and the difficulty
+with speech and swallowing are typical results of this affection which
+was here complicated by a spread of the septic processes into the neck
+and chest, a not uncommon event in the disease. The rapid onset of the
+conditions is rather unusual, but may be explained if we regard the
+case as a mild and unnoticed diphtheria, subsequently complicated by
+paralysis and by secondary septic infection, for which reason she came
+under observation.
+
+    ‘In Thasos, the wife of Delearces, who lodged on the plain,
+    through sorrow was seized with an acute and shivering fever.
+    From first to last she always wrapped herself up in her
+    bedclothes; kept silent, fumbled, picked, bored, and gathered
+    hairs [from the clothes]; tears and again laughter; no sleep;
+    bowels irritable but passed nothing; when urged drank a
+    little; urine thin and scanty; to the touch the fever was
+    slight; coldness of the extremities. _Ninth day_, talked
+    much incoherently, and again sank into silence. _Fourteenth
+    day_, breathing rare, large and spaced, and again hurried.
+    _Seventeenth day_, after stimulation of the bowels she passed
+    even drinks, nor could retain anything; totally insensible;
+    skin parched and tense. _Twentieth day_, much talk, and
+    again became composed, then voiceless; respiration hurried.
+    _Twenty-first day_, died. Her respiration throughout was rare
+    and large; she was totally insensible; always wrapped up in her
+    bedclothes; throughout either much talk, or complete silence.’
+
+We have here a description of low muttering delirium, a common end of
+continued fevers, as, for instance, Typhoid. It resembles the condition
+known to physicians as the ‘typhoid state’. Incidentally the case
+contains a reference to a type of breathing common among the dying. The
+respiration becomes deep and slow, as it sinks gradually into quietude
+and becomes rarer and rarer until it seems to cease altogether, and
+then it slowly becomes more rapid and so on alternately. This type of
+breathing is known to physicians as ‘Cheyne-Stokes’ respiration, in
+commemoration of two distinguished Irish physicians of the last century
+who brought it to the attention of medical men. In our own time it has
+been partially explained on a physiological basis.
+
+We may note that there is another and even better pen-picture of
+Cheyne-Stokes respiration in the _Hippocratic Collection_. We read
+of one ‘Philescos who lived by the wall and who took to his bed on
+the first day of acute fever.’ About the middle of the sixth day he
+died, and the physician notes that ‘the respiration throughout was
+_like that of a person recollecting himself_ and was large and rare’.
+Cheyne-Stokes breathing is admirably described as ‘that of a person
+recollecting himself’.
+
+Immense and, as some may think, overwhelming importance is laid by the
+Hippocratic writings upon the art of ‘Prognosis’, that is of predicting
+the course which the disease will take. The work to which the title
+_Prognostics_ is attached represents a very lofty standard of practice.
+We quote from it a description of the signs of death to which the
+name of _Hippocratic facies_ has become attached. It is imitated by
+Shakespeare in his description of the death of Falstaff in Henry V
+(_Act II, Scene 3_).
+
+    ‘You should observe thus in acute diseases; first the
+    countenance of the patient, if it be like those of persons
+    in health, and especially if it be like itself, for this is
+    best of all. But the opposite are the worst, such as these:
+    a sharp nose, hollow eyes, collapsed temples; the ears cold,
+    contracted, and their lobes turned out; the skin about the
+    forehead rough, stretched and parched; the colour of the face
+    greenish, dusky, livid or leaden.
+
+    ‘If the countenance be such at the beginning of the disease,
+    and if this cannot be accounted for by the symptoms, inquiry
+    must be made whether the patient has been sleepless, whether
+    his bowels have been very loose, or whether he has wanted food.
+    If any of these be confessed, the danger is to be reckoned so
+    far the less, and it will become obvious in a day and night
+    whether or no the appearance come of these. But if no such
+    cause exist and if the symptoms do not subside in this time, be
+    it known for certain that the end is at hand.’
+
+These glimpses will give some idea of Rational Medicine in the making.
+In the fourth century B.C. Medicine emerges as a definite part of the
+scientific consciousness. Rational Medicine is now in being.
+
+
+§ 4. _Aristotle._
+
+During the fourth century B.C. there lived and worked one whose thought
+has stamped itself on the whole subsequent course of the biological and
+medical sciences, and indeed of all Science.
+
+Aristotle (384-322 B.C.) was a provincial Greek and son of a Macedonian
+physician. At seventeen he became a pupil of Plato at Athens. After
+Plato’s death in 347 Aristotle crossed the Aegean to reside in Asia
+Minor. The main part of his biological observations was made during
+his stay there. In 342 B.C., at the request of King Philip of Macedon,
+Aristotle became tutor to Philip’s son, Alexander the Great. He
+remained in Macedon for seven years. About 336, when Alexander departed
+for the invasion of Asia, Aristotle returned to Athens, where he taught
+for the rest of his life. He died in 322 B.C., a few months after his
+pupil Alexander.
+
+Aristotle was the great codifier of ancient Science. On him all
+subsequent biological development, including that of modern times,
+is surely based. In his wonderful biological works, which are still
+read by naturalists, he discusses many problems current to this very
+day. He laid the basis of the doctrine of Organic Evolution in his
+teaching concerning the _Scala Naturae_ ‘Ladder of Nature’ (Fig. 10).
+He developed coherent theories of Generation and Heredity. He founded
+Comparative Anatomy and he dissected many animals. He did not, however,
+anatomize the human body.
+
+[Illustration: FIG. 10. The _Ladder of Nature_ according to Aristotle.]
+
+Aristotle gave good descriptions of some organs, regarded from the
+standpoint of Comparative Anatomy. These descriptions he sometimes
+illustrated by drawings,
+
+the first anatomical figures of which we have a record. In some cases
+these drawings can be restored with confidence. Thus, he gave an
+account of the uterus, the nomenclature of which has been retained in
+more or less modified form to our own time (Fig. 11). Among the best
+anatomical descriptions given by Aristotle is that of the ruminant
+stomach. Perhaps his most extraordinary anatomical feat is his account
+of the development of the dogfish _Mustelus laevis_, which he showed
+was attached to its mother’s womb in a way very similar to the embryo
+of a mammal (Fig. 12). This raised the admiration of the greatest
+modern morphologist, Johannes Müller (1807-58, pp. 211-13), and would
+in itself be sufficient to establish the claim of Aristotle to a place
+in the front rank of observing naturalists. Aristotle gave fairly
+accurate descriptions of the branches of the great veins and of
+the superficial vessels of the arm of mammals. He realized that the
+arteries are usually accompanied by veins. He described the generative
+and digestive organs of cephalopod Molluscs, and many other parts of
+many other animals.
+
+[Illustration:
+
+FIG. 11. The womb with the names of its parts as given by Aristotle.
+These names remain, in various forms, in modern anatomy.
+
+FIG. 12. Embryo dogfish, _Mustelus laevis_, after Johannes Müller. The
+little creature is shown attached to the wall of its mother’s womb,
+somewhat after the manner of a mammal.
+
+]
+
+Something should be said of the errors of Aristotle. Though an
+excellent Naturalist, he was in general much weaker in Physiology.
+Thus, he made no proper distinction between arteries and veins. He
+failed to trace any adequate relations between the sense organs, the
+nerves, and the brain. His refusal to attach great importance to
+the brain is remarkable. Primacy he placed with the heart, which he
+regarded also as the seat of the intelligence. This was contrary not
+only to the medical opinion of his day, but also to the popular view,
+voiced, for instance, by Aristophanes in his play _The Clouds_, written
+about 400 B.C., where we read of a man who had _concussion of the
+brain_. Moreover, Aristotle’s teacher Plato placed the seat of thought
+and feeling in the brain. From all we know of Aristotle, it seems
+probable that he did not take up this attitude without evidence. It
+seems likely that he had experimented on the brain and found it devoid
+of sensation. Hence his view, opposed to current belief, that it is
+not associated with thought. Aristotle regarded the brain simply as an
+agent for cooling the heart, and preventing it from being over-heated.
+This cooling process, he considered, was effected by the secretion of
+_phlegm_ (_pituita_), an idea still preserved in our anatomical term
+the _pituitary body_.
+
+The views of Aristotle have had a vast influence in determining
+the direction of medical thought. For more than two thousand years
+Aristotelian philosophy, in more or less corrupted form, constituted
+the main intellectual food of mankind. Without some knowledge of the
+biological verdicts of Aristotle, it is impossible to understand the
+course taken by Rational Medicine. The influence of Aristotle is
+specially evident in certain basic biological conceptions.
+
+The problem of the nature of Generation is one in which Aristotle
+never ceased to take an interest. Among the methods by which he sought
+to solve it was embryological investigation. His most important
+embryological researches were made upon the chick. His choice was most
+fortunate, and the chick has remained, to this day, the classical
+subject of embryological research. Aristotle asserts that the first
+signs of life in the hen’s egg are noticeable on the third day, the
+heart being visible as a palpitating blood-spot. As it develops, two
+meandering blood-vessels extend to the surrounding tunics. A little
+later, he observes, the body becomes distinguishable, at first very
+small and white, the head being clearly distinguished and the eyes very
+large (Figs. 46-7, p. 117). To follow the main features of the later
+stages was a comparatively easy task.
+
+Aristotle was greatly impressed by these phenomena. He lays stress on
+the early appearance of the heart in the embryo. Corresponding to the
+general gradational view that he had formed of Nature, he held that the
+most primitive and fundamentally important organs make their appearance
+before the others. Among the organs all give place to the heart, which
+he considered the first to live and the last to die. In the heart, as
+we have seen, he placed the seat of the intelligence.
+
+Thus, not only in his account of the ‘Ladder of Nature’, but also
+in his theories of individual development, Aristotle exhibits some
+approach to evolutionary doctrine. This is somewhat obscured, however,
+by his peculiar view of the nature of procreation. On this topic his
+general conclusion is that the material substance of the embryo is
+contributed by the female, but that this is mere passive formable
+material, almost as though it were the soil in which the embryo grows.
+The male, by giving the principle of life, the _soul_ (_psyche_),
+contributes the essential generative agency. But this _soul_ is not
+material, and it is not, therefore, theoretically necessary for
+anything material to pass from male to female. The material which does
+in fact pass with the semen of the male is, as the older philosophers
+would have said, an _accident_, not an _essential_. The essential
+contribution of the male is not matter but _form_ and _principle_.
+
+The female then only provides the _material_, the male the _soul_, the
+form, the principle, that which makes life. Aristotle was thus prepared
+to accept instances of fertilization without material contact, i.e.,
+in effect, _parthenogenesis_ or ‘virgin birth’. In the centuries that
+came after him such instances were not infrequently adduced, and this
+doctrine was given a special turn by Christian theologians. Belief in
+the ‘accidental’ character of the material contribution of the male was
+common among men of science till the nineteenth century. The general
+attitude as to the nature of fertilization set forth, for instance, by
+William Harvey (1578-1657, pp. 111-14) in his book, _On the Generation
+of Animals_, published in London in A.D. 1651, is practically identical
+with the views of Aristotle published in Athens about 350 B.C., just
+2,000 years earlier. It is of great interest to note that very recent
+embryological research goes some way to confirm this view of Aristotle.
+Without any intervention of the male sexual element, it is possible
+so to stimulate the egg mechanically as to produce a perfect animal
+which is thus fatherless from the first. The male element is indeed
+unnecessary and, in fact, transmits only hereditary characters.
+
+We must say something concerning Aristotle’s conceptions of the nature
+of Life itself. He was before all things a ‘vitalist’. For him the
+distinction between living and not-living substance is to be sought not
+in material constitution, but in the presence or absence of something
+that he calls _psyche_, which we may translate ‘Soul’. His teaching on
+this topic had the profoundest influence on subsequent anatomical and
+physiological thought.
+
+Aristotle’s theory as to the relation of this Soul to material things
+is a difficult and complicated subject. Its adequate discussion would
+take us beyond our theme. He holds, however, that the Soul is related
+to the idea of _form_. In living things the soul is that which gives
+form. It is the pervasion by the soul that leads to the determinate
+development of the body and its parts. This activity of the Soul, under
+the Aristotelian term _Entelechy_ (which we may perhaps translate ‘the
+indwelling perfectability’ or ‘purposiveness’, see _Preface_), has an
+important place in modern biological theory, which has, indeed, swung
+definitely in the direction of the Aristotelian position.
+
+Aristotle defines Life, existing in Matter, as ‘the power of
+self-nourishment and of independent growth and decay’. Of the Soul, the
+principle of Life, he distinguishes three orders or types, the lowest
+_vegetative_, or nutritive and reproductive, next the _animal_ or
+sensitive, and highest the _rational_ or intellectual soul. The last,
+he at first held, was peculiar to man, but later he modified this view.
+
+[Illustration: FIG. 13. The four _Elements_ in association with the
+four _Humors_ and the four _Qualities_.]
+
+The history of the reception of Aristotle’s science by later ages is
+very strange to modern eyes. Of all Aristotle’s scientific teachings,
+men clung most firmly for many centuries not to his finely thought-out
+biological conceptions, but to a doctrine of the constitution of
+matter of which the modern student hears nothing. Aristotle, following
+more ancient writers, held that there were four primary and opposite
+fundamental _Qualities_, the _hot_ and the _cold_, the _wet_ and
+the _dry_. These met in binary combination to constitute the four
+Essences or Existences which entered in varying proportions into the
+constitution of all Matter. The four Essences, or, to give them their
+usual name, _Elements_, were _earth_, _air_, _fire_, and _water_. Thus,
+water was wet and cold, fire hot and dry, and so forth. With this
+theory later writers combined the somewhat similar Hippocratic doctrine
+which held that the body was composed of the four ‘Humors’ or liquids:
+_blood_, _phlegm_, _black bile_ (melancholy), and _yellow bile_
+(choler). Some of the Hippocratic physicians had associated excess of
+the Humors with various types of bodily constitution. Their followers
+made much of the ‘temperaments’ resulting therefrom, and according
+to the prevailing humor they distinguished the sanguine, phlegmatic,
+melancholy or choleric temperament (Fig. 34, p. 97).
+
+These conceptions, now departed altogether from our scientific
+discipline, still persist embedded in our language. Poetry still uses
+such ideas as the ‘raging of the elements’ and ‘elemental forces’.
+We may yet speak of a ‘fiery nature’ or an ‘aerial spirit’. We know
+what is meant by a _sanguine_ or a _phlegmatic_ temperament, and a
+_melancholy_ or _choleric_ disposition, and such words conjure up
+real pictures in our minds (Fig. 34). Until it began to be undermined
+by Robert Boyle (1627-91) and others in the seventeenth century, the
+doctrine of the four elements persisted in its entirety, while ideas
+and terms derived from the old humoral pathology can, in fact, be
+traced in the medicine of the twentieth century.
+
+The biological activity of the school of Aristotle was continued after
+his death by his pupil Theophrastus (372-287 B.C.). Especially the
+writings on plants of Theophrastus are instinct with a thoroughly
+scientific spirit, and are rightly regarded as the basic documents
+of the science of Botany. Nevertheless, his works had little effect
+or influence on his contemporaries and successors. With Theophrastus
+the purely biological school of Aristotle may be said to come to an
+end. The biological sciences ceased, for many centuries, to be studied
+for their own sake and became mere handmaidens of Medicine. Neither
+mistress nor servant was the better for the change.
+
+
+
+
+II
+
+THE HEIRS OF GREECE
+
+(300 B.C. TO A.D. 200.)
+
+
+§ 1. _The Alexandrian School._
+
+Soon after Aristotle, about 300 B.C., a great medical school was
+founded at Alexandria in Egypt. That country had been conquered by
+Alexander the Great, after whom the town was named. On Alexander’s
+death, Egypt came under the rule of one of his generals, Ptolemy,
+who established a dynasty which became extinct with the famous Queen
+Cleopatra, thirty years before the Christian era. Alexandria was a
+favorite residence of this Greek dynasty and became more Greek than
+Egyptian. Ptolemy and his successors were patrons of learning, and
+at the Alexandrian school remarkable anatomical and physiological
+researches were made. These were the work of Greek physicians who, in
+the tradition of their people, were only too wont to associate their
+discoveries with sweeping theoretical generalizations, often on very
+inadequate bases.
+
+The two earliest medical teachers at Alexandria were also the greatest,
+Herophilus of Chalcedon, who flourished about 300 B.C., and his
+slightly younger contemporary Erasistratus of Chios. Herophilus may
+be regarded as the father of Anatomy, Erasistratus as the father of
+Physiology.
+
+Herophilus was probably the first to dissect the human body in public.
+He recognized the brain as the central organ of the nervous system and
+regarded it as the seat of the intelligence, thus reversing the verdict
+of Aristotle on the primacy of the heart. He was the first to grasp the
+nature of the nerves, which he distinguished as connected with motion
+and sensation (Fig. 98), though he did not separate them clearly from
+tendons and sinews. He greatly extended the knowledge of the parts
+of the brain. Certain parts of the brain still bear titles which are
+translations of those which he gave them. He also made the first clear
+distinction between arteries and veins.
+
+At the time of the institution of the Alexandrian medical school, and
+for long after, there flourished that view of the structure of the
+world known as _atomic_, propounded by the philosopher Democritus
+(_c._ 400 B.C.). The chief exponent of the theory was Epicurus
+(342-270), whose philosophy was of the order which we should now call
+‘materialistic’. For it the only ultimate realities were atoms and
+‘the void’, and everything was ultimately expressible in these terms.
+Epicurean philosophy was not without its reactions on Medicine at
+Alexandria, where its leading exponent was Erasistratus of Chios.
+
+Erasistratus was essentially a rationalist and professed himself a
+foe to all mysticism. In the last resort, however, he had to invoke
+the idea of Nature as a great artist acting as an external power,
+shaping the body according to the ends to which it must act. This is
+in contrast with Aristotle’s view of the ‘soul’ as an _Entelechy_ (p.
+33), an innate and inherent factor. Erasistratus sought to express
+his views in atomic terms, but, to make physiology intelligible, he
+added a conception, _Pneumatism_, found also among older thinkers.
+Pneumatism is the belief that the phenomena of life are associated with
+the existence of a subtle vapor, ‘pneuma’ or spirit, which permeates
+the organism, and causes its movements. This subtle vapor is held to
+have some affinities with the air we breathe. Pneumatism is, in fact, a
+primitive attempt to explain the phenomena of respiration.
+
+Erasistratus observed that every organ is equipped with a threefold
+system of ‘vessels’, vein, artery, and nerve, which divide to the
+very limits of vision, and he considered that the process of division
+continues beyond those limits. The minute divisions of these vessels,
+plaited together, he believed to make up the tissues. Veins, arteries,
+and nerves are, for him, made of minute tubes of the same nature as
+themselves, through which they are nourished. Blood and two kinds of
+pneuma are the essential sources of nourishment and movement. The blood
+is carried by veins. Air, on the other hand, is taken in by the lungs
+and passes to the heart, where it becomes changed into a peculiar
+pneuma, the _Vital Spirit_, which is sent to the various parts of the
+body by the arteries. This spirit is carried to the brain, in the
+cavities or ‘ventricles’ of which it is further changed to a second
+kind of pneuma, the _Animal Spirit_. The animal spirit is conveyed to
+different parts of the body by the nerves, which are hollow.
+
+In the brain Erasistratus observed the convolutions, noted that they
+were more elaborate in man than in animals, and associated this
+complexity with the higher intelligence of man. He distinguished
+between the main parts of the brain, the ‘cerebrum’ and ‘cerebellum’
+(Fig. 100, p. 210), and gave a detailed description of the ‘cerebral
+ventricles’ or cavities within the brain and of the ‘meninges’ or
+membranes that cover the brain. He considered that the cerebral
+ventricles were filled with _Animal Spirit_. (Compare Galen’s scheme,
+p. 58.)
+
+Erasistratus attained to a clear view of the action of muscles in
+producing movement. He regarded the shortening of muscles as due to
+distension by _Animal Spirit_ conveyed to the muscles by the nerves. We
+may note that similar theories as to the nature of muscular action were
+again set forth, on theoretical grounds, in the seventeenth century by
+Descartes (1596-1650, pp. 127-8) and by Borelli (1608-79, pp. 129-30),
+but were rebutted by the experiments of Swammerdam (1637-80, p. 123).
+We may recall that we are still in the dark as to the mechanism of
+contraction of muscle fiber, the structure of which was first revealed
+by Leeuwenhoek (1632-1723, Figs. 55-56A, p. 121).
+
+Erasistratus considered the chief cause of disease to be excess
+of blood or _Plethora_. Diseases thus caused differ according to
+their site. Among them are coughing of blood, epilepsy, pneumonia,
+tonsillitis, &c. Most of these diseases could be treated by diminishing
+the local supply of blood by starvation. Among his contemporaries and
+successors blood-letting was an habitual practice applied to almost
+every condition. Erasistratus employed it but rarely, and his followers
+banned it altogether. He was consistently opposed to violent remedies.
+Among the therapeutic measures which he favored were regulated
+exercise, diet, and the vapor bath.
+
+Erasistratus complained that many physicians of his time were not
+interested in Hygiene. He therefore wrote a treatise on the subject.
+Though he regarded Hygiene as a means of substituting prevention for
+cure, this did not prevent him from being extremely careful and precise
+in his treatment of cases.
+
+After the first generation or two, the activity of the Alexandrian
+medical school flagged, though the city long remained a great teaching
+center, and minor medical advances were made. Surgery (cf. Fig. 14)
+seems to have languished less than Medicine. The stagnation in medical
+matters at Alexandria is in contrast to the continued activity there in
+Mathematics, Astronomy, Mechanics and Geography.
+
+With the absorption of Egypt into the Roman Empire in 50 B.C. and
+the extinction of the Ptolemaic dynasty by the death of Cleopatra in
+30 B.C., Alexandria ceased to have great scientific importance. The
+school continued for centuries with restricted activity and devoid
+of all originality. Intellectually, it had become subordinate to the
+Metropolis. Rome was now mistress of the world and the future of
+Medicine must be considered from the point of view of the Roman Empire.
+
+[Illustration:
+
+FIG. 14. INSCRIBED TABLET OF ABOUT 100 B.C. from the wall of the temple
+of Kom-Ombos in Upper Egypt. The temple itself was built by Ptolemy
+VII (181-146 B.C.), but the carving is later. It is divided into four
+partitions. These illustrate the surgical instruments in use in Egypt
+during Alexandrian times.
+
+In the partition to the extreme left can be seen two cupping-glasses
+(cf. Fig. 8), a case of instruments (cf. Fig. 15), a pair of shears, a
+sponge, a probe, a pair of fine forceps, and two knives (cf. Fig. 9).
+
+In the next partition to the right can be seen two large forceps, two
+bags or flasks, a strigil, two magic eyes, a pair of scales, and two
+growing plants.
+
+In the next partition to the right can be seen several hooks of
+different forms, several knives, and two or three pairs of forceps.
+
+In the partition to the extreme right can be seen a bifid probe, a pair
+of tongs, a long-bladed knife, probes, a double hook, a saw, a cautery,
+and several objects probably intended to represent bandages. ]
+
+
+§ 2. _Medical Teaching in the Roman Empire._
+
+The original native Roman medical system was quite devoid of scientific
+elements and was that of a people of the lower culture. Interwoven,
+as is all primitive Medicine, with ideas that trespass on the domains
+of religion and magic, it possessed that multitude of ‘specialist
+deities’ which was so characteristic of the Roman cults. The entire
+external aspect of Roman medicine was changed by the advent of Greek
+science. Yet, notwithstanding the large medical field that the Western
+Empire provided, and the wide acceptance of Greek medicine by the upper
+classes, it is remarkable that the Latin-speaking peoples produced no
+eminent physician.
+
+At first scientific medical education at Rome was entirely a matter of
+private teaching. The earliest important scientific teacher there was
+the Greek Asclepiades of Bithynia (died _c._ 40 B.C.), a contemporary
+of the poet Lucretius and, like him, an Epicurean. Asclepiades, like
+Erasistratus, imported the atomic view of Democritus into Medicine. He
+deeply influenced the course of later medical thought, ridiculed the
+Hippocratic attitude of relying on the ‘healing power of nature’ which
+he regarded as a mere ‘meditation on death’, and urged that active
+measures were needed for the process of cure to be ‘seemly, swift and
+sure’. He founded a regular school at Rome which continued after him.
+
+At first the school was the mere personal following of the physician,
+who took his pupils and apprentices round with him on his visits. At
+a later stage such groups combined to form societies or colleges,
+where problems of the art were debated. Towards the end of the reign
+of Augustus (27 B.C.-14 A.D.) or the beginning of that of Tiberius
+(14 A.D.-37 A.D.), these societies constructed for themselves a
+meeting-place on the Esquiline Hill. Finally the emperors built
+halls or _auditoria_ for the teaching of Medicine. The professors at
+first received only the pupils’ fees. It was not until the time of
+the Emperor Vespasian (reigned A.D. 70-9) that medical teachers were
+given a salary at the public expense. The system was extended by later
+emperors.
+
+Thus Rome became a center of medical instruction. After a time
+subsidiary centers were established in other Italian towns. From Italy
+the custom spread and we meet traces of such schools at the half-Greek
+Marseilles as well as at Bordeaux, Arles, Nîmes, Lyons, and Saragossa.
+For the most part these provincial schools produced workaday medical
+men, few of whose writings have come down to us. They were perhaps
+largely training-places for the army surgeons. That class seldom had
+scientific interests, though Dioscorides, one of the most prominent
+physicians of antiquity, one who earned the respect of Galen and has
+deeply influenced the modern pharmacopoeia, served in the army under
+Nero. His book is, in fact, an extremely useful though ill-arranged
+compendium of drugs. Dioscorides wrote in Greek, and his work was not
+translated into Latin until the sixth century of our era.
+
+The earliest scientific medical work in Latin is the _De re medica_ of
+Celsus, which was prepared about A.D. 30. It is in many ways the most
+readable and well-arranged ancient medical work that we have. It is,
+however, not an original work but a compilation from the Greek, and the
+sole surviving part of a complete encyclopaedia of knowledge. Many of
+its phrases are closely reminiscent of the _Hippocratic Collection_.
+The ethical tone is high and the general line of treatment sensible and
+humane. Celsus, though almost forgotten in the Middle Ages, was the
+first classical medical writer to be printed (A.D. 1476).
+
+The treatise of Celsus opens with an interesting account of the History
+of Medicine. It then passes on to deal with diet and the general
+principles of therapeutics and pathology, next it discusses internal
+disease, and then turns to external diseases. The last part of the work
+is devoted to surgery, and is perhaps the most valuable of the whole.
+
+Celsus professes himself a follower of Asclepiades of Bithynia (p.
+41), but, unlike his master, he by no means despises the Hippocratic
+_expectant_ method of ‘waiting on the disease’. In many matters we are
+struck with
+
+his boldness as a surgeon. Thus he describes plastic operations on the
+face and mouth, and the removal of polypus from the nose. He tells too
+of the very dangerous operation for extirpating a goiter (p. 303), and
+of cutting for stone. He gives an excellent account of what might be
+thought the modern operation for removal of tonsils. Noteworthy also
+is his description of dental practice which includes the wiring of
+loose teeth and an account of a dental mirror. An idea of the surgical
+instruments in use in his time can be obtained from those recovered
+from Pompeii (Fig. 15).
+
+[Illustration: FIG. 15. ROMAN SURGICAL INSTRUMENTS of the first century
+A.D. found at Pompeii.
+
+    _a._ Forceps, probably for extracting teeth.
+
+    _b._ Small pocket-case of instruments containing sharp spoon,
+    probe, &c.
+
+    _c._ Fine-toothed forceps.
+
+    _d._ Trocar and cannula for tapping fluids confined in cavities.
+
+    _e._ Speculum for examining orifices and cavities.
+
+    _f._ Instrument for dilating wounds that they may be more fully
+    examined.
+]
+
+
+§ 3. _Medical Services of the Roman Empire._
+
+If, in Medicine itself, the Roman achieved but few advances, in the
+organization of medical service, and especially in the department which
+deals with public health, his position is far more noteworthy. All
+Latin writers on architecture give much attention to the orientation,
+position and drainage of buildings. From an early date sanitation and
+public health drew the attention of statesmen. Considering the dread of
+the neighborhood of marshes on the part of these practical sanitarians
+of Ancient Rome, and in view of modern knowledge of the mosquito-borne
+character of Malaria (pp. 284-5), it entertaining to find the mosquito
+net ridiculed by the poets Horace, Juvenal and Propertius!
+
+Sanitation was a feature of Roman life. Rome was already provided with
+_cloacae_ or subterranean sewers in the age of the Tarquins (6th cent.
+B.C.). The _Cloaca Maxima_ itself, the main drain of Rome, which is
+still in use, dates back to that period.
+
+The antiquity of hygienic ideas is seen in an interdict, by a law
+of about 450 B.C., against burials within the city walls and in the
+instructions issued to the town officials to attend to the cleanliness
+of the streets and to the distribution of water. Among these ancient
+laws we may note one attributed to the first king of Rome, which
+directed the opening of the body in the hope of extracting a living
+child in the case of a woman dying in pregnancy. It is the origin of
+the so-called ‘Caesarean section’ on the living mother, the method by
+which Caesar himself is said to have been brought into the world. At
+the date of these decrees physicians in Rome were either slaves or in
+an entirely subordinate position. Their status was improved by Julius
+Caesar (102-44 B.C.), who conferred citizenship on all who practised
+Medicine at Rome, in order to induce physicians to settle there.
+
+[Illustration: FIG. 16. AQUEDUCT OF NERO. This structure, when
+complete, conveyed part of the water-supply of Rome.
+
+(_From an engraving by Piranesi._)]
+
+The finest monument to the Roman care for the public health stands yet
+for all to see in the remains of the fourteen great aqueducts which
+supplied the city with 300,000,000 gallons of potable water daily. No
+modern city is better equipped (Fig. 16).
+
+Under the early Empire a definite public medical service was
+constituted. Public physicians were appointed to the various towns and
+institutions. A statute of the Emperor Antoninus of about the year A.D.
+160 regulates the appointment of these physicians, whose main duty was
+to attend to the poor. In the code of the Emperor Justinian (A.D. 533)
+is an article urging them to give this service cheerfully rather than
+the more subservient attendance on the wealthy. Their salaries were
+fixed by the municipal councillors. They were encouraged to undertake
+the training of pupils. Inscriptions attest the respect in which these
+state physicians were held in many towns.
+
+It is in connection with the army that we see the Roman medical
+system at its best. There was an adequate supply of military medical
+attendants who were well organized (Fig. 17). The defects of the Roman
+army medical system were, however, absence of any elastic scheme for
+the ranking of medical officers, and complete subordination of the
+medical to the combatant officer. These facts are of a piece with the
+general Roman indifference to theoretical science, and explain
+
+why the Roman army surgeons made no additions to knowledge. The social
+status of the medical staff in the Roman military hierarchy was that of
+the non-commissioned personnel, which included accountants, registrars
+and secretaries.
+
+[Illustration: FIG. 17. ROMAN ADVANCED DRESSING-STATION.
+
+(_From Trajan’s column._)
+
+To the left two Roman soldiers assist a wounded comrade. To the right
+a Roman military surgeon bandages the wounded thigh of a friendly
+ally. The costume of the surgeon is almost identical with that of the
+soldiers, though he carries a case for ‘first aid’ slung over his
+shoulder.
+
+]
+
+
+§ 4. _Roman Hospitals._
+
+The great contribution of Rome to Medicine--and it is a very great
+one--is the hospital system. It is a scheme that naturally arose out
+of the Roman genius for organization and is connected with the Roman
+military system. Among the Greeks, _iatreia_, ‘surgeries’, were well
+known; they were, however, the private property of the medical man.
+Larger institutions were connected with Aesculapian temples and there
+is evidence of some degree of scientific medical treatment in these
+places. In the Republican period the Romans were no better off and,
+despite the vast numbers of slaves, there was no provision for them
+when sick. A temple to Aesculapius had been established on an island of
+the Tiber in Republican times. It became the custom to expose the sick
+and worn-out slaves on this island of Aesculapius, to avoid the trouble
+of treating them. The Emperor Claudius (A.D. 41-54) decreed that such
+slaves were free, and that, if they recovered, they need not return to
+the control of their masters. Thus, the island became a place of refuge
+for the sick poor. We may regard it as an early form of public hospital
+(Fig. 18).
+
+Later writers speak of _valetudinaria_, ‘infirmaries’, for such
+persons, and give humane directions for their management. Such
+valetudinaria were in use even by free Romans. The excavations at
+Pompeii show that a physician’s house might even be built somewhat on
+the lines of a modern ‘nursing home’. It was probably in the provinces
+that private institutions first developed into subventioned public
+hospitals.
+
+This development of public hospitals naturally early affected military
+life. At first, sick soldiers had been sent home for treatment. As the
+Roman frontiers spread ever wider this became impossible and military
+hospitals were founded at important strategic points. The sites of
+several such military hospitals have been excavated. The best explored
+is near Düsseldorf and was founded about A.D. 100.
+
+From the military valetudinarium it was no great step to the
+construction of similar institutions for the numerous Imperial
+officials and their families in the provincial towns. Motives of
+benevolence, too, gradually came in, and public hospitals were
+founded in many localities. The idea passed on to Christian times,
+and the pious foundation of hospitals for the sick and outcast in the
+Middle Ages is to be traced back to these Roman valetudinaria. The
+first charitable institution of this kind, concerning which we have
+clear information, was established at Rome in the fourth century by
+a Christian lady of whom we learn from St. Jerome. The plan of such
+a hospital projected at St. Gall in the early years of the ninth
+century has survived. It reminds us, in many respects, of the early
+Roman military hospitals. These medieval hospitals for the sick must
+naturally be distinguished from the even more numerous ‘spitals’ for
+travellers and pilgrims, the idea of which may perhaps be traced back
+to the rest-houses along the strategic roads of the Empire.
+
+[Illustration: FIG. 18. ISLAND OF ST. BARTHOLOMEW IN THE TIBER AT ROME.
+(_From an engraving by Piranesi._)
+
+The island was the site of a temple to Aesculapius used as a refuge
+for worn-out slaves. It is the first known public hospital. The entire
+island is carved in the form of a ship. On its prow can be discerned
+the head of Aesculapius and his staff and serpent. ]
+
+
+§ 5. _Galen._
+
+The Latin culture, as we have seen, did not adapt itself easily to the
+prosecution of scientific Medicine. Long after Greece had ceased to
+exist as an independent state such medical writings as appeared were
+usually in the Greek rather than in the Latin language. This is true
+to the end, and the end came, so far as creative science is concerned,
+with the second half of the second century. The scene is then, and for
+centuries to come, mainly occupied by the huge overshadowing figure of
+Galen.
+
+Galen of Pergamum (A.D. 130-200) devoted himself to medicine from an
+early age, and in his twenty-first year we hear of him studying anatomy
+at Smyrna. To extend his knowledge of drugs he made long journeys
+to Asia Minor. Later he proceeded to Alexandria, where he improved
+his anatomical equipment, and here, he tells us, he examined a human
+skeleton. His direct practical acquaintance with human anatomy was
+limited to that skeleton, for dissection of the human body was no
+longer carried on in his time. Thus, his physiology and anatomy were
+derived mainly from animal sources.
+
+The general medical standpoint of the Galenic is not unlike that of
+the Hippocratic writings, but the noble vision of the lofty-minded,
+pure-souled physician has utterly passed away. In its place we have an
+acute, contentious fellow of prodigious industry, who is frequently
+satisfied with a purely verbal explanation. Yet he is an ingenious
+physiologist, acquainted with the internal parts, so far as this is
+possible from a devotion to dissection of animals, equipped with
+all the learning of the schools of Pergamum, Smyrna and Alexandria,
+and rich with the experience of a vast practice at Rome. Galen is
+essentially an ‘efficient’ man. He has the grace to acknowledge
+constantly his indebtedness to the Hippocratic writings.
+
+Some of Galen’s works are, however, mere drug-lists, little superior to
+those of Dioscorides (p. 43). With the depression of the intelligence
+that corresponded with the break-up of the Roman Empire, it was these
+that were chiefly studied and distributed in the West. The Greek
+medical writers after Galen were but his imitators and abstractors, and
+they usually imitated and abstracted Galen at his worst. Through some
+of them Galen’s works reached the West at a very early period in the
+Middle Ages.
+
+
+§ 6. _The Final Medical Synthesis of Antiquity._
+
+We now turn to the theoretical content of the vast mass of Galenic
+writings. These set forth a medical system of which the substance
+is based on the _Hippocratic Collection_ and the form derived from
+Aristotle. This synthesis, in more or less corrupted form, provided
+the theoretical basis of medical practice for the next fifteen hundred
+years. Galen’s view of the human body may be examined under two
+aspects, which we describe as (_a_) philosophical and (_b_) descriptive.
+
+First as to the philosophical aspect. Galen’s voluminous works are
+saturated with the theory that all structures in the body have been
+formed by the Creator for a known and intelligible end. In the
+anatomical works, masses of explanation, based on this view, dilute
+the often imperfect accounts of structures. Thus, following the
+Aristotelian principle that Nature makes nought in vain, Galen seeks to
+justify, the form and structure of every organ--nay, of every part of
+every organ--with reference to the functions for which he believes it
+is destined. To do this is to claim that in every work of Creation--of
+which Man’s body is a type--and in every detail of such work, we can
+demonstrate God’s design along known principles. It is to claim, in
+fact, a complete knowledge of the Laws of Nature. No modern man of
+science, however intoxicated with his own achievements, has as yet
+arrogated such powers to himself. To conceive that such claims should
+be made by a pious, theistically minded author, the reader must think
+himself back into a very different philosophical environment from that
+to which we are nowadays accustomed.
+
+The prevailing philosophy of Galen’s world was the Stoic. Now in the
+world of the Stoic philosopher all things were determinate, and they
+were determined by forces acting wholly outside Man. The type and
+origin of that determination the Stoic sought in the heavens, and found
+in the majestic and overwhelming procession of the stars. The recurring
+phenomena of the spheres typified, foreshadowed, nay, exhibited and
+controlled, the cycle of man’s life. Man dwelt in a finite world,
+bounded by a definite frontier--the sphere of the fixed stars. Within
+that spherical frontier all things worked by rule--and that rule was
+the rule of the heavenly bodies. Astrology had become one of the dogmas
+of the Stoic creed.
+
+To such a world Galen’s determination was in itself no strange thought.
+Yet Galen’s view was far from being wholly in accord with Stoicism.
+Though a determinism, it was a determinism of perfection in which all
+was fixed by a wise and far-seeing God, and was a reflection of His
+perfection. Now such a scheme did not ill fit the new creed which was
+just beginning to raise its head and was destined to replace Stoicism
+and all the other pagan schemes. Galen’s thought, in fact, made a
+special appeal to the Christian point of view, and this is, doubtless,
+the reason that his works have been preserved in larger bulk than
+those of any other pagan writer. The Galenic standpoint appealed
+equally to the theological bias of Islam, whose medical knowledge was
+based almost entirely on Galen.
+
+We may now turn from the philosophical to the descriptive bases of
+Galen’s medical system, namely to his Anatomy and Physiology.
+
+We may begin with the bones. These Galen had studied on an actual human
+skeleton at Alexandria. He divided them into long bones with a central
+canal and flat bones without such a canal. He had a fairly good idea
+of the bones of the skull. He regarded the teeth as bones, and he
+gives a good description of their origin. He recognized twenty-four
+vertebrae terminated by the _sacrum_. Galen gives accurate elementary
+descriptions of the vertebrae, of the ribs, of the breastbone, of
+the collar-bone, and of the bones of the limbs. He divides joints or
+junctions of bones into two main orders, those with movement and those
+without movement, and the titles that he gives to his main divisions
+have survived in our modern nomenclature.
+
+As regards the muscular system there can be little doubt that Galen’s
+work was in large part of a really pioneer character. Throughout
+his works the muscles are perhaps the structures that he describes
+most accurately. His writings contain frequent references to form
+and function of muscles of various animals. Thus, the dissection of
+the muscles of the orbit and larynx was performed on the ox, and the
+muscles of the tongue are described from the ape. Occasionally he
+indicates that he is aware of the differences between certain of the
+muscles he is describing from those of man. For his investigation of
+muscles Galen used particularly the Barbary ape (_Macacus inuus_),
+a creature anatomically near enough to man for a knowledge of its
+detailed structure to be applicable to human Surgery. (Figs. 19 and 20.)
+
+[Illustration:
+
+FIG. 19. DISSECTION OF HAND OF MAN.
+
+FIG. 20. DISSECTION OF HAND OF BARBARY APE.
+
+The ape’s hand shows all the main muscular and tendinous structures
+present in the human hand, though the proportional development differs
+somewhat. The same is true of other parts of the body. Galen’s
+anatomy, drawn from the Barbary ape, was thus quite serviceable for
+many surgical procedures. Apart from proportion, the most obvious
+anatomical difference in the hands of the two species is the position
+of attachment of the small severed muscle indicated by the asterisk in
+both cases.
+
+]
+
+Galen’s description of the brain and of the vascular system is inferior
+to his account of the bones and muscles. His account of the nervous
+system, other than the brain, occupies an intermediate position. His
+account of the origin of nerves from the brain has left its traces even
+in modern descriptive anatomy.
+
+Finally we may turn to Galen’s theory of the working of the human body,
+that is to his Physiology.
+
+The basic principle of life in the Galenic physiology was a _spirit_ or
+_pneuma_ drawn from the general World-spirit in the act of breathing.
+It entered the body through the windpipe or _trachea_ and so passed to
+the lung and thence, through the _arteria venalis_--which we now call
+the ‘pulmonary vein’--to the left ventricle of the heart, where it
+encountered the blood (Fig. 21). But what was the origin of the blood?
+To this question his answer was ingenious, and the errors that it
+involved remained till the time of Harvey (Fig. 43, p. 113).
+
+Galen believed that food-substance from the intestines was carried as
+‘Chyle’ by the portal vein to the liver. There it was converted into
+blood and endowed with a particular pneuma, the _Natural Spirit_, which
+bestowed the power of growth and nutrition. Part of this lower-grade
+blood was carried from the liver to the right ventricle, where it gave
+off impurities by way of the _vena arterialis_, our ‘pulmonary artery,’
+to the lungs, whence they were exhaled in the breath. The venous
+blood, thus continuously purified, ebbed to and fro in the veins
+for purposes of ordinary nutrition. A very small part of this venous
+blood passed through invisible pores in the muscular septum to the left
+ventricle. There it mixed with air drawn in from the lung by way of the
+_arteria venalis_, our ‘pulmonary vein’. From this mixture was produced
+a higher-grade blood, the arterial blood, instinct with the principle
+of life and charged with a second kind of pneuma, the _Vital Spirit_.
+Blood containing this second kind of pneuma ebbed to and fro in the
+arteries endowing the various organs with function. Such as reached the
+brain became there charged with the noblest essence of all, the third
+pneuma, the _Animal Spirit_ or breath of the soul. The _Animal Spirit_
+was carried from the brain by the nerves--believed to be hollow--and
+through them initiated the higher functions of the organism, including
+motion and sensation (Fig. 21).
+
+Among Galen’s most remarkable efforts are the investigations he made
+of the physiology of the nervous system. He tells of his experiments
+on the spinal cord. Injury to the cord between the first and second
+vertebrae caused, he observed, instantaneous death. Section between
+the third and fourth produced arrest of breathing. Below the sixth
+vertebra it gave rise to paralysis of the chest muscles, breathing
+being then carried on only by the diaphragm. If the lesion was lower
+the paralysis was confined to the lower limbs, bladder, and intestines.
+The physiology of the spinal cord is worked out most ably and in very
+considerable detail.
+
+Galen established no school, nor had he any definite followers. His
+self-satisfaction and love of controversy were not of the kind that
+would endear him to disciples. On his death in A.D. 200 the active
+prosecution of anatomical and physiological inquiry ceased absolutely.
+The curtain descends at once, and, for the subject we are discussing,
+the Dark Ages have begun.
+
+Rational medicine in the pagan world descends into darkness as surely
+and even more abruptly than Philosophy. The whole system is soon to be
+overwhelmed. Alexandria has long been in decline. A mob, fanatically
+Christian, has destroyed her school and library, with all the hoarded
+wisdom of the pagan past. Men of the new faith fix their eyes on the
+wrath to come and the glory after it. In the race for salvation, who
+will pause to consider this miserable tenement of clay? Antiquity is no
+more. A new age has begun.
+
+[Illustration: FIG. 21. GALEN’S PHYSIOLOGICAL SYSTEM.]
+
+
+
+
+III
+
+THE MIDDLE AGES
+
+(FROM ABOUT A.D. 200 TO ABOUT A.D. 1500.)
+
+
+§ 1. _The Period of Depression in Europe._
+
+The observational period of Antiquity closed with Galen. The centuries
+that follow exhibit progressive deterioration of the intellect. For
+that deterioration many causes have been assigned. An important factor
+was certainly the philosophical outlook of later paganism. Men lacked a
+motive for living. Their view of the World was dreary and without hope.
+It is sometimes alleged that the advent of Christianity was a factor
+in the decay of Science, but Science was, in fact, in headlong decay
+before Christianity was in a position to have any real effect on pagan
+thought.
+
+Christianity came to the ancient world as a protest and a revulsion
+against the prevailing and extremely pessimistic pagan outlook.
+Christianity brought men something for which to live. It was natural
+that it should oppose the philosophical basis of pagan thought. In
+this sense Christianity was certainly anti-scientific. Early Christian
+thought exhibits an aversion to the view which places the whole of
+man’s fate under the dominion, the inescapable tyranny, of Natural
+Law. It is, however, essential to remember that the early Church, in
+developing this opposition, was not dealing with living observational
+Science. The conflict was simply with a philosophical tradition which
+contained dead, non-progressive and misunderstood scientific elements.
+
+For some eight centuries from the time that Christianity finally
+replaced Paganism in the Roman Empire--from about A.D. 400 to about
+A.D. 1200--such remains of classical learning and classical science as
+survived were in monastic keeping. It was only in the monasteries that
+there were any who cared at all for these things, and it was only in
+the monasteries that manuscripts could be either written or preserved.
+We cannot be sufficiently grateful to the monks for having succeeded in
+preserving even as much as they did. Nevertheless, whether we consider
+what they saved or what they lost of medical literature, we can express
+no high opinion of either monastic taste or monastic judgment.
+
+The curse of the Science of Medicine, as of all sciences, has always
+been the so-called ‘practical man’, who will consider only the
+immediate end of his art, without regard to the knowledge on which it
+is based. Monkish medicine had no thought save for the immediate relief
+of the patient. All theoretical knowledge was permitted to lapse.
+Anatomy and Physiology perished. Prognosis was reduced to an absurd
+rule of thumb. Botany became a drug-list. Superstitious practices crept
+in, and Medicine deteriorated into a collection of formulae, punctuated
+by incantations, which became less understood and further removed
+from their originals at each copying. Medicine remained surrounded by
+sacred associations (Fig. 22), but the scientific stream, which is its
+life-blood, was dried up at its source.
+
+[Illustration:
+
+FIG. 22. EARLIEST KNOWN REPRESENTATION OF ST. LUKE AS A PHYSICIAN.
+From a seventh-century painting in the underground basilica of Saints
+Felix and ‘Adauctus’ at Rome. St. Luke, as an Evangelist, holds a
+scroll between his hands; as a Physician he carries suspended from his
+left arm a bag containing four instruments, one of which is a lancet.
+The head is tonsured like a monk’s. By courtesy of Rev. Father J. R.
+Fletcher.
+
+FIG. 23. PICTURE OF TREPHINING from a thirteenth-century manuscript.
+The surgeon is using a well-known and primitive form of drill, the mode
+of action of which will be understood by the accompanying diagram,
+shown as Fig. 24.
+
+]
+
+There was just one area in the Latin West where a slightly higher
+standard prevailed. In the South of Italy the Greek tongue still
+continued for centuries to be spoken and written. Though civilization
+had sadly deteriorated with the disorders of the times, yet there
+remained here and there in that region a slightly higher intellectual
+standard than prevailed elsewhere in Europe. Moreover, about the same
+time as the Norman Conquest in England, there was a Norman Conquest
+of South Italy also. The strong arm of the Norman administrator might
+wield the weapon of a tyrant, but at least it brought order where
+there had been anarchy. Learning under the Normans could lift a timid
+head. Notably at the town of Salerno, not far from Naples, there arose
+something resembling a medical school. At Salerno in the eleventh
+century there was a certain amount of translation of medical works from
+Greek into Latin. The choice of works for translation was very poor,
+but it was something that enough mental energy existed for the effort.
+
+[Illustration:
+
+FIG. 24. Figure to illustrate the mode of action of the instrument used
+by the surgeon in Fig. 23. The twist of the thong causes rapid rotation
+of the axis. The rotating point is pressed on the skull and gradually
+penetrates it. From a drawing of the sixteenth century.
+
+]
+
+Salerno differed too from other centers of learning of the time in that
+instruction was not entirely under monastic auspices (Fig. 25). Some,
+at least, of the Salernitan physicians were laymen. At the time of the
+Norman conquest of Salerno, the school was stimulated by the advent of
+a wanderer from the East, Constantine by name (died 1087). This man
+brought with him medical works in Arabic which he was able to translate
+into rude Latin. The Latin versions prepared by Constantine, corrupt,
+confused, barbarous, often almost incomprehensible, were yet a better
+intellectual fare than that on which the torpid mind of Europe had
+long fed. The Salernitan medical writings of the eleventh and twelfth
+centuries exhibit some faint-hearted attempts to return to Nature.
+Constantine was but the harbinger of the great ‘Arabian revival’ the
+further origins of which we must now seek to trace.
+
+[Illustration:
+
+FIG. 25. SCENE AT A SIEGE OF SALERNO from a manuscript prepared in
+South Italy early in the thirteenth century. An archer transfixes two
+of the defenders through the cheeks. A _medicus_ is aiding one of
+them. Two nurses, bearing drugs and dressings, attend the medicus. It
+illustrates the existence of lay physicians at Salerno at this date.
+The medicus is not tonsured.
+
+]
+
+
+§ 2. _Arabic Medicine._
+
+Barbarian incursions sapped and finally destroyed the Western Roman
+Empire. The influence of those incursions on the Eastern Empire was
+less dramatic. It is true that the intellectual outlook of the East
+Roman or Byzantine Empire was no less modified, in the course of time,
+than was that of the West. In the absence, however, of any collapse
+of the system of government, the ancient Greek learning or rather the
+documentary casing in which it was enshrined, was better preserved
+than were the Latin traditions. Men in the Eastern Empire could still
+read the ancient Greek medical works in the language in which they had
+been written, and, if their reading was unintelligent, it was at least
+persistent. Moreover, heretical Christian sects on the confines of the
+East Roman Empire prepared for themselves translations of many of the
+ancient Greek authors. One of these heretical sects, the Nestorians,
+exhibited great missionary activity. It was perhaps on this account
+that the Nestorians prepared translations of many Greek medical works
+into their own language, Syriac.
+
+In the seventh century, Islam arose and soon swept over vast areas
+that had erstwhile belonged to the Emperor of the East. The territory
+occupied by the Nestorians in the Near East came early under Moslem
+rule. The Moslems, at first indifferent to infidel learning, came
+gradually to appreciate it. In the ninth century a great and united
+Moslem Empire was established with its center at Bagdad. The need for
+translation of Greek scientific works into Arabic, the common language
+of Islam, now asserted itself. One after another the medical writings
+that had been turned into Syriac were translated into Arabic, and Greek
+Science in general and Greek Medicine in particular were thus spread
+far and wide in the Moslem world.
+
+Greek science in the Arabic version came in time to be better
+understood by Arabic-speaking students than it had been by any since
+Galen. Nor were the Arabic-speaking peoples content to rest on the
+texts that had thus descended to them from antiquity. A considerable
+number of Arabic writers produced works of their own, some not wholly
+devoid of originality. Unfortunately these men were without effective
+anatomical or physiological basis for their medical knowledge, though
+many of them were acute clinical observers, and, even from the modern
+point of view, some of their works are not wholly contemptible. Thus
+Rhazes (860-932), a native of Basra on the Persian Gulf, wrote a work
+containing the first known description of Measles, which he carefully
+distinguishes from Small-pox. The Persian Avicenna (980-1036) composed
+a vast encyclopaedia of medical knowledge, the so-called _Canon_, which
+served as the main text-book of Medicine both among the Arabic-speaking
+peoples and in the Latin West until the seventeenth century. The Jew,
+Isaac of Kairouan (852-952), composed a treatise on fevers which was
+the best account of the subject available in Europe during the entire
+Middle Ages. The Moor, Albucasis (11th cent.), left a text-book of
+surgery which was an important element in the revival of the subject in
+Italy and France.
+
+These are only prominent members of a vast school of writers who
+flourished in Arabic-speaking countries between the ninth and
+thirteenth centuries. The bulk and number of their writings is
+portentous. Many of their works were translated into Latin, often
+by Jewish translators (Fig. 26). These Latin translations caused a
+reawakening of the intellect of Europe, and provided the staple reading
+in the medieval universities throughout the Middle Ages.
+
+[Illustration:
+
+FIG. 26. A JEWISH TRANSLATOR receiving an Arabic medica volume from an
+Eastern potentate (right) and handing it, translated into Latin, to a
+Western monarch (left). From a thirteenth-century manuscript.
+
+]
+
+
+§ 3. _The Medieval Awakening._
+
+The Spanish peninsula had been inundated by the Islamic tide as early
+as the eighth century. After a while the waters began to recede. The
+speech and culture of Islam had become stamped upon the natives of the
+peninsula, and were only gradually replaced by the Latin civilization
+and dialect which we now call Spanish. During the centuries of Islamic
+retreat, there was thus a bilingual population in the peninsula, so
+that access to the Arabic learning became possible. The translations
+that were to have influence on Europe were always into Latin. To make
+or to obtain such translations many adventurous spirits journeyed from
+Christian Europe into Spain, or sometimes into Sicily where conditions
+were very similar. These men were aided in their work by native Jews or
+by Mohammedans. The heretical company which they kept, together with
+the strange and mysterious material which they brought back with them,
+earned them a reputation as magicians. The memory, for instance, of
+Michael Scot is connected with the Black Art, and has been presented by
+Sir Walter Scott in his poem _The Lay of the Last Minstrel_.
+
+The wizard Michael Scot (died 1235) journeyed in both Spain and
+Sicily, learned Arabic and Hebrew, and had commerce with Mohammedans
+and Jews. He turned a number of Arabic works into Latin, and, in
+particular, he prepared versions of the biological works of Aristotle
+(pp. 28-33) which, though corrupt and second-hand, had much influence
+in determining the direction of medical thought during the Middle Ages.
+
+There was a large class of such translators and commentators who made
+Arabic Medicine accessible to the West. This Arabic-Latin literature
+is generally characterized by the qualities most often associated
+with the words _medieval_ and _scholastic_. It is extremely verbose
+and almost wholly devoid of the literary graces. An immense amount of
+attention is paid to the mere arrangement of the material, which often
+occupies its authors more than the ideas that are to be conveyed.
+Great stress is laid on argument, especially in the form of the
+syllogism, while observation of Nature is entirely in the background.
+Above all, there is a constant appeal to the authority of the ancient
+masters, especially Aristotle and Galen. Lip service is often paid to
+Hippocrates, but his spirit is absent from these windy discussions.
+
+When the Latin translations from the Arabic reached the readers for
+whom they were intended, they were eagerly studied. The texts were,
+however, by no means permitted to remain in their pristine state,
+but were submitted to exactly the same process to which their Arabic
+authors had themselves subjected their Aristotelian and Galenic models.
+The Christian writers of the West treated the Latin translations of
+Rhazes, of Avicenna, of Isaac and of Albucasis (p. 67), as subjects
+for commentary. Their works were expanded, annotated, castigated
+again and again, and without any new inflow of ideas. The result is a
+progressive elaboration of form and deterioration of content throughout
+the centuries. Vast masses of argument, rebuttal, refutation and
+confirmation drowned again the human spirit which hardly recovered from
+its submersion until the sixteenth century.
+
+
+§ 4. _The Universities._
+
+Nevertheless, when these translations were new to Europe, and
+especially in the thirteenth century, they caused much stir. In
+this awakening a large part was played by the Universities. These
+were established in numbers during the thirteenth and the following
+centuries. University life gradually came to exercise a profound
+effect on social, political and intellectual conditions. In most of
+the Universities Medical Faculties grew up. The medical teaching was
+entirely theoretical and there was no clinical instruction, though at
+the beginning of the fourteenth century some advance was made by the
+introduction of brief and superficial anatomical demonstrations (p. 74).
+
+As a type of Medieval University, we may take Bologna, which was an
+important center of learning from a very early date (Fig. 27). As the
+Universities multiplied, they began to some extent to ‘specialize’.
+Bologna had appeared first as a Law School and continued to develop
+along the same line. In the second half of the thirteenth century it
+was by far the most important seat of legal learning in Europe.
+
+An organized Medical Faculty existed there as far back as 1156. The
+teaching at Bologna, as in other medical schools, consisted entirely
+of readings of Latin translations from Arabic which were becoming ever
+more accessible. Yet it was at Bologna that public dissection was first
+practised. The early advent of dissection has often impressed the
+historian. There was still no botany worthy of the name, no zoology,
+hardly any naturalistic art, no experimental science, no systematic
+record of observation in any department. Yet dissection had become
+recognized at Bologna by the end of the first quarter of the fourteenth
+century. The question is why men, so little interested in Nature and
+Nature’s ways, should have lent themselves to so repellent a process as
+dissection of the human body? The answer is that the earliest reason
+for examining the human body was simply the gathering of evidence for
+legal processes. As time went on, post-mortem examination passed into
+anatomical study. But still dissection did no more, and was asked to
+do no more, than verify Avicenna--whom nobody doubted. It was, in fact,
+little but an aid to the memory of students.
+
+At Bologna we can trace the rise of a surgical school beginning about
+the end of the twelfth century. Prominent among its early surgeons was
+William of Saliceto (1215?-1280?). He wrote a very able treatise on
+Surgery, containing a section on Anatomy. The anatomical portion is
+borrowed from the current Arabian anatomies, but contains some evidence
+of direct access to the dead human body. He includes in his work a good
+description of trephining the skull (Fig. 23).
+
+A most interesting contemporary of William of Saliceto was Thaddeus
+of Florence (1223-1303), who also taught at Bologna. This man
+perceived the importance of access to Greek sources, as distinct
+from Graeco-Arabic, and he encouraged the preparation of good Latin
+translations of medical works direct from the Greek. He stamped his
+personality on the whole development of Medicine at Bologna, and he
+is bound up with the beginning of dissection. But if Medicine owed a
+debt to Thaddeus for introducing better texts and better Anatomy, he
+did grave harm to the subject in another direction. The scholastic
+and argumentative form assumed by medieval Medicine is largely due to
+him, and it is to the assumption of this form that we owe the almost
+complete absence of scientific advance between the thirteenth and
+sixteenth centuries.
+
+[Illustration: FIG. 27. MEDIEVAL BOLOGNA, from a mural painting of
+about 1500 in the town-hall of the city. The city contained a number of
+towers, nearly all of which have now been destroyed.]
+
+
+§ 5. _Medieval Anatomy, Surgery and Internal Medicine._
+
+At the very end of the thirteenth century there came to Bologna a
+Norman student, Henri de Mondeville (about 1270-1320). In 1301 he
+settled at the famous Medical School at Montpellier in Southern France,
+and thus transplanted to France the medical, surgical and anatomical
+traditions of Bologna. Those traditions were of Arabic origin, and
+mainly borrowed from Avicenna.
+
+Contemporary with de Mondeville was one whose method of teaching shines
+as a good deed in a naughty world. Mondino di Luzzi (_c._ 1270-1326)
+was a pupil of Thaddeus and a fellow-student of Henri de Mondeville.
+He worked systematically at Anatomy and dissected the human body
+in public. His treatise on Anatomy, written in 1316, is the first
+modern work on the subject. Those who preceded him incorporated their
+anatomical work in larger treatises on Surgery, and do not refer
+directly to their own anatomical experiences. With Mondino this is
+changed. His work is essentially a practical manual of the subject
+and he is with justice called the ‘Restorer of Anatomy’. He had read
+widely among the Arabian anatomists, and naturally borrowed from them.
+Nevertheless, his work contains a considerable number of references to
+actual anatomical procedure. Moreover, he deals not only with Anatomy
+in our modern sense, but also includes Physiology and much discussion
+of the application of anatomical and physiological principles to
+Medicine and Surgery. His book thus gives a good deal of insight into
+the scientific knowledge of the day.
+
+[Illustration: FIG. 28. AN ANATOMICAL LECTURE AT PADUA in the fifteenth
+century, from a contemporary Italian woodcut.
+
+The professor stands in his ‘chair’, a great pulpit or ‘cathedra’,
+reading from his book--hence the English academic titles ‘Reader’
+and ‘Lecturer’ or ‘Lector’ (that is, ‘one who reads’). The body is
+dissected by a menial, whose work is guided by an assistant, who,
+with wand, points out (Latin _demonstrat_, hence our modern title
+_Demonstrator_) the lines of incision. Students in academic dress stand
+around, but do not themselves dissect. ]
+
+We would emphasize the fact that Mondino dissected _in person_. In this
+respect he was wiser than his successors until the time of Vesalius.
+As dissection gained formal inclusion in the curriculum, the professor
+became more haughty, further removed from the object of his study.
+Leaving his position by the body, where he might demonstrate to his
+students, he ascended his high professorial chair, a great elevated
+structure provided with steps and a reading-desk. From there he read
+from his text-book while a junior colleague pointed out the line of
+incision and a menial performed the actual dissection (Fig. 28). All
+was thus done at third-hand and according to the written word. We are
+in the scholastic period, and must not expect any frequent appeal to
+Nature. Having once got into his chair, it took a good deal to persuade
+the professor to descend from that dignified position. Thus, it is
+saying much for Mondino that he was his own demonstrator. He took the
+first and perhaps the greatest step. It was two centuries and more
+before the next step was taken.
+
+Most typical of medieval surgeons was Guy de Chauliac (1300-68),
+who studied at Montpellier, Paris, and Bologna, and practised at
+Montpellier and afterwards at Avignon, where he was a member of the
+Papal Court. He was a man of much learning, and his _Great Surgery_
+became the standard treatise on the subject during the later Middle
+Ages. It fixed medieval practice. It is to be found in scores of
+manuscripts and was frequently translated and printed. Among the good
+points of his practice is his acceptance of responsibility for certain
+operations, such as those for rupture and for cataract, which at that
+time were usually left to wandering charlatans who regarded themselves
+as specialists. A famous passage in his work describes the use of a
+narcotic inhalation frequently used during the Middle Ages and into
+modern times. Of such a narcotic it is written that:
+
+    I’ll imitate the pities of old surgeons
+    To this lost limb, who, ere they show their art,
+    Cast one asleep, then cut the diseased part.
+
+  (Thomas Middleton, _Women beware women_. First acted 1622.)
+
+The general character of Internal Medicine during the later Middle Ages
+was below that of Surgery. Modern clinical Medicine is firmly based
+on such sciences as Physiology, Pharmacology, Pathology, Biochemistry
+and Epidemiology. In the Middle Ages and far beyond, Physiology was
+still that of Galen, which had lost in exactness what it had gained
+in bulk from the Arabic and Latin commentators. Pathology was still
+that of the four humors. The knowledge of drugs was empirical, and the
+sciences of Pharmacology and Biochemistry as yet were not; while the
+medieval conception of the nature of epidemics was the very perversion
+of reason and common sense. Nevertheless, as we shall see, the Middle
+Ages ultimately succeeded in instituting a limited number of effective
+preventive measures.
+
+
+§ 6. _Medieval Hospitals and Hygiene._
+
+Undoubtedly an important development of medieval Medicine is its
+hospital system. The public hospital arose in pagan antiquity out
+of the Temples of Aesculapius and the military valetudinaria (p.
+49). The conception was seized on by Christianity and developed
+beyond all knowledge. In the early Christian centuries, _hospitalia_,
+‘guest chambers’ or ‘guest houses’, were set aside for the numerous
+_hospites_, or ‘pilgrims’. Similar buildings under the same title came
+to be instituted for the care of orphans, the aged, the blind, and
+other victims of fortune. Thus arose the medieval hospital system, of
+which ours is the direct outgrowth.
+
+In matters of Hygiene the Middle Ages are a byword. The health
+conditions of a medieval town were far below those of the same town
+under the Roman Empire. Water-supply was deficient, drains were
+absent, streets and houses filthy and overcrowded, rooms unventilated.
+Nevertheless, there is one important hygienic conception for which our
+own age owes a considerable debt to that which preceded it. Despite
+their scientific acumen in many departments, it is yet true to say
+that among the physicians of classical antiquity we find no consistent
+view of the transmission of infection by contact. Indeed the whole
+idea of infection was effectively absent from them, so that preventive
+measures based upon it could not be developed. It was reserved for the
+Middle Ages to conceive serious official measures against the spread
+of epidemics. These measures were consciously derived from the leper
+ritual of the Bible with its fundamental concept of isolation.
+
+[Illustration:
+
+FIG. 29. A HOSPITAL WARD in sixteenth century Paris. In the left aisle,
+a nun folds the hands of a dying patient, while a priest gives the
+Sacrament to another in the same bed. In front, nuns sew shrouds. The
+right aisle is more cheerful. Nuns minister to two patients in one bed,
+while a convalescent, fortunate in having a bed to himself, vigorously
+takes nourishment. In the centre nuns receive postulants and a royal
+founder kneels in prayer.
+
+]
+
+During the early centuries of the Christian era, Leprosy, which had
+till then been confined to the East, crept along the Mediterranean
+littoral and thence northward throughout Europe. The disease was
+from the first regarded as contagious, and various regulations were
+introduced to isolate and separate the unfortunate sufferers. The
+medieval treatment of lepers is one of the dark incidents of man’s
+inhumanity to man. The leper was banished from human society. He was
+declared legally dead. He was excluded even from church or allowed to
+attend only in special seats where a special basin of holy water was
+assigned to him. How rigorously this segregation from the ranks of free
+people was carried out by law is well known. The cruel edicts were,
+however, effective. In the course of centuries it freed Europe from
+Leprosy, of which it is said there were at one time some 20,000 cases
+in France alone. Thus about one person in 200 would have been a leper,
+and the burden of the leper on the community was comparable to that,
+let us say, of the feeble-minded and insane with us.
+
+Leper inspection, the regular examination of all suspects and carriers
+of leprosy, became a most elaborate business. It was entrusted to
+a special branch of the civil service and was gradually freed from
+ecclesiastical control.
+
+This preventive method of combating a chronic disease, which, as we
+know now, has a very low infectivity, had a peculiar and unlooked-for
+result. The meticulous system of warding off the contagion of leprosy
+so occupied the attention of physicians that they came to see allied
+conditions in the same light. So it was that in the thirteenth century
+the general concept became current of disease as contagious. A number
+of other diseases besides leprosy were recognized as infectious. Among
+these were Plague, fevers with obvious rashes, Phthisis, Granular
+Conjunctivitis, the Itch and Erysipelas. Municipal authorities were
+from time to time ordered to put patients suffering from one or other
+such diseases outside the city gates. They were forbidden to traffic
+in articles of food and drink and were placed under restrictions not
+unlike those of lepers. The devastating epidemic of the Black Death of
+1347-8 brought restrictions of this order into special force. Thus the
+Black Death had somewhat the same effect on the health administration
+of the day that the Cholera outbreaks of the thirties of the nineteenth
+century had upon modern Europe. The health service began to be put
+into more efficient order.
+
+In the later Middle Ages there were actually instances in which the
+Pest was averted or successfully combated by these means. This seems
+to have been the case of Milan and Venice between the years 1370 and
+1374. At that time the Plague was again advancing through Europe. The
+most drastic regulations were invoked to prevent infected persons from
+entering the cities, and these regulations came into force well in
+advance of the disease.
+
+There is one incident in this medieval attempt to prevent Plague that
+has left a mark on our language. The Republic of Ragusa, on the eastern
+side of the Adriatic, adopted and extended the regulations that had
+been so successful at Venice. A landing-station was established far
+from the city and the harbor. There incoming suspects had to spend
+thirty days in the open air and sunlight, and any who had traffic with
+them were isolated. The period of thirty days was spoken of as the
+_Trentina_. Later this was found to be not long enough. The thirty
+days became forty days, the _Quarantina_, whence we have the word
+_Quarantine_. The system of quarantine gradually spread through Europe.
+It was accompanied by very drastic destruction, by burning, of all
+goods belonging to the infected.
+
+These attempts to arrest epidemic disease were sometimes successful and
+the elaboration of quarantine measures was among the few advances with
+which we may credit the Middle Ages. The fact that we can now dispense
+with quarantine must not blind us to its value in conditions other than
+our own.
+
+
+
+
+IV
+
+THE REBIRTH OF SCIENCE
+
+(FROM ABOUT 1500 TO ABOUT 1700)
+
+
+§ 1. _The Anatomical Awakening._
+
+During the Middle Ages beliefs about physiology were always based
+on Galen. They were frequently confused and often the result of a
+misunderstanding of his work. In the fifteenth century, however, took
+place the so-called _Renaissance_ or _Revival of Learning_. Greek works
+which had been trickling in since the thirteenth century began to be
+recovered more rapidly, and to be more accurately studied. The first
+step towards any improvement on the views of Galen was naturally a
+proper understanding of what he had really said. For that there was
+needed a better knowledge of Greek than had been possessed by the
+Middle Ages. In the fifteenth century Greek scholarship made great
+advances and there was enthusiasm for classical learning. Accurate
+translations of the Greek works of Galen were made. The printing press
+was invented about the middle of the fifteenth century. Towards its end
+printed copies of the improved translations began to appear. So it came
+about that the Revival of Learning produced a revival of the ancient
+scientific knowledge.
+
+This scientific revival led to a new interest in Anatomy. During
+the Middle Ages the occasional dissections at the Universities were
+merely supposed to illustrate Avicenna and Galen (Fig. 28 and p. 72).
+Dissection became much more widely practised in the fifteenth century,
+but it was nearly the middle of the sixteenth century before any real
+and open discussion of Galen’s views took place in the Universities.
+
+There were, moreover, other influences at work. Along with the revival
+of learning there was also a renaissance of art. Some of the great
+Renaissance artists--Michelangelo, Raphael and Dürer among them--began
+to study the human form very closely. They soon found that to represent
+it accurately some knowledge of Anatomy, and especially of the bones
+and muscles, was needed. The artists, therefore, began also to dissect.
+Among these great artists were some who took more than a purely
+artistic interest in the structure and workings of the body. Of these
+the most important for us was Leonardo da Vinci (1452-1518). He was a
+man of enormously powerful and inquiring mind, and his achievements
+in science are at least as remarkable as his works of art. He had
+determined to write a text-book of anatomy and physiology. Though he
+did not publish it, many of his beautifully illustrated note-books on
+these subjects have survived.
+
+Leonardo was the first to question the views of Galen. He made
+careful first-hand investigations on the bodies of men and animals,
+and performed many physiological experiments. Though a man of the
+most lofty genius, centuries ahead of his time, yet his outlook is,
+in many respects, typical of his age. His interest in anatomical
+investigation is therefore not surprising, for such inquiries were
+then astir. It happened that he was particularly interested in the
+heart and blood-vessels. He reached the correct conclusion that,
+contrary to Galen, the branches of the air-tubes in the lungs do not
+come into relation with the heart, but, after branching and gradually
+diminishing in size, they finally end _blindly_. He inflated the lungs
+with air and found that, whatever the force used, air could not be
+driven from the air-tubes into the heart. He therefore inferred quite
+correctly that Galen’s _arteria venalis_ (our ‘pulmonary vein’) did not
+convey air to the heart, as the followers of Galen believed.
+
+Leonardo then turned to examine the structure and form of the heart
+itself. He prepared more accurate drawings of it than had been made
+by any before him, making sections and dissections and examining its
+valves (Fig. 30). Ultimately he succeeded in grasping the nature and
+action of the valves at the root of the great arteries as they arise
+from the heart, and he verified his view by remarkable experiments. He
+proved that the valves allowed the blood to pass in only one direction,
+and prevented its regurgitation. Yet Leonardo gives no complete or
+clear description of the action of the heart. He could not emancipate
+himself from the old idea of the passage of the blood from the right
+ventricle through the septum into the left ventricle (Fig. 21), though
+he sometimes seems doubtful about it.
+
+[Illustration:
+
+FIG. 30. DRAWING OF DISSECTION OF THE HEART by Leonardo da Vinci. The
+modern names of some of the more important parts have been added.
+
+]
+
+It must be remembered that Leonardo did not publish his researches. It
+is only recently that his note-books have become fully accessible. But
+although Leonardo’s work remained in manuscript, it must not be assumed
+that his views were wholly without effect on his contemporaries. At any
+rate, soon after his time the questions that he had raised concerning
+the heart and blood-vessels were attracting others and were generally
+regarded as forming an important problem needing solution.
+
+The task of writing an anatomical text-book based on direct
+observation, to which Leonardo did but put his hand, was achieved by
+one who was only four years old at the time when the great artist
+died. The central place in the unfolding drama is occupied by Andreas
+Vesalius of Brussels (1514-64). This extraordinary man studied first
+at the University of Louvain and afterwards at Paris. Anatomical
+instruction at these Universities had not improved much, if at all, on
+that of the Middle Ages. Vesalius soon tired of hearing long passages
+of Galen read out by the professor. He therefore resolved to go to
+northern Italy, where newer methods were being practised. Padua was
+the place of his choice. He immediately made his mark there, and was
+himself appointed professor when only twenty-four years of age. He
+established a scientific tradition at Padua which that University has
+retained to this day.
+
+No sooner was Vesalius settled at Padua than he applied himself with
+unparalleled diligence to lecturing and research. Students crowded
+to hear him (Fig. 31). To aid them he issued, in 1538, a short guide
+to anatomy and physiology. An examination of this shows that his
+physiological views were still those of Galen and Aristotle. After its
+issue Vesalius found that Galen and Aristotle were by no means always
+to be trusted. The realization of this led him constantly to doubt any
+statement by them. His scepticism was sometimes excessive, but it led
+him to put every statement made by his predecessors to the test of
+experience. This gives his later work an epoch-making value.
+
+[Illustration: FIG. 31. TITLE-PAGE of the work _On the Fabric of the
+Human Body_, by Vesalius, published in 1543.
+
+It shows a dissection scene at Padua. In the center stands Vesalius
+dissecting a female body. At the head of the table stands an
+articulated skeleton. At its foot are dissecting instruments. Eager
+students throng around. In the foreground attendants are squabbling.
+On one side an attendant holds a monkey, one on the other a dog, for
+Vesalius had often to resort to animal in lieu of human anatomy. Shut
+off by a bar are members of the lay public. Gallants, grey-bearded
+scholars, monks, and an enthusiastic bookworm may be discerned among
+them. Other observers crowd in from every vantage point, even from
+the windows in the roof. The naked man to the left has been used by
+Vesalius to demonstrate the surface markings of the underlying organs.
+The whole scene is busy and vigorous in the extreme. It should be
+contrasted with the academic calm of Fig. 28 drawn fifty years earlier.
+]
+
+During the next four years Vesalius had ampler opportunities to
+dissect than he had yet encountered. He devoted a fiery energy to the
+preparation of his great work. _The Fabric_ (that is ‘workings’,
+compare German ‘Fabrik’) _of the Human Body_ was printed in 1543, a
+magnificent and beautifully illustrated volume. It is a landmark in
+the History of Science, and a wonderfully full record of a prodigious
+number of accurately recorded discoveries and investigations made by a
+single observer.
+
+The masterpiece of Vesalius is not only the foundation of modern
+Medicine as a science, but the first great positive achievement of
+Science itself in modern times. As such it ranks with another work that
+appeared in the same year, the treatise of Nicholas Copernicus, _On the
+Revolutions of the Celestial Spheres_. The work of Copernicus removed
+the Earth from the center of the Universe; that of Vesalius revealed
+the real structure of man’s body. Between the two they destroyed for
+ever the medieval theories on the subjects of which they treat. But
+the work of Copernicus is one of close and subtle reasoning, still
+retaining many medieval elements, and is hardly a great exposition
+of what we now call the ‘Experimental Method’. The work of Vesalius
+far more nearly resembles a modern scientific monograph than does the
+treatise of Copernicus.
+
+The achievement of Vesalius was very well received by the scientific
+world. Nevertheless, soon after its publication, Vesalius resigned
+his professorship to take up the position of a court physician to the
+Emperor Charles V, the great monarch of the age. He was then only
+twenty-nine years old, but his scientific career was closed.
+
+The edition of the _Fabric_ was soon exhausted, and the demand for
+more copies was met by imitations of the work by other hands. At last,
+in 1555, Vesalius was induced to issue a second edition. This contains
+certain changes in point of view that are important for the subsequent
+development of physiology. Vesalius now no longer merely hints his
+doubts as to the character of Galen’s physiology; he openly asserts
+that he is unable to verify its fundamental bases.
+
+We may take a single instance of this new outspokenness. In his
+description of the septum of the heart, he had written in the first
+edition:
+
+    ‘The septum of the ventricles of the heart is very dense. It
+    abounds with pits on both sides. Of these pits none, so far
+    as the senses can perceive, penetrate from the right to the
+    left ventricle. We are thus forced to wonder at the art of the
+    Creator, by which the blood passes from right to left ventricle
+    through pores which elude the sight.’ (Compare Fig. 21, p. 59.)
+
+This passage is altered to something quite different in the second
+edition, where he writes:
+
+    ‘Although sometimes these pits are conspicuous, yet none, so
+    far as the senses can perceive, passes from the right to the
+    left ventricle. I have not come across even the most hidden
+    channels by which the septum of the ventricles is pierced. Yet
+    such channels are described by teachers of Anatomy, who have
+    absolutely decided that the blood is taken from the right to
+    the left ventricle. I, however, am in great doubt as to the
+    action of the heart in this part.’
+
+He further sets forth his whole policy with reference to Galen’s view
+in the following interesting passage:
+
+    ‘In considering the structure of the heart and the use of its
+    parts, I bring my words for the most part into agreement with
+    the teachings of Galen; not because I think these on every
+    point in harmony with the truth, but because, in referring at
+    times to new uses and purposes for the parts, I still distrust
+    myself. Not long ago I would not have dared to diverge a hair’s
+    breadth from Galen’s opinion. But the septum is as thick, dense
+    and compact as the rest of the heart. I do not, therefore, see
+    how even the smallest particle can be transferred from the
+    right to the left ventricle through it. When these and other
+    facts are considered, many doubtful matters arise concerning
+    the blood-vessels.’
+
+The work terminates with a little chapter _On the dissection of living
+animals_. We note that this, while dealing skilfully with the methods
+of physiological experiment, does not exhibit any very marked advance
+on the views of Galen.
+
+Among the experiments on living animals that Vesalius enumerates are
+excision of the spleen, the loss of which he showed was consistent
+with life; and the cutting of the nerves that supply the organ of
+voice, with resultant loss of that faculty. He demonstrated that
+longitudinal section of a muscle interferes little with its function,
+but cross section produces disability in proportion to the injury.
+Such experiments had been performed by Galen, who had also reached the
+same conclusion as Vesalius, that it is through the spinal cord that
+the brain acts on the various muscles of the limbs and trunk. Vesalius
+repeated Galen’s experiments on section of the spinal cord (p. 58). The
+most striking of his experiments were those on respiration. Here he
+showed that, even though the chest-wall be pierced, the animal may be
+kept alive if the lungs are continuously aerated by means of a bellows,
+and that a flagging heart may be revived by similar means.
+
+The work of Vesalius at once placed the knowledge of the human body
+in a new position. It cannot be said that he completed the task of
+describing the naked-eye structure of the human body. Yet he went so
+far towards this that no dramatic improvement has since been made
+upon his methods. It is a fair statement that the whole of modern
+Descriptive Anatomy may be treated as a comment and correction and
+amplification of Vesalius. His work moreover stimulated a host of
+investigators.
+
+[Illustration: FIG. 32. SKELETON from the anatomical work of Vesalius,
+1543.
+
+It is beautifully and dramatically posed, and the drawing is remarkably
+accurate. The figure leans against a tomb, contemplating a skull. In
+the front left-hand corner of the top of the tomb is a part of the bony
+structure which supports the organ of voice (H).
+
+The inscription on the tomb may be translated ‘Man’s spirit lives. The
+rest is Death’s portion’.
+
+The inscription at the top may be translated: ‘A delineation from the
+side of the bones of the human body, freed from the other structures
+which they support and placed in their correct positions.’ ]
+
+
+§ 2. _The Anatomical Reaction on Surgery._
+
+The immediate effect of the new knowledge of Anatomy was an improvement
+in Surgery. The Wars of Religion of the sixteenth and seventeenth
+centuries were fierce and prolonged, and the army surgeons of the time
+had much experience of the treatment of wounds. The most prominent of
+the military practitioners was the Frenchman, Ambroise Paré (1517-90).
+He perceived the importance of anatomical knowledge and adapted his
+discoveries to the needs of Surgery. Paré did much to elevate the
+surgeon’s profession from a despised handicraft to a position equal to
+that of other branches of the healing art.
+
+Apart from the introduction of anatomical discipline into Surgery,
+Paré’s four contributions to the surgical art were, firstly, his
+discovery that gunshot wounds are not ‘poisonous’ as had theretofore
+been thought, and that therefore they do not require the application
+of boiling oil, but are best healed by soothing applications;
+secondly, the cognate doctrine that bleeding after amputations should
+be arrested, not by the terrible method of indiscriminate use of the
+red-hot cautery, but by simple ligature; thirdly, his advocacy of
+the method of turning the child in its mother’s womb before delivery
+in certain abnormal cases; and fourthly, his ingenious devising of
+artificial limbs (Fig. 33). None of these four was without precedent.
+Nevertheless, the eminence, skill, and wide experience of Paré were
+the main factor in the spread of these practices. But the greatest
+of all Paré’s contributions to surgery was the service of his own
+personality, the example of his steadfast efforts to increase his
+knowledge of human anatomy and his skill in the art, and his constant
+emphasis on the surgeon’s duty to exert his utmost efforts to avoid or
+relieve the patient’s suffering.
+
+[Illustration:
+
+FIG. 33. ARTIFICIAL ARMS AND HANDS, designed and figured by Ambroise
+Paré, and used by him for wounded soldiers from about 1560 onwards.
+
+]
+
+In a famous passage Paré describes how he, a ‘freshwater soldier’, on
+his first campaign, watched the other surgeons following the old rule
+of treating all gunshot wounds with boiling oil. At first he formed
+his practice on theirs. The theory was that gunshot wounds contained a
+poison, which the boiling oil was believed to drive out. Paré tells of
+his agitation when one evening, his supplies having run out, men had to
+be treated without the boiling oil. Next morning he was astonished to
+find that every man whose wounds had been treated only with a salve had
+rested fairly comfortably, while all who had undergone the customary
+treatment were, as we may well believe, in great pain. ‘Then I resolved
+within myself never so cruelly to burn poor wounded men.’ Another
+saying of the shrewd old surgeon is the famous adage ‘I dressed him and
+God cured him.’
+
+Paré’s works were frequently reprinted and translated into various
+European languages, including English. They exercised the widest
+influence on surgical craft in the sixteenth and seventeenth centuries.
+Like Vesalius, he is an example and type of a large class. In every
+country surgeons arose who made an effort to utilize the new anatomical
+knowledge.
+
+
+§ 3. _The Renaissance of Internal Medicine._
+
+Internal Medicine lagged behind Surgery at this period. The anatomical
+reforms of Vesalius were unaccompanied by any commensurate advance in
+physiological knowledge, and without a scientific Physiology there can
+be no science of Internal Medicine. The practice of the physicians thus
+remained in effect that of the Middle Ages. The ruling idea was still
+that of the ‘four humors’ corresponding to the four ‘temperaments’
+(Fig. 13, p. 34, and compare Fig. 34, p. 97).
+
+There are, however, three respects in which we see an improvement
+of the physician’s art during the sixteenth and first half of the
+seventeenth century.
+
+Firstly, there was some improvement in the medical texts that were
+habitually read. More reliable translations were now available. Notably
+the great Hippocratic works became more widely disseminated. They
+formed a substitute for the old texts translated or mistranslated from
+the Arabic.
+
+Secondly, the extension of geographical knowledge and the formation
+of settlements and colonies brought new drugs upon the market. These
+were often a mixed blessing, for some of the drugs were useless and
+others dangerous. Nevertheless, to this process Medicine owes several
+important contributions, among them Ipecacuanha, Cinchona (p. 326),
+and, by no means least, Tobacco (Fig. 35). Apart from the amenities
+introduced by Tobacco, it was for long of great value as a narcotic
+drug. Moreover, there was a corresponding advance in Botany. The
+movement was cursed with the ‘practical’ spirit, and only those plants
+thought to have an application as drugs were exactly figured and
+described. Nevertheless, the beautifully illustrated herbals of the
+sixteenth and seventeenth centuries exercised, by the care and accuracy
+of their execution, an exemplary influence on the development of
+Biological Science in general and of Medical Science in particular.
+
+Thirdly, there was some advance in the knowledge of the natural history
+of infectious disease. A rational theory of the nature of infection was
+placed before the public as early as 1546 by the Veronese physician,
+Girolamo Fracastoro (1483-1553). He regarded infection as due to the
+passage of minute bodies from the infector to the infected. These
+hypothetical minute bodies had the power of self-multiplication. The
+conception bore a superficial resemblance to the modern germ theory of
+disease. An important contribution to the conception of epidemics was
+also made by the French physician Guillaume de Baillou (1538-1616),
+who reintroduced the old Hippocratic idea of ‘Epidemic Constitution’,
+i.e. that particular seasons and particular years are of their nature
+subject to particular diseases. The idea was extended and developed by
+the English physician Thomas Sydenham (1624-89), and it still has its
+value.
+
+[Illustration:
+
+FIG. 34. FIGURE ILLUSTRATING THE ‘FOUR TEMPERAMENTS’, from the Guild
+Book of the Barber-Surgeons of York, now in the British Museum. The
+figure was prepared about 1500. Above, to the left, is the _Melancholy_
+man, and to the right the _Sanguine_. Below to the left is the
+_Choleric_ man, and to the right the _Phlegmatic_. On the scroll work
+is written in English ‘Ther ar the iiij umors, thath ar oderwysse calde
+the iiij complecconis thath ar resceuid un to the iiij elementis,
+Hafyng the kynd of humors’, which may be rendered ‘There are the 4
+humors, that are otherwise called the 4 complexions, that are received
+unto the 4 elements, having the nature of humors’. For the theory
+compare Fig. 13, p. 34.
+
+]
+
+In connection with their epidemiological work these three men,
+Fracastoro, de Baillou, and Sydenham, made significant additions to
+the knowledge of particular infectious conditions. Thus, during the
+sixteenth and seventeenth centuries there arose an exact body of
+teaching concerning acute infectious diseases which was the necessary
+prelude to the introduction of more effective preventive measures at
+a later date. To one infectious disease we may refer more particularly.
+
+During the Middle Ages there had smouldered in various districts an
+obscure disease, sometimes more or less dimly distinguished under
+various specific names, but most frequently confused with Leprosy.
+Towards the end of the fifteenth century this disease, which was still
+imperfectly distinguished in men’s minds from Leprosy, broke out in
+epidemic and virulent form all over Europe. It caused great destruction
+of life and developed everywhere as a problem of national importance.
+Various titles were given it, such as ‘pox,’ ‘the French disease’, ‘the
+Spanish disorder’. Only tardily was it recognized that the disease
+was usually of venereal origin. Not till 1530, on the suggestion of
+Fracastoro, did it receive its modern cognomen _Syphilis_. From the
+time of its recognition, Syphilis has been pursued by a portentous
+mass of literature, the mere sifting and verification of which is a
+formidable task. Alarm, misunderstanding, religious feeling, false
+modesty, wilful misrepresentation, and change in type of the disease
+itself have all contributed their quota of obscurantism and fable to a
+naturally difficult subject (Figs. 35 and 36). Fracastoro did something
+to bring order out of the confusion. To him also we owe the first good
+scientific descriptions of several other destructive diseases, among
+which Typhus fever, now known to be conveyed by lice (p. 258), takes a
+prominent place.
+
+[Illustration:
+
+FIG. 35. THE EARLIEST PICTURE showing the use of Tobacco. From a
+work on Brazil, printed in Paris in 1558. In the center of a native
+hut stands an Indian suffering from Syphilis. Behind him, on the
+left, a man smokes a huge cigar over him as a curative measure.
+Right and left his arms are held by two figures who seek to suck
+the poison out of him. Another offers him a curative plant. Behind
+him is a ‘hammock’--the word is of American-Indian origin and means
+‘tobacco-bed’. Above his head are a monkey, a parrot, and a bale of
+tobacco.
+
+]
+
+De Baillou (1538-1616) first described Whooping Cough, and was the
+first to use the word _Rheumatism_ in the modern sense. He was moreover
+the first, since Hippocrates, to distinguish between Rheumatism and
+Gout. De Baillou’s works deeply influenced Sydenham, who held very
+similar epidemiological views, and uses a somewhat similar vocabulary
+(p. 100).
+
+We have seen how the knowledge of Anatomy forwarded Surgery, while,
+with the lag in Physiology, Internal Medicine remained in a backward
+state. It is well to recall however that a knowledge of Anatomy and
+Physiology will not, of themselves, make a man a scientific physician.
+The object which presents itself to a physician is neither a living
+anatomy nor a physiological model. It is a sick and suffering patient.
+The physician’s first task is to examine exactly the phenomena of
+sickness and suffering, and in doing this the first demand on his
+knowledge will be the history and fate of others who have endured like
+sickness and suffering. When he has ranged these instances in his mind
+he may turn, for explanation and relief, to the resources suggested
+by other sciences, Anatomy and Physiology among them. But all the
+Anatomy and Physiology in the world will not aid the practitioner who
+is unacquainted with the natural history of disease. This is the truth
+that was firmly seized by Thomas Sydenham.
+
+The Natural History of Disease was a subject which Sydenham pursued
+with lifelong devotion. Before his time the phenomena of disease had
+been classified, subdivided, discussed, and treated with all the
+subtlety and skill of scholastic thought. Men had now and again shaken
+themselves free from the shackles of the medieval system, and had
+here and there corrected the views of Galen or amplified the limited
+achievements of their predecessors. Yet none before Sydenham had set
+himself to consider all the actual cases of disease that lay before him
+as a subject of scientific description and analysis. That was the great
+achievement of the ‘English Hippocrates’. We should not find it easy
+to point to any important discovery to associate with his name. But he
+did more than discover. He initiated a new mode of approach. He was the
+founder of modern Clinical Medicine.
+
+In 1666 Thomas Sydenham published his classic work, _The Method of
+Treating Fevers_, dedicated to his friend Robert Boyle, ‘the Father
+of Chemistry’ (pp. 124-6). The book opens with the almost Hippocratic
+phrase ‘A disease, in my opinion, how prejudicial soever its cause may
+be to the body, is no more than a vigorous effort of Nature to throw
+off the morbific matter, and thus recover the patient’. We have here
+the _healing power of Nature_ of Hippocrates (p. 21), which had been
+obscured and overlaid in the twenty centuries which lay between the
+two great physicians. The works of Sydenham may reasonably be regarded
+as the first great commentary on the Hippocratic theme. Sydenham set
+well on its way the conception of infectious conditions as specific
+entities, a conception which has since been illuminated by the germ
+theory of disease (p. 224 ff.).
+
+[Illustration: FIG. 36. Allegorical picture illustrating the venereal
+plague Syphilis.
+
+From a work printed in Germany in 1496. The Virgin sits enthroned on
+clouds, crowning a crusader, who kneels at her right hand. The Holy
+Child on her knee sends forth the plague of Syphilis as a scourge on
+mankind. Two women, spotted with the rash of the disease, kneel in
+supplication before her on her left. In the foreground of the picture
+lies a corpse dead of the disease, the speckled ravages of which may be
+seen upon it.
+
+]
+
+
+§ 4. _The First Physical Synthesis._
+
+Manifestations of the Human Spirit are not accustomed to confine
+themselves exactly within the convenient limits of the centuries.
+Nevertheless, it happens that in the History of Science the year 1600
+does, in fact, correspond to something of the character of a real
+change in the current attitude to Nature. That year really ushers in
+the era of physical experiment. The last of the great transitional
+thinkers who mark the waning of Renaissance philosophy was Giordano
+Bruno, the martyr of science.
+
+Giordano Bruno (1548-1600), who was no practical scientist, had eagerly
+incorporated into his often fantastic philosophy the ill-worked-out
+conclusions of Copernicus (p. 88). Nominally adopting the Copernican
+theory, he modified it fundamentally. Copernicus, having placed the Sun
+at the center of the World, and made the Earth and other planets circle
+round it, had still left the stars at a fixed and definite distance, as
+had the ancient astronomers. The limitation of the sphere of the fixed
+stars was obnoxious to Giordano, and he removed the boundaries of the
+Universe to an infinite distance, in accordance with the principles
+of his philosophy. The change may seem unimportant save for astronomy,
+but, in fact, it came to influence every department of scientific
+thought, for the endlessness of Nature is implicit in the modern
+scientific attitude.
+
+Giordano was burned at the stake at Rome, after seven years’
+imprisonment, in 1600. In the same year the experimental era was
+ushered in with the work of William Gilbert (1544-1603), _On the
+Magnet_, in which he not only demonstrates experimentally the
+properties of magnets but also shows that the Earth itself is a magnet.
+In the same year, too, Tycho Brahe (1546-1601) handed over the torch to
+Johannes Kepler. Tycho was the last of the older astronomers who worked
+on the Aristotelian view of circular and uniform movements of heavenly
+bodies. Kepler was the real founder of the modern astronomical system.
+The period from 1600 onward lies with new men, Galileo (1564-1642) and
+Kepler (1571-1630) among astronomers and physicists, Harvey (1578-1657)
+among biologists, Descartes (1596-1650) among philosophers.
+
+The seventeenth century opened with an extraordinary wealth of
+scientific discovery. As we glance at the mass of fundamental work
+produced during that period, we perceive the major departments of
+Science, as we know them to-day, becoming clearly differentiated.
+The acceptance of Observation and Experiment as the only method of
+eliciting the Laws of Nature reaches an ever-widening circle. Even
+to enumerate the names of the seventeenth-century pioneers would be
+a formidable task. The sciences penetrated to the Universities and
+influenced the curricula. The number of scientific men became so large
+and so influential that separate organizations were formed by them in
+the interests of their studies. It is the age of the foundation of the
+‘Academies’, of which the English Royal Society is a type.
+
+From the multitude of workers on these subjects we can but select a few
+names. In the first half of the century Galileo and Kepler are the main
+exponents of natural law. Descartes takes his place here as the first
+since antiquity who sought to explain the phenomenal universe on a
+unitary basis. In the second half of the period comes the mighty figure
+of Newton, whose researches ushered in that phase in our story in which
+we live to-day.
+
+The early training of Galileo Galilei had been scholastic and
+Aristotelian. By 1590, however, he had begun to doubt, and was making
+experiments on the rate of acceleration of falling bodies. His
+conclusions were demonstrated in 1591 from the leaning tower of Pisa.
+By that famous experiment he showed, in the most public manner, the
+error of the Aristotelian view that the rate of fall was a function not
+of the weight of the object but of the period of fall. Revolutionary
+also was Galileo’s work of 1604. In that year a new star appeared in
+the constellation _Serpentarius_. He demonstrated that this star was
+situated beyond the planets and among the remote heavenly bodies.
+Now this remote region was regarded in the Aristotelian scheme
+as absolutely changeless. Although new stars had been previously
+noticed, they had been considered to belong to the lower and less
+perfect regions nearer to earth. To the same lower region, according
+to the then current theory, belonged such temporary and rapidly
+changing bodies as meteors and comets. But Galileo had attacked the
+incorruptible and unchangeable heavens.
+
+In 1609 Galileo made accessible two instruments that were to have a
+deep influence on the subsequent development of Science, the Telescope
+and Microscope. It is with the former instrument that his name is most
+frequently associated. His first discoveries made by means of the
+Telescope were issued in 1610. That year was crowded with important
+observations especially on the inner planets and notably on Venus. It
+had been rightly claimed in criticizing the Copernican hypothesis that,
+if the planets resemble the Earth in revolving round the Sun, only such
+parts of them should be luminous as are exposed to the Sun’s rays. In
+other words, they should exhibit phases like the Moon. Such phases in
+Venus were now actually observed by Galileo. In the following year he
+described sunspots and traced them round the Sun’s disk.
+
+We need not follow the further astronomical observations of Galileo,
+nor need we discuss the contest with the older school on which he
+embarked. It is sufficient to remind ourselves that the appearance
+of a new star, the behavior of the rings of Saturn, the observations
+of the phases of Venus and of the Sun’s spots, struck a blow at the
+Aristotelian astronomy comparable to that delivered against the
+Aristotelian physics by the falling weights from the leaning tower of
+Pisa. Aristotelian astronomy demanded heavens eternally changeless.
+Here were changes and new appearances in the heavens, clearly visible
+to all who would see.
+
+During these years too, Galileo was laying firm the foundations of the
+science of Mechanics. Out of his mechanical researches came a new way
+of looking at the objects of Nature which has profoundly influenced
+the entire subsequent course of science. That way is best expressed
+in Galileo’s own words, which place him among the philosophers whose
+thought influences all those who deal with scientific themes.
+
+    ‘As soon as I form a conception of a material or corporeal
+    substance, I simultaneously feel the necessity of conceiving
+    that it has boundaries and is of some shape or other; that
+    relatively to others it is great or small; that it is in this
+    or that place, in this or that time; that it is in motion or
+    at rest; that it touches, or does not touch, another body;
+    that it is unique, rare, or common; nor can I, by any act of
+    imagination, disjoin it from these qualities. But I do not find
+    myself absolutely compelled to apprehend it as necessarily
+    accompanied by such conditions as that it must be white or
+    red, bitter or sweet, sonorous or silent, smelling sweetly
+    or disagreeably; and if the senses had not pointed out these
+    qualities language and imagination alone could never have
+    arrived at them. Therefore I think that these tastes, smells,
+    colors, &c., with regard to the object in which they appear to
+    reside, are nothing more than mere names. They exist only in
+    the sensitive body, for when the living creature is removed
+    all these qualities are carried off and annihilated, although
+    we have imposed particular names upon them, and would fain
+    persuade ourselves that they truly and in fact exist. I do
+    not believe that there exists anything in external bodies for
+    exciting tastes, smells and sounds, &c., except size, shape,
+    quantity, and motion. If ears, tongues, and noses were removed,
+    I am of opinion that shape, quantity, and motion would remain,
+    but there would be an end of smells, tastes, and sounds, which
+    abstractedly from the living creature I take to be mere words.’
+
+This passage is a veritable Charter of Science. From Galileo’s day to
+ours, men of science have occupied
+
+themselves in measuring size, shape, quantity, and motion, the
+‘primary qualities’, and expressing their knowledge in that measured
+form. They have relegated colors, smells, tastes, sounds, and other
+sense-impressions to the position of ‘secondary qualities’, and have
+tried to express them, when they express them at all, in terms of the
+primary qualities. We need not enter on the philosophical discussion
+as to how far the primary qualities are in truth more real than the
+secondary, but it is a fact that, since the time of Galileo, Science
+has come to be regarded more and more widely as an exact process.
+_Science is Measurement._ It is a conception that has affected the
+medical no less than the other sciences, and it is a conception that
+Medicine, for good or ill, owes to Galileo.
+
+[Illustration:
+
+FIG. 37. SANCTORIUS IN HIS BALANCE. Sanctorius was able to eat and
+even to sleep in his balance, counterpoised by a weight working on
+the principle of the steelyard. He was thus able to test his weight
+under various conditions, and notably to estimate the amount of
+the ‘insensible’ perspiration. His were the first experiments on
+‘Metabolism’ (see p. 108).
+
+]
+
+
+§ 5. _The Revival of Physiology._
+
+The first to apply Galilean principles of measurement to biological
+matters was Sanctorius (1561-1636), a professor at Padua. He described
+a thermometer for use in taking the temperature of the human body
+(Figs. 39 and 40), and an apparatus for comparing the rate of pulse
+beats (Fig. 41). Both these he modified from devices suggested by
+Galileo (Fig. 38). It is an indication of the transitional character
+of the Science of the time that he describes these instruments in a
+commentary on a medieval translation of the _Canon_ of Avicenna (p.
+67). He also sought to compare the weight of the body at different
+times and in different circumstances. In the process of doing this, he
+demonstrated that the body loses weight by mere exposure, a process
+which he ascribed to ‘insensible perspiration’ (Fig. 37). By these
+experiments he laid the foundation of the modern study of ‘Metabolism’
+(p. 220).
+
+[Illustration:
+
+FIG. 38. The principle of Galileo’s thermometer. A tube ending in a
+bulb A is inverted over a mercury bath B. If the temperature fall the
+air in A will contract and mercury be drawn up into the tube. If the
+temperature rise the air in A will expand and mercury be driven out
+of the tube. The height of the mercury can be read on the scale SS.
+The reading will not be accurate because the instrument is, in fact,
+also a barometer, since the mercury in B is exposed to the atmospheric
+pressure, which will therefore affect the rise in the tube.
+
+FIG. 39. The application of the same system by Sanctorius who used a
+curved tube.
+
+FIG. 40 is not, as might be thought, a man trying to swallow a
+centipede, but the adaptation of the instrument of Sanctorius as a
+clinical thermometer.
+
+FIG. 41. Galileo’s simple and effective ‘pulsimeter’. It consists only
+of a weight suspended on a thread. This thread is held in the hand and
+the weight made to oscillate as a pendulum. As the thread is shortened
+the oscillations increase in frequency. The process is continued until
+the pendulum oscillates to time with the pulse. The length of the free
+thread is then read off on the accompanying scale. It was used by
+Sanctorius.
+
+]
+
+While Sanctorius was engaged in this pioneer work at Padua, the
+movement that Vesalius had inaugurated there was making further
+conquests in the purely biological line. Vesalius had been succeeded
+at Padua by a series of anatomists of great eminence. Perhaps the
+most prominent among these was Jerome Fabricius (1537-1619), usually
+called ‘of Aquapendente’, after the small Tuscan village where he
+was born. This Fabricius of Aquapendente taught at Padua for over
+fifty years, from 1565 till his death at eighty-two in 1619. He made
+many contributions to the advancement of anatomy, most of which had
+physiological bearings. Thus, he was the effective founder of modern
+embryology and the author of the first illustrated work on that
+subject, in which he describes the formation of the chick in the egg.
+He was the first to give accurate figures of the structure of the
+eye. He developed the mechanics of muscular motion. He added to his
+qualities as an observer the power of attracting younger men.
+
+In spite of all his powers, however, Fabricius never shook himself free
+from ancient views, and especially he was steeped in the theories of
+Aristotle and Galen. This backward-looking habit prevented his work
+from being as important as it might otherwise have been. In connection
+with the circulation, for instance, he made a striking discovery, but
+wholly failed to draw out its most important lesson.
+
+[Illustration:
+
+FIG. 42. DISSECTION OF A VEIN in the thigh and leg from a work _On the
+Valves of the Veins_, published by Fabricius in 1603 at Padua. These
+valves prevent the passage of the blood in any direction except toward
+the heart. They may be seen at the points P, Q, R, S, and T.
+
+]
+
+In 1600 he published his book, _On the Valves of the Veins_. In it he
+says that these structures are so placed that their mouths are always
+directed _toward_ the heart (Fig. 42), yet he never gets an inkling
+that the effect of these valves must be to prevent blood flowing
+into the veins except toward the heart. He is too set on the old
+Galenic physiology to permit such a revolutionary thought. The real
+importance of Fabricius is, therefore, not so much as an investigator
+but rather as a teacher, a capacity in which he shone above all other
+physiologists for generations to come. He would deserve our remembrance
+if only as the master of the discoverer of the circulation of the
+blood, William Harvey.
+
+The Englishman, William Harvey (1578-1657), after education at
+Cambridge, went to Padua in 1599, when Fabricius was at the height
+of his powers. Returning to England in 1602, he set up in practice
+in London. During the years which followed, he was dissecting and
+experimenting very industriously, and by 1615 had reached a clear
+conception of the circulation of the blood (Fig. 43), though he did not
+publish his discovery till some thirteen years later.
+
+To discuss the actual steps by which Harvey made his discovery
+would be beyond our scope. He had, however, been well trained in
+experimenting on living animals by Fabricius, and had read widely in
+anatomical literature. He was of a contemplative turn of mind and
+his quiet and cautious temper, united with his enthusiasm and skill
+as an experimenter, provided a superb mental equipment for a life of
+scientific investigation.
+
+Harvey, early in his work, reached two fundamental conceptions
+concerning the vascular system. He perceived that the valves in the
+veins would permit the blood to pass only towards the heart (Fig.
+43), while those in the great arteries arising from the heart would
+permit the blood to pass only away from the heart. In connection with
+the movement of the blood, Harvey’s crucial point is that it must be
+_continuous_, and _always in one direction_. This really clinches
+the matter, for consider the capacity of the heart. Let us suppose
+that either ventricle holds but 2 ounces of blood. The pulse beats 72
+times a minute and 72 × 60 times an hour. In the course of one hour,
+therefore, the left ventricle will throw into the aorta, or the right
+ventricle into the pulmonary artery, no less than 72 × 60 × 2 = 8,640
+ounces = 38 stones 8 lb. In other words, in one hour the ventricle will
+throw into the great artery more than three times the body weight of
+a heavy man. Where can all this blood come from? Whither can it all
+go? It cannot come from the ingested food and drink, for no one could
+consume so much in one hour! It cannot reach and remain in the tissues,
+for they would soon all burst and ooze with blood! The solution of the
+puzzle, Harvey came to see, is that it is the same blood that is always
+being pumped into the arteries, and the same blood that is always
+coming back through the veins. In other words the blood _circulates_, a
+fact which Harvey proceeded to demonstrate with convincing thoroughness
+(Fig. 43).
+
+[Illustration:
+
+FIG. 43. DIAGRAM TO ILLUSTRATE THE NATURE OF THE CIRCULATION OF THE
+BLOOD. Leaving the _left ventricle_, when the walls of that cavity
+contract, the blood is forced through the valves into the great artery
+known as the _aorta_. From the aorta it passes into smaller and ever
+smaller arteries, finally reaching the _systemic capillaries_ or the
+_portal capillaries_. After travelling through one or other capillary
+network it enters a vein. Thence it passes into larger and ever larger
+veins, until it ultimately enters the great vein known as the _vena
+cava_ that opens into the _right auricle_. It has now completed the
+Greater Circulation. As the right auricle contracts the blood passes
+through the valves between the right auricle and right ventricle into
+the _right ventricle_. From there it enters the Lesser Circulation,
+passing into the great _pulmonary artery_, which conducts it to the
+lung. In the lung the pulmonary artery breaks up into branches and
+finally into capillaries. Through these the blood travels until it
+reaches a tributary of the _pulmonary vein_ and finally the pulmonary
+vein itself. The pulmonary vein empties its blood into the _left
+auricle_. From the left auricle the blood passes at last into the left
+ventricle from which it started, having traversed both the Greater and
+the Lesser Circulations.
+
+To understand the change which Harvey wrought in the conception of the
+workings of the body, this description and diagram should be compared
+with the description and diagram on pages 56-59.
+
+]
+
+We may note that, though Harvey demonstrated the existence of the
+circulation, he was never able to follow it throughout, for he did not
+see the capillary vessels by which the blood is conveyed from the
+terminal branches of the arteries to the smallest tributaries of the
+veins. These were first demonstrated by Malpighi (p. 116).
+
+The knowledge of the circulation of the blood has been the basis of
+the whole of modern Physiology and with it of the whole of modern
+rational Medicine. The attitude of Galen and Aristotle towards the
+heart and the great vessels passed into the shadow. The blood, it was
+seen, is a carrier always going round and round on the same beat. What
+it carries, and why, how and where it takes up its loads, and how,
+where, and why it parts with them, these are questions the answering
+of which has been the main task of Physiology in the centuries that
+have followed. As each of the questions has obtained a more and more
+rational answer, so clinical Medicine has always made a step forward,
+and has come to approach more nearly to a true science. Thus it is that
+the work of Harvey lies at the back of almost every important medical
+advance.
+
+[Illustration:
+
+FIG. 44. THE VALVES in the superficial veins as seen in the bandaged
+arms of living men, from William Harvey’s great work on the
+_Circulation of the Blood_, printed in 1628. The bandage is seen on the
+upper arm in each case, and the valves are indicated, as in life, by
+nodes or swellings in the veins. If a finger is pressed along the vein
+from one valve to another as from node O to node H in a direction away
+from the heart, the vein from O to H will be emptied of blood. It will
+remain empty, since the valve at O does not permit the passage of blood
+away from the heart, but only towards it. This observation was Harvey’s
+starting point for his great discovery.
+
+]
+
+
+§ 6. _Microscopic Analysis of the Animal Body._
+
+The compound microscope was first made into an effective instrument by
+Galileo. It was, as it were, a _by-product_ of his invention of the
+telescope. With that instrument he had seen enough to convince himself
+that the movement of the Sun round the Earth was but an appearance.
+At the very time that Harvey was giving his first course of lectures
+securely in London, Galileo’s teaching was attracting the unwelcome
+attention of the Inquisition in Rome.
+
+Galileo’s microscopes, however, were far less satisfactory than his
+telescopes. For optical reasons which we need not discuss, these early
+compound microscopes failed to give a clear picture. With any high
+degree of magnification, the image was always blurred and distorted.
+More than three centuries were to pass before a better compound system
+was introduced. But about 1650 a way was found of constructing and
+mounting simple lenses of very high power. Many of the most important
+microscopical discoveries of the second half of the seventeenth
+century were, therefore, made with a simple lens. This was notably
+the case with much of the work of the great investigators Malpighi and
+Leeuwenhoek (Fig. 49 A).
+
+[Illustration:
+
+FIG. 45. LUNGS OF FROG, showing the capillary vessels from a figure
+by Malpighi in the rare first edition of his work _On the Lungs_,
+published at Bologna in 1661. A is the part of the larynx, B is the
+opening of the larynx into the trachea or air-tube leading to the lung.
+The letters EEE represent the outer surface of the lung and exhibit
+the network of capillary vessels. On the other side the sack-like lung
+has been laid open, and is viewed from the inside. The letters HHH are
+placed upon veins on the inner surface of the lung. These arise from
+capillaries which are indicated between the veins.
+
+]
+
+Marcello Malpighi (1628-94) was born in the year in which Harvey’s work
+was published. He became a professor at Bologna, having early developed
+great skill in minute investigation. His first work, which appeared in
+1661, supplied the element missing in the investigations of Harvey,
+for he describes the actual passage of blood from the arteries to the
+veins through the ‘capillary’ blood-vessels (Fig. 45). Harvey, who
+did not use a microscope, knew nothing of the capillaries. The object
+which yielded up the secret was the lung of the frog. This organ in the
+frog happens to be almost transparent, is very simple in structure,
+and is furnished on its surface with particularly conspicuous capillary
+vessels. Malpighi could hardly have selected an object better suited
+for this particular research. This important discovery of his drew the
+attention of scientific men in England. The Royal Society soon entered
+into correspondence with him, and during the remainder of his life
+undertook the publication of his researches.
+
+[Illustration: In 1673 Malpighi published in London his work _On the
+Formation of the Chick in the Egg_. Thirteen years later, in 1686, he
+published extensions and corrections of this work. Our figures are
+taken from the later work.
+
+FIG. 46 is the whole embryonic area, at about the end of the second day
+of incubation. The embryo itself is seen with its large head containing
+the three ‘cerebral vesicles’ (which are the rudiments of the brain),
+the large eye, the protuberant coiled heart (NM), from which vessels
+pass to the ‘vascular area’. The segmented vertebral column is well
+seen, as well as the vessels forming a network as they meander over the
+vascular area.
+
+FIG. 47 exhibits the embryo more enlarged and in greater detail.
+
+FIG. 48 is an enlarged figure of the heart; the part D will ultimately
+form the ventricle, B the auricle, and A the vena cava. At F the
+aorta sends forth three branches which unite again. The nature of
+these branches was not understood in Malpighi’s time. They have
+been explained in modern times by embryologists working under the
+inspiration of evolutionary theory as having once furnished the
+blood-supply to the gills of a fish-like ancestor.
+
+FIG. 49 is a part of the segmented vertebral column still more enlarged.
+
+]
+
+[Illustration:
+
+FIG. 49A. ONE OF LEEUWENHOEK’S MICROSCOPES. To understand the figure
+turn the book at right angles to the line of print. The object to be
+examined--here the tail of a small eel--is placed in water in the
+test-tube B. This test-tube is held firmly by two springs in the frame
+A. The microscope itself is simply a flat metal plate D, into which is
+let a very minute lens, the setting of which is shown above the letter
+D (when the head of the eel is downwards). The lens is focused by means
+of a fine screw which moves the whole plate.
+
+]
+
+The contributions of Malpighi to biological knowledge were very
+numerous and important. The study of early development, embryology as
+it is now called, was greatly extended by him. The later stages of
+embryological development had been investigated by Fabricius (p. 110)
+and some additions to the subject had been made by Harvey. Malpighi,
+applying his microscope to the earlier germ of the animal body,
+described in detail the development of the organs, notably of the
+heart and the nervous system (Figs. 46-49). He also demonstrated the
+minute structure of the skin, spleen and liver, in all of which there
+are anatomical structures that still bear his name. He investigated
+microscopically the structure and physiology of insects and plants, and
+his figures of the cell-walls of the latter are good and clear.
+
+[Illustration: FIGS. 50-53 illustrate the blood corpuscles and
+circulation after Leeuwenhoek.
+
+FIG. 50. Oval blood corpuscles of salmon showing nuclei.
+
+FIG. 51. Human red blood corpuscles.
+
+FIG. 52. Drawing of human red blood corpuscles for comparison with
+Leeuwenhoek’s figures.
+
+FIG. 53. Capillary network in web of frog’s foot. A, C and E
+are arterioles, B, D and F are venules.
+
+]
+
+A most remarkable contemporary microscopist was the Dutchman, Anthony
+van Leeuwenhoek (1632-1723). Without medical or scientific training,
+desultory and secretive in his mode of working, he was withal an
+observer of genius and a very shrewd investigator. During his long
+and industrious life he made a series of disconnected discoveries
+which for originality and importance have been surpassed by no other
+microscopic observer. He improved and extended the knowledge of the
+capillary circulation of which Malpighi was the discoverer (Fig. 53),
+he gave figures of the blood corpuscles (Figs. 50-1), of spermatozoa
+and of fibres of muscles (Figs. 55-56a), and advanced the knowledge of
+embryology. He always worked with a simple microscope, using lenses of
+exceedingly short focal length (Fig. 49A). It is astounding that, with
+such an instrument, he saw and figured bacteria as early as 1683 (Fig.
+54).
+
+[Illustration:
+
+FIG. 54. THE FIRST REPRESENTATION OF BACTERIA. They were figured by
+Leeuwenhoek in the _Philosophical Transactions of the Royal Society_ of
+London in 1683.
+
+]
+
+[Illustration: FIGS. 55-56A. Drawings of the structure of muscle made
+about 1682 by Leeuwenhoek.
+
+FIG. 55 shows a muscle teased up into bundles of fibres, magnified.
+
+FIG. 56 is a more magnified view of a bundle of fibres. The cut fibres
+are shown at the end.
+
+FIG. 56A is a very highly magnified view of a single fibre showing very
+clearly the striations that are very characteristic of voluntary muscle.
+
+]
+
+The short life of a second Dutch microscopist of the seventeenth
+century, Jan Jacobz Swammerdam (1637-80), was abbreviated yet further,
+as regards scientific achievement, by his insanity. In his brief
+working period he produced his _Bible of Nature_ which, alone of
+the scientific writings of his age, is still consulted by modern
+naturalists for the unique beauty and accuracy of its figures.
+He extended the knowledge of embryology and he made a series of
+physiological experiments which involved the very modern physiological
+device known as the ‘nerve-muscle preparation’. He is thus the founder
+of an important department of Physiology. Swammerdam showed that,
+during contraction, a muscle does not increase in bulk, and that
+therefore the nerve brings nothing to it in the way of the hypothetical
+‘nervous fluid’ in which many then believed (Fig. 63). He applied the
+same reasoning to the heart (Figs. 57-60). Swammerdam was perhaps the
+first to see the blood corpuscles. Like several of his contemporaries
+and followers, he made injection preparations of much beauty and
+delicacy. His great work was not published till after his death. The
+copper plates that he had prepared for it were found and purchased by
+Boerhaave (p. 140), who produced them at his own expense.
+
+These microscopists and several others in the seventeenth century
+did much to explore the minute structure of the animal body. Their
+revelations showed at once an unexpected complexity of all the parts,
+and an unexpected resemblance of some of those parts which appear
+diverse to the naked eye. Thus, the structure of the body came to be
+subjected to a process that we may call ‘microscopic analysis’. For
+long after the time of these classical microscopists no effective
+improvements were made in the microscope, and the progress of
+microscopic analysis lay almost dormant. With the improvements in the
+microscope of the nineteenth century, the method was taken up again
+with triumphant results.
+
+[Illustration: FIGS. 57-60. Experiments by Swammerdam to illustrate the
+nature of muscular contraction.
+
+FIG. 57 is the simplest form of what physiologists call a ‘nerve-muscle
+preparation’. It is merely a living muscle dissected away from the
+body, but with its nerve still attached. In the experiment the two
+tendons of the muscle are held by the two hands. An assistant pinches
+the nerve with forceps. The muscle thereon contracts and draws the two
+hands together.
+
+FIG. 58 shows the muscle passed through a glass tube. Its two tendons
+are fastened by two pins. When the nerve is pinched the pins are drawn
+towards each other, and the muscle, in contracting, fills the middle of
+the tube.
+
+FIG. 59 shows the nerve-muscle preparation enclosed within a tube.
+This tube has a narrow neck in which, at _e_, is a drop of water. The
+other end of the tube is closed by a cork. The nerve may be squeezed by
+pulling the thread _c c_, which passes through the cork and drags the
+nerve into a narrow wire loop.
+
+FIG. 60 is a similar experiment with the heart, which contracts and
+expands spontaneously and needs no irritation.
+
+The experiments 59 and 60 show that during ‘contraction’ no new
+substance passes into the muscle, since it does not then increase in
+size. This gives the death-blow to the conception of a ‘nervous fluid’
+passing into the muscle to cause contraction by distending it.
+
+]
+
+
+§ 7. _From Alchemy to Chemistry._
+
+During the sixteenth and the first part of the seventeenth century
+the basic science of Mechanics had been placed on a firm footing
+by Galileo. Astronomy, with Galileo and Kepler, had made the great
+break with the past. Anatomy and Physiology had put on their modern
+dress. Chemical knowledge, however, remained peculiarly backward.
+Many advances, it is true, had been made in technical processes,
+but investigations designed to throw light on theory were mostly
+prosecuted by the band of dupes and charlatans who, since the Middle
+Ages, had been seeking the Philosopher’s Stone. The old theory of the
+four elements, earth, air, fire, and water (p. 34), formed an ill basis
+for experiment. Some philosophers, it is true, had put forward crude
+atomic theories, but they had little experimental evidence to adduce.
+Nevertheless even the alchemists had made some advance and had, for
+instance, perfected a system of weighing.
+
+The great defect of the ancient view of matter was that it contained
+no definite conception of the nature of a _pure_ substance. Metals,
+for instance, were regarded, like other substances, as a mixture
+in certain proportions of the four elements of Aristotle (p. 34).
+Thus, the transmutation of one metal or one substance into another
+by distillation did not seem an absurdity, or even a task of special
+theoretical difficulty.
+
+The main agent in changing the chemical outlook was Robert Boyle
+(1627-91). He was a member of a small association of scientific men,
+the _Invisible College_, which met first in London, then in Oxford,
+and finally in 1663 was incorporated by Royal Charter as the _Royal
+Society_. These men were satisfied that the only way to learn anything
+effective about Nature was by observation and experiment. From their
+discussions all purely speculative views were excluded. They agreed
+to meet together solely to compare experiences, to demonstrate
+experiments, and to draw immediate deductions. None of them was more
+active in these matters than Boyle.
+
+The actual chemical and physical discoveries of Boyle were very
+numerous, but his great achievement, the real service he rendered to
+learning in general and to medicine in particular, was his introduction
+of a new spirit into Chemistry. Under him that study was no longer
+prosecuted for purely practical ends; it was set free from the mystic
+factor in Alchemy and it was loosed from the chains which bound it
+to Medicine, to the disadvantage of both. Chemistry thus became an
+independent science, the principles of which were to be ascertained by
+experiment, and its truths pursued for their own sake.
+
+Boyle demonstrated that the air is a material substance and has weight.
+By means of his air-pump, he proved clearly that this substance is
+necessary for the support of respiration (Fig. 63). The law of the
+compressibility of gases is still known by his name. Most important of
+all Boyle’s contributions to chemical theory was his adumbration of the
+conception of a chemical element in our modern sense, and his view,
+which he borrowed from another philosopher, of the atomic structure of
+matter.
+
+Under the inspiration of Boyle and his colleagues, chemical works
+of the second half of the seventeenth century exhibit in general a
+positive, cautious, experimental spirit, and show a great contrast to
+the mystical and obscure writings of the first half of the century,
+which have much affinity with Alchemy. A fine exponent of this new
+spirit was John Mayow (1645-79), who was prevented by an early death
+from fulfilling all his promise. He was the first to recognize clearly
+that there is a substance or principle in air which is concerned at
+once with combustion, respiration, and the conversion of venous into
+arterial blood. In this sense he was the discoverer of Oxygen (Figs. 74
+and 75).
+
+[Illustration: FIG. 61. ONE OF ROBERT BOYLE’S AIR-PUMPS. A cat has been
+placed in the receiver. It shows signs of asphyxia as soon as the air
+is exhausted by the pump.]
+
+
+§ 8. _The Medical Theorists._
+
+The great advances in the physical and biological sciences, instituted
+during the sixteenth and seventeenth century, left the old medical
+theories derelict. We have already traced the wrecking of the
+Galenic physiology. With its destruction, the old ideas concerning
+the three types of spirit, natural, vital, and animal, went by the
+board. The doctrine of the circulation of the blood (p. 113) and the
+investigations of the new Chemistry accorded ill with the old humoral
+pathology, which ascribed all disease to excess or defect of one of
+the four humors, blood, phlegm, bile, and melancholy (p. 34). Numerous
+fresh theories arose, of which the more important can be classed under
+the three headings _Iatrophysics_, _Iatrochemistry_, and _Vitalism_.
+
+
+(_a_) _Iatrophysics._
+
+The physical discoveries of Galileo and the demonstrations of
+Sanctorius (p. 108) and of Harvey (p. 111) gave a great impetus to the
+attempt to explain the workings of the animal body on purely mechanical
+grounds. The writers who took this point of view are known as the
+_Iatrophysicists_. One of the earliest and most impressive exponents of
+physiological theory along these lines was the French philosopher René
+Descartes (1596-1650). His work on the subject appeared posthumously in
+1662. It is important as the first modern book entirely devoted to the
+subject of Physiology.
+
+Descartes had not himself any extensive practical knowledge of the
+subject with which he was dealing. On theoretical grounds he set
+forth a very complicated apparatus which he believes to be a model
+of animal structure. Subsequent investigation failed to confirm his
+findings, and his work soon passed into oblivion. For a time, however,
+it attracted much attention and many followers. A strong point in his
+theory is the great stress laid upon the nervous system, and its power
+of co-ordinating the different bodily activities. Thus stated, his view
+may seem not far from the modern standpoint, though in fact he was
+grotesquely wrong in detail. An important part of his theory is the
+complete separation of Man from all the other animals. Man, according
+to him, differs from all other animals by his possession of a soul,
+which is situated in a structure in the brain known to physiologists
+as the ‘pineal body’! Animals, he held, have no soul, and all their
+actions and movements, even those which seem to express pain or fear,
+are purely automatic. It is the modern theory of ‘behaviorism’ with
+man excluded! (Figs. 62 and 63.)
+
+[Illustration:
+
+FIG. 62. DESCARTES’ conception of the relation of a sensory impression
+and a motor impulse. The image of the object ABC passes to the eye and
+is formed on the retina. Owing to the optical properties of the eye, it
+is there inverted. The image is inverted yet again within the brain,
+where it passes to the pineal gland H at the point _b_. The position
+and character of the image formed on the retina determines the nature
+and distribution of its effect on the pineal body. According to the
+nature and distribution of that effect is the result on the nerve,
+and through it, by the passage of nervous fluid, on the muscles. The
+movement in the nerve is initiated at the point _c_. The relation
+between _b_ and _c_ is an insoluble mystery in which is wrapped up the
+very nature of the soul. (From the posthumous work of Descartes on
+Physiology.) ]
+
+[Illustration:
+
+FIG. 63. DIAGRAM OF DESCARTES to illustrate his theory of nervous
+action. P R and _q s_ are nerves which supply the muscles of the eye
+T and V V. Descartes held that these nerves were hollow and provided
+with valves, which can be seen at the point at which the P R and _q s_
+first branch. These valves were partly controlled by little fibrils
+(which can be seen in the main stems of P R and _q s_ and in certain of
+their branches). These valves control the movement of the fluid within
+the hollow spaces of the nerves. Additional complication is lent to
+the scheme by the fact that P R and _q s_ intercommunicate at certain
+points. The view of Descartes, and all such theories of nervous fluid,
+were destroyed by the experiment of Swammerdam (Figs. 57-60), which,
+however, long remained unpublished.
+
+]
+
+More lasting was the achievement of Giovanni Alfonso Borelli
+(1608-79), an eminent mathematician who was professor at several
+Italian universities and the friend of Galileo and Malpighi. Stirred,
+like Descartes, by the success of Galileo in giving a mathematical
+expression to mechanical events, Borelli attempted to do the same with
+the animal body. In this undertaking he was, in fact, very successful.
+That department of Physiology which treats of muscular movement on
+mechanical principles was effectively founded and largely developed by
+him. Here his mathematical and physical training was specially useful.
+He endeavored, with some success, to extend mechanical principles to
+such movements as the flight of birds and the swimming of fish. When he
+came to an analysis of some of the other activities of the body, such
+as the action of the heart, or the movements of the intestines, he was
+less successful, and he naturally failed altogether in his attempt to
+introduce mechanical ideas in explanation of what we now know to be
+chemical processes, such as digestion in the stomach.
+
+Undeterred by Borelli’s failure, other writers sought to find
+mechanical explanations of physical processes. As is usual in such
+cases, the amount of theory was inversely proportional to the amount
+of knowledge. The views of some of the later ‘Iatrophysicists’ became
+very fantastic. Belated representatives of the school are the writers
+of the great French _Encyclopédie_ (1751-72), and notably its main
+author, the man of letters, Denis Diderot (1713-84).
+
+[Illustration:
+
+FIG. 64. DIAGRAMS FROM BORELLI, showing one of his attempts to analyse
+the movements of the muscles, in this case of the arm, according to the
+principles of the science of Mechanics as expounded by Galileo. The
+figure should be considered in conjunction with Fig. 65 opposite.
+
+]
+
+
+(_b_) _Iatrochemistry._
+
+Just as there were some who sought to explain all animal activity on
+a mechanical basis so others resorted to chemical interpretation.
+These may be termed _Iatrochemists_. The most prominent was Franciscus
+Sylvius (1614-72), professor of Medicine at Leyden. That university
+had become, in the second half of the seventeenth century, the most
+progressive scientific center north of the Alps. It was the seat of the
+first University laboratory, built at the instigation of Sylvius.
+
+Sylvius devoted much attention to the study of salts. He recognized
+that they were the result of the union of acids and bases, and he
+attained to the idea of chemical affinity--an important advance. He
+looked at the phenomena of life also from the chemical point of view.
+Well abreast of the anatomical knowledge of his day, and accepting
+the broader lines of mechanistic advance in Biology, such as the
+circulation of the blood and the mechanics of muscular motion, Sylvius
+sought to interpret other activities in chemical terms. His position
+and abilities as a teacher gave his views wide currency and he and his
+pupils occupy a large part of the field of medical theory until well
+into the eighteenth century.
+
+Under the influence of this school, almost all forms of vital activity
+were expressed in terms of ‘acid and alkali’ and of ‘fermentation’.
+The latter process was assumed to be of a chemical order, and no
+clear distinction was made between changes that are brought about by
+‘unorganized’ ferments, such as gastric juice or rennet, and changes
+that are brought about by the action of micro-organisms, such as
+alcoholic fermentation or leavening by yeast. Nevertheless, the school
+of Sylvius and its immediate successors added considerably to our
+knowledge of physiological processes, notably by their examination of
+the body fluids, especially the digestive fluids such as the saliva,
+and the secretions of the stomach and of the pancreas.
+
+[Illustration:
+
+FIG. 65. DIAGRAM OF MUSCULAR ACTION involved in lifting a weight in the
+hand. It illustrates how muscular movement may sometimes be resolved
+into terms of the lever. In practice, however, it is usually necessary
+to involve a whole system of levers, pulleys, resistances, &c., as
+Borelli clearly perceived. (Compare Fig. 64.)
+
+]
+
+
+(_c_) _Vitalism._
+
+Yet another school of medical theorists arose under the leadership of
+the German chemist and physician, George Ernest Stahl (1660-1734).
+Stahl is best remembered as the author of the famous theory of
+_phlogiston_, a hypothetical substance with which bodies were supposed
+to part during the process of burning (p. 151). He is important in the
+history of science for his success in grouping chemical phenomena and
+therefore in systematizing the study of the subject. For our purpose,
+however, Stahl stands as the protagonist of that view of the nature of
+the organism which now goes under the term _Vitalism_. Though expressed
+by him in obscure and mystical language, it is, in effect, a return to
+the Aristotelian position and a denial of the view of Descartes. To
+Descartes the animal body was a machine. To Stahl the word _machine_
+expressed exactly what the animal body was not. The phenomena
+characteristic of the living body are, he considered, not governed by
+physical and chemical laws, but by laws of a wholly different kind.
+These laws are the laws of the _sensitive soul_. The _sensitive soul_
+of Stahl is, in its ultimate analysis, not dissimilar to the _psyche_
+of Aristotle (p. 32). Stahl held that the immediate instruments, the
+natural slaves of this sensitive soul, were chemical processes and his
+Physiology develops along lines of which Aristotle could know nothing.
+This does not, however, alter the fact of his hypothesis being an
+essentially vitalistic one of Aristotelian origin.
+
+    *   *    *    *    *
+
+The language and the theories of the Iatrophysicists, the
+Iatrochemists, and the Vitalists of the seventeenth and eighteenth
+centuries have long been discarded by men of science in the form in
+which they were originally propounded. Nevertheless, they represent
+three attitudes to the activities of living things which have present
+and current meaning. Each seems to present some aspect of truth.
+Whether some physiological thinker will combine all three aspects into
+one coherent whole, it is for the future to decide. Yet it is certain
+that all three lines of approach remain of value, and the stimulus
+provided by each of the three inspires investigation at the present
+day. In this sense we enter on the period of modern Medicine in the
+seventeenth century. In this sense the foundations of modern rational
+Medicine may be said to have been laid by Borelli, Sylvius and Stahl,
+with Galileo, Boyle and Harvey standing behind them.
+
+
+
+
+V
+
+THE PERIOD OF CONSOLIDATION
+
+(FROM ABOUT 1700 TO ABOUT 1825)
+
+
+§ 1. _The Reign of Law._
+
+During the sixteenth and seventeenth centuries the human mind cast
+off its medieval vestments and, having refreshed itself at the spring
+of Antiquity, turned to array itself in the garments of the New
+Philosophy. The advent of new ideas and new knowledge had been very
+rapid. The _method_ of Research had been determined by Galileo at the
+beginning of the seventeenth century. The _meaning_ of Research was
+determined by a second great investigator, Newton, at the end of the
+same century.
+
+The change wrought in the thought of their time by Vesalius, Galileo,
+Harvey and their like was quantitative rather than qualitative. They
+discovered new laws of Nature, but the discovery of such new laws was
+hardly unprecedented. Law had been traced in the heavens from of old.
+The rules of planetary and stellar motion had been gradually developed
+from the simple astronomical theories of the ancients. The great
+astronomers of the sixteenth and seventeenth centuries did not hesitate
+to appeal to the records and doctrines of medieval writers, for new
+mathematical relationships of the heavenly bodies had been elicited
+even during the Middle Ages. In the sixteenth century Astronomy under
+Tycho (died 1601) put her house in order for the ‘Great Instauration’
+of the coming age. And then Galileo startled the world (1604) with that
+new star of his (p. 104), among the most remote heavenly bodies in the
+very region held by the Aristotelian and Platonic schemes to be utterly
+changeless. The Revolution in Thought had begun, though no new order
+had been established.
+
+By 1618 Kepler had enunciated his ‘three laws of planetary motion’,
+bringing these movements into an intelligible relation with each other.
+Then the experimental philosophers set forth to establish terrestrial
+mechanics. They determined the mode of action of gravitation, and
+Galileo came near to the ‘three laws of motion’ which we call Newton’s.
+But it was Newton who first affirmed them clearly and succeeded in
+linking them with Kepler’s laws of planetary motion. Before Newton, no
+man had shown or perceived that rule by which the natural succession of
+earthly phenomena is in relation to that of the heavenly bodies. Nay,
+Faith and Reason alike would have been against such a view. To prove
+that the relationship amounted to identity, to move men’s minds to see
+that the force that causes the stone to fall is that which keeps the
+planets in their path, this was Newton’s unique achievement. It was
+Newton who first enunciated a law whose writ ran alike in the Heavens
+and on the Earth. With Newton the Universe acquired an independent
+rationality, and the whole cosmology of Aristotle, of Galen, and of the
+Middle Ages lay in the dust.
+
+When Newton had completed his work, the Gravitation of the Earth and of
+the Heavens was seen to be one, and all the Mechanism of the Universe
+lay spread before him. The vision was set forth in his _Principia_
+(1687). It established a view of the structure and working of the
+Universe which has survived to our own generation.
+
+And now as to the change wrought in men’s minds. It was something more
+than a Revolution. It was the establishment of a New Order. Newton
+conceived a working Universe wholly independent of the Spiritual Order.
+As to how far his vision is philosophically tenable and as to how far
+he realized its nature, these are matters which we need not discuss
+here. There can, however, be no doubt that Newton utterly destroyed the
+very foundations of medieval thought. With Newton there sets in the
+last stage of ‘scientific determinism’.
+
+During the two centuries and a half since the _Principia_ appeared,
+Science has developed prodigiously along the lines into which Newton
+led her. In reliance on the universality of Natural Law, the stars in
+their courses have been paced, weighed, measured, analysed. The same
+process, directed to our own planet, has traced its history, determined
+its composition, demonstrated its relation to other bodies. Physicist
+and chemist have suggested a structure in terrestrial matter similar
+to that of the stars and suns. The world has been reduced to a unitary
+system. Wherever men have sought Law, they have found Law. With search
+skilful enough and patient enough, Law has ever emerged. It has been
+_the Age of the Reign of Law_.
+
+It is true that in our own time philosophers in general have come to
+see that these Laws of Nature are within us as much as without; that
+they are, in part at least, the result of the structure of our minds.
+This is a point of view, however, which has not affected, and perhaps
+will not affect, the working man of science. His constant occupation,
+since the days of Newton, has been the pursuit of Law, and he has
+always been satisfied that Law has only to be sought in order to be
+found. This conception has affected the medical and biological sciences
+very deeply. Thus the influence of the Newtonian philosophy is as
+traceable in them as it is in the astronomical and physical sciences.
+Galileo showed men of science that weighing and measuring are worth
+while. Newton convinced a large proportion of them that weighing and
+measuring are the _only_ investigations that are worth while. The
+question as to whether this view is ultimately true or philosophically
+justifiable does not need discussion at the moment. The point, for our
+immediate purpose, is that the view has been and is very widely held.
+
+
+§ 2. _The Rise of Clinical Teaching._
+
+The eighteenth century dawned with the refreshing breeze of Newtonian
+philosophy blowing through it. During the previous two hundred years
+there had been an immense amount of new and fruitful research along
+diverse lines. Chemistry and Mechanics, Botany and Comparative
+Anatomy, Descriptive Anatomy and Experimental Physiology, Epidemiology
+and Microscopic Analysis, all had yielded startling results. The
+new generation was bewildered with the very mass and novelty of the
+material. The Biologists of the time must have been well nigh hopeless
+of reducing their vast accumulations to order, when they contemplated
+the beauty and symmetry of the mathematical relations that Newton
+and his followers had introduced into Cosmic conceptions. Thus the
+eighteenth century is a period for Biology of pause and consolidation
+during which attempts were made to introduce unitary conceptions
+into the mass of accumulated material. It was, moreover, a period of
+consolidation not only of ideas but also of teaching. These tasks
+at first turned men’s minds away from the immediate accumulation of
+further knowledge. So it is that the first half of the eighteenth
+century exhibits something of a gap in the progress of Research. The
+medical field is largely filled by two great figures, Boerhaave and
+Haller.
+
+Until the seventeenth century there was no systematic clinical
+teaching. The Universities gave medical degrees on the basis of a
+spoken disputation. No contact with the patient was demanded. The
+first effective attempt to change this was at Leyden, where about 1636
+clinical teaching was instituted. Owing to this, and to the fact that,
+as at Padua, students of every religious denomination were accepted,
+Leyden became much frequented by foreign and especially by Protestant
+students. The attractions of the place were increased by Sylvius (pp.
+131-2) who, in the second half of the seventeenth century, added
+laboratory instruction to his clinical teaching. Leyden had several
+eminent anatomists, while its botanic garden and museums added to the
+practical character of the medical instruction that it offered.
+
+Hermann Boerhaave (1668-1738) was first appointed as a teacher at
+Leyden in 1701. At once the medical school attained a front rank
+reputation which rapidly came to surpass even that of Padua. Boerhaave
+had very few beds at his disposal, but never did man make better
+use of his opportunities. Besides clinical, chemical, botanical
+and anatomical instruction he followed such of his patients as died
+into the post-mortem room and there demonstrated to his students the
+relation of lesions to symptoms. He is thus the introducer of the
+method of medical instruction still in vogue in our modern medical
+schools.
+
+Boerhaave was a man of wide culture. He rescued and published the
+plates of the priceless _Bible of Nature_ of Swammerdam (p. 121). He
+brought to Leyden the best anatomist of his age, Bernard Siegfried
+Albinus (1697-1770). With him Boerhaave edited in superb form the
+collected works of Vesalius (1725, p. 85 ff.). The edition exhibits
+remarkable prevision of the scientific needs of the scholarship of
+our own time. To Albinus, and indirectly to Boerhaave, we owe the
+most beautiful of all works on muscular anatomy (1747), a book still
+in current use (Fig. 66). Apart from his clinical ability and acumen
+Boerhaave was a skilled chemist, botanist, and anatomist.
+
+With all these accomplishments Boerhaave was better able than any man
+of his time to achieve something like a medical synthesis, to bring
+all the sciences to the service of the patient. Taking one thing
+with another, considering his influence as a teacher, his clinical
+acumen, his power of inspiring younger workers, his wide learning,
+his balanced vision, his eagerness for new knowledge, his sanity, his
+humanity, his generosity, and his prophetic power, Boerhaave must
+be regarded as the greatest physician of modern times. To him the
+debt of British Medicine, and through it of British well-being, is
+quite incalculable. Through his pupils he is the real founder of the
+Edinburgh Medical School, and through it of the best medical teaching
+in the English-speaking countries of the world. The success of the
+Edinburgh school, founded while the great Leyden professor was still in
+his prime, can be ascribed to two causes which are perhaps reducible to
+one--the inspiration of Boerhaave. These two causes are, firstly, the
+enthusiasm of its early teachers, and, secondly, the concentration of
+all the medical teaching, both clinical and subsidiary, in one great
+university school.
+
+[Illustration: FIG. 66. TWO PLATES FROM BERNARD SIEGFRIED ALBINUS.
+_Anatomical Plates of the Muscles of Man_, Leyden, 1747. These are the
+most beautiful and among the most accurate anatomical figures ever
+published.]
+
+
+§ 3. _Physiology passes to the Modern Stage._
+
+The only figure in the eighteenth century whose influence is comparable
+to that of Boerhaave is his pupil, the Swiss Albrecht von Haller
+(1708-77), one of the most accomplished men of all time. In actual
+scientific achievement Haller stands, indeed, far above his master.
+He achieved distinction as poet, botanist, anatomist, and novelist,
+carried on a prodigious correspondence, was an exceedingly learned
+bibliographer, and perhaps the most voluminous of all scientific
+authors. His special distinction, however, is as a physiologist.
+
+Haller’s great work, _Elements of the Physiology of the Human Body_
+(1759-66), marks the modernization of the subject of which it treats.
+Of the highest importance were his researches on the Mechanics of
+Respiration, on the formation of bone, and on the development of the
+embryo. He did good work on the action of the digestive juices. His
+most important contributions, however, are his conceptions of the
+nature of living substance and of the action of the nervous system.
+These conceptions formed the main background of biological thinking
+for a hundred years, and are still integral parts of physiological
+doctrine.
+
+All departments of Medicine must be influenced by the views we may hold
+on the nature and action of the nervous system, just as all parts of
+the body are influenced and indeed are linked together by that system.
+Thus the growth in knowledge of the physiology of the nervous system is
+extremely important to us if we would gain a true idea of the progress
+of Rational Medicine.
+
+When we look into the history of nervous Physiology before Haller, we
+shall be struck by the smallness of the observational foundation of a
+vast speculative structure. That we may be the more charitable in our
+judgment of such fanciful developments, we may recall that the Mind is
+so constructed that it can take little interest in the accumulation of
+instances unless it can adduce general laws therefrom. Theory is thus
+as necessary to practice as practice to theory. The earlier doctrines
+of the nature of nervous action are, however, so unlike those we
+now hold that we can afford to pass over them lightly. They consist
+of speculations on the topic of the seat of the soul, together with
+explanations which suppose the passage either of a fluid or of some
+chemical change down the nerves. Haller was the first to construct a
+theory of the nervous system that has an appearance of modernity.
+
+During the seventeenth century the favorite doctrine of nervous action
+supposed the existence of a nervous fluid. This, it was held, passed
+down the nerves to inflate or extend the muscle fibers. Inflation was
+supposed to shorten the fibers and so the muscle came to contract. An
+exquisite experiment by Swammerdam with his nerve-muscle preparation
+had disproved this (p. 123). But Swammerdam’s work was unknown till
+published by Boerhaave in 1736, and so the matter stood till Haller’s
+time.
+
+Haller concentrated the problem on an investigation of the fibers.
+A muscle fiber, he pointed out, had in itself a tendency to shorten
+with any stimulus, and afterward to expand again to its normal length.
+This capacity for contraction Haller, following a predecessor, called
+_irritability_. He recognized the existence of ‘irritability’ as an
+element in the movement of the viscera, and notably of the heart, and
+of the intestines. The feature of ‘irritability’ is that a very slight
+stimulus produces a movement altogether out of proportion to itself,
+and that it would continue to do this repeatedly so long as the fiber
+remained alive.
+
+But besides the force inherent in a muscle fiber Haller showed that
+there was another force which comes to it from without, is carried
+from the central nervous system by the nerves, and is the power by
+which muscles are normally called into action. This force, like that
+of irritability, is independent of the will, and like it can be called
+into action after the death of the animal. Haller thus distinguished
+the _inherent muscular force_ from the _nerve force_. Both these forces
+he further distinguished from the natural tendency to contraction and
+expansion, under changing conditions of humidity, pressure and so on,
+of all tissues, living or dead.
+
+Haller, having dealt with the question of movement, turned to that
+of feeling. He was able to show that the tissues are not themselves
+capable of sensation, but that the nerves are the sole channels or
+instruments of this process. He showed how all the nerves are gathered
+together into the brain, and he believed that they tended to its
+central part. These views he supported by experiments and observations
+involving injuries or stimulation to the nerves and different parts
+of the brain. He ascribed special importance to the cortex, but the
+central parts of the brain he regarded as the essential seat of the
+living principle, the Soul.
+
+Throughout his discussion Haller never falters in his display of the
+rational spirit. He develops no mystical or obscure themes, and,
+although his view of the nature of Soul may lack clarity, he separates
+such conceptions sharply from those which he is able to deduce from
+actual experience. He is essentially a modern physiological thinker,
+and certain of his themes were developed by workers who come on the
+frontiers of what we have called the ‘period of consolidation’.
+
+Among these workers we would select the Scottish surgeon Sir Charles
+Bell (1774-1842), who in 1811 showed that of the two roots from the
+spinal cord by which all the nerves of the body arise one root conveys
+only sensory elements while the other conveys only motor elements (Fig.
+98, p. 208). By this discovery Bell not only completed the views of
+Haller on the central nervous system, but also brought them within the
+range of practical Medicine.
+
+
+§ 4. _Some Physiological Advances._
+
+Haller provided a philosophical basis to physiological conceptions.
+There were, however, other workers of the time who added to the
+knowledge of actual workings of the animal body. First among these,
+both in time and eminence, stands the English country clergyman
+Stephen Hales.
+
+The Rev. Stephen Hales (1677-1761) was by temper a biologist, but he
+had received a training in Mathematics and Physics. With this ideal
+equipment, he proceeded to investigate the Dynamics of the Circulation.
+His method consisted in applying the principle of the pressure gauge
+or manometer to living things. By tying tubes into the arteries and
+veins of animals, he was able to record and measure the blood-pressure.
+He thus laid the foundation of an important mode of studying the
+diagnosing disease. He extended his exact investigations into most of
+the mechanical aspects of the circulation. He computed the circulation
+rate and he estimated the actual velocity of the blood in veins,
+arteries, and capillary vessels. He made a very important contribution
+by showing that the capillary vessels are liable to constriction and
+dilatation, a knowledge that has since become not only important for
+physiological theory but of primary significance to the practising
+physician (p. 309). He began to explore the wonderful mechanism of
+the heart by which that organ adjusts itself to its needs of output.
+He exhibited his versatility by important contributions to many other
+departments, as, for instance, his discoveries on Respiration, his
+improvements in Ventilation (Fig. 67), and his campaign for Temperance.
+All his work is characterized by simplicity and directness, the supreme
+marks of his genius.
+
+[Illustration:
+
+FIG. 67. WINDMILL VENTILATOR designed by the Rev. Stephen Hales, and
+erected by order of the Aldermen of the City of London, in 1752, on the
+roof of Dick Whittington’s Gate at Newgate Prison. From a print in the
+British Museum.
+
+]
+
+In the meantime considerable progress was made in the knowledge of the
+digestive processes. The French naturalist, René Antoine de Réaumur
+(1683-1757), best remembered for his thermometer (1731) and for his
+superb work on insects (1734-42), made a series of experiments on
+gastric digestion in birds (1752). By an ingenious contrivance he
+succeeded in obtaining gastric juice in a pure state. He was able to
+demonstrate its power to dissolve food substances in a test-tube kept
+at body temperature. This was important, since many believed that
+the process of solution was the result of a churning process induced
+mechanically by the muscles of the stomach-wall. Réaumur thus gave the
+death-blow to the Iatrophysical conception of digestion (p. 130).
+
+The investigation of gastric digestion was further pursued by a
+versatile Italian, the Abbé Lazaro Spallanzani (1729-99), who showed
+that the churning action is an aid, but not an essential, to the
+process of digestion (1782). He proved that digestion was not of the
+nature of putrefaction and differed essentially from the fermentation
+of wine. Spallanzani thus improved on the view of Sylvius (p. 132),
+and took a step towards that solution of the natures of putrefaction,
+fermentation, and digestion which was finally provided by Pasteur (p.
+225). He showed that the gastric juice was secreted by the stomach
+itself, and not introduced into it from other organs. A suspicion
+that the gastric juice contained a free acid crossed his mind. He
+observed that it curdled milk and so began our knowledge of a separate
+ferment, that of ‘rennet’. Spallanzani’s results may be summarized
+by saying that he showed that gastric juice had a solvent power _sui
+generis_, and that this power or faculty was of a different order from
+putrefaction or vinous fermentation.
+
+The phase of digestive physiology represented by Réaumur and
+Spallanzani was brought to a close by the English physician William
+Prout (1785-1850), who demonstrated in 1823 the existence of free
+Hydrochloric Acid in the stomach. He showed that the presence of this
+acid was necessary for gastric digestion, but that the actual process
+of solution of food was the work of another agent. The matter was at
+last brought into the range of medical practice by an American Army
+Surgeon, William Beaumont (1785-1853), who, in the ten years ending
+1833, had the opportunity to investigate gastric juice in a man who,
+having been shot in the stomach, had a permanent fistula. Through this
+the juice could be obtained and the lining membrane of the stomach
+examined at will.
+
+[Illustration:
+
+Experiments illustrating the effects of metallic contacts on the nerves
+and muscles of frogs’ legs. From A. Galvani, _On Electric Forces_, 1792.
+
+FIG. 68. Contact is established between water in two dishes. In one
+lies the end of the nerve with the spinal cord and vertebral column
+attached. In the other are the feet of the frog.
+
+FIG. 69 shows contact by a metal bar with two damp mats on one of which
+lies the spinal cord and on the other are the feet.
+
+FIG. 70 shows a broken contact which can be completed by bringing the
+metal rods together.
+
+]
+
+An important department of Physiology was opened by the extension
+of the knowledge of electric phenomena to the living body. Static
+electricity had been studied since the beginning of the seventeenth
+century. Luigi Galvani (1737-98) of Bologna, while investigating the
+susceptibility of nerves to irritation, showed that nervous action
+could be induced by electrical phenomena (1791). He was, as a matter of
+fact, producing an electrical current. Many thought at the time that a
+new kind of ‘animal electricity’ had been produced and they dubbed it
+‘galvanism’.
+
+Alessandro Volta (1745-1827) of Pavia, deviser of the ‘Voltaic pile’
+(Figs. 71-3), had long been working at electricity. He was able to
+demonstrate (1800) that galvanism is without any essential animal
+relationship, and showed that a muscle can be thrown into continuous
+contraction by repeating electric stimulations.
+
+Humbug and misunderstanding in connection with the electrical relations
+of living tissues were rife, and it was not till after the period we
+are now considering that electricity came to take a place in rational
+Medicine. The change came with E. Du Bois-Reymond (1818-96), who took
+the matter up scientifically about the middle of the nineteenth century
+(1843 onwards). He showed that a nervous impulse is accompanied by the
+passage along the nerve of a change of electrical potential. It should
+be added that, despite all the work since done upon the nervous system,
+this is still the only physical accompaniment of a nerve impulse that
+has been detected.
+
+[Illustration: FIGS. 71, 72, and 73. From an article by Volta, _On the
+Electricity excited by the mere Contact of Substances of different
+kinds_, published in 1800.
+
+FIG. 71 is the famous ‘Couronne de tasses’. It consists of a series of
+vessels containing salt water, in which are steeped plates of alternate
+silver A and zinc Z. The plates are connected by strips of metal _a_
+_a_ _a_. If the first and the last cup be connected by a conductor, a
+current flows from one to the other.
+
+FIG. 72 is a simple voltaic pile, consisting of alternate disks of
+silver and zinc, sandwiched between wet strips of leather. The pile
+is held by glass rods _m_ _m_ _m_. From the lowermost disk a strip of
+metal passes to a vessel containing salt water. A current will pass
+from the uppermost disk to the vessel if the two are connected by a
+conductor.
+
+FIG. 73 is a similar apparatus with two piles connected by a metal
+plate _c c_, and two vessels _b_ _b_. A current will pass between the
+two vessels _b_ _b_ if they are joined by a conductor.
+
+]
+
+
+§ 5. _Discovery of the Nature of the Air._
+
+The seventeenth century saw advances in the knowledge of the air.
+Boyle (1654, p. 124) had shown by means of his air-pump that air was
+a material substance and could be weighed. By exhausting the air from
+a vessel in which an animal had been placed, he showed that it was
+this material substance and no ether, spirit, or other mysterious
+entity which supported respiration. Mayow (1668, p. 126) proved that
+a part only of the air was necessary for life, and later that this
+same part was removed equally by respiration and combustion (Figs.
+74-5). His work was forgotten for a hundred years. The great theorists,
+Stahl, Boerhaave and Haller, knew him not, and Stahl’s doctrine of
+_phlogiston_ set back the hands of the clock. No advance was made till
+the work of Joseph Black (1728-99) which appeared soon after the middle
+of the eighteenth century.
+
+[Illustration: FIGS. 74 and 75, illustrating the chemistry of burning
+and breathing, from a work issued by Mayow in 1674. The experiments
+show the essential similarity of the two processes in their effect upon
+the air.
+
+FIG. 74. A candle is burning and a piece of inflammable material is
+being ignited in a glass vial by a burning-glass, the mouth of which is
+under the surface of the water. The air can, if desired, be changed or
+sampled through the attached tube.
+
+FIG. 75. A mouse confined under a glass cover. The air under this cover
+communicates with that in the vessel below, and can be cut off more or
+less completely by means of a more or less porous diaphragm.
+
+]
+
+Black was a cautious investigator and his success was due to the
+accuracy of his measurements. He was aware of the fact that chalk, when
+heated, is transformed into quicklime (equation 1, p. 152), thereby
+losing its power of effervescing with acids, but gaining the power of
+absorbing water (equation 2). In modern nomenclature, the changes are:
+
+  (1) CaCO_{3} = CaO + CO
+  (2) CaO + HO = Ca(OH)_{2}
+
+The first achievement of Black was to show that in the process of
+heating the chalk lost weight (equation 1). This was a blow at the
+phlogiston theory, for it had been supposed that quicklime consisted
+of chalk _plus_ phlogiston, and that the phlogiston was conveyed to it
+during the heating. Black now showed that if slaked lime be treated
+with a mild alkali, such as the carbonate of sodium, it is changed back
+to the state in which it was before heating, in fact into chalk, while
+the mild alkali is converted into a caustic alkali. As we now express
+it:
+
+  (3) Ca(OH)_{2} + Na_{2}CO_{3}  = CaCO_{3} + 2NaOH
+
+Black’s triumph consisted essentially in showing that reactions (1) and
+(3) were indefinitely reversible and that the same amount of CaCO_{3}
+could always be extracted from (3) as was put into (1). Moreover, he
+showed that a definite amount of chalk, whether heated into quicklime
+or not, neutralized an equal weight of acid, the only difference being
+that the neutralization took place with effervescence and loss of
+weight if the chalk were unheated, and without effervescence or loss of
+weight if the chalk were first heated into quicklime. Thus:
+
+  (4) _Unheated_ CaCO_{3} + 2HCl = CaCl_{2} + H_{2}O + CO_{2}
+  (5) _Heated_ CaO + 2HCl = CaCl_{2} + H_{2}O
+
+The substance given off by the chalk in (1), absorbed by it in (3),
+and produced by the reaction (4), he named _fixed air_. We now call it
+_Carbon dioxide_. The conversion of caustic lime into ordinary chalk
+by exposure, CaO + CO_{2} = CaCO_{3}, proves that Carbon dioxide is a
+normal constituent of the atmosphere. Black learned something of its
+properties, and his work is also of very great importance as the first
+detailed quantitative study of a chemical reaction and its reversal.
+The properties of Carbon dioxide were further investigated (1766) by
+Henry Cavendish (1731-1810).
+
+The next advance in the chemistry of the air was made by the English
+Unitarian Divine, Joseph Priestley (1733-1804). A series of important
+observations was made by him in the seventies and eighties of the
+eighteenth century. He showed that green growing plants would make
+respired air again respirable, and that they gave off a respirable
+gas. In 1774 he prepared Oxygen by heating certain oxides, though,
+still hampered by the phlogiston theory, he failed to recognize the
+nature of the oxygen he had produced. The conclusions of his striking
+experiments on blood, which he showed to depend on this same agent for
+its changes from venous to arterial, were similarly vitiated.
+
+[Illustration:
+
+FIG. 76. APPARATUS from Joseph Priestley’s _Experiments and
+Observations on different Kinds of Air_, Birmingham, 1774. In the
+background can be seen an experiment on the effect of combustion on
+confined air. There are also two cylinders inverted over water in which
+green plants are growing. In one of them the growing plant has given
+off a gas (oxygen) which Priestley showed could support both combustion
+and respiration. In the foreground under a bell-jar are some mice on
+which Priestley performed respiratory experiments.
+
+]
+
+The real passage to the modern point of view in our knowledge of the
+air was made by the brilliant French chemist Antoine Laurent Lavoisier
+(1743-94). He made an extensive quantitative investigation of the
+changes during breathing (Fig. 77), burning, and calcination. In the
+course of these he discovered the true composition of respired air, and
+showed how both Carbon dioxide and water are normal products of the act
+of breathing. If clear grasp of the implication of discovery be made
+the test, Lavoisier must be regarded as the discoverer of Oxygen.
+
+Cavendish (1731-1810) had already discovered the composition of
+water (1785). Lavoisier concluded that water and Carbon dioxide are
+produced by the process of oxidation in the lungs, and that it is
+this oxidization process, and not any innate quality of a mysterious
+character in the body or in the blood, that is responsible for the
+bodily heat. Lavoisier introduced much of the chemical nomenclature
+that we still employ. So far as respiration is concerned, subsequent
+research has added much to his standpoint. In the purely chemical
+aspect, however, it has altered little, though we now know that the
+tissues and not the lungs are the seat of oxidation.
+
+[Illustration:
+
+FIG. 77. LAVOISIER in his laboratory making experiments on breathing.
+To the right Madame Lavoisier sits at a table, taking notes. Lavoisier
+stands behind, directing. To the left is the subject of the experiment.
+His face is covered with a mask provided with a valve. He is breathing
+into the apparatus. An assistant feels his pulse while a second
+assistant collects the respired air in a bell-jar inverted over a
+trough.
+
+From a contemporary sketch.
+
+]
+
+
+§ 6. _Morbid Anatomy becomes a Science._
+
+The main intellectual movement of the seventeenth and eighteenth
+centuries had been focused, so far as Medicine was concerned, on the
+manner of working of the animal body, the department that we now term
+Physiology. It was necessary to obtain clear concepts of the action of
+the body in health before venturing into discussion of its action in
+disease. Towards the end of the seventeenth century, an industrious
+compiler had put together all the then published records of post-mortem
+examinations up to his time. During the first part of the eighteenth
+century many practitioners in Physic and in Surgery published
+isolated cases or groups of cases connected with particular diseases.
+Boerhaave regularly attended post-mortem examinations (p. 140). No
+general pathological principles had, however, yet been elicited on a
+scientific basis. The theories of disease such as those of Boerhaave
+were perforce still mainly speculative, for there were no extensive
+records of the correlation of symptoms during life with the appearances
+of the organs of the body after death, the subject we now call ‘Morbid
+Anatomy’. This gap was first effectively bridged by Morgagni.
+
+Giovanni Battista Morgagni (1682-1771) was professor at Padua for no
+less than fifty-six years. During this time he performed an enormous
+number of post-mortem examinations, and made important contributions
+to Descriptive Anatomy. In his seventy-ninth year, eleven years before
+his death, there emerged from his enormous experience his work _On
+the sites and causes of disease_. This classical treatise may still
+be read with profit. Its leading feature is the very careful way in
+which actual cases are recorded. The life-history of the patient, the
+history of his disease, the events in connection with his final illness
+and death, are all recounted with detail and care. The condition of
+the organs at the post-mortem examination is minutely described and
+an attempt is made to explain how the symptoms were the result of the
+lesions. Morgagni is justly said to have introduced the ‘anatomical
+concept’ into the practice of medicine. This concept is one of the main
+elements in modern diagnosis, and a modern physician, in reflecting
+on a case, considers first whether he is able to express the symptoms
+in terms of lesion. There are many lesions of great importance and
+frequent occurrence which Morgagni was the first to describe.
+
+The task which Morgagni had undertaken was worthily continued by the
+Scot, Matthew Baillie (1761-1823), nephew, pupil, and heir of William
+Hunter (p. 165). Baillie was a successful London practitioner. He
+followed a new and convenient method in arranging his work according to
+organs instead of by symptoms, as Morgagni had done. Baillie performed
+post-mortem examinations on several men of eminence, among them Dr.
+Johnson, whose lung he describes (see Fig. 78).
+
+The task of naked-eye pathological anatomy, effectively begun by
+Morgagni, was effectively completed by Karl Rokitansky of Vienna
+(1804-78). His work (1842-6) was based on an experience extending
+over 30,000 post-mortems! Though disfigured by a bizarre theory,
+it left but few gaps for subsequent workers. From now on, the
+science of Pathology was to be prosecuted in a new spirit and with
+new instruments. Even in his own day Rokitansky was something of an
+anachronism, with his pure naked-eye anatomy hardly ever involving
+experimental evidence on the one hand or the findings of the microscope
+on the other.
+
+[Illustration:
+
+FIG. 78. PART OF THE LUNG OF DR. SAMUEL JOHNSON, from a drawing
+published by Matthew Baillie. Johnson was a fat, unwieldy man, with
+a great barrel chest, who suffered for many years from shortness of
+breath. These are common associations with the pathological condition
+known as _Emphysema_, in which the lungs, which are normally of fine
+spongy texture, become full of abnormally large cavities, so that, as
+Baillie remarks, they come ‘to resemble the air cells of the lungs of
+amphibious animals’ (cf. Fig. 45, p. 116). In the figure B represents
+the external part of the lung and A its cut surface. On the cut surface
+the large cellular structure can be seen. The very dark points are the
+orifices of cut branches of the pulmonary vessels.
+
+]
+
+
+§ 7. _Clinical Methods and Instruments._
+
+The great teachers of the earlier eighteenth century, though better
+equipped as regards knowledge than their predecessors, had hardly any
+better means of diagnosis. Pulse-measurers and thermometers such as
+those of Sanctorius and Galileo (p. 109) had proved impracticable by
+the bedside. The microscope had not yet entered into Clinical Medicine.
+Chemical analysis as applied to disease had proved, as yet, of little
+value.
+
+The first efficient instrument of precision to merit clinical
+adoption was the ‘pulse watch’, by Sir John Floyer (1649-1734), an
+English provincial physician. It was introduced as early as 1707 as a
+‘Physician’s Pulse Watch’ and was an instrument constructed to go for
+just one minute. At that time the making of a twenty-four hours watch
+with a seconds-hand presented great mechanical difficulties. Floyer’s
+invention was not widely adopted at the time. Attempts were also made
+to introduce a thermometer into practice, but again the construction of
+suitable instruments proved impossible.
+
+Effective pulse watches and clinical thermometers did not penetrate
+into the general practice of Medicine till well into the nineteenth
+century. Two instrumental advances of first-class importance to
+Medicine were, however, introduced during the later eighteenth century.
+These were the methods of Percussion and Stethoscopy.
+
+Percussion of the surface of the body yields notes of varying degrees
+of resonance. Its application has proved of great value to the
+physician in outlining the position of the organs and of lesions,
+especially those of the chest. It was invented by Leopold Auenbrugger
+(1722-1809), a Viennese physician who first introduced it in 1761. Like
+the thermometer, it was very slow in entering the general practice of
+Medicine.
+
+Auenbrugger deserves great credit for his invention, but he did not
+work out its application with anything like the completeness that
+the Breton physician, René Théophile Hyacinthe Laënnec (1781-1826),
+applied to his ‘stethoscope’ (1819). Laënnec’s instrument was of the
+uni-tubular type that is now seldom seen. At first, indeed, he used a
+mere roll of paper. His idea was rapidly diffused into every country.
+
+But Laënnec did far more than introduce a useful and convenient device
+into Medicine. He explored with extraordinary skill the physical signs
+in the chest which correspond to a large number of diseases. The major
+part of our chest-lore and much of the technique and nomenclature of
+chest examination come direct from him. Despite continual bad health
+and the shortness of his life, Laënnec’s brilliance and devotion to
+duty at a hospital in Paris enabled him to transmit his views and
+methods to many other physicians, both French and foreign. He is
+unquestionably among the greatest physicians of all time. Clinical
+medicine assumes with him a completely modern aspect. In reading his
+work one feels that, had he been called in consultation by a medical
+man of our own day, the two would have been able to understand each
+other perfectly, after only a little adjustment and explanation.
+
+[Illustration: FIGS. 79-82. LAËNNEC’S WOODEN STETHOSCOPE, from his work
+of 1819, _On Instrumental Auscultation_.
+
+FIG. 79 is the complete instrument.
+
+FIG. 80 is the instrument in section.
+
+FIG. 81 is the ear-piece unscrewed.
+
+FIG. 82 is the detachable chest-piece terminating in a thin metal tube.
+
+]
+
+
+§ 8. _Surgery and Obstetrics._
+
+During the eighteenth century the improved knowledge of Normal and
+Pathological Anatomy was a great aid to the surgeon. The technique of
+Surgery was certainly improved. Operations were now being performed
+with success that could not before have been attempted. Nevertheless
+few important new principles were introduced until long after the
+nineteenth century had dawned. It is indeed probable that as a means
+of life-saving Surgery had an almost inappreciable effect on vital
+statistics until the advent of Anaesthesia and Antiseptics. Even the
+greatest surgeon of the eighteenth century, John Hunter, introduced no
+fundamental new surgical principles. True, the names of many surgeons
+of the period have become associated with operations invented or
+introduced by them, but it was not till after the advent of antiseptic
+methods that these were practised with full success. There are but two
+surgical matters in which advances of great significance can be said to
+have been made. These were the treatment of Venereal Disease and the
+treatment of Labor.
+
+Syphilis, which existed in Europe in the later Middle Ages, had
+usually been confused with Leprosy and other conditions (p. 98). Its
+treatment by Mercury had been practised at least as early as the
+fifteenth century, perhaps as an inheritance from the Arabic-speaking
+physicians. During the sixteenth and seventeenth centuries various
+other remedies were tried (Fig. 33); much quackery arose around them.
+In the eighteenth century the accumulated experience of generations
+returned again to Mercury. Satisfactory methods of administration were
+evolved and the treatment became standardized. It hardly changed until
+the twentieth century.
+
+[Illustration:
+
+FIG. 83. LYING-IN SCENE in the sixteenth century from a contemporary
+work on midwifery. Drinking and feasting is going on in the room where,
+in addition to the patient, there are two men, five women, and two
+children. A dog chews a bone on the floor, cooking is in progress in
+the adjoining room. Food and drink is being forced on the unfortunate
+patient herself. The whole scene, which is intended to portray an
+upper-class household, suggests carousal, disorder, and dirt, as well
+as ignorance of the most elementary principles of hygiene.
+
+]
+
+The treatment and care of women in Labor made considerable progress
+during the period of which we are treating. We have seen how there were
+advances even during the sixteenth century (p. 93) by such a writer as
+Paré. Works on obstetrics intended for women were often printed in the
+sixteenth century in France, England and Germany. Scientific obstetric
+
+works were produced especially in France in the second half of
+the seventeenth century. The obstetric forceps was known, but was
+still a family secret. At the time and for long after, there was a
+great objection on the part of pregnant women to treatment by men.
+The midwives were for the most part ignorant, dirty, unskilful and
+superstitious, and the loss of life and health that resulted from
+their mishandling was enormous. The objection to the ‘man midwife’ was
+only gradually overcome, though his advent was unquestionably attended
+by a fall in the mortality. About the middle of the eighteenth century,
+moreover, the obstetric forceps came into wider use. One of the ablest
+and most successful of the obstetric physicians was William Hunter
+(1718-83), the brother of John Hunter.
+
+[Illustration: Early obstetric instruments.
+
+FIG. 84 is the very dangerous and brutal _Speculum matricis_ used to
+force open the mouth of the womb in cases of difficult labor. A similar
+instrument has been used since antiquity to dilate wounds.
+
+FIG. 85 is an even more terrible and powerful instrument, the
+_Apertorium_, provided with a sharp edge by means of which the mouth of
+the womb was violently cut or torn.
+
+In the seventeenth century less heroic measures began to be used, and
+the obstetric forceps was introduced.
+
+FIG. 86 shows a pair of obstetric forceps as used in the seventeenth
+century. The instrument is the direct ancestor of that now in use,
+which, however, is a vast improvement upon it. The obstetric forceps
+was invented by a member of an hereditary family of man midwives, at
+the beginning of the seventeenth century. The nature of the instrument
+was long kept a secret. This particular instrument was found by
+accident in 1813, having been hidden under the floor by a member of the
+family of the inventor.
+
+]
+
+Despite the absence of any great new principle in the surgery of the
+period, there can be no doubt that a new spirit was introduced by
+John Hunter (1728-93). His complex and interesting character demands
+better treatment than it has yet received. As an investigator his
+powers were superb, but, like Leonardo, he was handicapped at every
+turn by literary incoherence. Nevertheless, with him Surgery begins
+to appear, at last, as a real Science and not as a mere applied Art.
+Hunter brought to bear on the subject a mind stored with ideas drawn
+from Comparative Anatomy and Pathology. Quick to detect analogy, shrewd
+in his scientific judgments, tireless and unsparing of himself in his
+pursuit of truth, a victim of disease self-inflicted in the service of
+science to which he was tragically a martyr in his death, he shows as
+a heroic figure, rendered no less heroic by some very human failings.
+Fully to appreciate so incoherent a writer, it is unfortunately
+necessary to wade through many works written in his own clumsy and
+ill-arranged manner. To gain any real idea of this great personality we
+must consult the writings of his contemporary colleagues.
+
+So far as actual advances are concerned, two may be connected with
+Hunter’s name. Firstly, in the treatment of the deadly condition known
+as ‘Aneurysm’ he introduced a method of operation which is still in
+vogue. Secondly, he enormously improved the method of making and
+ordering a museum. His monument is the Hunterian Museum in London,
+based on his specimens of which many may still be seen there. The
+museums of Natural History, as now constituted in all civilized
+countries, have been influenced by, if they have not been derived from,
+that which he literally gave his life’s blood to found. He was right
+when he said musingly in his illness, ‘You will not easily find another
+John Hunter.’
+
+[Illustration:
+
+FIG. 87. JOHN HUNTER’S COUNTRY HOUSE at Earl’s Court, Kensington,
+before its demolition in 1886. This house was in the country in
+Hunter’s day, though its site is now a busy part of London. For many
+years he used it as a laboratory and menagerie, and much of his best
+work was done there.
+
+]
+
+
+§ 9. _The Beginnings of the Science of Vital Statistics._
+
+Attempts to combat widespread disease and to improve the public
+health are to be found in the history of all civilizations, both
+ancient and modern. Nevertheless, the rational method cannot come into
+operation until it has exact data upon which to work. Such data may
+be numerically expressed, a fact first appreciated by the versatile
+English physician and inventor, Sir William Petty (1623-87), who is
+usually regarded as the father of the science of Political Economy. In
+1662, and on many subsequent occasions, he joined a friend in issuing
+_Natural and Political Observations upon the Bills of Mortality_ of
+London. In this work he endeavored to deduce population, death-rates,
+disease prevalence, and other matters of vital statistics from the
+crude figures of the day. He was fully aware of the imperfection of his
+materials, and on this account he urged the necessity of providing a
+system and a government department for the collection of trustworthy
+statistics. In his _Political Arithmetick_ (1683), the basic work of
+modern Economics, he displays ideas of a very modern character. Among
+these is his view that the true wealth of a country is to be sought in
+its efficient man power.
+
+A number of Petty’s fellow members of the Royal Society began to take
+interest in statistics. Chief among these was Edmund Halley, the
+astronomer (1656-1742). Toward the end of the century (1693) Halley
+produced a mass of statistics on the chances of life at various ages,
+designed for the estimation of the price of annuities. During the
+eighteenth century numerous writers devoted themselves to similar
+investigations. An important contributor to the mathematical basis
+of vital statistics was the French Huguenot and friend of Newton,
+Abraham de Moivre (1667-1754). His _Doctrine of Chances_ (1715) and
+his _Annuities upon Lives_ (1725) are important contributions to the
+subject. His celebrated hypothesis that among a body of persons over
+a certain age the successive annual decrease by death may be esteemed
+as nearly equal (that ‘the decrements of life are in arithmetical
+progression’) was under discussion for a century, but is now accepted.
+
+In 1761 a Prussian clergyman, J. P. Süssmilch (1707-82), produced an
+extraordinary theological work, _The Divine Ordinance manifested in the
+Human Race through Birth, Death, and Propagation_. Its object was to
+exhibit God’s design in the constancy of the numerical relationships
+of vital statistics. Despite the motive--somewhat unpromising for a
+scientific treatise--the work is of great historic and scientific
+importance, for it was based upon a vast mass of statistics and showed
+a great advance in method. It stressed the importance of accurate data
+and the necessity for numerous observations, if reliable conclusions
+were to be drawn. From the time of the publication of the work of
+Süssmilch, the statistical study of population advanced rapidly. The
+basis of statistics was greatly improved by the introduction of the
+census system which was put into action in England in 1801.
+
+The science of vital statistics was placed on a firm foundation by the
+Belgian astronomer Lambert Quetelet (1796-1874). His principal work,
+_On Man and on the Development of his Faculties, An Essay on Social
+Physics_, contains an account of his statistical researches on the
+development of the physical and intellectual qualities of man and on
+the ‘average man’ both physically and intellectually considered. He
+followed this in 1848 by his treatise, _On the Social System and the
+Laws which govern it_. In it he shows how the numbers representing the
+individual qualities of man may be grouped round the numbers referring
+to the average man in a way corresponding to the principles of the
+theory of probabilities. This conception, elaborated and further
+analyzed, has formed the basis of all subsequent researches in vital
+statistics.
+
+
+§ 10. _Military, Naval, and Prison Medicine._
+
+The eighteenth century saw some of Petty’s principles put into
+practice. There was, as yet, but one section of public life in which
+scientific principles of preventive medicine could be applied. Only
+in the Army and Navy were the sufferers from disease under adequate
+control and observation, and only there were proper statistics of
+sickness and health available. Thus, many of the most important
+movements in Preventive Medicine during the eighteenth century, both
+in England and other countries, were initiated by naval and military
+surgeons.
+
+Among military medical reformers an important place is taken by a
+Scottish pupil of Boerhaave, Sir John Pringle (1707-82). He had a large
+military experience in the British army, occupied a position of great
+influence, and was able to get many of his views and reforms generally
+accepted. Pringle was among the first to see the importance of ordinary
+putrefactive processes in the production of disease, and quite the
+first to apply these principles in hospitals and camps. Important
+conclusions on these matters were published in his _Experiments upon
+Septic and Antiseptic Substances, with Remarks relating to their Use
+in the Theory of Medicine_, which appeared in 1750. He identified
+‘gaol fever’ or typhus with ‘hospital fever’. He laid down important
+rules for the hygiene of camps which involved avoidance of marshes,
+proper drainage, and adequate latrines. His most permanent service
+was probably his suggestion that army hospitals should be regarded
+as neutral, and be mutually protected by belligerents. This great
+physician is a good illustration of the ‘new humanity’ which came into
+public life in the eighteenth century. In much of that movement one may
+feel the influence of that most humane of physicians, Hermann Boerhaave
+(pp. 140-1).
+
+Hardly less important than the work of Pringle for the Army was that
+of his brother Scot, James Lind (1716-94), for the Navy. Lind was a
+pupil’s pupil of Boerhaave. He had a long naval experience and in 1753
+wrote an important work on Scurvy, then a very common and fatal disease
+at sea. He demonstrated how this might be prevented by the adequate use
+of fresh fruit or, when this was not available, of lemon juice. Fresh
+water had always been a difficulty of sea voyages. Lind arranged for
+sea-water to be distilled for the purpose. He introduced rules for the
+prevention of typhus on ships, and made great improvements in naval
+hygiene. His essay of 1757 _On the most effectual means of preserving
+the Health of Seamen_ is a classic. He also wrote an important _Essay
+on Diseases of Europeans in Hot Climates_, which opened the campaign
+for the conquest of the tropics (p. 270).
+
+Lind, like Pringle, is one of a type that is very fully represented
+in the eighteenth century. A worthy representative of that school
+was Captain James Cook (1728-79), the explorer, who adopted Lind’s
+principles. He established a record in one of his voyages to the South
+Seas. The voyage lasted three and a half years, and many hardships had
+to be endured, but out of 118 men only one died, and he was consumptive
+when he embarked from England. Of a different type was the Manchester
+health reformer, Thomas Percival (1740-1804), who worked to introduce
+the reforms of Pringle and Lind into civilian life. The work of
+Percival leads on naturally to Southwood Smith and Chadwick (pp. 193-5).
+
+The eighteenth century was essentially a period of individual effort.
+The time was not yet ripe for public action on a large scale in
+matters of Hygiene. Pringle, Lind, and Percival had, however, their
+humanitarian parallels among prison reformers. Scientific attempts to
+improve the ventilation and sanitation of prisons had been instituted
+by the Rev. Stephen Hales (pp. 146-7). None brought greater devotion
+to the task than John Howard (1726-90), a native of London who spent
+his vigorous powers in investigating the prison system. His researches
+extended to the hospital, quarantine and prison systems of France,
+Flanders, Holland, Germany, Italy, Greece and Turkey (Fig. 88). His
+reports were directly instrumental in the improvement of the hygiene
+both of prisons and hospitals, as well as in the institution of
+special fever hospitals in many countries. Some aspects of Howard’s
+work were carried on by the great Quaker philanthropist Elizabeth Fry
+(1780-1845), others came within the field of activity of Southwood
+Smith and Chadwick (pp. 193-5).
+
+The eighteenth-century humanitarian movement was active and had many
+able representatives in the United States. Foremost among them was
+Benjamin Franklin (1706-90), while in the ranks of Medicine none takes
+a higher place than Benjamin Rush of Philadelphia (1745-1813). Rush
+was particularly revolted by public punishments, to the abolition of
+which he devoted much energy. In matters of Hygiene Rush was ahead of
+his time. He wrote on the hygiene of troops and laid special stress
+on fresh air and cleanliness of body and mind as an aid to health. He
+had a peculiar horror and repulsion for alcoholic intemperance. He
+was responsible for the first systematic work on insanity published
+in America. He left a fine account of a Yellow Fever epidemic at
+Philadelphia, and he approached the truth in his view that the disease
+arose in Philadelphia itself and was not brought as an infection from
+without.
+
+[Illustration: FIG. 88. AN EIGHTEENTH-CENTURY QUARANTINE STATION
+(Naples).
+
+From John Howard’s _An Account of the principal Lazarettos in Europe_,
+Warrington, 1789.]
+
+
+§ 11. _The Industrial Revolution._
+
+During the eighteenth century the character of English civilization
+became modified by a factor which has since profoundly influenced all
+civilized countries. There was a rapid increase in the number and size
+of the towns. The main cause of this was the transformation of Industry
+by the use of mechanical power. The change that resulted in the life
+and outlook of the people was very profound. These changes and the
+causes that gave rise to them are usually spoken of as the ‘Industrial
+Revolution’. That revolution had effects that were both wider and
+deeper than followed any other such single upheaval in history. With
+the mechanical elements that were at the back of the Industrial
+Revolution, such as the improvements in transport, the invention of
+industrial machinery (Fig. 90), the enclosure of common land, the new
+position of agriculture, we are not here directly concerned. What does
+affect our story is the increasing urbanization of the population,
+which began early in the eighteenth century, increased rapidly soon
+after the middle of the eighteenth century, and has progressed
+continuously ever since. In this matter England is but a type,
+for all other civilized countries followed in her wake, though at a
+somewhat later date.
+
+Along with the growth of towns and the increased population there was
+an increased demand for food. The country became better cultivated and
+better drained, and there were many improvements in agriculture. Thus,
+certain diseases began to diminish, notably Malaria, essentially a
+disease of undrained and ill-cultivated lands. The expulsion of this
+disease, as of Typhus, was the work of the nineteenth century (p. 283).
+
+It is often assumed that the physical evils of life became accentuated
+by the rise of the great towns. Nevertheless, investigation shows
+that the opposite has been the case. During the eighteenth century
+men and women began to crowd into the great towns from the country.
+They were, in fact, right in their choice, for their chances of life
+there were greater than upon the land. In the rural districts infamous
+housing conditions, an overcrowding beyond anything which we now
+encounter, exposure to weather, uncertainty and fluctuation in the
+prices of commodities, low wages, unpassability of roads in winter
+time, inaccessibility of medical aids, combined to render life, and
+especially child life, more precarious than in urban areas.
+
+[Illustration:
+
+FIGS. 89 and 90 illustrate the passage of the textile trade from home
+industry to factory work with the consequent break-up of the family as
+the labor unit. Textiles were the first important articles of commerce
+to be thus affected, but others rapidly followed. The pictures are
+typical of the Industrial Revolution.
+
+]
+
+The improvement of hygienic conditions in the towns began in England
+soon after the middle of the eighteenth century. Westminster obtained
+an Improvement Act in 1762, Birmingham in 1765, the City of London in
+1766, Manchester in 1776, and most of the other provincial towns soon
+followed. As a result of such Acts noisome streams which were but open
+drains were covered in, the streets were paved and lighted, and the
+sewers improved. There were still many glaring defects of sanitation
+which have occupied and still occupy reformers, but by the end of the
+eighteenth century the general appearance of a street in one of the
+more advanced cities was much what it now is. The change from the
+medieval conditions of a century before was at least as great as the
+changes that have since taken place.
+
+[Illustration:
+
+FIG. 91 shows how the population of England and Wales started to
+increase rapidly about 1750, with the beginning of the Industrial
+Revolution. The chart covers a period in which statistics were not
+exact. The figures for it have had to be estimated, but they are
+probably accurate as round numbers. The census returns are available
+from 1801.
+
+]
+
+[Illustration:
+
+                                                             1910-12
+  _Age_  1730-9 1740-9 1750-9 1760-9 1770-9 1780-9 1790-9 _Males_ _Females_
+   10      36·9   37·0   37·3   36·9   36·7   37·5   38·2    --        --
+   20      29·1   28·9   29·2   29·3   29·4   29·9   28·4   42·35     46·71
+   30      23·7   23·5   23·8   24·1   24·1   24·9   24·4   33·87     37·94
+   40      19·6   19·2   19·4   19·6   19·5   19·5   19·5   26·03     29·67
+   50      16·1   15·8   15·7   16·1   15·9   15·7   15·8   19·09     22·17
+   60      12·2   12·4   12·1   11·9   11·9   12·0   11·9   13·09     15·39
+   70       9·4    8·6    8·7    8·5    8·3    8·7    8·5    8·17      9·57
+   80       5·9    5·7    5·7    5·7    5·7    6·3    6·2    4·79      5·39
+
+Showing the expectations of life in London for each decade from
+1730-1800, with recent data for comparison.
+
+  _Age_ 1730-9 1740-9 1750-9 1760-9 1770-9 1780-9 1790-9 1911-12
+  10-20    6·5    5·9    5·9    7·1    8·2    7·1    6·5      --
+  20-30   17·5   17·6   17·2   17·9   17·3   16·4   15·1     3·7
+  30-40   27·1   26·3   26·1   25·2   25·0   23·9   23·7     6·2
+  40-50   36·6   38·6   35·9   36·3   35·5   35·4   34·3    11·7
+  50-60   45·5   47·9   45·7   42·1   45·0   44·7   44·6    21·1
+  60-70   61·4   63·4   63·7   64·4   62·8   64·7   64·1    40·3
+  70-80   83·7   98·3   96·4  101·8  105·0  101·7  104·4    87·3
+  80-90  143·1  150·4  151·0  153·0  152·7  153·0  155·1   181·9
+
+Showing the death-rates at Age groups in London for each decade from
+1730-1800, with recent data for comparison.
+
+FIG. 91A. TABLES showing that vital conditions in the eighteenth
+century did not deteriorate but improved with the Industrial
+Revolution. ]
+
+But if the streets had improved there was much under and around them
+which would horrify us now. Water-supply, as in London, was usually
+drawn mainly from surface wells and rivers. In most towns a continuous
+water-supply was unknown. Even when water mains existed, the supply
+to the houses was limited. Thus, even in the early nineteenth century
+London houses had a water-supply only three times a week, and then only
+for a few hours at a time. The water mains were often defective, and
+there was not always that clear distinction between a water main and a
+sewer that we now regard as desirable. Floods were a constant trouble
+in all riverside towns. Cesspools were in use even in London as late as
+the middle of the nineteenth century, and water-closets did not become
+general, even in the better houses, until about 1828. The methods of
+disposal of sewage hardly bear relation. In London the sewage simply
+polluted the rivers.
+
+The improvement of such conditions as these could only be made by State
+action. The eighteenth century did well where individual activity
+was concerned. It was reserved for Southwood Smith (p. 193) and
+Chadwick (p. 194) to introduce into the sphere of practical political
+action the truth, set forth by Bentham (pp. 190-2), that all factors
+which influence the health of the country must be the concern of the
+Legislature.
+
+We gladly pass from this darker picture to the Hospital and Dispensary
+Movement which took its rise about the middle of the eighteenth
+century. Many of the great hospitals both in England and in Continental
+countries were either founded or rebuilt about this time. Thus, the
+London Hospital was rebuilt in 1752, St. Bartholomew’s in 1730-53.
+Between 1700 and
+
+1825 no less than 154 hospitals and dispensaries were founded in
+the British Isles. Though defective from the modern point of view,
+yet under the influence of the sanitary reformers, Hales (p. 146),
+Pringle (p. 169), Lind (p. 170), and Percival (pp. 170-1), these were
+incomparably better equipped, better ventilated and better found than
+such institutions would have been at the beginning of the eighteenth
+century. The notes of the industrious Howard (p. 171) give us a very
+complete picture of them, and one that is more favorable than might,
+perhaps, have been expected.
+
+A defect of the hospitals of the time was certainly the nursing.
+This, however, was somewhat better in the Lying-in-Hospitals, where
+the services of a higher type of woman were available and where
+ladies served on the committee of management. The general state of
+the hospitals remained much the same until transformed by the changes
+in surgery and nursing in the second half of the nineteenth century,
+though a number of special fever hospitals and pest-houses were
+established.
+
+Something must be said of the more prevalent diseases of the Industrial
+Revolution. Stress is often laid on the effect of urban conditions
+on child life. Yet there can be little doubt that historically the
+movement has been beneficial to it. This comes out well in the
+death-rates. Thus, in England in the period around 1740, before the
+industrial revolution had begun, about 75 per cent. of children born
+died before the age of five. In the period around 1800, when the
+industrial revolution had set in, the percentage of deaths had fallen
+to about 41. In the period 1915-24 it was about 14. Among the most
+characteristic diseases of children is Rickets. It is very difficult
+to trace the early history of this disease, but its incidence seems
+to have been very high about 1700, and to have fallen progressively
+throughout the eighteenth century. This fall, it has been suggested,
+was due to agricultural improvements which led to better supplies of
+better-fed meat. It was these improvements and better supplies that, in
+their turn, made the big towns possible.
+
+We have already spoken of Scurvy on ships. It was, however, well known
+on land, especially in winter when green vegetables were not to be
+had. Lind (p. 170) in 1753 found it common in the land population. The
+advances in agriculture removed it altogether from the land diseases
+during the eighteenth century.
+
+[Illustration: FIG. 92. ST. BARTHOLOMEW’S HOSPITAL AT SMITHFIELD,
+LONDON, in 1720.]
+
+[Illustration: FIG. 93. A VIEW OF THE PEST HOUSE in Tothill Fields,
+London, in 1796. From a print in the British Museum.]
+
+§ 12. _Control and Recognition of Epidemic Diseases._
+
+Over one department of public health there was State supervision
+during the eighteenth century. The ports were guarded against the
+introduction of Epidemic Diseases, and especially against Plague.
+Throughout the eighteenth and early nineteenth century there was Plague
+in the Near East which extended at times to various parts of Europe.
+It was epidemic in Russia in 1709 and some 150,000 died of it. In 1719
+it spread to Eastern Central Europe. One historic outbreak was at
+Marseilles and Toulon in 1720, when 90,000 died. The outbreak caused
+great alarm in England, but did not reach this country, nor has there
+since been any outbreak here. Quarantine is now regarded as antiquated,
+vexatious, inhumane, expensive, and ineffectual. It seems probable,
+however, that during the eighteenth century, when drastically enforced,
+as in France with the Marseilles epidemic, it had indeed the effect
+of keeping the disease within bounds. Incidentally, it led to the
+foundation of many plague hospitals or Lazarettos, of the conduct of
+some of which Howard (p. 171 and Fig. 88) speaks well.
+
+During the eighteenth century Small-pox was never absent from this
+country. From time to time the disease became epidemic, and there
+were grave and fatal outbreaks. Thus, in 1774 there was an outbreak
+of small-pox at Chester. Next year an investigation was made of the
+degree to which the population had suffered. It was then found that
+before the outbreak there were in Chester only 15 per cent. who had
+not already had the disease. The incidence on those unprotected by a
+previous attack was 53 per cent., with a death-rate of about 17 per
+cent. of those actually infected and of about 9 per cent. of the entire
+unprotected population.
+
+With the certainty of contracting small-pox before their eyes, men
+sought a way of getting it in a mild form. Outbreaks of small-pox
+varied greatly in virulence, and infection with a mild form would
+lead to protection from a graver one. In the East a method of direct
+inoculation of the disease from a patient suffering from a slight
+attack was widely in vogue from an early date. The practice attracted
+little attention in Europe until Lady Mary Wortley Montagu (1689-1762)
+studied it at Constantinople. It was then soon taken up in England, and
+became recognized on the Continent.
+
+The efforts of Lady Mary in England were reflected on the other side of
+the Atlantic. The famous Puritan leaders, Increase Mather (1639-1723)
+and Cotton Mather (1663-1728), turning from their exploits against
+the witches, ardently urged the operation. In England the learned
+Dr. Richard Mead (1673-1754), an eminent and far-seeing physician
+who exercised very great influence on the medical world in his day,
+published in 1747 a work in which he supported the practice of
+inoculation with all the weight of his authority. During the subsequent
+half-century the practice spread widely. The operation was largely in
+the hands of specialists who were not always medical men.
+
+Such was the state of affairs when the country practitioner Edward
+Jenner (1749-1823) came upon the scene. In 1796 a dairymaid became
+infected with a disease of the udders of cows, distantly resembling
+small-pox. She developed pustules on her hand. Jenner inserted a
+little of the matter from one of these into the arm of a boy of eight,
+who developed typical cow-pox. Jenner next inoculated this boy with
+small-pox, which, however, failed to develop. The evidence, so far as
+it went, was complete. It is an entire justification of what might seem
+nowadays to be a reckless experiment, that at that time inoculation
+of small-pox was a normal and effective defensive procedure. The
+disease of cows has since become known as Vaccinia, and the process of
+inoculating it as _Vaccination_.
+
+[Illustration:
+
+FIG. 94. HAND OF DAIRYMAID infected with cow-pox from a cow’s udder.
+From Edward Jenner, _Inquiry into the Causes and Effects of the
+Variolae vaccinae, a Disease discovered in some of the Western Counties
+of England, particularly Gloucestershire, and known by the name of the
+Cow Pox_, London, 1798.
+
+]
+
+The discovery of vaccination, important though it be, is a mere
+trifle compared to the train of new work and new thought that has
+been opened out by it. The whole study of Immunity, which has now
+become an independent science, arises from it. The work of Pasteur (p.
+225), Lister (p. 239), and Koch (p. 234), and a large part of modern
+therapy, are among the achievements of this movement.
+
+Besides Plague and Small-pox, many other epidemic diseases became more
+clearly understood during the period we are considering. Among these
+was Scarlet Fever, the history of which is particularly interesting
+for the variations which it has shown in virulence. It first became
+clearly recognizable as a mild disease without prominent symptoms about
+1650. Good observers in the half-century that followed considered it a
+new disease. In England it continued to be of little importance till
+about 1748, when it began to be associated with grave throat symptoms
+and to be confused with Diphtheria. This phase continued for about ten
+years. The virulence then dropped and the disease continued of slight
+consequence till 1785. It then grew virulent again and remained so till
+about 1808. The malignancy then fell again and remained low for about
+thirty years. It rose about 1837 and from then till 1884 it was one of
+the great killing diseases, especially of childhood. Since then, the
+mortality from it has steadily decreased.
+
+During most of its history Scarlet Fever has been liable to greater
+or less confusion with Diphtheria. The clinical distinction was first
+clearly made in 1826 by Pierre Bretonneau of Tours (1771-1862), who
+gave Diphtheria its present name. The same French physician performed
+the first successful tracheotomy in a case of Diphtheria. He is also
+known for pioneer work in the recognition of Typhoid Fever.
+
+
+
+
+VI
+
+PERIOD OF SCIENTIFIC SUBDIVISION
+
+(FROM ABOUT 1825 ONWARDS)
+
+
+§ 1. _Origins and Implications of Scientific Specialization._
+
+We have seen how the philosophy of Newton, with its implication, the
+Reign of Law, which is the Uniformity of Nature, has come to pervade
+scientific thought (p. 137). Now, before Newton as after him, there
+were certain natural divisions of scientific activity corresponding,
+in some degree, to the types and faculties of men. Since Science
+first began there have been Mathematicians, Biologists, Physical
+Experimenters, because in fact the particular powers which enable
+a man to reach distinction in one of these departments are of less
+value in the others. Until the period of which we are now to treat,
+investigators were accustomed to explore at large within these great
+departments. Such specialist professions as Actuarial Calculators,
+Economic Entomologists, Physical Chemists, or, in the department
+of Medicine, Medical Statisticians, Aural Surgeons, or Vaccine
+Therapists--familiar to us now--were unknown and undreamt of then. This
+subdivision is a new thing, and is a characteristic product of the
+period of which we have now to treat. The subdivisions, unlike those
+of old, are largely artificial. Thus, the Aural Surgeon who deals with
+the organ of hearing cannot be separated clearly by his training, his
+powers and faculties, his operative skill, nor even perhaps by his
+field of work, from the Stomatologist who deals with the mouth, or
+the Rhinologist who deals with the nose. Nevertheless these minute
+subdivisions are convenient and beneficent in medical as in other
+departments. The question of scientific specialization is so important
+and characteristic that we must examine it a little farther.
+
+It is often thought that, since no man can compass all knowledge,
+this scientific subdivision is merely an attempt to compass a part
+of that growing mass of knowledge which is becoming progressively
+less compassable in its entirety. The movement, however, both in
+origin and development, is less simple than this, for there never
+was a time when a man could know all that was known about his world.
+In this respect our own age is even as other ages. Were the view
+philosophically tenable--which it is not--that Science becomes yearly
+less comprehensible, our outlook would be gloomy indeed. For since
+there is no evidence of any increase in the mental capacity of the
+human race--at least in historic time--such a view would imply a
+progressive diminution in the number of those competent to treat any
+wide scientific area, and a corresponding progressive separation
+from each other of minds with scientific insight. Fortunately such
+conditions do not prevail; the view that they do is simply due to a
+gross, yet widespread, misconception of the nature of Science.
+
+Equally fallacious is the idea, which has become diffused by the
+existence of scientific specialization itself, that the progress of any
+science is to be measured by the mass of observations that its votaries
+have succeeded in accumulating. This is far from being the case. The
+advance of a science is measured by the degree with which it succeeds
+in bringing a multiplicity of observations under general laws. Judged
+by this standard, we should probably rate very highly, for example,
+the present state of what is called _Demography_, the study of the
+life conditions of communities, while we should rank much less highly,
+for example, the present state of the study of Aural Surgery. Yet, for
+one publication on Demography there must be many on Aural Surgery.
+In the one case, however, the accumulation of knowledge follows a
+well-directed and rational scheme. In the other it is prompted and
+occasioned by the immediate needs of individual sufferers. This must
+not be considered as derogatory to those whose task it is to treat
+the sufferers. The point is that the one department, of its nature,
+exhibits the rational spirit better than does the other.
+
+Since Rational Medicine is the subject that we treat here, we shall
+select for discussion those departments which best illustrate
+its spirit. This does not imply, and is not meant to imply, any
+belittlement of the less fortunate departments. On the contrary, the
+less any scientific department has succeeded in eliciting general laws,
+the more necessary it is that those most capable for the prosecution of
+such advance should devote their attention to that department. It may,
+indeed, reasonably be urged that a leading defect in our scientific
+organization is that men of scientific insight crowd to just those
+studies where their special powers have already been best exhibited.
+
+In previous chapters, dealing with more remote times, we have been able
+to place our facts in historic perspective. Despite the enormous mass
+of scientific literature dating from the seventeenth, eighteenth, and
+early nineteenth centuries, there is no real obstacle to selecting
+what is most important in it. True, it is beyond the power of any
+one student to examine all this literature at first hand, but it has
+been arranged and indexed, posterity has passed its verdict, and the
+historian can find his way through the thicket. It is also true that
+important advances are sometimes forgotten, as happened to Mayow’s
+discovery of Oxygen in the seventeenth century (pp. 126, 151), which
+was repeated by Priestley a hundred years later (p. 154). But the
+fact that we know of such neglected discoveries shows that, however
+unjust the fates may have been to Mayow, yet his influence has not been
+underestimated by later historians. The History of Science, therefore,
+can up to a certain point be written along the same lines as political
+or economic history.
+
+The face of affairs changes, however, when we pass into a period which
+differs for different topics, but may be roughly defined as beginning
+somewhere between about 1820 and about 1870. We then begin to encounter
+the very questions with which men of Science are occupied in our own
+time. Since many of these questions still remain unsettled, it is
+impossible for the historian to say with certainty which are the most
+fruitful lines of work. The most he can hope to do is to distinguish
+the most influential and stimulating thinkers and observers from those
+who have been less so, and to say something about the ideas with which
+the more important schools of thought were instinct.
+
+When we look into the origin of the system of specialization, whether
+in Medicine or in any other department of Science, we shall find
+certain philosophical tendencies at work of which the modern man of
+Science is the heir, though often the unconscious and sometimes the
+ungrateful and even the misunderstanding heir. Neither men of Science
+nor medical men are always philosophers, or at least not always
+consciously so. Nevertheless, they are as surely influenced by the
+streams of thought of their time as they are by their heredity and
+their physical environment. The general tendencies of Medicine in this
+or in any other age cannot be interpreted without some reference to
+the intellectual atmosphere in which it has arisen and in which it has
+flourished.
+
+The intellectual atmosphere in which scientific specialism arose was
+that of the so-called ‘Utilitarian Philosophy’. Many of the dicta
+of that school, which came into prominence toward the end of the
+eighteenth century, are still used as part of the language of men of
+Science and others. ‘The greatest happiness of the greatest number’
+is a formula launched upon our common speech by Joseph Priestley
+(1733-1804, p. 154). The pursuit of such happiness as the main object
+of human activity is taught by the ‘Utilitarian’ philosophy, a word
+coined by the English political and social thinker, Jeremy Bentham
+(1748-1832). To Bentham, the founder of that philosophy, we owe such
+useful additions to our language as ‘codification’ and ‘international’,
+and these, together with ‘utilitarian’, give us some clue to the
+character and mode of his thought. It is probable that no thinker had a
+larger share than Bentham in ushering in the era of the subdivision of
+the sciences.
+
+Bentham made a sustained attempt to draw a parallel between the
+physical and the social sciences, and this gave him a special
+influence over medical thinkers and especially over those that dealt
+with the public health. His pupil, John Stuart Mill (1806-73), speaks
+of his master’s mode of working as ‘the chemical method’. It is
+thus not remarkable that Bentham should exert a profound influence
+on Medicine, both directly and indirectly. The peculiarly logical,
+uncompromising and perhaps un-English character of his mind, while it
+prevented him, fortunately for himself, from taking an active share in
+the task of government, did not prevent him from influencing those who
+did. Specifically, he is the direct begetter of our modern system of
+organization of the Science of Preventive Medicine.
+
+[Illustration:
+
+FIG. 95. A CARTOON OF THE EARLY NINETEENTH CENTURY illustrating the
+condition of children in the factories of the time. A bale is directed
+to Sir Robert Peel. This is the first Baronet (1750-1830), father of
+the statesman. Peel the elder was a cotton-spinner who imported from
+the London workhouses deserted children whom he treated well, but used
+to work his factories in Lancashire. He was a Member of Parliament
+and in 1802 carried the Act which was the forerunner of all factory
+legislation, _An Act for the Preservation of the Health and Morals of
+Apprentices and others, employed in Cotton and other Mills_.
+
+]
+
+
+§ 2. _The Revolution in Preventive Medicine._
+
+Of all the many changes in Medicine and Medical thought that the
+Period of Scientific Subdivision has witnessed, none have been
+more revolutionary than those in the department which deals with
+Preventive Medicine. Great and important reforms were introduced
+during the course of the eighteenth century. These, however, even
+when the result of legislation, were the outcome of the effort of
+individuals, or were concerned with the Army and Navy (p. 169). In the
+period that follows, the Public Health becomes a general political,
+legislative, and administrative matter, and ‘Prevention’ becomes its
+watchword. The public consciousness--moralists will call it the public
+_conscience_--had been aroused, and has never again entirely slept. The
+chief agent in the awakening process, the intellectual force at its
+back, was and is Jeremy Bentham.
+
+Rational Medicine has, in general, no national frontiers. To it men
+of all the national units have made important contributions. But the
+care of the Public Health in the period on which we now enter, being
+an affair of legislation and administration, has developed along
+national lines and it is difficult to discuss it save on a national
+basis. It is a source of justifiable national pride that Britain has,
+from the first and throughout, been the leader of the Public Health
+movement. But while we lose little and gain much by telling the story
+from the British point of view, it has still to be remembered that,
+just as Rational Medicine has, fortunately, no spiritual frontiers,
+so, unfortunately, sickness and suffering have no physical frontiers.
+Epidemics pass the most scientifically constructed boundaries upon the
+surface of the map, and without a passport. In our time this evident
+proposition has obtained, at least, formal recognition. International
+health legislation has at last appeared. A future historian of Rational
+Medicine will be able to write his chapter on the Public Health
+from the point of view of Humanity at large. The historian who has
+the misfortune to be born too early must still content himself with
+treating the subject along national lines.
+
+
+(a) _Preventive Medicine in Britain._
+
+If Bentham be the spiritual father of Public Health legislation, the
+protagonists whose names must be associated with the development of the
+movement along practical lines in England are Thomas Southwood Smith
+(1788-1861) and Edwin Chadwick (1800-90).
+
+Thomas Southwood Smith was a Unitarian minister, and long combined this
+office with that of physician. Settling in London in 1820 he came under
+the influence of Bentham. By his essay on _The Use of the Dead to the
+Living_ he did something to remove the odium attached to dissection.
+The scandals of the time and the common sense of the ‘utilitarians’
+(p. 190) led to the passing of the Anatomy Act of 1832. Thus by a
+proper legal process bodies became available for dissection by medical
+students. Bentham died just before this Act became law and by his will
+left his body to Southwood Smith to be the subject of dissection and
+of an anatomical lecture.
+
+Southwood Smith’s services to the spread of interest in Public Health
+were very numerous. He circulated a simple and popular _Philosophy of
+Health_ (1835). He served on a board of inquiry as to the condition
+of children in factories (1832, cp. Fig. 191), and he was especially
+useful to the Poor Law Commissioners by reason of his exceptional
+knowledge of fevers. He was the founder of a ‘Health of Towns
+Association’ (1840), and of another association for ‘improving the
+Dwellings of the Industrial Classes’ (1842). In 1848 he became a member
+of a new government department, the ‘General Board of Health’ (p. 195).
+His official reports on Quarantine (1845), Cholera (1850), Yellow Fever
+(1852), and on the results of sanitary improvement (1854), were of
+world-wide use.
+
+Edwin Chadwick (1800-90), who was not a medical man, introduced to
+public notice what he called the ‘sanitary idea’, a conception that
+colored the whole of his extraordinarily active life. He sat on
+Government Commissions on Poor Law, on Police, and on the investigation
+of the condition of factory children. One of his Reports (1833), issued
+while he and the century were both in the early thirties, recommended a
+system of inspection with a view to limiting children’s hours of work.
+The current system of pensions and of trade instruction to soldiers and
+sailors is the descendant of a scheme of Chadwick’s devising. An item
+in the evidence attached to one of his Reports is the public provision
+of open spaces for recreation, a topic of current interest at the
+moment of writing.
+
+At the time of the accession of Queen Victoria in 1837 Chadwick was
+agitating for the appointment of a Sanitary Commission. Two years
+later, as a result of a grave epidemical outbreak in London, the
+Commission was appointed. Its reports, which drew wide attention at
+the time, have had a large share in determining the general course of
+health legislation in the ninety years that have since elapsed. The
+scientific basis of health legislation can only be determined if proper
+vital statistics be available. The Registration Act of 1838, under
+a developed form of which we still live and die, was in essence his
+work. If we search into the history of any department of the scientific
+treatment of the Public Health, we shall always ultimately work back
+either to Southwood Smith or to Chadwick and through them to Bentham.
+
+Among the most important documents for which Chadwick was responsible
+was the _Parliamentary General Report on the Sanitary Condition of the
+Labouring Population of Great Britain_ (1842). It came to fruit in 1848
+with the _Public Health Act_, which established a new governmental
+department, the ‘General Board of Health’ (p. 196). The same year saw
+the passage of the _Nuisances Removal and Diseases Prevention Act_,
+by which summary action in such matters was rendered possible on the
+complaint of specially authorized local authorities. Just as the Board
+came into action there was an outbreak of Cholera in England, of which
+54,000 persons died. The statistics available under the new system made
+possible the deduction that the infection is conveyed by drinking-water
+and led to suitable precautions. This is one of the many instances in
+which the practice of prevention of a germ-borne disease preceded
+any knowledge of its organic cause, or indeed any direct knowledge of
+disease germs at all.
+
+The first town in England to appoint a Medical Officer of Health was
+Liverpool. The City of London followed in 1848, when Simon took office.
+After Southwood Smith and Chadwick, Sir John Simon (1816-1904) was the
+foremost figure in the history of the Public Health of this country. He
+later became medical officer to the ‘General Board of Health’. The work
+of this Board--together with its medical officer--was taken over, for
+political and administrative reasons, by the Privy Council. The medical
+department of the Privy Council became in 1871 part of the Local
+Government Board, the medical functions of which were absorbed by the
+new Ministry of Health in 1917.
+
+To Simon are due the abolition of urban cesspits and improvement of
+the system of sewers, and the institution of sanitary inspectors and
+legislation concerning housing and overcrowding. One important result
+of these measures was that it became possible to abandon the cruel and
+wasteful system of quarantine that had been of value in the eighteenth
+century. Simon’s plan, which was gradually adopted, was to trust to
+the same preventive methods for foreign as for native infections. This
+was, of course, only possible with an efficient sanitary service such
+as he succeeded in instituting. Such measures were aided by laboratory
+investigations, begun by a small staff. At first largely occupied
+with examinations in connection with actual outbreaks, its scientific
+functions rapidly grew. Working on a wider basis, these functions have
+been performed for the nation since 1911 under the direction of the
+Medical Research Council.
+
+[Illustration: FIG. 96. ANNUAL DEATH-RATE IN LONDON PER THOUSAND LIVING
+OVER A PERIOD OF 85 YEARS.
+
+It will be seen that the curve begins definitely to take a downward
+trend about 1870. It has been falling ever since. It is now less than
+half of what it was sixty years ago. This fall is largely, though
+not entirely, due to decrease in infant mortality. Some of the more
+important epidemics are indicated. Typhus disappears as an important
+cause of death in the forties and Cholera and Small-pox in the sixties.
+Since then the death-rate has been considerably influenced by Influenza
+outbreaks.
+
+]
+
+
+(b) _Preventive Medicine in the United States._
+
+In the United States the history of the national Public Health Service
+has been very different from that of the English system. The same
+philosophical tendencies have been at the basis of the American as of
+the English system. In the United States, however, the National Service
+has been linked with the Army and Navy in a manner quite foreign to
+British traditions. The Federal health system had its origin in the
+old Marine Hospital Service, first authorized by Congress in 1798.
+This enabled the President to appoint medical officers at ports and
+elsewhere for the purpose of giving medical treatment to disabled
+merchant seamen. The funds were obtained by a tax on those employed on
+American vessels.
+
+The first marine hospital under the Act was at Norfolk, Va., in 1800.
+In 1802 a marine hospital was built for the port of Boston, and from
+time to time hospitals were built at other important seaports. To
+provide for the relief of seamen on inland waters Congress passed in
+1837 an Act for the appointment of a board of advisory medical officers
+of the Army. A number of hospitals were established on its advice.
+
+The evolution of public health functions from this service was along
+natural lines. The medical officers, in providing care for the
+American merchant marine, were often the first physicians to diagnose
+such diseases as Cholera, Yellow Fever, Small-pox and the like,
+which were being imported into the United States. In the epidemics
+of Cholera which occurred in certain ports of the United States the
+marine hospitals and their medical officers were utilized for the
+relief of those suffering from the disease. During the Civil War the
+marine hospitals, together with the medical officers, were used by
+the military authorities, both North and South, for the care of the
+military forces.
+
+Not until 1878 did Congress authorize any extensive use of the Marine
+Hospital Service as a Federal Health Service. An Act of 1878 gave
+broad powers to the Service to co-operate with State and local health
+authorities in the control of disease, especially of Yellow Fever.
+In 1890 Congress decided to utilize the Marine Hospital Service as
+the Federal Health agency for the prevention of inter-State spread of
+Cholera, Yellow Fever, Small-pox and Plague. In 1893 the powers of
+the Marine Hospital Service in this regard were extended to cover all
+infectious and contagious diseases, in co-operation with State and
+local health agencies.
+
+The efficiency of the Marine Hospital Corps in the control of epidemic
+diseases became widely recognized. In 1889 Congress passed an Act which
+made possible the further organization of the Marine Hospital Corps,
+and provided that the officers be commissioned in grades similar to
+those of the medical department of the United States Army. An Act
+of 1875 had already provided that the Surgeon-General (supervising
+surgeon) should be appointed by the President, with the consent of the
+Senate.
+
+In 1893 the Marine Hospital Service was organized into the Federal
+Health Service. Congress continued to impose additional health
+functions upon the Service, and in 1902 changed its name to the ‘Public
+Health and Marine Hospital Service’ and made it a health service in
+name as well as function. The larger part of its duties, up to this
+time, had been the combating of epidemics, especially those of Yellow
+Fever, which from time to time swept the country. With the threat of
+Bubonic Plague in 1900 at San Francisco, the Marine Hospital Service
+was placed in charge of control methods and succeeded in preventing any
+extensive spread of the disease.
+
+In addition to the quarantine and hospital functions, the activities
+of the Service soon came to include research and educational work. In
+1902 Congress authorized the establishment of the Hygienic Laboratory
+for investigating Cholera, Yellow Fever, and other conditions.
+The Laboratory grew rapidly and is now a very important research
+institution, equipped for carrying on pathological, zoological,
+pharmacological, bacteriological, chemical, and physiological work.
+
+From the control of epidemics, the Public Health and Marine Hospital
+Service began to develop control measures for the more common
+contagious and infectious diseases, such as Typhoid Fever, Diphtheria,
+and Scarlet Fever. The history of the wonderful control of Typhoid
+Fever which has taken place in the United States within the past
+twenty years is a part of the history of the Public Health Service in
+co-operation with State and local health agencies. Typhoid fever, which
+formerly took a toll of more than 50,000 lives annually, is responsible
+for the death of a mere fraction of this number at the present day.
+
+The development of health functions of the Public Health and Marine
+Hospital Service continued until Congress in 1912 changed the name to
+its present one, the ‘United States Public Health Service’, and at the
+same time gave it broad powers to investigate the diseases of man and
+the pollution of navigable streams and lakes.
+
+During the courses of Federal development the separate States of the
+Union were not devoid of protagonists of State intervention in matters
+of public health. Among these was Lemuel Shattuck (1793-1859), who,
+like Chadwick, was no medical man, but a student of social problems.
+Under the influence of Chadwick he drafted in 1850 the _Report of
+the Massachusetts Sanitary Commission_. This publication set forth a
+complete scheme of Public Health organization. The formation of the
+first State Board of Health in Massachusetts was, however, delayed
+till 1869. In this matter Massachusetts was, in fact, anticipated by
+Louisiana, which obtained a State Board of Health in 1855, and by New
+York City, which obtained a Board of Health in 1866. Most of the States
+followed in the seventies. The seventies and eighties were the decades
+in which the general principles suggested by the work of Pasteur and
+Koch were put into effect. The working hypothesis of sanitarians
+of the time was that filth and ill-drainage were direct factors in
+the production of epidemic disease. The view is now untenable, but
+there was unquestionably an immense improvement in health conditions
+resulting both directly and indirectly from the improved drainage,
+water-supply, housing, and the like that the agitation had stimulated.
+
+As the bacteriological discoveries of the time became generally
+accepted, they were widely applied on American soil to the
+administrative control of disease, notably by the New York Department
+of Health under Hermann M. Biggs. That body, in 1892, instituted a
+bacteriological laboratory, the scope of which has steadily increased.
+Its work in connection with Diphtheria is elsewhere discussed (pp.
+265-6).
+
+To follow into our own time the development of factory legislation,
+vital statistics, school medical service, local health authorities,
+municipal laboratories and clinics, methods of food inspection, would
+be to write a text-book of Public Health Administration. In all these
+developments we see working the rational spirit in the peculiarly
+English field of Preventive Medicine. The spirit of Rational Medicine
+cannot function, however, without material upon which to work. The
+basis, the elementary matter, as it were, of that material, is the
+conception we form of the nature of the bodily processes. Such
+a conception it is the function of Physiology to provide and to
+Physiology we therefore now turn.
+
+[Illustration: FIG. 97. THE OLD _DREADNOUGHT_ HOSPITAL SHIP.
+
+A ‘Seamen’s Hospital Society’ was founded in England in 1817. Its first
+hospital was the _Grampus_, an old 50 gun ship moored off Greenwich.
+This was succeeded in 1830 by the _Dreadnought_, 104 guns, and this
+in 1857 by the _Caledonia_, 120 guns, renamed _Dreadnought_. In 1870
+this last wooden _Dreadnought_ was broken up and the patients were
+transferred to a building on shore close by. The darkness, damp,
+ill-ventilation, noisiness and septic character of a wooden ship made
+it thoroughly unsuitable for hospital purposes.
+
+In 1899 the ‘Seamen’s Hospital Society’ established a special Hospital
+and School for Tropical Diseases such as are peculiarly common among
+seamen. ]
+
+
+§ 3. _The Transition to a Physiological Synthesis._
+
+Modern developments in physiological knowledge introduce an important
+period in the History of Medicine, for the study of the functions of
+the body is a natural portal of entry to the study of the perversions
+and suspensions of those functions that we call disease. The general
+character of physiological thought during the modern period may perhaps
+be described as the ‘synthetic study of the animal body’. The study
+has become synthetic because organs have not been studied so much in
+and for themselves as in relation to other organs. There has been, in
+fact, during the period, an increasing consciousness of the integration
+of the organs into one organic whole, the entire process being under
+the control of the nervous system, the various parts of which are
+themselves integrated (p. 308). This movement has, to some extent,
+mitigated the ever growing evils of scientific specialization.
+
+
+(a) _Anatomy and Embryology in the Earlier Nineteenth Century._
+
+Let us first glance at the state of anatomical knowledge in the early
+and middle nineteenth century. The general structure of the animal body
+was well known. Descriptive Anatomy was not far from where it now is.
+Comparative Anatomy, which had made good progress, was given a fresh
+impetus by the researches and by the authority of a brilliant group of
+French investigators, headed by Baron Georges Cuvier (1769-1832), whose
+influence spread to England, Germany, and America, where the leading
+exponents were Richard Owen (1804-92), Karl Gegenbaur (1826-1903), and
+E. D. Cope (1840-97). Cuvier was a biological dictator whose opinion
+did much to encourage investigation, and something to discourage some
+important investigators. His services to Comparative Anatomy can hardly
+be overrated. There was, however, still no effective knowledge of the
+anatomical differences between the races of man, while the species of
+man and of allied forms, whose skeletons palaeontologists have since
+described, were quite unknown.
+
+As regards knowledge of the process of Development of the animal body,
+the broad lines of Embryology were being put on a firm basis by Karl
+Ernst von Baer (1792-1876), whose work was finished in 1837, though he
+lived another forty years. The subject was to be given a new meaning by
+the evolutionary school, which applied to new details and to particular
+instances the work of Charles Darwin (1809-82). Foremost of this school
+was Francis Maitland Balfour (1851-82).
+
+
+(b) _Chemical Physiology in the Earlier Nineteenth Century._
+
+The analysis of the functions and workings of the body had advanced far
+less than the knowledge of its structure. The study of Respiration was
+perhaps in the best position. The elementary conception of Respiration
+attained by Lavoisier at the end of the eighteenth century (p. 155)
+was hardly extended till E. F. W. Pflüger of Bonn (1829-1910), in
+the sixties and seventies of the nineteenth century, showed that the
+essential chemical changes of respiration do not occur in the blood or
+in the lungs, but in the tissues.
+
+A very important figure in the scientific world of the thirties and
+forties of the nineteenth century was the German Justus von Liebig
+(1803-73), professor of Chemistry at Giessen. He was a convinced
+mechanist, and over the door of the University Laboratory which he
+founded he had inscribed the dictum _God has ordered all His Creation
+by Weight and Measure_. His great achievement was his application of
+chemical knowledge to physiology. He did much to introduce laboratory
+teaching, and certain apparatus which he invented is still in constant
+use.
+
+Liebig greatly improved the methods of organic analysis and notably he
+introduced a method for determining the amount of urea in a solution.
+This substance is found in human blood and urine, and was the first
+organic compound to be ‘synthetized’, that is to say, built up from
+inorganic materials. It is of very great physiological importance.
+This is due to the fact that it is regularly formed in the body in the
+process of breaking down the characteristic nitrogenous substances
+known as proteins. Along with his colleague, Friedrich Wöhler
+(1800-82), who had already synthetized urea, Liebig wrote a famous
+paper (1832) in which he showed, for the first time, that a complex
+organic group of atoms--or ‘radicle’ as it is called--is capable of
+forming an unchanging constituent through a long series of compounds,
+behaving throughout as though it were an element. This discovery is of
+primary importance for our conceptions of the chemical changes in the
+living body.
+
+From 1838 onwards, Liebig devoted himself to attempting a chemical
+elucidation of living processes. In the course of his investigations
+he did pioneer work along many lines that have since become well
+recognized. He taught the true doctrine, then little recognized, that
+animal heat is the result of combustion, and is not ‘innate’ (compare
+p. 156). He classified articles of food with reference to the functions
+that he conceived they fulfilled in the animal economy. An outcome of
+this was his food for infants and his extract of meat. Very important
+was his teaching that plants derive the constituents of their food,
+their carbon and nitrogen, from the carbon dioxide and ammonia in the
+atmosphere, and that these compounds are returned by the plants to the
+atmosphere in the process of putrefaction. This discovery made possible
+a philosophical conception of a sort of ‘circulation’ in Nature. That
+which is broken down is constantly built up, to be later broken down
+again. Thus the wheel of Life goes on, the motor power being energy
+from without, derived ultimately from the heat of the sun.
+
+It was very unfortunate that Liebig conceived and adhered to a totally
+wrong view of the nature of putrefaction and fermentation, which it
+took Pasteur long years to displace.
+
+
+(c) _Nervous Physiology in the Earlier Nineteenth Century._
+
+From Chemical Physiology we turn to glance at the knowledge of the
+Nervous System. Charles Bell and his contemporaries (p. 145) had
+attained to a clear distinction of the nature of motor and sensory
+nerves and their separate origin from the two spinal roots (Fig.
+98). The next fundamental contribution was made by Marshall Hall
+(1790-1857), who established the difference between volitional action
+and unconscious reflex (1833).
+
+The fundamental ideas in the conception of reflex action had already
+been adumbrated by Descartes. In the view of that philosopher, any
+stimulus is transmitted along nerve-fibers to the central nervous
+system. There, on account of existing nervous connections, it gives
+rise to a fresh impulse which passes along outgoing nerve-fibers
+to the active organ, muscle, or gland, which is thereby excited to
+activity (p. 128). Thus, every action of the organism, and its life
+as a whole, conforms to definite laws. These laws must be directed
+to its preservation, or organisms would cease to exist. It is thus
+possible to look on organisms simply as elaborate mechanisms. Except
+that we know that we ourselves think and feel, we might eliminate mind
+from our consideration of the action of beings other than ourselves.
+Such was the view taken by the mechanists and other members of the
+iatro-physical school (pp. 127-131), which followed, to a greater or
+less extent, the teaching of Descartes. The course of physiological
+advance may be described, briefly, as the expulsion of the mental
+element from process after process associated with vital activity. This
+avenue leads on to a philosophical discussion whither we shall not now
+follow. It will suffice, at the moment, to remind the reader that only
+through the channel of _his own_ thinking and feeling is he able to
+follow these physiological discussions at all.
+
+The conceptions of Descartes and of his successors were greatly
+extended by Marshall Hall. Interest was lent to Hall’s work by the
+contemporary discovery by French observers of what was regarded as a
+special center governing respiration--a very important reflex--in the
+lower part of the brain. Hall’s work gave ‘reflex action’ a permanent
+place in Physiology.
+
+[Illustration: FIG. 98. DIAGRAM OF TRANSVERSE SECTION OF THE SPINAL
+CORD AND THE MAIN NERVES DERIVED FROM IT.]
+
+[Illustration: FIG. 99. DIAGRAM TO ILLUSTRATE SIMPLEST FORM OF REFLEX
+(cf. Fig. 98).
+
+An afferent impression from a sense organ to the spinal cord may give
+rise to an efferent impulse by a purely intra-spinal process. This
+impulse may be of the nature of a complex and balanced muscular act
+involving a whole system of muscles, some of which may be antagonistic
+to each other. All this may take place not only unconsciously, without
+any intervention from the higher nerve-centers in the brain, but even
+in an animal from which the brain has been removed. On the other hand,
+channels exist (and are indicated in the diagram) for passage of
+impressions to and impulses from higher centers. These higher centers
+in many cases control or modify the resulting muscular or other action
+to a greater or less degree.
+
+]
+
+Since Hall’s time there has been a great extension of the conception of
+reflexes. It has been shown that, besides the simple nervous arc (Fig.
+99), there are more complex nervous arcs which depend for their action
+on the integrity of an elaborate mechanism. The nervous system is
+‘integrated’ under higher and higher centers, till at last the highest
+centers of the brain are reached (pp. 308-11). Many of the ordinary
+acts of life, sneezing, coughing, standing, walking, even breathing,
+are expressible as reflexes. The attempt has also been made to press
+the ‘instincts’ into the same category. But it is difficult to separate
+the instinctive from the volitional elements or to define either. Vast,
+therefore, as is the development of this department of physiology, it
+is a very delicate task for the historian to pass any verdict upon it.
+The ultimate value of all this work must depend upon the conception
+that the next generation attaches to the mental element in vital
+phenomena. There is evidence of reaction at the present time from the
+extreme mechanist physiological position.
+
+Lastly, in the discussion of work on the nervous system comes the
+question of the localization of functions of the brain. The possibility
+of such localization is a very ancient speculation. The idea was
+developed along rational lines, in the first third of the nineteenth
+century, by certain Viennese workers who, having made important
+contributions to science, unfortunately afterwards degenerated into
+phrenological quacks. Later several German observers began the study of
+the electrical excitation of those parts of the cortex of the brain
+which specially control movement (Fig. 100). The work was continued and
+developed by a number of distinguished French and English observers,
+among whom Paul Broca (1824-80), Hughlings Jackson (1834-1911),
+and Sir David Ferrier (1843-) should be commemorated. Under their
+influence many operations usually regarded as involving complex mental
+processes, such as vision, speech, reading, writing, drawing, have been
+represented as depending on simple nervous relationships. Centers for
+the initiation of these operations have been described. Of late years,
+there has been reaction from this mechanical conception of the brain as
+an organ of the mind. The older school has, however, achieved clinical
+success especially at the hands of the great French physician Jean
+Marie Charcot (1825-93) and his pupils.
+
+[Illustration: FIG. 100. DIAGRAM TO ILLUSTRATE SOME OF THE MAIN FACTS
+OF CEREBRAL LOCALIZATION.]
+
+
+§ 4. _The Experimental Foundations of Modern Medicine._
+
+We may turn back to consider those who have been the immediate
+progenitors of modern Physiology. Among these, three men stand out
+beyond all others. In order of seniority, and perhaps of genius, they
+are Johannes Müller, Claude Bernard, and Karl Ludwig.
+
+
+(a) _The Work of Johannes Müller._
+
+Johannes Müller (1801-58) was the greatest physiologist Germany has
+produced, and perhaps the greatest physiologist of all time. His
+genius was of the universal type and, despite his early death, he
+attained equal distinction in every department which he touched. Among
+these were Comparative Anatomy, Embryology, Physiological Chemistry,
+Psychology and Pathology. He was a careful scholar, well versed in the
+history of the subjects which he taught, and as great a teacher as he
+was an investigator. A very large number of the best-known men who have
+advanced Medicine during the nineteenth century were his pupils while
+he was a professor at Berlin. His lovable character was pervaded by a
+mystical tendency.
+
+Müller’s text-book of Physiology began to appear in 1834. It introduced
+into the subject the comparative and psychological points of view,
+which were not fully appreciated until the generation that followed.
+The most remarkable generalization associated with his name--and
+one further developed by Ewald Hering (1834-1918)--is the ‘Law of
+Specific Energies’. According to this law each sensory nerve, however
+stimulated, gives rise to its own specific sensation and to no other.
+Conversely, the same stimulus applied to different organs of sense
+produces a different sensation in each organ--that sensation, in fact,
+that is its specific attribute. Thus electrical, mechanical, thermal
+stimulation produce only the sensation of light when applied to the
+optic nerve. On the other hand, any particular form of stimulation, for
+example electrical, produces sensations of light, smell, hearing or
+taste if applied to the appropriate nerves.
+
+A moment’s reflection will enable the reader to realize the very
+great philosophical importance of these conclusions. They provide
+experimental evidence that the things of the external world are not
+in themselves discernible by us. Such external things we know only by
+the events to which they give rise acting on our senses, and yet from
+one and the same event utterly different sensations arise within us.
+To beings with senses different from ours the world also would be
+different. The ‘Law of Specific Energies’ is thus fundamental for our
+view as to the range of validity of Scientific Method.
+
+Among other important contributions of Johannes Müller to the
+physiology of the nervous system were his experimental confirmation
+of Bell’s researches on the spinal roots (p. 145) and his experiments
+on the production of the voice. He launched important theories in
+explanation of color vision, of the mechanism of hearing, and of the
+phenomena of fever. He was one of the first to use the microscope in
+pathology and he was one of the founders of Physiological Chemistry.
+
+Like every investigator Müller made mistakes. In 1840 he stated that
+the velocity of a nervous impulse could never be measured. By 1852 his
+gifted pupil, Hermann von Helmholtz (1821-94), had measured it. Much of
+Helmholtz’s work hardly comes within our department. He was, however,
+inventor of the instrument known as the _Ophthalmoscope_, by means of
+which the interior of the eye can be examined. This is the main factor
+which has enabled Ophthalmology to develop along true scientific lines
+(p. 319).
+
+
+(b) _The Work of Claude Bernard._
+
+Claude Bernard (1813-78), the great French physiologist, was Müller’s
+junior by twelve years and was in almost every respect a contrast to
+him. His mind was of that peculiarly French type to which anything
+mystical is abhorrent. He had few eminent pupils who owed much to
+him directly, but the influence of his ideas, through his writings,
+can hardly be exaggerated. Especially Bernard was the founder of
+‘Experimental Medicine’, that is of the artificial production of
+disease by chemical and physical means. This is one of the most
+important scientific movements within our field.
+
+Bernard’s great discovery, which occupied him for over ten years,
+was that the liver has the power of building up and storing certain
+highly complex substances, derived from the food and brought to it
+by the blood. The substances thus stored, and notably that known as
+_glycogen_, are distributed to the body according to its needs, in
+simplified and modified form. Now Wöhler in 1828 had synthetized urea
+(p. 206) and it was well recognized that this substance is a final
+degradation product which the body manufactures by breaking down the
+substances derived from food. It was also recognized that from this
+breaking-down process the bodily energy is obtained. Bernard showed
+that the body could build up complex chemical substances as well as
+break them down. This destroyed the conception, then still dominant,
+that the body could be regarded as a bundle of organs, each with its
+appropriate and separate functions. Bernard thus introduced what we may
+call a ‘Physiological Synthesis’, a conception of great import for the
+development of medical ideas.
+
+No less important, and bearing on the synthetic view of the working of
+the animal body, was Bernard’s work on the physiology of digestion.
+Up to the time of Bernard, an elementary knowledge of the facts of
+digestion in the stomach constituted the whole of digestive physiology.
+While Bernard was working on the glycogenic function of the liver,
+another worker had suggested that the secretion of the organ known as
+the ‘pancreas’, or sweetbread, emulsifies fats. Soon after, a German
+researcher showed that pancreatic juice acts on starch. Bernard now
+stepped in and cleared up the whole subject. He showed that digestion
+in the stomach is, as he described it, ‘only a preparatory act’. He
+proceeded to demonstrate that the pancreatic juice, passing into the
+intestine, emulsifies the fatty food substances there and splits them
+up into fatty acids and glycerin. He further demonstrated the power
+of the pancreatic juice to convert starch into sugar, and he showed
+that it has a solvent action on such ‘proteids’ or organic nitrogenous
+substances as have not been dissolved in the stomach.
+
+The third great achievement of Bernard was his exposition of how the
+blood-supply to the different parts of the body is regulated. This we
+now call the ‘Vaso-Motor Mechanism’. In 1840 the existence of muscle
+fibers in the coats of the smaller arteries was discovered. Bernard
+showed that the contraction and expansion of the ‘arterioles’ is
+associated with a complex nervous apparatus. The reactions of this
+apparatus depend upon a variety of circumstances in a variety of other
+organs; again an illustration of the close and complex interdependence
+of the various functions of the body upon each other.
+
+
+(c) _The Work of Karl Ludwig._
+
+Karl Ludwig (1816-95) held a series of professorships at Marburg,
+Zürich, Vienna and Leipzig. He was, after Müller, the greatest of
+German physiological teachers, and he surpassed even Müller in the
+number of his pupils. As a physiologist he was chiefly remarkable for
+his ingenuity as an inventor, for his wide and deep knowledge of the
+physical sciences and for his extreme generosity in handing over his
+work to his pupils.
+
+Among the many lines of investigation of fundamental importance which
+Ludwig initiated, some of the most remarkable depended on the discovery
+of new methods. Just as the microscope had opened to the anatomist
+unexplored fields of research by bringing him into closer relation with
+objects which were hitherto beyond his scrutiny, so the rapid progress
+of physics and chemistry had placed more exact modes of observation and
+of measurement within reach of the physiologist. But the application
+of these methods was attended with great difficulty; there was no
+physiological laboratories, no instruments, no capable mechanicians
+to whom the physiologist could apply for assistance. Under such
+conditions, ingenuity and resource were indispensable to success, and
+in these qualities Ludwig was pre-eminent.
+
+Accordingly, we find that two of the most important of the early
+investigations of Ludwig were as much due to his ingenuity as an
+inventor as to his clear grasp of the physiological questions which
+his inventions were intended to elucidate. The most interesting of
+these inventions, or rather adaptations, is the mechanically rotating
+drum or _kymograph_, as it is called. The word itself is derived from
+two Greek words which mean ‘wave writer’. This instrument is now
+widely used, not only in Physiology but in every department of Science
+in which permanent records of any continuous movement are desired.
+The most familiar instance is the self-recording barometer. The
+kymograph--the use of which had been suggested by Thomas Young (p. 319,
+and Fig. 101) in 1807--led to much wider applications of the method of
+automatic record. Ludwig himself applied it to indicate the movements
+of respiration, as well as the variations in arterial pressure.
+Subsequently it became further adapted to the ‘graphic method’, and
+it serves not only for the investigation of animal movements of every
+conceivable kind, but even for the transient and delicate electrical
+changes which are associated with vital action.
+
+An instrument invented by Ludwig is the mercurial blood-pump, the
+purpose of which is to separate from a known quantity of blood, derived
+directly from the circulation, the mixture of gases which it yields to
+a vacuum. This is an indispensable apparatus for the investigation of
+the physiology of breathing.
+
+Ludwig devoted much attention to the physiology of secretion. Here his
+work has been of great importance in connection with the time-honored
+discussion between the ‘vitalists’ and the ‘mechanists’. He succeeded
+in showing that the process of secretion can be so transformed
+experimentally as to do external mechanical work. This was victory
+for the mechanist theory. The idea has since been applied to many
+structures.
+
+It is impossible to attempt here any general summary of the conclusions
+reached by physiological research since Ludwig. Some have affected
+the actual practice of Medicine. Others are too recent or too little
+certain to have reacted in this manner. It is, however, safe to say
+that the more important conclusions of the three modern founders of
+the science, Müller, Bernard, and Ludwig, form the main scientific
+background of the clinical practice of our time. The results of the
+movement that they represent, together with the knowledge of the
+cellular structure of the body (§ 5, p. 219) and of the life-histories
+of the disease-causing organisms (§ 6, p. 224), are the three main
+groups of ideas which separate the physician of our day from Laënnec
+(p. 161).
+
+[Illustration: FIG. 101. THOMAS YOUNG’S KYMOGRAPH.
+
+The cylinder H turns with the axis AB on which it is rigidly fixed. It
+is rotated by a handle at A which raises the weight C. When the weight
+is allowed to fall the cylinder rotates automatically. The rest of the
+apparatus is devised to secure constancy in rate of rotation. This was
+done by utilizing the effects of centrifugal force.
+
+(As the rate of rotation increases the pendula D and E fly apart, they
+separate the weights F and G. These move with friction which increases
+as they separate, thus decreasing the rate of rotation.)
+
+The movements of the pen at K are transferred into permanent graphic
+form by writing on the rotating cylinder H.
+
+]
+
+
+§ 5. _The Cell Theory and Cellular Pathology._
+
+During the process of the microscopic analysis of plants that took
+place in the seventeenth century a number of observers distinguished
+the walls of plant-cells and the word _cell_ was introduced into the
+English language. Less clearly, a similar structure was discerned in
+animals. No real understanding of the nature of cells was, however,
+reached. Little farther progress was made in the eighteenth century,
+but just at its close a young French microscopist, Marie François
+Xavier Bichat (1771-1802), likened the microscopic structure of the
+animal body to the substance of a woven fabric. The word he used was
+the old French term _tissu_. He perceived that the different parts
+of the body, bones, muscles, nerves, blood-vessels, and the like,
+each presented a characteristic microscopic pattern. According to
+these appearances he analyzed the parts of the body into twenty-one
+‘tissues’. Study of this kind came to be called ‘Histology’ (Greek
+_histos_ = web).
+
+During the seventeenth, eighteenth, and early nineteenth centuries,
+some advances were made in the knowledge of those organisms whose
+bodies are made up of only one cell, but their essential nature was
+still unappreciated. In the early nineteenth century a number of
+botanists and others were observing cells and cell contents. But no
+important advance in the interpretation of the appearances was made
+until the matter was taken up by Schleiden.
+
+Matthias Jakob Schleiden (1804-81), professor at Jena in 1838, put the
+matter in a new light. He noted, as had certain of his predecessors,
+the constant presence in every cell of the structure we now call the
+‘nucleus’, and came to the conclusion that it is essential to the
+life of every cell. He reached the conception, moreover, that in a
+multi-cellular organism, such as a tree, every cell has a double life,
+one an essential and independent one, pertaining to its own development
+alone, the other an incidental and dependent one, in so far as it is
+an integral part of the plant. His work was somewhat vitiated by a
+fanciful conception of the origin of new cells.
+
+The work of Schleiden was amplified and corrected in 1839 by Theodor
+Schwann (1810-82), a pupil of Müller. He showed that the tissues of
+animals, like those of plants, are susceptible of analysis into cells,
+and the difficulty of this process arises from the extreme modification
+of such cells as have developed for various special purposes. He showed
+too that the ovum or egg of animals is, in the first instance, a single
+cell, and that the cells of the body are derived and descended from it.
+He demonstrated that the entire animal or plant body is composed either
+of cells or of substances that are excreted or thrown off by cells.
+He gained some insight into the life of animal cells and in doing so
+he invented the very useful word _metabolic_. The word means ‘liable
+to change’. It was used by Schwann, and is still habitually used in
+modern Medicine to indicate chemical changes within the body which are
+specially associated with living activity.
+
+Contributions to the cell theory were made by other botanists. Hugo
+von Mohl of Tübingen (1805-72) distinguished the contents of the
+vegetable cell just under the cell-wall from the watery sap that fills
+the interior, introducing for it the term _protoplasm_ (1846). The
+Swiss, Karl v. Nägeli (1817-91), by chemical examination proved that
+protoplasm is nitrogenous and differs from other cell constituents
+(1862).
+
+The cell theory was placed on a firm and clear footing by Max Schultze
+(1825-74), successor of Helmholtz (p. 213) as professor of Anatomy at
+Bonn. He defined the cell as ‘a lump of nucleated protoplasm’ (1861),
+introduced the idea of protoplasm as ‘the physical basis of life’, and
+showed that it presented essential similarities, physiological and
+structural, whether in plants or animals, and whether in higher or
+lower forms.
+
+The study of tissues, Histology, was raised to the status of an
+independent science by the Swiss, Albrecht von Kölliker (1817-1905),
+pupil of Müller and professor at Würzburg, who wrote the first
+text-book on the subject (1850-52). Apart from this achievement,
+Kölliker is remarkable for having reached some of the conclusions in
+connection with heredity that are associated with the name of Mendel,
+of whose work he knew nothing.
+
+Even more influential on medical thought than Kölliker was Rudolf
+Virchow (1821-1902) of Berlin, one of the leading names in modern
+Medicine. There is indeed hardly any department of medical thought that
+has not gained something from Virchow’s work. His great achievement
+is the way in which he carried the Cell Theory into the analysis of
+diseased tissues. In his _Cellular Pathology_ (1858) he analyzes
+diseased tissues from the point of view of cell formation and cell
+structure. Important sections of the science of Cellular Pathology have
+been explored so well by Virchow that they have been little extended
+by his successors. He initiated the familiar idea that the body may
+be regarded as ‘a cell State in which every cell is a citizen’.
+Disease is often but a civil war. The white blood corpuscles, which
+have the power of engulfing and rendering innocuous bacteria and other
+foreign bodies, have been compared to police or scavengers. In some
+respects Virchow was strangely conservative, and notably he opposed the
+evolutionary view of the origin of living forms. Virchow’s conceptions
+of the functions of the white blood corpuscles were largely extended
+by the Russian biologist Élie Metschnikoff (1845-1916) and the English
+worker Almroth Wright (1861-).
+
+Since Virchow and Kölliker the study of the intimate structure and
+workings of the cells themselves, as distinct from the tissues,
+has become a separate and independent science under the name of
+_Cytology_. It may even be extended to the study of cells in disease as
+_Cyto-Pathology_.
+
+Among the major developments of Cellular Pathology and Cyto-Pathology
+is the study of abnormal ‘new growths’. The most malignant types of
+these belong to the group known as the ‘Cancers’. The occurrence of
+most of these becomes more frequent as life advances (Fig. 135). Their
+cytological features are now well known. A cancer consists essentially
+of an increase of cellular tissue, following abnormally rapid
+multiplication of one type of cell. The new growth is equipped with
+a blood-supply which enables it to increase at the expense of other
+tissues and regardless of their needs.
+
+Cancers almost always arise at one point, and are very seldom multiple
+in origin. It is fairly established that they are not infectious or
+contagious, and there is no very satisfactory evidence that a tendency
+to them is inherited. Our scientific knowledge of Cancers is largely
+derived from animals. Cancers are ‘specific’ in the sense that those of
+one animal species will not grow when inoculated into another species.
+An immense amount of work has been done on inoculated Cancers, but it
+has become evident that some physiological factor is involved in Cancer
+incidence such that an inoculated Cancer is not entirely comparable
+with so-called ‘spontaneous’ Cancer. As to what that physiological
+factor can be we are still in the dark.
+
+Although we know nothing effective as to this physiological factor,
+yet experiments in the artificial production of Cancer, apart from
+inoculation, have been attended with success. That various forms of
+chronic irritation are associated with the onset of Cancer has long
+been clinically recognized. It has been found possible to reproduce
+experimentally this relation between irritation and new growth, and
+so, for example, to induce Tar Cancer in mice. Nevertheless, it must
+be admitted that Cancer investigation is in an unsatisfactory state,
+and has yielded fewer positive results than any other department of
+Pathology of comparable importance. It is possible that we do not yet
+know enough of normal Cell Physiology to investigate with profit the
+forms of cellular perversion known as Cancer.
+
+[Illustration:
+
+Drawings by Theodor Schwann to illustrate the nature and origin of
+animal cells. All are highly magnified.
+
+FIG. 102. The first step in the origin of cartilage from cellular
+tissues. At the lower part the young cells are without cell-walls. In
+the upper part they have formed walls and are beginning to secrete
+cartilaginous substance. Nuclei and nucleoli are clearly visible.
+
+Above is shown a piece of maturer cartilage, in which the cells are
+imbedded in a mass of cartilaginous material.
+
+FIG. 103. Pigment cells, such as are characteristic of the skin of the
+frog. In the lowest cell, which is contracted, the nucleus is concealed
+by the pigment. The upper two are more expanded and in them nuclei can
+be seen.
+
+FIGS. 104 & 105 show how structures of very diverse form can be
+differentiated from cells of the same type.
+
+FIG. 104. Young cells from a developing feather. These cells may
+enlarge, secrete hard walls, and form the fine spongy tissue of the
+inner part of the shaft of the feather. Or the cells may elongate, the
+protoplasm become granular, and finally break up into fibers (Fig.
+105). These form the tough fibrous matter of the outer part of the
+shaft of the feather. In either case, the nucleus disappears and the
+cell dies.
+
+]
+
+
+§ 6. _Establishment of the Doctrine of the Germ Origin of Disease._
+
+The view that many diseases, especially those of a contagious or
+infectious nature, originate from the invasion of the body by
+special organisms and their multiplication within the body, came
+into prominence in the second half of the nineteenth century. There
+had been many previous adumbrations of this view and, in its final
+establishment, more than one hand may be discerned. Above all others
+who have worked in this field towers the mighty figure of Louis Pasteur
+(1822-95). We shall do no grave injustice to any man if we treat the
+scientific demonstration of the doctrine as the product of his superb
+genius.
+
+The opening of Pasteur’s interest in disease can be seen in his work
+on fermentation. At first he was faced with the opposition of Liebig.
+According to that eminent chemist, fermentation was not the result of
+vital activity but was a purely chemical change (p. 207). A ferment
+he regarded as an unstable organic product, the character of which
+determined the manner of decomposition of the medium in which it is
+placed. Pasteur demonstrated that, as there is a specific alcoholic
+ferment, so there is a specific milk-souring ferment. Any nitrogenous
+matter present in a fluid containing it will serve as food for the
+development of a ferment, but will not of itself induce fermentation.
+Ferments have, he demonstrated, the power of reproduction. Pasteur
+rapidly seized on the idea of the specificity of ferments. An
+albuminous sugar solution can be converted into various products by the
+addition of various ferments. According as one sows, so will one reap.
+The milk-souring ferment, Pasteur concluded, is organized and living,
+and its action is correlated to its development and organization. No
+life, no ferment; no ferment, no fermentation.
+
+[Illustration: FIG. 106. ORGANISMS OF FERMENTATION HIGHLY MAGNIFIED
+from Louis Pasteur’s _Studies on Beer_ of 1876.
+
+1. Bacillus of Turned Wine. 2. Ferment of Soured Milk. 3. Butyric
+Ferment. 4. Ferment of Ropy Wine. 5. Ferment of Vinegar. 6. Amorphous
+deposit. 7. Sarcinae.
+
+]
+
+During the next years Pasteur applied himself to a study of ferments
+and notably of those which involve deterioration of wines and beers.
+This led him to perceive that there is a great multiplicity and
+variety of these organisms. Now it was an old and well-known view
+that fermentation, putrefaction, and the infection of disease had much
+in common. It was perfectly natural, therefore, for Pasteur to regard
+the latter in the light of a vital process. A great difficulty was,
+however, the demand that any such doctrine made on the germ-bearing
+capacity of the air. Cities were not slow to avail themselves of this
+weakness, and pointed out that, according to Pasteur, the air must
+be one solid mass of germs! For the opponents of Pasteur the living
+organisms found in the process of fermentation or decomposition were
+the result, not the cause, of the process. These organisms were
+regarded by them as spontaneously generated in the fermentation
+process. Thus arose a discussion of the old theme of spontaneous
+generation.
+
+By 1859--the year of publication of Darwin’s _Origin of
+Species_--Pasteur was engaged in controversy as to the ‘Origin of
+Life’. The discussion specially turned round what were then regarded as
+the lowest forms of life, the Bacteria. Were they ever spontaneously
+generated, or were they not? If a flask of broth, supposedly sterilized
+by boiling, went ‘bad’ and organisms appeared in it, was it certain
+that they had come from without, or could they have been spontaneously
+generated by the broth itself? Life must begin somewhere. Then why
+not here at this lowest stage? If this view be justifiable, Pasteur’s
+doctrine of the nature of ferments must fall to the ground.
+
+Pasteur had thus before him the task of proving a universal negative--a
+task impossible in Formal Logic. But Science is not Formal Logic. In
+the end he clinched the matter by an exquisitely simple experiment
+which must, at once, carry conviction. A flask with a long S-shaped
+neck is filled with a putrescible fluid. It is heated to boiling, to
+kill all organisms, and then left in the still air of a room. Air can
+enter, but any floating germs that enter naturally fall on the floor
+of the S-shaped neck of the flask. Months may go by without any change
+in the liquid, but once the neck is severed, so that organisms can
+enter freely from the air, fermentation sets in within a few hours, and
+organisms can be detected in the liquid. Only living organisms from the
+air can have caused the change.
+
+[Illustration:
+
+FIG. 107. PASTEUR’S CRUCIAL EXPERIMENT to prove that fermentation or
+putrefaction is the result of the action of air-borne organisms. The
+S-shaped flask contains a putrescible fluid such as meat broth. The
+flask containing the broth is subjected to prolonged heating to destroy
+all organisms. It is then left in position with the mouth open. Days,
+weeks, months, even years, may pass without sign of putrefaction. No
+organisms reach the broth, since any that enter the open mouth fall on
+the floor of the neck and remain there. Sever the neck of the flask so
+that organisms can fall from the air directly on to the surface of the
+fluid and these multiply. In a few hours putrefaction sets in. This
+is shown by the formation of a film or scum on the surface just below
+the severed neck. Microscopically the broth is seen to be teeming with
+organisms.
+
+]
+
+The first disease which Pasteur was able to demonstrate as causatively
+related to a living organism was a condition that was devastating the
+silk-worm industry of France. In 1866 he proved the contagiousness of
+the disease, showed that it was due to a living organism, and followed
+the organism through the life-history of moth, egg, worm, and chrysalis.
+
+In 1870 the Franco-Prussian war broke out. Pasteur now decided to make
+investigations into the diseases of beer, his object being to improve
+the French brews and to carry the war into the enemy’s camp by making
+them equal to the German! He succeeded in isolating special organisms,
+mostly yeasts, which produced defects in beer (Fig. 106). This work
+naturally led to an enlargement of his views on the nature and action
+of micro-organisms.
+
+About this time Pasteur was elected a member of the French Academy
+of Medicine, a very unusual honor for one not a medical man. Lister
+had already begun his teaching, based partly on the work of Pasteur,
+and indeed his first important paper on antiseptic surgery had been
+published in the very year of the Franco-Prussian war. On entering the
+Academy Pasteur found himself faced by all kinds of ancient prejudices
+and misconceptions in connection with his new doctrine, and especially
+with his denial of spontaneous generation. Among his supporters was the
+physiologist, Claude Bernard (p. 213). His work proceeded to more and
+more triumphant issues.
+
+The first disease that affects man on which Pasteur was able to throw
+light was Anthrax, in relation to which his work interdigitates with
+that of Robert Koch and some other observers. Anthrax is a deadly
+and highly contagious condition which commonly affects cattle, but
+sometimes spreads to man. As early as 1855, a German observer had
+noted microscopic rod-like objects in the blood of beasts dead of
+the disease. In 1868 an older French contemporary of Pasteur had
+shown that a bacillus is not simply the inseparable companion of the
+disease, but also is its cause and its only constantly acting cause. At
+this time the losses of cattle from Anthrax in France were enormous.
+The character of the outbreaks had been studied and seemed wholly
+unexplained by what was known of the bacillus. Farmers found that they
+lost cattle in fields from which infected animals had been excluded for
+months or even years. How was it to be explained?
+
+The explanation was, in fact, advanced in 1876 by the German observer,
+Robert Koch of Berlin (1843-1910), whose work was now beginning.
+He showed that the anthrax bacilli under certain conditions formed
+‘spores’, that is to say small encysted bodies, exceedingly resistant
+to heat and to other changes of external conditions (Fig. 108). This
+discovery opened up a new field which was cultivated by Koch and
+Pasteur and their followers.
+
+[Illustration: FIG. 108. BACILLI OF ANTHRAX, from a culture, highly
+magnified.
+
+    The rod-like organisms are growing typically in chains. Some of
+    the rods have white clear spots in them. These are the highly
+    resistant ‘spores’.
+]
+
+While making his studies on ferments in 1863, Pasteur had witnessed the
+formation of spores in the organisms of butyric fermentation, but had
+failed to grasp their significance. In 1869 he had again found spores
+forming in the organisms of silk-worm disease, and had shown that they
+resisted prolonged drying. On the basis of their resistance he had
+explained the persistence and latency of the silk-worm disease. Other
+observers had had similar experiences. The investigations of none of
+them, however, approached in brilliance and completeness those of Koch.
+
+Koch found that spores always form in the blood and tissues of animals
+dead of Anthrax, provided that
+
+(1) the temperature is suitable, and (2) there is sufficient
+oxygen. These two conditions, temperature and oxygen, were found to
+be necessary. Below 18° Centigrade spores are not formed; at 30°
+Centigrade they occur at the end of thirty hours; at 35° Centigrade
+in twenty hours. The rapidity with which spores are formed is,
+therefore, proportional to the amount of heat. Oxygen was also found
+to be indispensable. Anthrax blood, if deprived of oxygen, ceases to
+be virulent in twenty-four hours without putrefaction. When the blood
+is allowed to putrefy the virulence also disappears if putrefaction
+exhausts the oxygen quickly enough to prevent the spores having time to
+form. If the spores have already formed, putrefaction does not kill
+them, nor does it prevent them from developing later if circumstances
+become favorable. The persistence of the disease and its return in
+an infected country was thus explained. It was the spore which was
+the agent of preservation, which persisted where the conditions of
+temperature and of aeration had permitted it to form, and which always
+held itself in readiness to make new victims.
+
+The matter was carried further by Pasteur in 1877. At that time he
+did not know of all the work of Koch. He succeeded in obtaining pure
+cultures of Anthrax. The question was then still being debated in
+France as to whether Anthrax was caused by a ‘virus’, that is to say a
+non-living poison, or by a microbe. Pasteur had long been a believer in
+the microbic theory, and it seemed to him probable that the blood of an
+animal infected with Anthrax, if sown in a suitable medium, would stock
+it solely with anthrax bacilli which he could then keep pure for an
+indefinite time in successive cultures, as he had done with yeast and
+other ferments.
+
+Experiment proved this to be the case, and showed that the anthrax
+organism multiplied abundantly in urine made neutral or slightly
+alkaline. From that time the problem was solved. Take a series of
+cultures of the organism, transferring each time one drop from the
+preceding culture into 50 c.c. of fresh urine. The first dilution
+is 1/1000, the second one in a million, the third one in a thousand
+million. After ten cultures it falls to such a figure that the
+original drop of blood has been drowned in an ocean. Everything that
+it carried with it, to which we might attribute the production of
+Anthrax--red corpuscles, white corpuscles, granules of all sorts--is
+either destroyed by the change of medium or is widely disseminated in
+this ocean and is lost. Only the organism can escape the dilution. Why?
+Because it has multiplied in each of the cultures. A drop from the last
+culture killed a rabbit or guinea-pig as surely as a drop of anthrax
+blood. It was, therefore, to the organism that the virulence belonged.
+A conclusion of the first rank was firmly established.
+
+With a ‘pure culture’ of Anthrax in his possession Pasteur was able
+to experiment in a way which none had previously attempted. The most
+interesting stage of his work was now entered upon. He perceived that
+there are some species of animals which are refractory to Anthrax.
+Such are the birds. Nevertheless, the blood of a bird, when drawn
+from the animal, is an excellent culture medium for the bacterium.
+Why does it resist infection in the animal? Pasteur showed that the
+anthrax organism will not live in the bird because the living-blood
+in full circulation is filled with an infinite number of corpuscles
+which, in order to live and perform their physiological function, need
+free oxygen. When, therefore, the anthrax organism enters normal blood
+of living birds, it meets competitors ready to seize the oxygen for
+their own use. But the blood of other animals besides birds contains
+corpuscles eager for oxygen. Why can anthrax grow in them and not
+in birds? This question Pasteur answered by a convincing series of
+experiments (1878). The normal temperature of birds is higher than that
+of mammals and is, moreover, higher than that at which the growth of
+the anthrax organism is most vigorous. Thus the blood corpuscles of
+the bird have the anthrax bacteria at a disadvantage. But if, by a cold
+bath, the temperature of a bird be lowered to that of a mammal, and if
+anthrax organisms be injected into the blood-stream, they will grow and
+flourish at the expense of the bird.
+
+The experiments with Anthrax on fowls led to experiments on the same
+creatures with another disease, the virulence of which was known
+to vary, Chicken Cholera. Thus arose naturally Pasteur’s ideas and
+observations in the department of Immunity (p. 261).
+
+If Pasteur can be said to have laid the foundations of the knowledge
+of the nature of infection, it is to Koch that we owe the main basis
+of the technique by which diseases are now studied. He it was who
+elevated Bacteriology into the position of a separate science. Soon
+after his work on Anthrax he published a remarkable research which
+placed our knowledge of wound infection on a firm footing. He is thus
+among those who helped to create modern surgical technique. Many other
+communications came from him. None was of more far-reaching importance
+than his demonstration of the organism of Tuberculosis in 1882. All
+subsequent work in connection with Consumption and allied conditions
+has been rendered possible only by this discovery of Koch. Other
+investigations associated with his name are on Cholera and on Sleeping
+Sickness. Koch was unquestionably the greatest bacteriologist that the
+world has seen. His genius was limited as compared to that of Pasteur,
+but his exquisite technical skill and acumen have never been excelled.
+
+Since the time of Pasteur and Koch, the study of infectious disease
+has developed along various special lines. The work of these two
+men, however, has determined the direction of those lines, and
+they themselves are the most typical, as well as the greatest,
+representatives of the most important of all movements in modern
+Medicine.
+
+
+§ 7. _Anaesthesia._
+
+The aspect of surgical practice was dramatically changed during
+the course of the nineteenth century by two discoveries, that of
+Anaesthesia and that of the Antiseptic method. It will be convenient to
+consider Anaesthesia first.
+
+There were from the earliest times many devices for producing more
+or less complete unconsciousness during surgical operations. An idea
+of the extremes to which surgeons at the beginning of the nineteenth
+century were put in this matter can be gathered from a glance at some
+of their devices (Fig. 108a).
+
+The new era began in 1846 when the dentist, William Thomas Green Morton
+(1819-68), demonstrated at the Massachusetts General Hospital the
+simplicity and safety of Ether anaesthesia. The idea immediately caught
+on. Before the year was out Ether was being used for surgical purposes
+in England. In January, 1847, Sir James Young Simpson (1811-70) was
+using it in Edinburgh for obstetric purposes. A few months later he
+adopted Chloroform, which had been prepared by Liebig in 1832.
+
+The use of the drugs spread very rapidly and almost as rapidly changed
+the character of surgical technique. Until the adoption of anaesthesia,
+speed was of primary importance in surgical procedure. Excessive speed
+now became a matter of less importance, and operative neatness and
+completeness took its place as the chief quality of good surgery.
+Moreover, operations of a more drastic character could be undertaken
+since the shock to the patient was minimized. Women in labor were found
+to bear Chloroform peculiarly well and safely, and its use in midwifery
+steadily spread despite some foolish and fanatical opposition.
+
+Soon after the introduction of anaesthetics efforts were made by
+various methods to secure a painless state of a part without involving
+unconsciousness. The first successes were obtained in 1884 at Vienna
+with applications of solutions of the alkaloid (p. 325) Cocaine,
+first to the eye, then to the nose and other parts. Cocaine, or some
+derivative of it, has ever since been much used in Medicine. It was
+soon being given by injection under the skin for small superficial
+operations. Next, good results from injecting solutions of it into the
+nerves were obtained by several American surgeons, earliest of whom
+was W. S. Halsted (1852-). His work of 1885 was extended in 1898 by
+Harvey Cushing (1869-). Yet another American surgeon, J. L. Corning
+(1855-), introduced the method of so-called ‘spinal anaesthesia’.
+This is secured by injecting a solution of Cocaine or one of its
+derivatives into the spinal canal and thereby inducing insensibility to
+pain (‘analgesia’) below the site of injection. In 1908 the American G.
+W. Crile (1864-) introduced a valuable method of combining local and
+general anaesthesia, whereby he minimized the effects of ‘shock’ (pp.
+310-11) during the progress of the operation.
+
+From first to last almost all the pioneer work upon anaesthetics and
+analgesics has been of American origin. Even the word _anaesthesia_
+is an American invention. It was introduced or at least familiarized
+by Oliver Wendell Holmes (1809-94), the distinguished and brilliant
+author of the ‘Breakfast Table’ series. Laughing Gas was first applied
+to dental purposes a short time before Ether was given its surgical
+application, and its introduction for this purpose was the work of the
+American dentist Horace Wells (1815-45), of Hartford, Connecticut.
+
+[Illustration:
+
+FIG. 108a. SCREW adapted to the lower limb, as used by surgeons in the
+eighteenth century and the early nineteenth century, to compress the
+nerves in order to secure analgesia during amputation. Its application,
+however, was extremely painful in itself and injurious to the part
+operated on.
+
+]
+
+
+§ 8. _The Revolution in Surgery._
+
+This history of antiseptic surgery is inseparably linked with the name
+of Lord Lister (1827-1912), whose work naturally dovetails into that of
+Pasteur. Lister’s attention was first called to the work of Pasteur in
+1865. But Pasteur’s views on the life of micro-organisms came to a mind
+that had been prepared for them. Lister had had, moreover, a long and
+varied surgical experience and had been present at the first operation
+performed in England under Ether anaesthesia in 1846.
+
+At that time and for long after, Surgery was cursed by the constant
+fear of sepsis. A vast amount of death and suffering was due to this
+cause, and surgeons were reluctant to perform many operations that
+we should now regard as trivial. Lister’s first attempt to make any
+scientific analysis of the septic state is to be found in a paper by
+him on _The Early Stages of Inflammation_ (1853). He showed that the
+effects of irritation on the tissues are twofold. Firstly, there is
+a dilatation of the arteries which is developed through the nervous
+system. Secondly, there is an alteration in the tissues on which the
+irritant acts directly. This alteration imparted, as Lister thought,
+an adhesiveness to both the red and the white corpuscles, making them
+prone to stick to one another and to the walls of the vessels, and so
+giving rise to stagnation of blood and ultimately to obstruction.
+
+Some years before (1847) A. V. Waller (1816-1870), a pupil of Magendie,
+had shown that during the process of inflammation there is an active
+migration of white blood corpuscles through the walls of the capillary
+blood-vessels. Waller’s observations attracted but little attention at
+the time. They were, however, amply confirmed in 1878 and the following
+years by the German pathologist Julius Cohnheim (1839-84), a pupil of
+Virchow. Cohnheim showed that this process of migration of white blood
+corpuscles is the essence of inflammation and that when inflammation
+goes on to suppuration the pus that is formed consists largely of white
+blood corpuscles in a dead and disintegrating state.
+
+Irritation, and the reaction of the body against it, ‘inflammation’,
+are encountered in all injuries in which the healing is not direct
+and healthy. It was those cases of injury in which the healing was
+indirect and unhealthy which then formed the surgeon’s chief problem.
+Of these there are a variety, now rare, then very common and fatal,
+as Blood-Poisoning, Erysipelas, Pyaemia, Septicaemia, Hospital
+Gangrene, and that form, then so common as to be almost normal, simple
+suppuration of a wound.
+
+About 1861 Lister began to teach publicly that the occurrence of
+suppuration in a wound is determined ‘simply by the influence of
+decomposition’. The nature of decomposition was revealed to him by the
+writings of Pasteur. From him he learned that putrefaction was, in
+fact, a fermentation, and that it was caused by the growth of minute
+microscopic organisms borne by the air. It was generally supposed that
+air was the cause of sepsis, and precautions were taken to exclude it
+from wounds. But Lister now saw that not air but that which it carried
+was the mischief-maker.
+
+The general course of action was now clear to him. As a laboratory
+proposition the destruction of the organisms of the air was simple. The
+problem was to exclude them from wounds during and after operation. The
+solution of that problem developed as ‘Antiseptic Surgery’, which later
+became ‘Aseptic Surgery’. At first he paid most attention to air, as
+the source of infection. He recognized, however, that he must also deal
+with the germs present in the wound and on his hands. Of the methods
+available for ridding the air of its germs, viz. heat, filtration, and
+chemical action, he chose the last.
+
+At that time carbolic acid was in use as a means of treating sewage. At
+first, therefore, Lister tried lint soaked in crude carbolic. This he
+found liable to cause superficial sloughing and death of the tissues.
+He next obtained a purer acid, using a solution in oil. A putty formed
+of common whitening and a solution of carbolic acid in linseed oil was
+used as a dressing. He adopted later a system of spraying the part
+during operation (Fig. 109).
+
+[Illustration:
+
+FIG. 109. THE ‘DONKEY ENGINE’, an apparatus designed and used by Lord
+Lister to maintain a carbolic spray over a part during operation. The
+engine is worked by the up and down movement of the handle to the right
+and the spray is delivered through the tube to the left.
+
+]
+
+When Lister began his work, amputation of a limb was a very fatal
+operation. Yet it had to be performed in most cases of severe fracture
+in which the bone was exposed because, without it, death from sepsis
+was almost certain. The improvement in Lister’s own records of
+amputation, incident upon his adoption of the antiseptic method, is
+well brought out by his own figures:
+
+  _Years._   _Cases._ _Recovered._   _Died._       _Mortality._
+  1864-66      35          19          16     43% without antiseptics
+  1867-70      40          34           6      15% with antiseptics
+
+These results were considered extraordinarily good in their day. It
+is an index of the further advance since Lister’s first attempts that
+results ten times as good would now be regarded as unsatisfactory.
+Moreover not only has the further development of Lister’s method
+rendered amputation safer, but also it has enabled the surgeon to treat
+many cases without amputation, when before he would have been compelled
+to resort to that measure.
+
+Lister first recorded his observations on the antiseptic system of
+surgery in 1867. Apart from the technical advances that he then set
+forth, he recorded also many new pathological facts that have since
+proved of great practical importance. Thus he showed that an uninfected
+clot, if undisturbed, can become organized into a living tissue, and
+that a piece of dead bone may be absorbed in an aseptic wound. These
+are now matters of common knowledge, but then they were instrumental
+in introducing a radically new outlook.
+
+Lister gradually perfected his technique, chiefly in the direction of
+using milder antiseptics and adopting heat for the sterilization of
+instruments and dressings. The antiseptic system was given its military
+application in France during the war of 1870. It was soon taken up also
+by German surgeons. The history of surgery since Lister’s day has been
+very often told. An important element in it is the gradual supersession
+of ‘antiseptic’ by ‘aseptic’ methods (p. 248).
+
+The Listerian system, in rendering surgery safer, had also the
+effect of opening up many fields of operation that had previously
+been regarded as impracticable. Especially is this the case with
+abdominal surgery, which effectively dates from the introduction of
+the antiseptic system. Lister was often misunderstood and some of his
+contemporaries, and some even of those who opposed him, were really
+practising his system without knowing it.
+
+Among the most important reactions of antiseptic surgery was that upon
+the conduct of labor. Here Lister had a predecessor, as he gladly and
+generously acknowledged. This was the unfortunate and almost insane
+Viennese genius, Ignaz Semmelweis (1818-65). At the great lying-in
+hospital at Vienna in which he was an assistant the death-rate at one
+time rose to thirty per cent., the so-called ‘puerperal fever’ being
+the active cause. The women were attended by students or physicians
+who were visiting the post-mortem room. Semmelweis showed that the
+infective material that conveyed the fever was brought by the hands of
+the operator from the dead bodies and he showed that puerperal fever
+was caused by decomposed animal matter. By insisting on the hands
+of the operators being sterilized, Semmelweis succeeded in 1846 in
+enormously reducing the mortality. After the acceptance of Lister’s
+antiseptic system the methods of Semmelweis were universally introduced
+into the practice of Midwifery. Another predecessor of Lister was
+Oliver Wendell Holmes. As early as 1843 he pointed out that the
+mysterious ‘puerperal fever’ was contagious, and carried by the hands
+of the operator. He suggested precautions not dissimilar to those of
+Semmelweis.
+
+[Illustration: FIG. 109A. OPERATING TABLE USED BY LORD LISTER in the
+Glasgow Royal Infirmary.]
+
+
+§ 9. _Some Modern Surgical Advances._
+
+Among the most capable surgeons of Lister’s own day was Thomas Spencer
+Wells (1818-97) of London. This great operator had been opening the
+abdomen successfully for certain conditions since 1858. By 1867 his
+methods were approaching the Listerian. Under Lister’s inspiration
+he further improved his technique and did more than any other man to
+raise the possibilities of abdominal surgery. Spencer Wells stands
+out for the extreme simplicity, directness, and effectiveness of
+his methods (Fig. 111), and for his exceptionally conscientious care
+as an operator. His name is commonly attached to an instrument of
+his invention of catching the bleeding ends of cut blood-vessels.
+The familiar ‘Spencer Wells forceps’ is at this day probably more
+frequently used than any other surgical instrument (Fig. 110).
+
+[Illustration: FIG. 110. ‘SPENCER WELLS FORCEPS.’]
+
+[Illustration:
+
+FIG. 111. SPENCER WELLS performing an abdominal operation about 1870.
+The picture illustrates the extreme simplicity of the methods of this
+great surgeon. It also shows a method of administering chloroform. Air
+is pumped through a bottle into a mask held at a variable distance from
+the face of the patient.
+
+]
+
+Since the time of Lister many branches of Science have contributed to
+the development of surgical technique. No addition to the surgical
+armory has, however, been more important than that made by the
+physicist Wilhelm Conrad Röntgen (1845-1923). In 1895 he found that
+when an electric discharge passes through a high vacuum rays are
+emitted that are far more penetrating than ordinary light. These rays
+have since then been placed in series with light rays, ultra-violet
+rays and infra-red rays, and it has been shown that they differ from
+these only in their wave-length. The surgical application of the
+Röntgen or X-rays was at once made to the examination of bone. Since
+then the more accurate knowledge of the properties of these rays
+has made them of value in exploring almost every organ of the body.
+Radiography is now constantly applied in the diagnosis of medical and
+surgical conditions of the organs of the chest and abdomen.
+
+The more dramatic achievements of modern surgery, the drastic
+operations that surgeons are now able to perform on the great cavities
+of the body--head, chest, and abdomen--have attracted much public
+attention. Nevertheless few surgical advances have relieved so much
+suffering and disability as the unsensational development in the
+treatment of fractures.
+
+After the advent of Listerian methods the technique of the treatment
+of compound fractures was gradually perfected. Simple fractures--which
+are far commoner--continued, however, to be treated with splints in
+the traditional fashion. Plaster of Paris bandages, which came into
+wide use in the ’seventies, were some improvement; but prolonged
+immobilization of a limb, in either splints or plaster bandages, always
+involves much subsequent pain and stiffness, lasting, at best, for
+months. To obviate this, Massage--a practice of immemorial antiquity
+in Folk Medicine--had been introduced into Surgery in the sixteenth
+century by Ambroise Paré (pp. 92-94). The subject was little heard
+of till the last thirty years of the nineteenth century. The pioneer
+was the Dutch surgeon Johann Mezger (1839-1900), through whom some
+scientific advance was made.
+
+[Illustration: FIG. 112. AN OPERATION IN THE SIXTEENTH CENTURY.
+
+The semi-conscious patient lies face downward on an elaborately
+carved bed. The bearded surgeon, dressed in his ordinary clothes, is
+trephining his skull and is rotating the trephine between his hands.
+Against the side of the bed lounges a gallant to whom a servant brings
+refreshment. In the background are two women assistants. A male
+assistant is spreading a plaster and another warming a towel over a
+brazier. Note that all present, surgeon, nurses, assistants, &c., wear
+their ordinary dress. No arrangements are made for washing. In the
+foreground is a cat playing with a mouse. ]
+
+The introduction of X-rays into Surgery made for very accurate
+diagnosis of the state of fractures. It has thus gradually become
+possible to treat a large proportion of these injuries without
+immobilization either by splints or plaster. In many cases the injured
+limb is merely held in correct position between sandbags and massage
+used from the first. Much stiffness and disability is thereby avoided
+and the length of the period of treatment greatly shortened. The rise
+of a class of scientifically trained Masseurs has made possible a wider
+application of this valuable curative procedure.
+
+Improvements in methods of operation have been very numerous during
+the last generation. Many can be appreciated only by those with
+technical knowledge. In 1886 Ernst von Bergmann of Berlin (1836-1907)
+introduced steam sterilization of dressings and thus moved toward the
+replacement of antiseptic by aseptic methods. W. S. Halsted, then
+of New York, had been working to the same end. In 1890, finding it
+impossible to sterilize the hands completely, he introduced the rubber
+gloves now universally employed by surgeons during operations. Much
+important work in experimental surgery has been done by Alexis Carrel
+of New York (1873-) and some of his laboratory methods have become
+available in surgical practice. The technique of abdominal surgery has
+been greatly advanced by many workers, important among whom are J. B.
+Murphy (1857-1916) of Chicago and the brothers Charles and William Mayo
+(1865 and 1861) of Rochester, Minnesota. The surgery of the brain was
+prosecuted in England by Rickman Godlee (1849-1925), the nephew and
+biographer of Lister, by Victor Horsley (1857-1916), and above all by
+William Macewen (1848-1926), a successor to Lister’s chair at Glasgow
+and one of the finest exponents of Listerian methods. The surgery of
+the nervous system in general, and that of the brain in particular, has
+been carried to extraordinary refinements in America by Harvey Cushing.
+There can be no doubt that during the twentieth century advances in
+Surgery have been more important and more numerous in the United States
+than in any other country.
+
+[Illustration: FIG. 113. AN ABDOMINAL OPERATION UNDER MODERN CONDITIONS
+
+Only those directly concerned with the operation are present in the
+room. All wear aseptic clothes and aseptic rubber gloves. Every source
+of infection is guarded against and all breathe through masks. The
+patient is covered by aseptic cloths and only the part operated on is
+exposed.
+
+]
+
+
+§ 10. _Bacteriology becomes a special Science._
+
+We have seen the microbic view of the origin of disease demonstrated
+as a reality by Pasteur (pp. 224-35) and extended to special disease
+conditions by him and by Koch (pp. 229-32). While the French observer
+stood above all men for the clearness and steadiness of his vision and
+for his persistence and resource in following what he had seen from
+afar, his German colleague had a genius for visualizing particulars
+and for adapting mechanical devices and scientific discoveries to
+particular ends. Koch thus vastly improved and elaborated the methods
+for detecting and examining minute organisms. The significance of his
+results was at once recognized, but the complexity of the technique
+involved and the time and training necessary demanded the elevation of
+the subject into the position of a special science.
+
+Though but fifty years old, the science of Bacteriology has itself
+undergone repeated subdivision. Noteworthy though the results of this
+process of constant subdivision have proved, it must be emphasized
+that the state of scientific subdivision cannot be final, and is
+indeed without meaning unless it lead to a subsequent synthesis--an
+event which we still await. It is the general Laws reached by these
+special sciences that are philosophically important, and the specialist
+himself is often ill-placed and ill-equipped for the estimation of the
+true significance of such Laws. The philosophic thinker who deals with
+generalities and centuries must often be content to pass the details in
+silence. Nor is this true only of the professed philosopher. It applies
+no less to the philosophical physician. It is his task to try to see
+life steadily and see it whole. He must think both in terms of the
+individual life and of the community life, and for him the results of
+the bacteriologist, the physiologist, and of all their colleagues are
+as means to an end. It is from this standpoint that we should seek to
+visualize the fruits that bacteriological science in this last age has
+laid at the feet of humanity.
+
+With Koch’s work on Anthrax in 1876, on the bacteria that commonly
+infect wounds in 1878, and with his great discovery of the bacillus
+of Tuberculosis in 1882, the study of the infective diseases entered
+on a new stage. The enemy had been seen and was now known for what he
+was. The bacteriologist had succeeded in making prisoners. These had
+been isolated and made to live in test-tubes. Moreover, the organisms
+had been compelled to dwell alone without mixing with other species.
+They had been obtained, as bacteriologists say, in ‘pure cultures’,
+and delicate methods of detecting and differentiating them had been
+developed. With a pure culture in his hands, the bacteriologist can
+determine the influences favorable or unfavorable to the growth of the
+disease organism, and he can investigate conditions that can exalt,
+destroy, or modify its activity (p. 233).
+
+An important series of criteria established by Koch have remained the
+tests by which the disease-bearing character of these organisms can be
+established. To prove that an organism is the inseparable cause of any
+disease we need to demonstrate:
+
+1. The constant presence of the organism in every case of the disease.
+
+2. The preparation of a pure culture, which must be maintained for
+repeated generations.
+
+3. The reproduction of the disease in animals by means of a pure
+culture removed by several generations from the organisms first
+obtained.
+
+These conditions have been fulfilled for many diseases. Evidently the
+third test can be applied only in conditions to which animals other
+than man are susceptible. Now in this matter the organisms that produce
+disease vary greatly. Some, for instance those of Anthrax, are easily
+conveyed to a variety of species of animals; others, for instance
+those of Syphilis, are with difficulty conveyed to very few species of
+animal; yet others, for instance human Malaria, cannot be conveyed to
+any animal save man.
+
+Some light is thrown on the life-history of the second and third
+classes by recent discoveries. The science of Comparative Pathology,
+that is the knowledge of the relations of the diseases of different
+species of animals, is of very recent growth. It has already
+demonstrated, however, the existence of organisms bearing some
+resemblance, for instance, to those of human Syphilis and human Malaria
+as the cause of disease in animals. By studying the life-history of
+these organisms in animals and by studying their effect on animals,
+valuable side-lights have often been thrown on the allied diseases in
+man. Moreover, in exceptional cases and in some special diseases, it
+has been possible to convey a disease experimentally to man.
+
+A second important factor has gradually come into prominence with the
+extension of bacteriological knowledge. It is evident that not all
+men are subject to all human diseases. Even in the most destructive
+epidemic there are some that escape. These lucky ones may be naturally
+‘immune’. Many diseases, such as Measles, seldom recur in individuals
+who have been infected, so our lucky ones may thus have an ‘Acquired
+Immunity’.
+
+The general nature of Immunity we shall presently discuss (p. 259),
+but we note here that Immunity may be relative or absolute, and may,
+moreover, vary according to the circumstances of the individual. Thus,
+for instance, a well-fed, well-housed person of temperate habits,
+living an open-air life, is unlikely to develop consumption. Restrict
+his diet, confine him in an office, deteriorate his mode of life,
+and he may well fall a victim to it. The investigation of facts such
+as these on a large scale has demonstrated that the _soil_ in which
+disease grows is of no less import than the _seed_ from which it grows.
+The problem of disease causation is thus immensely complex. We are
+only just beginning to draw up general laws on the subject, and in
+approaching it we are beyond the frontiers of our positive knowledge.
+Turned back from this difficult borderland, we must content ourselves
+with surveying a part of the better-known territory and considering a
+few specific bacteriological achievements. These we may now consider
+under the headings of the diseases associated with them.
+
+
+§ 11. _Some Important Bacteriological Results._
+
+_Diphtheria_ is a disease for which physicians now habitually demand
+a bacteriological diagnosis. Bretonneau of Tours (p. 185), working on
+clinical and post-mortem material, and without the use of a microscope,
+was able to distinguish Diphtheria as a specific disease (1826). Half
+a century later (1883) Edwin Klebs (1834-1913) of Zürich, a pupil
+of Virchow, described the specific organism of the disease. In the
+following year Friedrich Loeffler (1852-1915), a Prussian and an
+assistant of Koch, succeeded in cultivating it. The organism has since
+been known as the ‘Klebs-Loeffler Bacillus’. Its study has thrown much
+light on the nature of bacterial action in general and has, moreover,
+led to important therapeutic developments (p. 263).
+
+Of all diseases destructive of human life, none is so dramatic as
+_Plague_, the scourge of mankind throughout history. The bacillus
+of Plague was discovered independently by the Japanese Shibasaburo
+Kitasato (_c._ 1860-), a pupil of Koch, and by the Frenchman Alexandre
+Yersin (1863-), a pupil of Pasteur, during an epidemic at Hong Kong
+in 1894. These two observers cultivated the organism and reproduced
+the disease by inoculation of pure cultures in animals. It had long
+been observed that outbreaks of a deadly disease of rats and mice
+were liable to precede Human Plague. These ‘epizootics’ which precede
+‘epidemics’ are now known to be due to the bacillus of Plague. A mass
+of evidence has been collected to show that the normal carrier of
+the Plague infection is the rat flea. This knowledge has led to the
+formulation of effective measures for the control of Plague. These
+measures are based on the wholesale extermination of the rat population
+which harbors the infective fleas. The study of the Natural History
+of the Plague Bacillus has also led to prophylactic measures for the
+safety of individuals.
+
+[Illustration:
+
+FIG. 114. BACILLI OF DIPHTHERIA FROM A CULTURE. Highly magnified. In
+cultures these bacilli are liable to degenerate into thick club-shaped
+forms several of which are here seen.
+
+]
+
+[Illustration: FIG. 115. BACILLI OF PLAGUE FROM A CULTURE. Highly
+magnified.]
+
+_Malta Fever_ is a disease of much wider distribution than its name
+implies. Not only is it found throughout the Mediterranean area, but
+it is also encountered in China, South Africa, and parts of both North
+and South America. It is a long, tedious and wearing disease, and
+though the mortality from it is low, yet it was at one time one of the
+main causes of disability in the British army at Malta. In 1887 an
+English military surgeon, David Bruce (1855-), succeeded in cultivating
+a characteristic bacillus from the spleen of a patient dead of the
+disease, and he established its causal relation to Malta Fever. In 1904
+its mode of propagation was studied by a British Government Commission.
+The goat was shown to be the normal host of the bacillus, and in Malta
+50 per cent. of these animals were found to be infected. The disease,
+it was discovered, is usually transmitted by goat’s milk. The knowledge
+has led to the application of very effective precautions (Fig. 116).
+
+[Illustration:
+
+FIG. 116. DIAGRAM SHOWING THE INCIDENCE OF MALTA FEVER in the British
+garrison at Malta immediately before and immediately after the
+institution of the preventive measure of cutting off the supply of
+unboiled goats’ milk. The figures of 1905--before the new regulation
+came into force--are represented in black. The figures in the margin
+refer to the number of cases per ten thousand of strength. The figures
+for 1907 are represented in white on the same scale. There is a drop in
+the maximum monthly incidence from 94 to 2. The size of the garrison
+itself remained almost constant throughout the period. ]
+
+Among the most anciently described diseases is the condition known as
+_Tetanus_ or ‘Lockjaw’. There are unmistakable references to it in the
+_Hippocratic Collection_ and notably in the _Aphorisms_. Two of these
+
+references we have already quoted (p. 23). A general association
+of Tetanus with wounds has long been recognized. In the eighties
+the disease was shown to be transmissible from animal to animal. It
+was, moreover, experimentally produced in animals by the inoculation
+into them of garden mold. In 1889 Koch’s pupil, Kitasato, obtained
+the Bacillus of Tetanus in pure culture and conveyed the disease to
+animals. He found the organism would grow only in the absence of
+Oxygen. It is, in fact, a type of a large and now well-known group,
+the ‘anaerobic’ bacteria. The natural habitat of the Tetanus Bacillus
+has been proved to be soil, and especially richly manured soil. The
+knowledge of the bacillus, of its habitat, and of its mode of growth
+has led to the development of a valuable protective process.
+
+Looking backward from the standpoint of present-day knowledge we can
+trace _Typhoid Fever_ far back in history. Nevertheless, it was not
+till 1837 that the distinction between the two distinct conditions
+known now as ‘Typhoid’ and ‘Typhus’ was first clearly made. This was
+the work of an American physician, William Gerhard (1809-72), of
+Philadelphia. The English were backward in adopting the distinction.
+The organic cause of Typhoid Fever was first seen in 1880 by Karl
+Joseph Eberth (1835-1927), a pupil of Virchow, and after him it is
+known as ‘Eberth’s Bacillus’. It was not isolated, however, until some
+years later. It is an inhabitant of the intestine, and its natural
+history was obscured by confusion with certain other and very similar
+organisms, which also dwell in the intestine. These have now been
+fairly differentiated from each other, and in the course of this
+process the ‘flora’, both normal and pathological, of the intestinal
+canal has become well known. Moreover, it has been shown that typhoid
+organisms are not always of the same species, but that several
+closely allied forms produce several closely allied diseases. Lastly,
+certain of the effects wrought by the typhoid group of organisms on
+the body, which is their host, have been exactly investigated. These
+investigations have led to improved methods of recognition of the
+disease, that is to say, _diagnosis_, and also of prevention of its
+incidence, that is to say, _prophylaxis_. To these methods of diagnosis
+and of prophylaxis we now turn.
+
+[Illustration:
+
+FIG. 117. BACILLI OF TETANUS FROM A CULTURE. Highly magnified. The
+drum-stick forms are very typical.
+
+]
+
+[Illustration:
+
+FIG. 118. BACILLI OF TYPHOID FEVER FROM A CULTURE. Highly magnified.
+The long flagellae, which are constantly in motion and are very
+characteristic of these organisms, are well seen. ]
+
+
+§ 12. _The Study of Immunity._
+
+In the production of disease by living organisms two main factors
+are involved. There is, firstly, the multiplication of the organisms
+themselves, and there is, secondly, the production by the organisms
+of poisonous substances or _toxins_. The former phenomena are spoken
+of as _infection_, the results of the latter come under the title of
+_intoxication_ or _toxic_ effects. The first toxins to be investigated
+were those isolated from putrefying substance and named _ptomaines_
+(1876, by false formation from Greek _ptoma_ ‘a corpse’). These are, in
+fact, definite chemical substances of the group known to chemists as
+‘alkaloids’ (p. 325). Later, toxins were prepared from actual disease
+organisms such as those of Typhoid and Tetanus (1888). The method was
+introduced of filtering the bacteria away from their fluid cultures
+and thus obtaining a bacterium-free liquid containing the poisonous
+bacterial products. This was the starting point of the scientific
+study of toxins. These, it soon became clear, were either substances
+which were normally sent out by the bacteria, _exotoxins_, or they
+were normally retained within the bacteria and could only be obtained
+in solution by breaking up the bodies of the bacteria, _endotoxins_.
+The use of these toxins has been essential for the scientific study of
+Immunity.
+
+The word _Immunity_ is derived from a Latin word which means ‘exemption
+from military service’. In Medicine it indicates an exemption, relative
+or absolute, from the incidence of a disease. Immunity in the medical
+sense is of various kinds. There is ‘species immunity’, some species
+not being liable to diseases to which others fall victims. There is
+relative and there is absolute immunity. There is innate and acquired
+immunity. Of acquired immunity there is a natural immunity resulting
+from the ordinary contraction of a disease, and there is an ‘artificial
+immunity’. It is only artificial immunity that is in the hands of the
+physician.
+
+Artificial immunity itself is of two kinds, and both kinds are of use
+and of importance in Medicine. There is an _Active Immunity_, which is
+produced directly by injection of disease organisms or their products.
+It is found, however, that if a high degree of active immunity be
+attained the blood serum of the immunized animal, when injected into a
+second animal, may itself produce a state of immunity. The state thus
+indirectly produced is described as _Passive Immunity_.
+
+The early observers found that when organisms are cultivated outside
+the body they lose their virulence to a greater or less degree. Pasteur
+found this for Chicken Cholera (p. 234). He found, moreover, that such
+‘attenuated cultures’, when inoculated, protect against the disease.
+By the use of attenuated cultures he succeeded in establishing a state
+of ‘Active Immunity’ against Chicken Cholera. But there are many other
+ways of attenuating the virulence of an organism. Thus, in 1882,
+Pasteur showed that to grow Anthrax bacilli at a high temperature would
+reduce their virulence. These bacilli of reduced virulence could be
+injected into a sheep. They would give the animal the disease in a mild
+form and protect it against further attacks of the disease. They acted,
+in fact, in the same way as did the old ‘Inoculation’ of Small-Pox (p.
+183).
+
+It has been found, however, that the same kind of immunity which is
+produced by administering attenuated cultures is sometimes given even
+by dead cultures. Nearly all active immunization is therefore done by
+inoculating such killed cultures. These are usually called ‘Vaccines’
+from the analogy which they bear to vaccination. The most familiar and
+effective ‘vaccine’ is that against Typhoid. Moreover, it has been
+found that in certain cases the principle of the induction of Active
+Immunity may be applied directly in the treatment of disease. The
+conditions that respond best to this line of treatment are those which
+present some localized infection, such as a boil or carbuncle. In such
+cases we must suppose that, while the local capacity for resistance
+is lowered, yet reserves of resistance in other parts of the body can
+be brought into play. These reserves are called up by the signal that
+reaches them by the reaction of the body against the Vaccine.
+
+It has been shown that, for the production of Active Immunity, the
+actual bodies of the disease organisms are not always necessary. In
+some cases, toxins obtained from these disease organisms are themselves
+sufficient to induce Active Immunity. The matter may become of great
+medical importance in the future and is already applied for Diphtheria
+(p. 265).
+
+We turn to ‘Passive Immunity’. The fact that Immunity can be
+transferred from one animal to another via the serum proves that the
+immunizing serum contains substances antagonistic to the bacterium
+or toxin against which immunity is conveyed. These antagonistic
+substances are spoken of as _Antibodies_. A series of very important
+observations on Antibodies has been made, and may in time profoundly
+modify not only our views of Disease but also our whole conception
+of the workings of the living body. We find that it is not only
+toxins that stimulate the formation of antibodies. Antibodies can be
+elicited also by the introduction into the tissues of the living body
+of red blood corpuscles, of embryonic tissue, and of various soluble
+tissue-constituents of animal or vegetable origin. We are still only
+on the threshold of the investigation of this subject, which may be as
+important philosophically as it is therapeutically.
+
+
+§ 13. _Some Practical Applications of Immunity._
+
+We may now consider a few special applications of our knowledge of the
+defences against bacterial action.
+
+_Diphtheria_ is a disease in which the characteristic organisms are
+found only locally, and in artificially produced cases only at the
+site of inoculation. It therefore seemed probable from the first that
+the symptoms were due not to the organisms themselves but to poisons
+that they threw off, that is to their ‘exotoxins’. This was given
+demonstrational form in 1889 by two pupils of Pasteur, Pierre Roux
+(1853-) and Alexandre Yersin (1863-), who investigated many of the
+properties of these toxins. In the following year (1890) Emil von
+Behring (1854-1917), a Prussian Army Surgeon, and Kitasato showed that
+it was possible to produce a Passive Immunity against Tetanus by a
+serum from an infected animal, the immunity being efficient against 300
+times the fatal dose of Tetanus. Their paper contains for the first
+time the word _antitoxic_. Immediately after, von Behring showed that
+against Diphtheria, too, immunity could be obtained by injecting serum
+from an animal that had been previously injected with living cultures
+of the Diphtheria bacillus. This epoch-making discovery of von Behring
+was soon given a practical application. It was found possible to induce
+a degree of immunity even after the onset of the disease. The first
+human case was a child in a clinic at Berlin in 1891. Antidiphtheritic
+serum was placed on the market in 1892. In a few years’ time its
+administration had become a routine part of the treatment of the
+disease. Diphtheria antitoxin is one of the greatest additions to
+therapeutics. With competent administration the case mortality of
+Diphtheria is one-half or one-quarter of what it is without the use of
+Antidiphtheritic serum. (Fig. 119.)
+
+[Illustration:
+
+FIG. 119. DEATH-RATE OF CASES OF LARYNGEAL DIPHTHERIA IN PUBLIC
+HOSPITALS IN LONDON. Antitoxic serum came into use in London in 1895
+and into full use in 1896. As its application became more general and
+as the method of administration improved the death-rate from this very
+grave condition progressively fell. ]
+
+An important aspect of the reaction of the body to the Diphtheria toxin
+was revealed by B. Schick of Vienna in 1908. The technique of inducing
+it was perfected by him in 1913, and the test is known by his name.
+He showed that susceptibility to the disease could be detected by the
+behavior of the skin after injection of minute doses into it. It has
+thus been found that new-born infants are seldom susceptible and that
+the proportion of susceptibles increases up to two years of age, but
+that then it diminishes. The actual proportions of susceptibles, as
+estimated in a large number of cases in New York City in 1919, are as
+follows:
+
+                   Of those under 3 months  15%   are susceptible
+  Of those between  3 months and  6 months  30%   are susceptible
+  Of those between  6 months and  1 year    60%   are susceptible
+  Of those between  1 year   and  2 years   70%   are susceptible
+  Of those between  2 years  and  3 years   60%   are susceptible
+  Of those between  3 years  and  5 years   40%   are susceptible
+  Of those between  5 years  and 10 years   30%   are susceptible
+  Of those between 10 years  and 20 years   20%   are susceptible
+                   Of those over 20 years   15%   are susceptible
+
+These figures show why Diphtheria is mainly a disease of childhood
+and is relatively seldom encountered in adults. They also make it
+evident that steps for protecting individuals against contracting the
+disease--‘prophylactic measures’ as they are called--need only be taken
+with a fraction of the population. The useful term _Prophylaxis_ is
+derived from a Greek word meaning a watchman or guard. It is used to
+describe preventive measures against disease in general, but is more
+specially applied to that form of protection which is achieved through
+the artificial production of Immunity.
+
+Such prophylactic measures are now available against Diphtheria.
+They differ from those in use against any other disease, since the
+substance injected is neither the living infective material as in
+vaccination against Small-pox (p. 184), nor is it a killed culture of
+the organisms as in immunization against Typhoid (p. 268), nor is it
+the serum of an immunized animal as in the protective measures against
+Tetanus (p. 267). The Toxin itself (mixed with an experimentally
+determined proportion of its antitoxin) is now in wide and effective
+use as a prophylactic against Diphtheria. The method was proposed by
+von Behring (cp. p. 264) in 1913. The details, however, have since
+been worked out in the laboratories of the New York City Department
+of Public Health and have been mainly the work of W. H. Park (1863-).
+The susceptibles are first determined by the Schick test and are then
+immunized against the disease. The immunization reduces the likelihood
+of contracting the disease to about one quarter.
+
+Plague differs from Diphtheria in that the organisms, instead of
+being local, pullulate throughout the body of the victim. As in the
+case of most diseases of this type, the toxins of Plague are chiefly
+_endotoxins_, unlike those of Diphtheria, which are _exotoxins_
+(p. 263). Thus, the filtrate of a culture of Plague Bacilli is but
+little toxic and confers little or no immunity. Protective vaccines
+of a killed culture of Plague Bacilli are, however, prepared, and
+these confer considerable immunity. It is claimed that they reduce
+the liability to the disease by about three-quarters, and the case
+mortality by about one-half. Prophylactic inoculation against Plague
+is associated especially with the name of the Russian investigator
+Waldemar Haffkine (1860-), a pupil of Pasteur, who was for many years
+in the service of the British Government in India, the Plague center of
+the world.
+
+After Diphtheria one of the earliest diseases of which the toxins were
+investigated was _Tetanus_. Kitasato found in 1891 that the filtrates
+of pure cultures injected into animals are very toxic. A peculiar
+feature is the incubation period of some days that occurs between
+the inoculation and the advent of the symptoms. This fact had been
+referred to, more than two thousand years earlier, in the _Aphorisms_
+of Hippocrates (p. 23). Moreover, it has been found that, soon after
+inoculation, the Tetanus toxin disappears from the blood-stream. This,
+it has been shown, is due to its affinity for nervous tissue, with
+which it rapidly enters into some sort of combination. The fact is of
+clinical significance and of therapeutic application.
+
+By injection of small and progressively increasing doses of Tetanus
+toxin into animals, a high and long-lasting degree of immunity to
+the disease is produced. The serum of such immunized animals has the
+capacity to protect animals susceptible to the disease against an
+injection of a fatal dose. It is now a routine treatment to inject
+serum derived from an immunized horse into those who have wounds likely
+to result in Tetanus. Owing to the rapid disappearance of the Tetanus
+toxin from the blood-stream, and owing to its tendency to unite with
+nervous tissue, it is important to inject the serum as soon as possible
+after the infliction of the wound. In some cases it is advisable to
+inject the serum into the sheath that surrounds the spinal cord in
+order to give it as rapid access to the nervous centers as possible.
+During the Great War prophylactic doses of Antitetanic Serum were given
+to every wounded man after 1914. Before the practice was adopted, the
+incidence of Tetanus among the wounded was 16 per 1,000. After the
+introduction of this line of treatment as a routine, the incidence fell
+to 2 per 1,000. Countless lives were thus saved. Antitetanic serum
+should be injected as early as possible in every case of a large ragged
+wound, especially if contaminated with soil.
+
+_Typhoid Fever_ differs from Diphtheria, Plague, and Tetanus in that
+it can hardly be conveyed to animals. It has thus proved impracticable
+to produce anything in the way of passive immunity in man. On the other
+hand, there is no disease in which the production of active immunity
+by means of Vaccines of dead cultures has been attended with more
+favorable results. The researches which led up to the introduction
+of active immunization against Typhoid Fever are bound up with
+investigations concerning the diagnosis of the disease which are of
+wide importance in connection with several other diseases.
+
+The discovery of Antibodies (p. 262) gave rise to great activity in
+their investigation. Among the most interesting and important of the
+antibodies is a group which will cause ‘agglutination’ or clumping
+of the disease organisms with which they are specially associated.
+This reaction is specific for the corresponding organisms, within
+certain limitations. Given, therefore, (1) a pure culture of an
+organism, and (2) the knowledge of the highest degree of dilution of
+the serum containing such an antibody that will cause agglutination of
+that particular organism, the physician has in his hands a means of
+detecting or excluding infection with that organism. The method was
+especially studied by the Parisian investigator Fernand Widal (1862-),
+who in 1896 succeeded in making it practicable for Typhoid Fever, and
+his name is attached to the test. It is now universally applied in that
+disease. Similar tests have been devised for Malta Fever and for other
+conditions.
+
+There are other groups of antibodies that have been investigated. Some
+of these possess the power of dissolving the corresponding organism.
+They are, therefore, known as _Bacteriolysins_. Their existence
+gives a certain insight into the defensive mechanism of the animal
+body against bacterial invasion. They are sometimes of practical use
+in distinguishing types of disease-producing bacteria. The method
+is applicable, for example, in detecting certain types of dysentery
+organisms.
+
+Another group of antibodies act not against bacteria but against
+certain specific substances. Antibodies of this type were first
+detected by the Belgian workers Jules Bordet (1870-) and Octave Gengou
+(1875-) in the year 1900. The physician avails himself of the existence
+of such an antibody in the test that is applied for Syphilis, which was
+introduced in 1904 by Ehrlich’s pupil, August von Wassermann (1866-),
+and is known by his name.
+
+Of late years a special aspect of Immunity has come into view in
+connection with the so-called ‘Carrier Problem.’ With many diseases,
+acquisition of Immunity on the part of the patient implies the death
+within his body of the organism that has been causing the disease.
+There are conditions, however, in which the organisms may lurk in some
+individuals long after the symptoms have subsided. These persons may
+even contract the disease so lightly that they are unconscious of it,
+but nevertheless they become capable of conveying it. Such individuals
+are known as _carriers_. Evidently the existence of carriers introduces
+special difficulty into attempts to delimit an infective disease in any
+population.
+
+Among the diseases of known bacterial origin that are sometimes
+conveyed by carriers are Typhoid Fever, Diphtheria, and Spotted Fever
+or Cerebrospinal Meningitis. A special case of the Carrier Problem is
+afforded by Infantile Paralysis, a disease due to ‘ultra-microscopic’
+organism--since the virus is ‘filtrable’ (p. 274). This disease, like
+that of Cerebrospinal Meningitis, is probably transmitted by carriers
+who do not themselves suffer.
+
+Typhoid Fever, Diphtheria, Influenza, Scarlet Fever, and many other
+conditions are often conveyed by ‘ambulant’ cases. This term is applied
+to those cases which, while definitely suffering from a disease, do
+not regard themselves as ill enough to take to their beds but continue
+their ordinary avocations. Such ambulant cases are not less but more
+dangerous to their neighbors than those more severely stricken.
+
+The whole study of the Carrier Problem is in its infancy. It is beset
+with extraordinary difficulties. In the case of Diphtheria and Typhoid
+Fever, however, the demonstration that a suspected individual is or is
+not a ‘carrier’ is easy. The difficulty is to trace him in the first
+instance!
+
+
+§ 14. _The Conquest of the Tropics._
+
+Nowhere in Medicine has the rational spirit been more triumphantly
+vindicated than in connection with the diseases peculiar to hot
+countries. The increase in the habitability of the Tropics may be
+traced to two main causes. First is the application of the ordinary
+laws of Hygiene. Second is the increasingly exact knowledge of the
+microbic origin of tropical diseases, leading to a more complete
+apprehension and a stricter application of the laws of Hygiene.
+
+We have glanced at the great changes wrought in the social
+organization of temperate countries by the rise of modern Hygiene (pp.
+172-78), which commenced to be felt about the middle of the eighteenth
+century. The death-rate then began to fall, and has fallen steadily
+ever since. The mid-eighteenth century marks, for temperate countries,
+the end of the ‘Middle Ages’ of Hygiene. But with the advent of the
+modern period the fall in the death-rate in temperate countries has not
+been the only change in the public health. Even more significant is a
+change in the _causes_ of death.
+
+Certain diseases have gradually receded from the more civilized and
+settled temperate countries, and are now almost unknown there. Thus,
+Malaria, Plague, Typhus, Leprosy and Dysentery, once of world-wide
+distribution, have come to be regarded as more or less distinctively
+‘tropical’ diseases. A time is approaching when we shall be able
+to place other diseases with which temperate countries are still
+afflicted, such as Typhoid Fever, in the same category. The ultimate
+exclusion of Typhoid as a disease of civilized communities is suggested
+by the death-rates of England and Wales.
+
+
+_Average Annual Death-rate in England and Wales from Typhoid per
+million living._
+
+  1871-80  1881-90  1891-1900  1901-10  1911-20  1921-26
+    332      198       174        91       35       24
+
+In the category of such removable diseases which, being excluded from
+temperate countries, are regarded as tropical are Malaria, Plague,
+Typhus, Leprosy, and certain forms of Dysentery. These diseases are
+‘tropical’ only in the sense that it is in the Tropics that the general
+hygienic conditions most favorable to their development are still
+found. If the hygienic conditions of the Tropics could be raised to
+those of the civilized temperate countries--a task, it is true, of very
+great difficulty--these particular diseases might become as rare there
+as they are with us. Indeed, it is possible to foresee a world in which
+a number of these so-called tropical diseases will have disappeared
+altogether.
+
+There are, however, other diseases that are tropical in another sense.
+Such diseases have seldom or never visited the shores of temperate
+countries, or at least have obtained no lasting foothold there, even
+when the conditions have been favorable to them. Among such diseases
+are Yellow Fever, Sleeping Sickness (which must not be confused with
+the so-called ‘Sleepy Sickness’), Beri-Beri, Dengue, Sprue, Kalar-azar,
+and a host of other less known conditions.
+
+It must be said, to avoid misunderstanding, that ‘the Tropics’ in the
+medical sense is a region considerably wider and far less well-defined
+than the geographical Tropics. Moreover, despite the existence of
+diseases peculiar to the Tropics, ‘tropical diseases’ form no natural
+group based on any common organic causation. The organisms that give
+rise to the various ‘tropical diseases’ differ from one another just
+as much as the organisms that give rise to the diseases of temperate
+countries.
+
+Since we cannot speak of tropical diseases on the basis of their
+common causation, we are forced to deal with them as separate entities
+and especially from the point of view of their prevention. We will
+therefore select two diseases, the history of which illustrates the
+process by which the Tropics have been rendered safer both for European
+and for native races. These will serve as types, and we will choose
+one from the truly tropical group which does not invade temperate
+climes, and the other from the group which is being gradually excluded
+from temperate climes. No better instances of these two groups can be
+adduced than Yellow Fever and Malaria.
+
+[Illustration:
+
+FIG. 120. A common Malaria-carrying mosquito × 3.
+
+FIG. 121. The Yellow Fever-carrying mosquito × 3.]
+
+
+(a) _Yellow Fever._
+
+In discussing the history of Yellow Fever, as of many other conditions,
+it is perhaps best to begin at the end, for modern knowledge of the
+organic cause of a disease often illumines and gives a meaning to
+historical records.
+
+In 1918 the Japanese investigator Noguchi observed a very delicate
+and minute spiral organism in the blood of a case of Yellow Fever at
+Guayaquil, the principal port of Ecuador, on the West Coast of South
+America, one of the most important endemic centers of the disease.
+Noguchi showed that guinea-pigs inoculated with the blood of this
+infected case developed symptoms similar to those of Yellow Fever, and
+he was able to demonstrate the same organism in the sick guinea-pigs.
+He passed the disease by means of inoculation from one guinea-pig
+to another. He succeeded in obtaining pure cultures of the organism
+on artificial media. He passed such cultures through a series of
+guinea-pigs and finally recovered it in pure culture again. He showed
+that different strains vary greatly in virulence, a fact in accord with
+the great variability in the gravity of attacks of Yellow Fever.
+
+One of the reasons why the discovery of this organism has been so long
+delayed is doubtless the very small numbers in the blood of patients
+suffering from Yellow Fever. Thus, the toxins must be extremely
+powerful. Indeed, it has been shown that 1/10,000 of a cubic centimeter
+of a virulent culture rapidly induces fatal symptoms in a guinea-pig.
+
+There are other important points about the Yellow Fever organism. It
+passes through a stage in which it is so small as to be beyond the
+reach even of microscopic vision. This fact is known because the blood
+of a Yellow Fever patient is infective when passed through any but
+the finest filters. The organism in fact exists in what is called a
+‘Filter-Passing’ stage. Of late years a number of infective diseases
+have been shown to be due to filter-passing organisms of this type.
+Among them is the organism of the disease known as Infantile Paralysis
+(p. 270). The study of ‘filter-passers’ bids fair to be in itself a
+special science.
+
+Finally, Noguchi threw light on the nature of Yellow Fever epidemics.
+He was able to pass the parasite from one guinea-pig to another, not
+only by inoculation in the ordinary way, but also by means of the bite
+of a species of mosquito which has long been known to be the carrier
+of the disease for man. He showed that a period of some twelve days’
+duration within the body of the insect is necessary for the parasite
+again to develop its dangerous phase. The period of incubation in
+man, that is, the time that passes between the infective insect bite
+and the appearance of the disease, is 3-5 days, but 12-14 days is the
+period that usually elapses after the introduction of a case of the
+disease before other cases occur. The discrepancy is now explained.
+The disease is not infectious except through the mosquito, so the
+developmental period of the parasite within the mosquito corresponds to
+the incubation period of the epidemic.
+
+Outbreaks of Yellow Fever have struck the public imagination, have
+given rise to folk tales and have inspired poets. The story of the
+_Flying Dutchman_ is that of a ship stricken with Yellow Fever. The
+specter ship is supposed by sailors to haunt the seas around the Cape
+of Good Hope, and to bode ill for those who see it. A murder was
+committed on the ship, and following it ‘Yellow Jack’ broke out. All
+ports were closed to the wretched crew, who finally all died of the
+disease. The _Flying Dutchman_ was the subject of an opera by Wagner
+and a novel by Marryat. A picture of a ship smitten by Yellow Jack is
+to be found in Coleridge’s _Ancient Mariner_.
+
+An historic case may be quoted. In 1837 a barque named _Huskisson_ was
+at Sierra Leone. She was lading when Yellow Fever appeared among the
+crew. All but two or three died. Yellow Fever broke out in the colony,
+but gradually died down. The _Huskisson_, in the meantime, remained in
+harbor without hands for three months. At last, hands were obtained,
+tempted by very high pay. Again the Yellow Fever broke out among them
+and again nearly all died. They were bitten by infected mosquitoes
+which remained in the ship during the three months. Many cases, no
+less dramatic, are on record. The disease is among those which are
+peculiarly common and fatal among medical men. Thus, Senegal has twice
+been denuded of medical men by Yellow Fever. In 1830 six died out of
+twelve, and in 1878 twenty-two out of twenty-seven.
+
+An attack of Yellow Fever confers Immunity. In children it assumes a
+mild form, and therefore, in countries where the disease is endemic,
+the population consists largely of the survivors of attacks. On this
+account terrible outbreaks of the _Flying Dutchman_ or _Ancient
+Mariner_ type are always either on immigrant ships or in places which
+have remained long unvisited by the disease, in other words such
+outbreaks occur under conditions in which immune persons are few or
+absent.
+
+The distribution of the Yellow Fever mosquito is wider than the
+distribution of Yellow Fever at the present day, but Yellow Fever is
+never found, save in sporadic outbreaks, where the mosquito cannot live
+permanently. The distribution of the mosquito corresponds, however,
+to the areas where the disease has in the past, from time to time,
+established itself, but is smaller than the area wherein sporadic
+outbreaks have been reported.
+
+During the seventeenth and eighteenth and even the nineteenth century
+there were repeated outbreaks of Yellow Fever far beyond the region to
+which it is now confined. Along the eastern shores of North America it
+has at times extended as far north as New York, and there have been
+destructive outbreaks in Baltimore, Philadelphia, and even Boston. The
+disease has been found along most of the littoral of South America. In
+the Old World it has visited chiefly West Africa, where it was imported
+very early by the slave trade. It has visited at times Spain, Portugal,
+and Italy with devastating epidemics, and has even occasionally made a
+call in France and once in England. The last considerable outbreak in
+Europe was at Madrid in 1878.
+
+England has always had important interests in the West Indies. During
+the eighteenth and first half of the nineteenth century she had,
+moreover, large military establishments there, which were regarded as
+very bad stations. In Thackeray’s _Vanity Fair_, which refers to the
+period just after the Napoleonic wars, the disreputable and unfortunate
+Rawdon Crawley is sent as governor to ‘Coventry Island’ in the West
+Indies, and is not expected to last long! There are many historic
+occasions on which the British forces in the West Indies lost almost
+incredible numbers from Yellow Jack, garrisons being practically wiped
+out. In Jamaica the mean annual mortality in the garrison was for many
+years 185 per 1,000! In the Bermudas the mortality was about 80 per
+1,000. One should remember that soldiers are picked men in the prime of
+life, and that these mortality rates were in places now regarded as
+health resorts! A hundred years ago, Jamaica had the highest death-rate
+in the Empire, with the exception of West Africa, where the mean annual
+mortality of whites at Sierra Leone was 362 per 1,000!
+
+Conditions in the West Indies began to improve definitely from about
+1850 onwards. At that time there was no effective knowledge of the
+organic cause of Yellow Fever, nor, for that matter, of any other
+tropical disease. Only lately has the basic reason for this early
+improvement become obvious. From about 1850 onwards the water-supply
+in the more settled parts of the West Indies, and notably in the
+larger towns, came to be arranged by pipes. Now these towns were the
+special resorts of the Yellow Fever mosquito. The removal of open
+standing water, the enclosure of water-supplies, and the introduction
+of ordinary modern sanitation in the clearing away of rubbish, did good
+work without any knowledge of the organic cause of the disease.
+
+We now know the life-course of the Yellow Fever mosquito. We know
+her breeding habits and how the water-living larvae congregate
+specially in the small collections of water in the neighborhood of
+houses. Precautions have been taken against them and under favorable
+circumstances the disease has completely disappeared in well-managed
+districts under British and American control. The romantic story of
+the destruction of Yellow Fever in the Panama zone, in Cuba, Puerto
+Rico, Jamaica, Barbadoes, Trinidad, New Orleans, has been too often
+recited to be detailed again. Every one has heard of the tragic event
+in connection with the American Mosquito Commission of 1900 and of the
+death of Lazear. He and his colleagues, led by Walter Reed (1851-1902),
+finally proved that the disease is never conveyed by bedding, or by
+clothes, or by other objects, but always and only, in nature, by the
+bite of an infected mosquito.
+
+During the experiments of the American Commission, cases of Yellow
+Fever were produced in volunteers by bites of infected mosquitoes, by
+injection of blood of infected patients, and by injection of _filtered_
+blood serum of infected patients (p. 74). With this knowledge in his
+hands, the American chief sanitary officer of Havana, William C. Gorgas
+(1854-1920), began to destroy mosquitoes systematically and to treat
+all Yellow Fever patients under mosquito nets. Within three months
+Havana was free from Yellow Fever for the first time for one hundred
+and fifty years. These wonderful results are brought out by a table:
+
+
+_Deaths in Havana from Yellow Fever._
+
+  _Year._  _Deaths._ _Year._ _Deaths._
+  1885       165     1895       553
+  1886       161     1896     1,282
+  1887       532     1897       858
+  1888       468     1898       136
+  1889       303     1899       103
+  1890       308     1900       310
+  1891       356     1901        18
+  1892       357     1902         0
+  1893       496     1903         0
+  1894       382     1904         0
+
+Except for the semi-civilized states of Central and South America,
+Yellow Fever is now generally under control. It is perhaps not always
+realized, however, that, while the local extinction of this disease
+may be among the future triumphs of modern science, its substantial
+control over large areas is part of the history of world hygiene (p.
+278), and that it is part of the very same movement that has made our
+own cities healthier and more habitable than they were in the Middle
+Ages.
+
+
+(b) _Malaria._
+
+The history of Malaria, which is also carried by a mosquito, is very
+different from that of Yellow Fever. Malaria was, till recent times,
+a disease of temperate as well as of tropical countries. The old name
+for the disease is _Ague_. The word _Malaria_ is of no great antiquity
+in the English language. It came into use only in the eighteenth
+century. Like the word _Influenza_, it is of Italian origin, and,
+like _Influenza_, it carries with it a forgotten pathological theory.
+_Malaria_ is simply _mal aria_, that is, ‘bad air’. So _Influenza_
+is _the influence_, that is to say, the influence of unpropitious
+planets or comets that were held to rain down poison into the air. It
+was believed that these diseases were the result of local atmospheric
+conditions. In Rome and the Campagna the natives still believe that
+just as the sun goes down the air becomes specially poisonous.
+
+While the _term_ Malaria is comparatively modern, nevertheless,
+recognizable accounts of the _condition_ are perhaps more ancient
+than those of any other disease. Of all diseases produced by
+micro-organisms, Malaria has perhaps changed its type least during the
+course of historic time. The disease is distinctly described in several
+places in the _Hippocratic Collection_.
+
+The conception of diseases as separate entities is, of course, modern.
+In the case of most infectious diseases, therefore, we cannot hope
+to follow the history very far back. But the symptoms associated
+with a malarial attack are so definite that there is no difficulty
+in tracing the disease with certainty as far back as 1000 B.C. The
+real division into ancient and modern times comes, for this disease,
+with the use of Cinchona, which is the plant from which Quinine (p.
+326) is now derived. Very soon after the introduction of Cinchona in
+the seventeenth century, fevers came to be habitually divided into
+those which respond to Cinchona and those which do not. Cinchona--and
+therefore its derivative, Quinine--is one of the drugs that we owe
+to the discovery of the New World (p. 95). The rind of the Cinchona
+tree was taken as a remedy by the aborigines. In Europe, where it was
+introduced by Jesuit missionaries, it became known as ‘Jesuits’ bark’.
+It was popularized by Sydenham (p. 100) and has ever since been widely
+used in medicine.
+
+[Illustration: FIG. 122. GEOGRAPHICAL DISTRIBUTION OF INDIGENOUS
+MALARIA IN ENGLAND AND WALES ABOUT 1860.]
+
+Sydenham gave a good description of Malaria. During the seventeenth
+and eighteenth centuries epidemic after epidemic of ‘Ague’ swept over
+England as over other European countries. These epidemics spread from
+their endemic centers, the low-lying ill-drained, swampy districts,
+where the Malaria mosquito could breed freely in the slowly flowing
+water. Of such places the principal in England were the Fens of
+Cambridgeshire, Lincolnshire, and the surrounding counties, the marshes
+on either side of the estuary of the Thames in Kent and Essex, the
+marshes of Romney and Pevensey on the South coast, and those around
+Bridgewater near the Bristol Channel (Fig. 122). There Malaria was
+never absent, though it differed greatly in prevalence and severity in
+different years. Ague remained prevalent in London as late as 1859.
+The proportion of ague cases to the total number of in-patients and
+out-patients at St. Thomas’s Hospital in London from 1850-60 varied
+from between 12 per 1,000 at lowest to over 60 per 1,000 at highest.
+Thus, over one-twentieth of the patients in a large London hospital
+suffered from what we now regard as a tropical disease, within the
+lifetime of men who are still with us!
+
+In London the rise in the value of land led to the erection of the
+Thames Embankment, which effectually reclaimed the land around
+the river. Extensive works of drainage were at the same time being
+undertaken in other infested districts. These soon had their now
+well-known effect. In 1864 Malaria was found to be rapidly diminishing
+everywhere, and to have left many of its old haunts. The disease
+retreated rapidly. At the beginning of the twentieth century a
+systematic search was made for a native case in England. After much
+labor one single case was at last found. It may safely be prophesied
+that native Malaria will never again be anything but a rare disease in
+any temperate country with an efficient sanitary service.
+
+The story of the discovery of the malarial parasite is worth
+recounting. These organisms inhabit the red blood corpuscles and
+were first seen by Alphonse Laveran (1845-) in 1880 in Algiers. His
+observations were extended by French and Italian observers, who showed
+that the sudden rise in temperature in Malaria coincides with a process
+of division of the parasite. Later the suggestion that the parasite
+might be conveyed to man by the mosquito was made by Patrick Manson
+(1844-1922). The matter was clinched in 1898 by Ronald Ross (1857-),
+who showed that the malarial parasite necessarily passes through a
+stage in the stomach of the mosquito. The process was first traced by
+Ross in a malarial parasite that is peculiar to certain birds, and
+was subsequently demonstrated for the allied species of parasite that
+produces human Malaria.
+
+We have here an illustration of the value of comparative pathological
+studies. Since the demonstration of the life-cycles of the malarial
+parasites of man (Fig. 123), the chief attention of hygienists
+interested in
+
+Malaria has been directed to the mosquito (Fig. 124). Controlling the
+breeding of the mosquito has proved the best method of reducing the
+incidence of the disease. Engineering and sanitary works in some places
+previously infested with Malaria have had the effect of almost entirely
+eliminating disease. The classical instance is the Panama zone, where,
+as is well known, the two mosquito-born diseases, Yellow Fever and
+Malaria, have disappeared. There are now many areas in the Tropics,
+previously infested, in which the disease is almost unknown. There are
+many devices for dealing with the mosquito larvae.
+
+By advances such as have been made in the knowledge of Yellow Fever and
+Malaria, those areas of the Tropics which are under proper sanitary
+control have become far safer habitats. There is good hope of an early
+and rapid extension of the process, ultimately rendering new areas of
+the Tropics suitable for permanent habitation by the white races and
+healthier and happier places for the colored.
+
+[Illustration: FIG. 123. THE LIFE-HISTORY OF THE PARASITE OF MALARIA
+
+The life-histories of the parasites of the malarial diseases of man
+have been completely traced. The parasites run through a double cycle,
+one in man and the other in the mosquito. In our diagram the cycles of
+only one species are represented; there are however two other special
+malarial parasites in man.
+
+On either side the head of the mosquito involved is diagrammatically
+shown, just below the ‘cycle in man’.
+
+In man the parasites conveyed by the bite of the mosquito (32) or
+formed by a division of a parasite already in the blood (7) make their
+way into the red blood corpuscles (1 and 2), develop there (3 and
+4). Some of them ultimately divide to go through the same cycle (5,
+6, 7 and back to 1, 2). The process of division corresponds to the
+period of fever. Others develop into crescent-shaped bodies (8, 9 and
+10), which can be differentiated into two slightly different forms
+corresponding to two sexes (9 male, 10 female). These, if sucked up by
+a biting mosquito of the right species, pass into the animal’s stomach
+where they develop further (11, 12, 13 male; 14, 15, 16 female) and
+end by dividing into forms which conjugate (17). The resultant of this
+conjugation or union of the two sexes (17) develops into a lanceolate
+form (18, 19, 20) which passes into the cells of the mosquito’s stomach
+(21, 22) and finally penetrates these cells (23). The parasite then
+secretes a cell-wall and forms a ‘cyst’ (24), which enlarges (25).
+The enlargement continues while the nucleus breaks up (26, 27, 28).
+In the cyst, which is still growing, a large number of needle-like
+forms develop, each of which contains a fragment of the nucleus (29).
+Finally the cyst bursts (30), the needle-like forms are cast forth into
+the body of the mosquito, and ultimately lodge in her salivary glands
+(31). When the mosquito bites another man, she injects some of her
+saliva into him through her proboscis. Thus she infects his blood with
+some of the needle-shaped parasites that lurk in her salivary gland
+(32). So the cycle is re-enacted again and again. We may note that to
+prevent this process of repeated reinfection it is only necessary to
+break either cycle at one point. Thus destruction of mosquitoes or of
+their breeding-places will suffice, or, again, protection of human
+hosts from bites of mosquitoes will be sufficient. Either process, if
+persisted in, will lead to the extinction of the parasite in the region
+under supervision. In England both methods have been in operation and
+the disease is almost extinct there so long as any of the malarial
+mosquitoes remain in one district. However, the disease can always be
+reintroduced by the introduction of subjects of malaria from without.
+
+(From C. M. Wenyon’s _Protozoology_, Vol. II, by kind permission of
+Messrs. Baillière, Tindall and Cox. Slightly reduced in size.)]
+
+[Illustration: FIGS. 124 and 125. A common Malaria-carrying mosquito
+and a common gnat sometimes confused with the Malaria-carrying
+mosquitoes. They are both in sitting posture and may be easily
+distinguished by the attitude that they then assume.]
+
+[Illustration:
+
+FIG. 126. CHART OF CASES OF MALARIA reported in Italy in recent years,
+showing the seasonal variation of the disease. The date of the year
+is written, in each case, below a vertical line corresponding to
+midsummer. It will be seen that the maximum incidence is always in
+the months July to September, and the minimum incidence is always in
+the months January to March. This incidence corresponds to the known
+facts of the life-history of the mosquito and of the evolution of the
+malarial parasite within the body of the mosquito. ]
+
+
+§ 15. _The Changed View of Insanity._
+
+Insanity is as old as History. The Bible, Homer, and the _Hippocratic
+Collection_, for instance, recount numerous examples of the disease.
+Until the nineteenth century there was practically no scientific
+knowledge of the conditions classed as insanity. Nevertheless,
+hospitals for the insane were instituted at an early date. A well-known
+instance is Bethlem Hospital or _Bedlam_ in London, which was developed
+as an insane asylum in the fourteenth century.
+
+The new era in the treatment of insanity begins with the abolition of
+the old system of restraint. This was primarily due to two noble-minded
+men, one a Frenchman and the other an Englishman. Philippe Pinel
+(1745-1826), physician at the Bicêtre and afterwards at the Salpêtrière
+at Paris, at great personal risk both to his life and liberty,
+insisted on freeing from their chains the unfortunate lunatics under
+his charge. His _Medico-philosophical Treatise on Mental Alienation_
+(1791) was devoted to championing the humaner treatment of the insane.
+His contemporary, the Quaker philanthropist William Tuke (1732-1822),
+succeeded in 1792 in establishing at York a small retreat for the
+insane, where the antiquated, unnecessary and cruel restraints were
+abolished (Fig. 127).
+
+While Pinel was beginning the humaner treatment of insanity in France,
+considerable interest was aroused in the subject in Germany. There,
+however, the medical profession was still under the influence of the
+mystical Stahl (pp. 132-3), who regarded all forms of insanity as
+perversions of the moral tendencies of the soul, produced by sin!
+
+In France Pinel was succeeded in 1810 by Jean Étienne Dominique
+Esquirol (1772-1840). The influence of Esquirol was as radical for
+the scientific study of the subject as had been that of Pinel for the
+humane treatment of the sufferers. Esquirol threw himself into the
+task of founding properly conducted asylums, and he produced in 1838
+his monumental work _On Mental Diseases considered in their Medical,
+Hygienic, and Legal relations_. It is the first important, rational,
+scientific treatise on the subject. Esquirol abandoned the barren type
+of speculation that had characterized previous works on the subject
+and devoted himself to the systematic collection of data. He was able
+to sketch out some of the main forms of insanity, including that now
+known as ‘General Paralysis of the Insane’. This disease was finally
+differentiated by one of his pupils. Another pupil of Esquirol was the
+first to succeed in the training of idiots. The main school of French
+alienists is descended from Esquirol. In the early forties his work
+resulted in the foundation of journals and societies devoted to the
+study of Insanity in France, England, the United States, and Germany.
+
+England was behind France in her treatment of the Insane. Not until
+1828 were there proper laws governing their certification. In 1844 the
+great and good Lord Shaftesbury (1801-85), the seventh Earl, brought in
+his Bill establishing the Board of Lunacy Commissioners with the duty
+of inspecting all lunatic asylums. It was a subject to which that great
+philanthropist gave much thought. The same period saw also an awakening
+in the United States, where Miss Dorothea Lynde Dix (1802-87) carried
+on a very successful campaign for the better treatment of the insane
+and the establishment of proper houses for their reception. Her labors
+resulted in the foundation of many asylums on a reformed model in the
+United States and Canada. In 1845 the provision of asylums out of the
+local rates was made compulsory on the local Justices in England.
+
+The late sixties and early seventies saw in every country a further
+change for the better in the treatment of the Insane. The causes of
+this improvement were two. On the one hand, Insanity came generally
+to be recognized as a group of diseases which, like other diseases,
+have usually a traceable physical basis. On the other hand, the great
+improvement of the system of nursing under the inspiration of Florence
+Nightingale (pp. 298-300) began to reach the asylums. In 1877 there
+was a Parliamentary investigation into the care of the Insane in
+England and Wales, and in 1890 the duties of asylum administration were
+transferred from the Justices to the County Councils. This has resulted
+in an immense improvement in the accommodation and treatment of the
+insane poor in England. At the same time the order of a magistrate
+became necessary for the consignment of a private patient to an asylum.
+In 1913 provision was made for the mentally defective, who do not come
+within the Lunacy Act. Lastly, with the establishment of a Ministry of
+Health in 1917, the general control of the Insane has passed to that
+body.
+
+Many types of insanity have been traced to an organic cause in the
+Nervous System itself. The Morbid Anatomy, both coarse and microscopic,
+of some of these diseases has become recognized. Chief among them is
+the well-known condition known as ‘General Paralysis of the Insane’.
+During the intensive study of the factors in the causation of Insanity
+it has become clear that in some groups, as in General Paralysis, which
+is always preceded by Syphilis, a ‘toxic cause’ is at work. Other
+types of toxic insanity are due to the actual intake of a poisonous
+substance. This is sufficiently evident in cases which are associated
+with Alcoholism. There is also evidence that in a considerable
+number of cases toxic conditions result from perversion of metabolic
+processes, or, again, are associated with ‘deficiency’ states (pp.
+302-8). This is a very hopeful finding, since by removing the toxic
+cause, or by remedying the deficiency, relief may be possible.
+
+Much less hopeful is the outlook with those forms of insanity,
+especially common in the adolescent, which are of the nature of a
+perversion of development. Such is the large group known as ‘Dementia
+praecox’. These cases almost invariably originate from a mentally
+unsatisfactory stock. This is less so with the Epileptic insane, though
+a considerable proportion of epileptics may be classed with those
+who are born mentally defective and are liable to give rise to a bad
+stock. Whatever view may be taken of the question of the artificial
+limitation of human fertility, it is almost impossible to imagine that
+the free breeding of these classes of defectives, epileptics and their
+congeners, will continue unchecked in any civilized community.
+
+The general care and treatment of the insane has improved out of
+all knowledge during the last quarter of a century. It is probable
+that there is now no class of sick person who is more skilfully and
+considerately cared for.
+
+From time to time an alarm is raised at the rapid increase in Insanity,
+and it is a fact that the proportion of certified insane has been,
+for some time, steadily rising. A considerable part of this rise is
+certainly due to the greater willingness of the insane themselves to
+enter an asylum, and of their friends to allow them to do so. Part of
+the rise in numbers of the insane is due to their increased length of
+life under improved treatment. It must be remembered that more than 90
+per cent. of the insane in England and a similar percentage in other
+countries are paupers, who are not readily discharged as they have no
+means of support. Mild mental cases and the senile insane go now to
+the improved asylums. Before they would have been kept at home or sent
+to a rate-supported or a State infirmary. The general conclusion of
+those best qualified to judge is that Insanity, if increasing at all,
+is doing so only very slowly.
+
+[Illustration: FIG. 127. ‘THE RETREAT’ NEAR YORK FOUNDED IN 1792
+
+being the first institution in England where the insane were accorded
+humane and scientific treatment.]
+
+
+§ 16. _The New Movement in Psychology._
+
+During the last half-century various new points of view have entered
+into our conception of Mind and its disorders. The evolutionary view
+of the origin of man, which was brought to wide notice by Charles
+Darwin, not only in his _Origin of Species_ of 1859 but also in his
+_Descent of Man_ of 1871 and his _Expression of the Emotions_ of 1872,
+has given rise to new ideas as to the nature of many instincts and
+emotions. These views have been co-ordinated with our knowledge of
+lower types of man, both in his existing state and in his extinct and
+fossil forms. Much that we call Insanity has been found to be related
+to what is normal in other and less developed environments. The Mind,
+breaking free from its habitual restraints, ‘reverts to a lower type’.
+There is a constant though unconscious ‘conflict’ in the mind, which is
+variously resolved.
+
+Whole schools of Psychology have arisen in the discussion of the nature
+and resolution of these conflicts. Sigmund Freud of Vienna (1856-)
+takes the leading place among those who have dealt with this subject.
+He holds these conflicts to be rooted in sex and has introduced
+the method of _Psycho-analysis_, which lays great stress on the
+subconscious or unconscious element in mental life. Largely under the
+direction of C. G. Jung of Zürich (1875-), preventive and curative
+measures, based on this view, have been introduced into medicine.
+It has been established that painful experiences, lurking in the
+unconscious mind, disturb the equilibrium of health. Such disturbance
+is often of the nature of a struggle to repress into the unconscious
+unpleasant memories which are tending to surge up into the conscious.
+The psycho-analyst seeks to release the repressed experience into the
+conscious. The recognition and consideration that follow a success in
+this attempt is often far less painful than the repression. Persistent
+unreasonable fears on the part of adults, but especially of children,
+are frequently thus dispersed.
+
+The importance of suitable environment to children has always been
+recognized. But a new significance has been given to the mental
+impressions received in infancy by cumulative evidence of harmful
+results in the adult life of events in the early years of life that
+are seemingly forgotten. This recognition of the enduring character of
+mental impressions has led to a movement for the better instruction of
+mothers, and has thus been a factor in the remarkable development, in
+recent years, of work for infant welfare.
+
+It is recognized, moreover, that certain instincts--such, for
+example, as the self-regarding instinct and the sex instinct--must
+have expression. Mere repression of such instincts is always harmful,
+but they are susceptible of a process of transformation, technically
+known as _sublimation_, to an almost indefinite extent. Thus the
+self-regarding impulse need by no means lead to the inconvenience and
+discomfort of others, but, rightly guided, may develop into a sense
+of personal responsibility for the welfare of others. So, too, sex
+instinct is but one aspect of that creative vital activity on which
+depends the continuance not merely of the human race but also of the
+culture that the race has built up. The sex instinct is thus habitually
+sublimed into other creative channels, and there are many altars,
+beside those of Venus, at which young men and women may kindle their
+essential fires.
+
+
+§ 17. _The Revolution in Nursing._
+
+During the Middle Ages, and in Catholic countries after the
+Reformation, attendance on the sick in Hospitals and elsewhere was the
+task of religious sisterhoods. In Protestant countries the absence of
+these sisterhoods necessitated the employment of women specially for
+the purpose. The task was not an attractive one, nor did any social
+distinction attach to it. The profession of nurse became despised
+and was followed, for the most part, by a low and illiterate type of
+woman, though midwives were sometimes better educated and of a higher
+class (p. 180). The great philanthropists of the eighteenth century
+(pp. 171-72) could do little to improve the nursing profession.
+The conditions of employment formed the root of the evil. The vast
+improvement that has resulted in health and happiness to our whole
+population from the improvement in the character and training of nurses
+is probably seldom realized, even by medical men. Yet it may reasonably
+be doubted whether all modern medical and surgical advances put
+together--apart from Preventive Medicine and Infant Hygiene--have saved
+as many lives as the Reform of Nursing.
+
+The reader may gain some insight into the life of a nurse from the
+conditions that prevailed until beyond the middle of the nineteenth
+century at a very good and well-managed English provincial hospital,
+the Radcliffe Infirmary at Oxford. The salary of a nurse was £5 a
+year. There was no distinction between a nurse and a domestic servant.
+One nurse only was the allowance for a ward of seventeen patients. A
+nurse’s day began at 6 a.m. The wards were cleaned till 7, when a bell
+was rung and each nurse had to bring down her ashes and sift them under
+the direction of the porter, who then gave her coals for the day. She
+took breakfast with the patients, who helped her, so far as they were
+able, with the ward work. At 2 p.m. she went to the servants’ hall,
+where she had her dinner in company with the servants on daily hire.
+During the dinner the ward was left in charge of a patient. After
+dinner she took away a plate of meat and vegetables for her supper. For
+the night there was normally only one nurse for the whole hospital of
+about 100 beds. There were no regular holidays, and the nurse was never
+allowed to leave the hospital before 6 p.m. The practice of nurses
+receiving gratuities from patients continued till 1870 and even beyond.
+Those patients who wished to secure a nurse’s early attention for their
+dressings gave tips, those who did not frequently had to wait.
+
+What sort of woman could such a system produce? That some nurses at
+least were kind and skilful, even under such conditions, is a fact, and
+is pleasing evidence of the natural goodness and wisdom that reside in
+the human heart. Many, however, can have been no better than Sairey
+Gamp and Betsy Prig.
+
+The first important reform in Protestant countries began in Germany,
+through the influence of Elizabeth Fry (p. 171). In 1822 Theodor
+Fliedner (1800-64), the young pastor of the church at Kaiserswerth, a
+little town on the Rhine near Düsseldorf, visited England and was much
+impressed by Elizabeth’s teaching and example. Returning to his charge,
+he devoted himself to the spiritual and physical care of jail-birds. In
+1833 he and his devoted wife Frederica (1800-42) opened a refuge for
+discharged female convicts. From them the couple turned their attention
+to the sick poor. The conception of an organized body of specially
+trained women crossed their minds. In 1836 they opened a small hospital.
+
+At this hospital six young women of the most spotless character were
+induced to serve as ‘deaconesses’. It was their duty to perform all
+the tasks of the hospital in rotation. The physicians who attended the
+hospital gave them instruction. The Kaiserswerth idea rapidly spread
+and the ‘Kaiserswerth Deaconesses’ became and remain an important
+order, which is still occupied in good works in many parts of the
+world. The conception of the order is different from that of most
+religious orders in that the members make no attempt to withdraw from
+the world, and marriage is not forbidden to them. Moreover, the duties
+of the Kaiserswerth deaconesses are rather different from and more
+varied than those of a sick-nurse. They include teaching, both secular
+and religious, nursing, household duties, management of children and
+convalescents. In 1865 a preparatory school for probationers was opened.
+
+In England Anglican orders of a somewhat similar character were formed
+in the forties and fifties. In 1850 and 1851 Florence Nightingale
+(1820-1910), who was a lady of good social rank, visited Kaiserswerth,
+and went through a regular training there. She was profoundly impressed
+by the extremely high character of the deaconesses, most of whom were
+only peasant women. The next three years she spent in writing and in
+examining hospitals in her own country.
+
+Florence Nightingale’s opportunity came with the outbreak of
+the Crimean War in 1854, and the rapid breakdown of the medical
+services, which contained no women nurses. The French had a number
+of ‘religieuses’ to nurse their sick, and a feeling of shame arose
+in England at the neglect and mismanagement of the British sick and
+wounded. The Secretary of State for War asked Florence Nightingale to
+go to the Crimea to organize a nursing service. She left at once with
+thirty-eight nurses whom she selected personally. Ten of these were
+Roman Catholic sisters and all the others had had nursing experience.
+From that event dates the Revolution in Nursing. Florence Nightingale
+performed marvels under conditions of great difficulty (Fig. 128) and
+in the face of determined opposition. She returned home in 1856 a
+national heroine. She had no difficulty in establishing a school and
+home for nurses at St. Thomas’s Hospital in London in 1860. The example
+was followed by the other London hospitals.
+
+Florence Nightingale was a woman of the most powerful will and an
+admirable organizer and administrator. Her system of nursing contained
+many new features, not quite all of which have stood the test of time.
+That nursing rapidly and steadily improved from the moment she was in
+authority cannot at all be doubted. Looking back, it is apparent that
+the immediate success of her methods was due to two main factors. First
+was her capacity to secure women of high character and good social
+position to accept positions of responsibility. Second was her removal
+of the control of the nursing staff entirely from the hands of men into
+those of women. Her influence soon passed across the Atlantic, and she
+was associated with the United States Sanitary Commission and the women
+who took charge of army nursing during the American Civil War.
+
+While Florence Nightingale was reforming Nursing, her contemporary,
+Mary Carpenter (1807-77), was applying herself to the kindred task
+of looking after neglected children, establishing Reformatory and
+Industrial Schools and improving the position of Indian women. She
+obtained a large measure of public support and exercised considerable
+influence in America, which she visited in 1873. Many other
+distinguished and devoted women worked on similar lines.
+
+Among the indirect results of the activity of Florence Nightingale was
+the establishment at Geneva in 1864 of the International Red Cross
+Committee, the branches of which have done good service in many wars
+and have been no less useful in peace.
+
+Florence Nightingale opposed anything in the way of State registration
+of nurses. Concentrating on a high ideal of competence and character
+for the nurse, she failed to grasp some of the secondary effects of
+her own scheme. A large nursing service is now a necessity in every
+civilized country, as a result of her efforts and example. Having
+regard to human imperfections, we can as little hope that every woman
+who nurses will be a born nurse, devoted to her task, as that every
+doctor or teacher will have a natural vocation for his work. In an
+imperfect world mankind must protect itself against the incompetent and
+the unfit. Registration is a way--doubtless an imperfect way--of doing
+this. A Nurses’ Registration Act became law in England in 1919.
+
+There have been many improvements in the details of the training of
+nurses, incident on the changes in Medicine and Surgery during the last
+half-century. Apart from these, the main improvements in Nursing have
+been due firstly to an increased interest in the welfare and health
+of the nurse herself, and secondly to the recognition that Nursing is
+a profession for which, as for Medicine, some preliminary scientific
+knowledge should precede professional training. Thus, the very long
+hours of the nurse have of late been reduced, and in the best schools
+instruction is now given to nurses in Anatomy, Physiology, Hygiene,
+Bandaging, and Cookery, before the commencement of actual hospital work.
+
+Further developments will probably be along the lines of State and
+Municipal Nursing Services. Since Health is a public as well as a
+private concern, the same must be true of the training and work of
+nurses.
+
+[Illustration: FIG. 128. FLORENCE NIGHTINGALE RECEIVING WOUNDED AT
+SCUTARI
+
+_From a painting by Jerry Barrett_]
+
+
+§ 18. _Some Modern Physiological Concepts of Clinical Import._
+
+The vast activity in the sciences of Physiology and Pathology during
+the last fifty years, and their repeated divisions into independent
+sciences, each prosecuted by its own specialists, have yielded many
+ideas which have been imported into the clinical practice of Medicine.
+It is impossible to say which of these are of permanent value. All
+previous ages have had to discard part of the practice and a large
+proportion of the medical ideas that have been handed down to them, and
+there is no reason to suppose that the age that follows us will differ
+from those which have gone before us. Some ideas that have entered
+Medicine from the physiological laboratory, pushed by interested
+parties or seized on in despair by physicians at a loss for a line of
+treatment, are already seen by men of experience and judgment to be no
+permanent addition to our store. Other lines of physiological thought
+are still under discussion by them.
+
+There are, however, certain physiological conceptions which, apart from
+their general implications in the economy of the body, have received
+such wide application that their future, as an organic part of medical
+practice, seems assured. Certain of these conceptions demand discussion
+in even the most cursory survey of medical development.
+
+
+(a) _Ductless Glands and Internal Secretions._
+
+The nature and action of the various glands of the body has been a
+classical physiological field. Malpighi (pp. 116-20) was the first to
+investigate the structure of these organs, and he was followed by many
+others. It became evident that many glands, such as the liver, the
+salivary glands, and the tear glands, are provided with ducts or tubes,
+which carry off the characteristic secretion of the glands. These
+secretions can be examined with comparative ease--as happened early
+with the secretion from the stomach, or ‘gastric juice’ (pp. 146-48),
+and later with the secretion of other glands. There remain, however,
+certain glands unprovided with ducts. The action of such ‘ductless
+glands’ long remained a mystery. Of these the type is the ‘Thyroid
+gland’. Much of our physiological knowledge of this organ, together
+with the conception of its function as indispensable to normal life,
+has come through Surgery.
+
+It had long been known that certain symptoms were associated with
+enlarged Thyroid gland or ‘Goitre’. Attempts to remove the organ
+surgically were made after the introduction of antiseptic methods.
+Goitre is particularly common in Switzerland, and it is not remarkable
+that the technique of the very dangerous operation for the surgical
+removal of goitres was first perfected by Swiss surgeons, among whom
+Theodor Kocher (1841-1917) has taken the first place. The study of
+cases that had had their Thyroid glands removed gave a clue to the
+nature and action of the gland.
+
+It was found that those surgically deprived of the Thyroid gland
+develop abnormal slowness in movement and response. The temperature is
+low, the pulse small, the muscles are torpid and sometimes rigid, and
+there is a failure in ordinary fine muscular movements. The patient
+shows a thickening and swelling of the skin and presents a dull and
+very characteristic appearance. When the operation was performed on
+one whose growth was not yet complete, development was checked. Such a
+patient remains infantile or childish both in body and mind.
+
+The conditions were recognized by Swiss surgeons in the seventies
+as resembling those of a spontaneous disease to which the name
+_Myxoedema_ was attached. Further the close relationship both of the
+surgical and of the spontaneous condition to the state of idiocy known
+as _Cretinism_ came gradually into view. In Switzerland, as in other
+parts of Europe, stunted beings known as _Cretins_ had long been known.
+These defectives are sometimes goitrous, sometimes without a Thyroid
+gland, but their general appearance and condition is an exaggerated
+version of what has been described for those with Thyroid glands
+removed (Fig. 129).
+
+[Illustration: FIGS. 129 and 130. CRETINOUS INFANT BEFORE AND AFTER
+THYROID TREATMENT.
+
+_From the Collection of the Royal College of Surgeons._]
+
+The result of these observations was to direct the attention of
+physiologists to the Thyroid gland. It was soon found that the symptoms
+of Thyroid deprivation could be experimentally produced in animals.
+Moreover, it was shown by Moritz Schiff of Berne (1823-1890), in
+1884, that the results of the removal of the Thyroid might be avoided
+if the animal were fed regularly on an extract of the glands. The
+results were soon applied to man and have led to one of the greatest of
+medical triumphs. By its means sufferers from myxoedema and cretinism
+can be either cured or improved. A drivelling and idiotic cretinous
+child, adequately treated with Thyroid, enters on a normal process
+of development. The improvement is almost incredible, and the child
+rapidly passes into a healthy and happy state, so that it is literally
+true to say that his own parents would not recognize him (Fig. 130).
+Further, the gland may be given in excessive doses, and a condition
+produced that closely resembles a well-known pathological condition
+known as ‘Exophthalmic Goitre’, which is similarly susceptible of
+experimental investigation.
+
+The facts here enumerated justify the deduction that the Thyroid
+gland secretes something which is essential to normal well-being. The
+organ has no duct, and the secretion is, therefore, never normally
+thrown out of the body. The Thyroid is, in fact, an organ of what is
+called ‘internal secretion’. Investigations on this secretion led to
+the isolation of the active principle as a pure compound known as
+_Thyroxin_ in 1916. The story of the Thyroid has recently (1926) been
+rounded off by the preparation of Thyroxin synthetically. The synthetic
+product has been given with effect in cases of Myxoedema.
+
+The observations made on the Thyroid directed further attention to
+other ductless organs of which a number have been shown to have their
+own ‘internal secretions’. Furthermore, it has been demonstrated that,
+among organs which throw out their products through a duct, there are
+those which also send an internal secretion into the blood-stream.
+Among these are the essential organs of sex, the testicle and ovary.
+The effect of castration on the general physique is well known. It may
+be compared with the effect of ‘spaying’ or the removal of the ovary.
+This operation leads to an assumption by the female, in more or less
+modified degree, of the secondary sexual characters of the male.
+
+Peculiarly interesting for their practical results have been certain
+investigations made of late years upon the organ known as the
+‘Pancreas’. The Pancreas has a duct which opens into the Intestine
+just below the Stomach. It has long been known that the secretion of
+the Pancreas is related to the amount and fate of sugar in the blood.
+The association of disease of the Pancreas with the symptom known as
+‘Diabetes’, in which sugar appears in the urine, was also familiar.
+Later it became apparent that it was not the Pancreas as a whole that
+was related to the process but only certain isolated and peculiarly
+formed nests of cells. It is now possible to administer extracts of
+these cell-nests with very favorable results on the course of certain
+types of Diabetes. The extract is now in wide use under the name of
+_Insulin_.
+
+Among the ductless glands that have been best investigated are the
+so-called ‘suprarenal bodies’, which lie above the kidneys. As with
+the thyroid gland, the attention of physiologists was directed to
+these bodies as a result of clinical observations. These observations
+date back to the middle of the nineteenth century. In the last years
+of that century it was observed that an extract of the suprarenal
+bodies, injected into the circulation, caused a rise in blood-pressure,
+an effect opposite to that following the extirpation of the glands.
+The administration of extract from suprarenal bodies has found wide
+clinical application. Unlike the extract of thyroid, the effect of this
+extract is very temporary. It is easily oxidized and rapidly disappears
+from the blood. It belongs to the group of substances which are
+known as _hormones_. The active element in a suprarenal extract, the
+‘suprarenal hormone’, has been recently prepared by a synthetic process.
+
+The nature of hormones has only come clearly into view of late years.
+The word ‘hormone’ is formed from a Greek word meaning ‘to excite’.
+The internal secretions have, in general, functions of considerable
+physiological complexity, and act, for the most part, slowly and
+continuously. The hormones are, however, exceptions to this rule. They
+act rapidly and in an excitatory manner. These substances appear to be
+of relatively simple chemical structure. They are easily oxidizable,
+so that they rapidly disappear from the body. They act, in fact, as
+‘chemical messengers’, producing a state of ‘chemical correlation’ of
+the different parts of the body which is comparable to the better-known
+and more widely recognized ‘nervous correlation’.
+
+The hormones represent a very ancient and primitive physiological
+mechanism. In organisms consisting of but one cell, in which there
+are very few differentiated organs, the messages from one part of the
+body to another are necessarily of a chemical or hormonic character.
+In higher multi-cellular animals the intercommunication between
+different parts of the body is maintained, for the most part, by a
+specially developed nervous system. Certain necessary messages are,
+however, still conveyed by chemical messengers. The development of
+the conception of hormones has been especially the work of the London
+physiologist E. H. Starling (1866-1927).
+
+Internal secretions and especially hormones form part of the
+increasingly complex picture of the working of the animal body. They
+are not only of great physiological value, but have also entered
+the department of practical therapeutics. They are, moreover, of
+philosophical importance, since they yield us a conception of the body
+in which every part is dependent on every other part, and the whole is
+subject to a process of ‘integration’ or linkage into a unitary system.
+We have glanced at the mechanism of chemical integration. We have now
+to turn to the mechanism of nervous integration.
+
+
+(b) _Nervous Integration._
+
+If the simple reactions of animal bodies are tested, it will be found
+that they clearly serve certain ends. Lightly touch the foot of a
+sleeping child and it will withdraw it. Tickle the ear of a cat and
+it will shake it. Exhibit savory food to a hungry man and at once
+his digestive process will get to work--his mouth will ‘water’.
+These instances might be multiplied a hundredfold. Such reflexes
+are admirably adapted to their ends. Many of them will continue
+in an animal in which the spinal cord is severed from the brain.
+Nevertheless, in the higher animals, and especially in man, they are
+controllable to a greater or less extent by the will. But to leave the
+question at that would give a false idea of the extremely complex
+integrative functions performed by the nervous system. Thus, the
+spinal cord, which, to the naked eye, is a longitudinal and little
+differentiated nervous mass, is, in fact, a collection of nerve-centers
+which have historically, both in the individual and in the race, been
+formed by the union of a series of separate segments. Each one of these
+segments is dependent on the action of the next segment in a fashion
+somewhat similar to that in which the actions of the cord itself are
+dependent on the brain. Each of the sections governs certain functions
+or movements of the body. There is thus a very complex process of
+integration which runs right through the nervous system.
+
+The investigation of the bodily functions of a chemical and physical
+nature reveals that these activities are far more largely under
+nervous control and discipline than was at one time conceived to be
+possible. Thus, the main factor in the activity of any part is its
+blood-supply, but the blood-supply is largely determined by the state
+of contraction of the vessels of supply, which are in their turn under
+nervous control. So it is with the state of nutrition of the muscles,
+with the action of the sweat glands of the skin, with the mechanism of
+childbirth, and with a thousand bodily states with which both physician
+and biologist are concerned.
+
+The investigation of nervous integration is especially associated
+with the name of Sir Charles Sherrington of Oxford. As the outcome
+of his work the picture formed of the nervous apparatus is that of a
+machine in which some parts work spontaneously, automatically, and with
+complete uniformity; others, though mainly automatic, are susceptible
+of various degrees of alteration and adjustment; others need
+intermittent or constant attention, and demand for their functioning
+fresh supplies of energy at longer or shorter intervals; while,
+finally, others have hardly yet taken a fixed form and are improvised
+as occasion demands. Thus the nervous system is a system of systems of
+every degree of independence.
+
+These systems, each with a certain individuality of its own, date from
+every stage of Evolution, the more ancient being, as a rule, the more
+automatic and the less dependent on other systems. The most ancient,
+the chemical messenger or ‘hormonic’ system (pp. 306-8), we share with
+the lowest living things which consist of only one cell. Very recent
+are the factors in the nervous system that are specially developed in
+man as contrasted with the higher apes. Such are those associated with
+the delicate co-ordination of sensory impressions and motor impulses
+involved in such acts as speaking, reading, writing and the like. Each
+of these systems, high or low, ancient or recent, has its own place
+in the body. For many the exact position of the controlling center is
+demonstrable and some of the lower systems can function without the aid
+of any other systems save those which control their nutrition.
+
+Among these nervous relations there is one which calls for special
+mention on account of its great clinical importance. The state
+of ‘shock’, the general nature of which is vaguely understood by
+everybody, has been given a more exact physiological meaning of late
+years, especially by the American surgeon G. W. Crile (1864-). It has
+been found possible to localize ‘shock’ experimentally. If a section
+of the spinal cord of an animal be cooled to a point just above
+freezing, the part of the body below the cooled level passes into a
+state of ‘shock’, that is to say, its reflexes no longer respond to
+irritation in the normal fashion. This shock effect is due to the
+removal of some influence exercised by the higher parts of the nervous
+system. In the experiment the shock effect is induced by an external
+agent, but there is an internal mechanism within the nervous system
+itself, which can cause it under appropriate conditions.
+
+
+(c) _Vitamins._
+
+There are no current medical problems that are more discussed than
+those of nutrition. It has long been recognized that articles of diet
+may be classified according to their constitution into ‘proteins’,
+‘carbohydrates’, and ‘fats’. If an animal is fed on a diet containing
+these in correct proportion, but in a perfectly pure state, it will
+become ill and ultimately die. The onset of illness and death will be
+the more rapid if it be a young animal. This fact, observed as long
+ago as 1880, was reinvestigated by F. Gowland Hopkins of Cambridge
+in 1906, from whence dates our real knowledge of a very important
+subject. He found that, in the case of rats, the addition of a very
+small quantity of milk to this chemically pure diet would induce normal
+growth. The milk must therefore contain some growth-promoting substance
+or substances other than protein, fat, or carbohydrate. The result of
+many similar experiments by a large number of observers has shown that
+almost all fresh food contains such growth-promoting substances. They
+have been named ‘vitamins’.
+
+Several of these vitamins have been distinguished. None, however,
+has been isolated, and we depend for our knowledge of them on our
+investigation of their mode of action. One, known as _Vitamin A_,
+is produced in the growing green parts of plants, and is especially
+necessary for the promotion of growth. Vitamin A is abundant in
+cod-liver oil. It has been shown that the necessity for Vitamin A
+can to some extent be evaded if the animal is exposed to sunlight or
+ultra-violet rays. Moreover, it has been shown that the absence of
+Vitamin A or of some allied substance is associated with the disease
+of the bones known as ‘Rickets’ or ‘Rachitis’. The history of this
+disease (p. 181) is made intelligible by our knowledge of these facts.
+Rickets can be shown to be most prevalent under precisely those social
+conditions in which articles of diet containing Vitamin A are scarce
+and the amount of sunlight is inadequate.
+
+Our knowledge of this topic is in the process of active extension.
+The question of the actual influence of sunlight and of the rays of
+various wave-length which go to make it up is still too uncertain for
+discussion here. There is a special aspect of this topic, however, to
+which we may refer. It has been demonstrated that stable-fed cows, fed
+not on fresh food but on oil-cake, yield milk of little antirachitic
+power. It has, however, been shown that this milk becomes antirachitic
+after exposure to ultra-violet light. Therefore, some antirachitic
+substance is produced in the milk, as in the body, by the action of
+ultra-violet light. Now recent research has shown that the antirachitic
+elements are associated with a chemical substance known as _Cholestrol_
+which is of the nature of a complex alcohol. Nevertheless chemically
+pure Cholestrol has no antirachitic power, though it, too, acquires it
+by exposure to ultra-violet light. By chemical means 99·9 per cent. of
+rayed and antirachitic Cholestrol has been recovered as pure Cholestrol
+without antirachitic power. Therefore the antirachitic power, that is
+the vitamin factor, resides in the remaining one-tenth per cent. of
+rayed Cholestrol. The further investigation of this fraction may be
+expected to yield results of great importance both theoretically and
+practically.
+
+Another substance of the same order exists in the husks of rice. If
+animals such as fowls be fed on a diet of rice deprived of its husks,
+they develop a nervous affection. Now a somewhat similar nervous
+affection known as ‘Beri-beri’ is known in the East among natives who
+live on milled rice. The disease, whether in human beings or chickens,
+may be cured or avoided by giving the husks of the rice separately.
+The substance thus conveyed has been named _Vitamin B_. There is yet
+another disease, Scurvy (p. 170), which occurs in those who have been
+deprived of fresh food. _Vitamin C_, which cures this, is specially
+found in the juices of oranges and lemons. Our knowledge of ‘deficiency
+diseases’, of which Scurvy is one, is only just beginning. It may
+well be that they are of wider occurrence than has been supposed, and
+vitamins may be important curative and preventive agents.
+
+
+§ 19. _Knowledge of the Eye and its Disorders._
+
+From an early date the treatment of ailments of the eye has stood
+somewhat apart from the rest of medical practice. Moreover, the
+knowledge of the structure and functions of the parts of the eye has
+not kept closely parallel with that of other departments of anatomy
+and physiology.
+
+[Illustration: FIG. 131. DIAGRAM TO SHOW THE STRUCTURE OF THE EYE,
+REPRESENTED IN SECTION. For description see pp. 314-15.]
+
+The eye is a roughly spherical organ, enclosed in a tough capsule, the
+_Sclerotic coat_ (Fig. 131). The transparent front of this capsule, the
+_Cornea_, is the curved window through which we look upon our world.
+There is a watery space, the _Anterior Chamber_, behind the Cornea,
+at the back of which is situated the _Lens_, a horny transparent
+structure. In front of the Lens is a ring-shaped pigmented muscle which
+shuts out light from the Lens, except at the center, and gives the
+characteristic color to the eye. This circular colored muscle is the
+_Iris_, and the hole in its center is the _Pupil_. The pupil becomes
+smaller or larger with contraction or expansion of the Iris. This
+change is a reflex and unconscious act, depending on the amount of
+light and also on the degree to which the eye is adjusted to examine
+near objects.
+
+The edge of the Lens of the eye is attached by the circular _Suspensory
+Ligament_ to the circular _Ciliary Muscle_. The Ciliary Muscle, by
+contracting or relaxing, alters the form of the Lens (Fig. 132).
+This change in form of the Lens is part of the process of adjustment
+to near or distant vision. Behind the Lens is the large _Posterior
+Chamber_, containing a transparent gelatinous substance. At the back
+of the posterior chamber is the sensitive area or _Retina_, which is
+the essential organ of vision, and is backed by a pigmented coat, the
+_Choroid_. The Retina is continuous with the _Optic Nerve_, along which
+an artery enters the globe of the eye. At the point where this artery
+pierces the Retina there is the so-called _Blind Spot_.
+
+A ray of light penetrating the eye from the center of the Cornea
+through the center of the Lens falls on or near a specially sensitive
+area, the _Yellow Spot_, and images formed there are more distinctly
+perceived than those formed elsewhere. When an object is examined
+closely, the observer makes the attempt to bring the image of it on
+to his Yellow Spot. Any injury to the Yellow Spot causes a great
+diminution in clearness of vision. Man and his allies, the zoological
+group known as the ‘Primates’, are the only mammals, except the cat
+tribe, that possess a Yellow Spot. There can be little doubt that the
+possession of this Yellow Spot has done much to raise the importance
+of vision among the senses in the Primates. It has thus been a very
+potent factor in the evolution and elevation of Man himself.
+
+The eye is an optical instrument which, like other instruments,
+performs its functions with something less than perfection. Most purely
+optical errors of the eye can be remedied by spectacles. These aids to
+vision are of very great importance, since, by the time middle life is
+reached, few are fortunate enough to read in comfort without them. The
+introduction of spectacles, therefore, enormously extended the active
+intellectual life. Their social effects are incalculable.
+
+The commoner optical errors may be classified under four heads.
+
+First and commonest there is ‘old sight’. When a healthy eye adjusts
+to near vision, the Ciliary Muscle contracts towards its attachment
+at the junction of Conjunctiva and Sclerotic. This draws forward and
+relaxes the Suspensory Ligament. The elasticity of the Lens, no longer
+constrained by the Ligament, causes it to assume a more convex form.
+This more convex form is appropriate to the correct focussing of a
+near object on the Retina. At or about the age of forty-five the Lens
+usually begins to lose its elastic power, and thus has difficulty in
+adapting to near vision. The trouble is remedied by the use of convex
+glasses for reading or other near work.
+
+A second common error is the so-called ‘far sight’. In this form--save
+in extreme cases--the eye is competent for distant objects, but those
+that are near are not clearly seen. The incapacity for near vision is
+due to a deformity--usually innate--of the eye. The eye is too short
+along the axis _xy_ (Fig. 131). The resulting optical error can be
+remedied by the use of convex spectacle lenses.
+
+[Illustration:
+
+FIG. 132. DIAGRAM TO SHOW THE NATURE OF ACCOMMODATION OF THE EYE TO
+NEAR VISION. The Ciliary muscle, by contracting, pulls forward the
+lateral attachment of the Suspensory Ligament to the Sclerotic. Thus
+the ligament is relaxed and in turn relaxes its pull on the Lens. The
+Lens thereon becomes more convex. As age advances the Lens loses this
+power and so the sight fails for near vision.
+
+]
+
+Thirdly, there is the so-called ‘near sight’. In this state near
+objects can be clearly seen, but vision fails with those that are more
+distant. Near sight is usually an acquired condition. The eye is too
+long along the axis _xy_ (Fig 131). The resulting optical error can be
+remedied by the use of concave spectacle lenses.
+
+Fourthly, there is ‘irregular sight,’ known as ‘astigmatism’. In
+extreme cases of this condition no perfectly clear image can be
+formed of any object, whatever its distance. It is in some measure
+both congenital and acquired, and is due to an irregular deformation
+of the optical apparatus of the eye. The remedy for astigmatism is a
+compensatory deformation of the spectacle lens, which may need, in
+other respects, to accord to the convex or concave form, according as
+the deformation of the eye is of the far-sighted or near-sighted type.
+
+Historically optical errors of the eye were relieved by spectacles
+before the nature of the defects was understood. The first suggestion
+of the use of convex lenses as an aid to old sight was made by Roger
+Bacon (1214-94) in the thirteenth century. Spectacles with convex
+lenses for old or for far sight first came into use about 1300. By the
+fifteenth century they were widely known. It may well be that their
+adoption, by prolonging reading life, had an important effect upon
+that process of extension of knowledge that we dub the ‘Revival of
+Learning’. Concave lenses for the relief of near sight came in towards
+the end of the fifteenth century, but were not widely used till the
+eighteenth century. Astigmatic lenses were not contrived till well into
+the nineteenth century.
+
+In 1874 S. Weir Mitchell (1830-1914), a very able American physician,
+showed that the eye strain resulting from astigmatism was associated
+with many nervous conditions. Weir Mitchell’s name is familiarly
+associated with a line of treatment of these conditions. Since his
+discovery it has been the practice to examine for optical error all
+sufferers with headache and other neurotic symptoms.
+
+For long there was no means of estimating the degree of error, whether
+of old sight, far sight, or near sight, save by trial on the part of
+the patient himself. Spectacles were a common object of the hawker’s
+trays, and from them the sufferer selected the specimen that suited him
+best. The first essential improvement in this state of affairs was an
+elucidation of the mode of action of lenses. The paths of light rays in
+their passage through a lens were first correctly determined at the
+beginning of the seventeenth century by the astronomer Johannes Kepler
+(1571-1630). Knowledge of optics advanced during the seventeenth and
+eighteenth centuries, but the optical errors of the living eye were not
+accurately estimated until the time of the great Dutch ophthalmologist
+Frans Cornelis Donders (1818-89). The system of prescribing and fitting
+spectacles that is now in vogue dates from the publication of his
+work, _The Anomalies of Refraction and Accommodation_, in 1864. Hardly
+less important was the invention of the ophthalmoscope by Hermann von
+Helmholtz (p. 213). Very important also was the introduction of ‘test
+types’ for examining errors of vision by the Dutch ophthalmologist
+Hermann Snellen (1834-1904).
+
+One of the most remarkable minds that has ever applied itself to
+medical problems was that of the Quaker physician Thomas Young
+(1773-1829). He was a man of immense learning, and is remembered
+for having been the first to decipher Egyptian hieroglyphics. Young
+explained the power of the eye to ‘accommodate’ for near vision. This
+faculty of ‘accommodation’ was, he showed, due to changes in the
+curvature of the crystalline lens (Fig. 132). In his memoir _On the
+Mechanism of the Eye_ (1801), Young gave the first scientific account
+of Astigmatism. His theory of color vision and his doctrine that light
+is due to waves in the ether are still important. His ‘wave theory’
+of light completely replaced the old view, the so-called ‘emission
+theory,’ that light is due to something material which goes forth from
+the luminous object. While we are referring to Young we may remind
+the reader that his work on ‘Energy’ lies at the back of all modern
+Physics, in the history of which he takes an extremely important place.
+
+The operative treatment of the eye is of great antiquity. The most
+important operative procedure is that for ‘cataract,’ a condition
+caused by an opacity of the lens. ‘Couching’ for cataract, that is
+depressing the opaque lens, was practised by Alexandrian surgeons
+in the third century B.C. It is described by Celsus (p. 43) in the
+first and mentioned by Galen (p. 50) in the second Christian century.
+Contemporary with these authors are descriptions of the actual
+extraction of the lens affected with cataract.
+
+In Imperial Roman times there were surgeons who devoted themselves
+exclusively to cataract operations. These were practised during the
+Middle Ages by the Arabs and to a less extent by the Westerns. For the
+most part the operations were performed by wandering quacks, who were,
+however, often very skilful. In the sixteenth century operations on the
+eye began to pass into the hands of recognized medical practitioners.
+The advances in the knowledge of the anatomy and physiology of the eye
+in the eighteenth century enabled the French surgeon Jacques Daviel
+(1696-1762) to explain the real nature of cataract, which is usually
+nothing but a senile change in the lens of the eye. His knowledge made
+it possible for him greatly to improve the operation for extraction, so
+that, over a large range of cases, he had only 11 per cent. of failures.
+
+The modern era of ophthalmic surgery was ushered in by Donders (p.
+319), von Helmholtz (pp. 213 and 319), and Albrecht von Graefe
+(1828-70). The last was a professor at Berlin who greatly improved the
+operation for cataract and introduced or improved many other important
+operations on the eye. He was one of the first to make important
+clinical observations with the ophthalmoscope, and he showed how the
+instrument may be made to yield information not only of the condition
+of the eye itself, but also of the brain and of its membranes, an
+application which has become of the greatest value in later medical
+developments. Though he died before the most important work of Pasteur
+and Lister had become generally accepted, von Graefe was yet practising
+a system of surgery which was not far from aseptic.
+
+As with most departments of Medicine, so also with Ophthalmology,
+the most significant advances during the last generation have been
+in the direction of prevention rather than cure. Prominent among
+these measures are, firstly, school inspection with the consequent
+early detection and isolation of infectious cases of conjunctivitis;
+secondly, maternity welfare accompanied by prompt notification and
+treatment of the very dangerous and sight-destroying ‘Ophthalmia of the
+New-born’; thirdly, improved light regulation in factories and schools;
+and, fourthly, adequate provision of spectacles for school children
+with errors of vision.
+
+The recognition of the infectious character of the very chronic
+and sight-destroying disease known as _Trachoma_, or ‘Granular
+Conjunctivitis,’ has been of great importance for the Public Health.
+The disease is common in the near East and in Eastern Europe and by no
+means rare in slum quarters in the West. A rigid system of inspection
+of immigrants, together with quarantine combined with treatment, has
+done much to diminish its ravages in the United States.
+
+
+§ 20. _Investigation of the Nature and Action of Drugs._
+
+
+(a) _Entry of Vegetable Drugs into the Pharmacopoeia._
+
+An examination of the list of drugs that are in use at the present
+day--apart from those which have been introduced by the scientific
+movement of the last generation--yields some surprising results. Some
+thirty per cent. of the crude vegetable drugs in the modern official
+Pharmacopoeia were known in remote antiquity. The Egyptian medical
+papyri mention, among others, Aloes, Caraway, Castor Oil, Coriander,
+Dill, Fennel, Juniper, Mint, Myrrh, and Turpentine. Among Egyptian
+mineral remedies still in use are salts of copper and of lead. Assyrian
+medical tablets refer to most of the Egyptian drugs as well as to a
+number of others, among which are Almond Oil, Aniseed, Galbanum, and
+Liquorice. Among Assyrian mineral remedies that are used by us to this
+day are Alum and Bitumen. Early Indian medicine had a very copious
+pharmacopoeia. _Cannabis indica_, known as ‘Hashish’ or ‘Indian hemp’,
+Cardamoms, _Cassia fistula_, _Datura stramonium_, and _Nux vomica_ are
+among the valuable Indian herbs now in use in scientific medicine,
+while Mercury preparations were perhaps ultimately of Indian origin.
+
+The medical herb lore of the Greeks comes to us chiefly from
+Dioscorides (p. 43), who mentions about five hundred plants. A large
+number of these are still in our own Pharmacopoeia. Among these,
+besides those of Egyptian, Assyrian, and Indian origin, are Ammoniacum,
+Belladonna, Camomile, Catechu, Cinnamon, Colchicum, Colocynth, Crocus,
+Galls, Gentian, Ginger, Hyoscyamus, Lavender, Linseed, Male Fern,
+Mallow, Marjoram, Mustard, Poppy, Rhubarb, Sesame, Stavesacre, Storax,
+Terebinth, Tragacanth, and Wormwood. About thirty-seven per cent. of
+our Pharmacopoeia was known to the later Greeks. From them the Arabs
+derived, adding, however, enormously to their drug-lists, so that we
+may say that about fifty per cent. of our drugs were in use by the
+Arabic-speaking physicians of the Middle Ages. With the discovery of
+America further important additions were made. Of these we have already
+discussed the introduction of Cinchona, Ipecacuanha, and Tobacco (p.
+95). Few important additions were made in the eighteenth century,
+though among them was Digitalis (p. 328).
+
+
+(b) _Active Principles._
+
+One of the things that separate the practice of Medicine of our time
+from that of previous ages is our power to give drugs in ‘pure’ form.
+This means not only that we can secure drugs without adulteration, but
+also that the active substances in drugs can be chemically isolated
+and given without admixture. Most drugs used in Medicine are, in fact,
+of vegetable origin. The possibility of giving them in chemically pure
+form depends upon the discovery, early in the nineteenth century, that
+plants owe their poisonous and remedial properties to small quantities
+of _Active Principles_, which are susceptible of chemical extraction
+and isolation. Thus the science that deals with the action and nature
+of drugs, _Pharmacology_, really took its rise about a hundred years
+ago, though many had experimented with drugs at an earlier date.
+
+Further progress in the same direction has been made by the so-called
+‘synthetic’ preparation of drugs. Certain substances of vegetable
+origin do not readily yield their active principles and to extract them
+very complex chemical processes may be involved. There are special
+obstacles to the complete purification of other drugs, even when they
+have been obtained in a relatively pure state. These difficulties can
+sometimes be surmounted by the preparation of the drug from inorganic
+materials. This synthetic process of preparation is now possible for
+many substances that are of medical application. Furthermore, when
+a drug can be thus synthetically prepared, it is often possible to
+try chemical variants upon it, and thus to obtain a more effective
+preparation.
+
+In former times a vast number of drugs were habitually employed
+by physicians, and they were often given in very complicated
+prescriptions. ‘Polypharmacy’, the giving of many drugs, is a vice
+from which Medicine has now in large part freed itself. The number of
+drugs given by scientific physicians is far fewer that it was. For
+this there are several reasons. Firstly, many drugs were found useless
+for the purpose for which they were administered, and were at times
+even dangerous. Secondly, since attention has been drawn to the active
+principles of drugs rather than to the crude natural drugs, it has been
+seen that, in fact, many of the drugs that were being given were merely
+duplicates one of another, and that often the administration of the
+active principle itself was more effective and more reliable than that
+of the source from which it was obtained.
+
+What then is the nature of the drugs now being administered by
+scientific physicians? They fall into a number of classes. The nature
+and action of some of these is so simple that no prolonged discussion
+of them is necessary. There are, for instance, the inorganic acids
+and alkalis, the primary action of which, when taken internally,
+can be determined by a series of experiments on gastric juice in a
+test-tube kept at body temperature. Again, there are soluble inorganic
+salts, which are absorbed unchanged from the alimentary canal. These
+have the effect of increasing secretions. Their purgative effect is
+well known, though the physiological details of their action are not
+yet clear. There are yet other substances, such as metallic Mercury
+in ‘grey powder’ or Bismuth, which act mechanically, even when
+administered internally. Over and above these simpler substances, and
+in addition to the traditional vegetable substances which have been in
+use as medicines for centuries, there are others which have only been
+accessible during the last few generations. We have already discussed
+under separate headings the derivatives from animal glands, such as
+of the Thyroid (p. 305), of the Adrenals (p. 307), or of the Pancreas
+(p. 306), as well as the bacterial Vaccines (p. 261) and Antitoxins
+(p. 267). We now turn to pure chemical substances of vegetable origin.
+Of these mention may be made especially of the groups known as the
+_Alkaloids_ and the _Glucosides_.
+
+
+(c) _The Alkaloids._
+
+By ‘Alkaloid’ is understood a nitrogenous substance, usually of
+vegetable origin, which forms salts with acids. The alkaloids are
+mainly obtained from the dicotyledonous plants. Generally they occur
+in nature in combination with plant acids such as citric or tartaric
+acid. The alkaloid group contains some of the most important drugs that
+we possess. Among them are Morphine, Strychnine, Cocaine, Atropine, and
+Quinine.
+
+The investigation of the alkaloids began with the nineteenth century.
+Morphine was isolated from Opium by the Parisian apothecary Charles
+Derosne (1780-1846) in 1803. He failed, however, to recognize its
+chemical affinities, which were first grasped by the German apothecary
+Adolf Sertürner (1783-1841). Their work, however, attracted but
+little notice until attention was drawn to it by the great French
+chemist Joseph Gay-Lussac (1778-1850), in 1817. The result was the
+concentration of much scientific ability on the alkaloids. Prominent
+among the early investigators were the French pharmacologists Pierre
+Joseph Pelletier (1788-1842) and Joseph Caventou (1795-1878). Between
+1818 and 1820 they isolated from Cinchona (p. 95) certain alkaloids
+allied to Quinine, from Nux vomica the alkaloid Strychnine and certain
+of its allies, and from Coffee the alkaloid Caffeine. Pelletier
+in conjunction with the distinguished chemist Jean-Baptiste Dumas
+(1800-84) followed this by a quantitative examination of a number of
+alkaloids in 1823. The first alkaloid to be used as such in medicine
+was Strychnine. It was introduced in 1821 by the French physiologist
+François Magendie (1783-1855), the teacher of Claude Bernard.
+
+In the thirties and forties of the nineteenth century Liebig, who had
+developed his doctrine of radicles (p. 206), attempted to determine
+the formula of alkaloids. He was followed by Wöhler (p. 206). Since
+then an immense amount of work has been done in investigating the
+chemical nature and physiological action of alkaloids. The general
+result has been to reveal the fact that each alkaloid-yielding plant
+contains not one but a number of alkaloids. Those from the same plant
+often have similar but not identical action upon the animal body. The
+differences in physiological action of allied alkaloids have occupied
+much of the attention of pharmacologists. The accurate knowledge of
+these differences has made possible a far greater finesse in the
+administration of alkaloid drugs than was previously possible. Some
+alkaloids can be prepared synthetically, but the process is mostly of
+theoretical rather than practical importance.
+
+
+(d) _The Glucosides._
+
+The Glucosides are an ill-defined group which have in common the
+property of yielding a sugar-like substance--usually glucose itself--as
+a result of certain chemical processes. They are mostly of vegetable
+origin and the history of their investigation has been parallel with
+that of the alkaloids. The first glucoside to be isolated was Salicin,
+which was obtained from willows in 1819. It is the active principle of
+the very ancient remedy for rheumatism, ‘Oil of Wintergreen’. Salicylic
+acid was introduced into Internal Medicine in 1873 and its derivative,
+Aspirin, in 1899. Both drugs are of great importance, and many other
+derivatives of Salicin are in use. Salicin and its derivatives can
+be prepared synthetically, and the synthetic products are in use in
+Medicine.
+
+Of all the glucoside-yielding plants, perhaps medically the most
+important is the Foxglove, _Digitalis purpurea_. The use of the plant
+was known to some of the medieval herbalists, and is, moreover,
+recommended in the German and English printed herbals of the sixteenth
+and seventeenth centuries. Foxglove is mentioned as a folk remedy
+in George Eliot’s _Silas Marner_, the story of which refers to a
+period round about 1750 before the Industrial Revolution, ‘when the
+spinning-wheels still hummed busily in the farm-houses’ (Fig. 89). It
+was introduced into scientific Medicine in 1785 by William Withering
+(1741-99) of Birmingham in his _Account of the Foxglove_, which gives
+details of numerous cases treated with it.
+
+Digitalis long resisted the attempts to extract an active principle,
+but since the seventies it has yielded to investigators a whole series
+of glucosides. Digitalis and its derivatives have become of much
+importance, especially in the treatment of cardiac conditions. Despite
+the success in obtaining glucosides from the Foxglove, the extract of
+the plant itself continues in wide use.
+
+
+(e) _The Study of Pharmacology._
+
+Since the middle of the nineteenth century the investigation of the
+physiological action of drugs has been mainly in German hands. The
+most prominent exponents of the method have been Karl Binz (1832-1912)
+and Oswald Schmiedeberg (1834-1921), both professors at Dorpat, where
+there has been a pharmacological laboratory since 1849. The first
+pharmacological laboratory in America, that at Ann Arbor established in
+1893, and the first in England, that at University College, London,
+established in 1905, were successively occupied by A. R. Cushny
+(1866-1926). The work of these and of other pharmacologists has not
+tended to increase but to reduce the number of drugs. Nevertheless,
+some new drugs of great importance have been introduced by them. Of
+these, among the more valuable is Amyl nitrite, the inhalation of which
+was first recommended by T. Lauder Brunton (1844-1916) as early as 1867
+as a remedy in certain cases of sudden heart seizure.
+
+Improvements have been made not only in the drugs themselves but
+also in modes of administration. The ancient methods of inunction
+and inhalation, as well as other older methods, have been greatly
+elaborated in modern times, and are now of wider application than
+they were. No advance of this order compares in importance with the
+introduction of the Hypodermic Syringe by the ingenious French surgeon
+Charles Gabriel Pravaz (1791-1853). By means of this instrument various
+drugs can be injected directly into the subcutaneous tissues or into
+the veins. This mode of administration is more accurate and under
+better control than any other, and the action of the drug so injected
+is swifter and more sure.
+
+
+(f) _Chemotherapy._
+
+During the twentieth century the outlook on drug treatment has
+been modified by the success obtained in the _specific_ treatment
+of certain diseases, that is to say, treatment by remedies which
+strike at a particular disease and no other. Until quite recently
+scientific Medicine recognized very few specific remedies. It had been
+ascertained that Cinchona owes its value in Malaria to the alkaloid
+Quinine (p. 326), which acts as a specific exterminator of the malaria
+parasites, and not simply as a remedy for fever in general. It had
+also been ascertained that Ipecacuanha owes its value in tropical
+Dysentery to the alkaloid Emetine, which acts similarly as a specific
+exterminator of the protozoal organisms which are the infective agents.
+Quinine and its allied alkaloids and Emetine and its allied alkaloids
+were practically the only specifics the value of which had been
+scientifically proved, except Mercury for Syphilis.
+
+About the beginning of the twentieth century arose the new
+‘Chemotherapeutic’ movement as it came to be called. This movement was
+initiated by the studies of natural Antibodies (p. 262) by Paul Ehrlich
+of Frankfurt (1854-1915). Antibodies are strongly antagonistic to the
+parasitic organism the toxin of which has elicited them, but, on the
+other hand, they are quite harmless to the animal body in which they
+reside. Here are ideal remedies provided by Nature herself. Ehrlich
+compared them to magic bullets, constrained by a charm to fly straight
+at their objective and to injure no other. No such perfect artificial
+drugs have yet been produced. The problem of Chemotherapy is rather how
+to poison the parasite as much as possible while poisoning the host as
+little as possible.
+
+When Ehrlich began the study of Chemotherapy observers had long known
+that certain aniline dyes have a special affinity for certain cells
+or organisms. Indeed the affinity of certain of the dyes for certain
+bacteria had made possible the work of Koch on Tuberculosis and on
+other diseases. As far back as the seventies and eighties much
+work had been done on the subject, and the action of these dyes had
+interested a large variety of investigators. Ehrlich’s first results
+were on a protozoal parasite, which infests dogs. By injecting small
+doses of a certain aniline dye into the veins of the infected animal
+it was found possible to destroy the parasites while doing very little
+injury to the dog.
+
+[Illustration:
+
+FIG. 133. THE ORGANISMS OF SYPHILIS IN A SMEAR FROM THE LOCAL
+INFECTION. Highly magnified. They are best seen by means of a special
+optical arrangement in which the outlines of the objects appear
+glistening white and the background black. The round objects are pus
+corpuscles, the two spiral objects the organisms of syphilis. ]
+
+At this point Ehrlich turned aside from the aniline dyes to study
+the effects of much more toxic substances. He selected the compounds
+of arsenic for the purpose. After prolonged research, he obtained an
+arsenical derivative which proved very toxic to parasitic protozoa and
+little toxic to their animal hosts. When a vast number of experiments
+had been made, this substance was tried in 1910 in cases of human
+Syphilis. This disease had been shown by Fritz Schaudinn (1871-1906)
+in 1905 to be due to a protozoal parasite, the _Spirochaeta pallida_
+(Fig. 133). The results obtained by the new remedy were very
+satisfactory and a valuable specific was thus added to the medical
+armory. The drug became widely known as 606, since this is its number
+in the series of the arsenic derivatives with which Ehrlich had
+experimented. In the meantime others had been at work along lines
+suggested by the aniline experiments. Their investigations led in 1920
+to the discovery of a specific against the deadly _Sleeping Sickness_
+or _Negro Lethargy_. This drug is known as _Bayer 205_ from the firm
+that prepared it and the number in the series of substances that were
+tested.
+
+Since the first preparation of 606 and 205 some interesting facts have
+emerged concerning their action as well as the action of Quinine,
+Emetine, and other specific remedies. It has been found that the
+toxicity of these substances to the parasites against which they are
+aimed is much greater when the parasites are within the body than when
+the drugs are applied to the organisms outside the body. In other
+words, the drugs do something to the body, or the body does something
+to the drugs, that is inimical to the parasite. The nature of that
+something is still under discussion. In the case of Quinine it seems
+that the Quinine so affects the red blood corpuscles that the malarial
+parasites cannot enter them and so cannot go through their sexual
+cycle (Fig. 123). Thus the Quinine does not act as a direct poison
+but attacks the parasite in a much more subtle manner. In the case
+of other parasites the action of the specifics is more difficult to
+understand. It should be pointed out, however, that the chief victories
+of Chemotherapy have been in dealing with the protozoal rather
+than the bacterial diseases. A main task of future Medicine will be
+the discovery of means of eliciting antibodies against the various
+bacterial infections. For this there is more immediate hope from the
+use of remedies of vital origin than from those synthetically produced.
+
+
+§ 21. _Interpretation of Collective Medical Data._
+
+The drawing of a deduction of scientific value from experience is
+by no means a simple process. In many sciences the investigator has
+the power to control experience; in other words he can _experiment_.
+But even the interpretation of experiment needs special precautions.
+The physical experimenter must, for instance, make sure that he has
+but one ‘variable’. Thus, if examining the effects of pressure on
+a gas, he must see that in raising or lowering pressure he is not
+altering temperature, or if recording the effects of temperature he
+must satisfy himself that he is eliminating those of pressure. In
+experiments upon living things the limitation of the field of action to
+one simple factor is often--perhaps always--impossible. The biological
+investigator is therefore accustomed to accompany his experiment with
+‘controls.’ Thus, if he wishes to ascertain the effect on the growth
+of animals of feeding with milk that has been boiled, he must feed one
+series of animals on unboiled milk while he is experimenting with a
+series fed with the boiled milk. He must take steps to ensure that the
+two series are similar as regards age, strength, size, &c., and that
+the conditions under which they live are identical, except as regards
+the one factor the results of which he seeks to ascertain.
+
+When the observer is dealing with human material, it is very seldom
+that he can either restrict the number of variables to one or secure an
+adequate series of controls. Physicians are habitually in a position in
+which action of some kind is demanded. They cannot await the conclusion
+of laboratory researches, which may extend over years, for the patient
+must be relieved at once or die. Being often unable to use those most
+reliable instruments of science, experiment or observation under
+control conditions, physicians have come to rely on what is called ‘a
+general experience of disease’.
+
+One of the commonest fallacies of such general experience is assignment
+of causative relationship between two conditions, simply on the ground
+that they frequently occur in association. Thus it is a fact--and one
+to which attention has been drawn by medical observers--that rheumatic
+affections and red-headedness are often found together. But both
+conditions are common and it has not been satisfactorily demonstrated
+that the association of the two is any commoner than their frequency
+in the population at large would render probable. Such general
+experience is therefore very fallible and is incapable of scientific
+expression, though it is often very valuable and sometimes indeed
+entirely indispensable. To give such experience scientific expression,
+to place it in terms of the ‘primary qualities’ of the founders of
+modern Science (pp. 106-7), it is necessary to put it into statistical
+form. Statistical statement thus becomes of the highest importance
+for medical progress. Medical statistics, when prepared from proper
+material and drawn up with the requisite skill, are at once the most
+exact and the most generalized expression of medical experience.
+
+[Illustration:
+
+FIG. 134. DIAGRAM ILLUSTRATING THE ALTERATION IN THE PERCENTAGE OF
+AGE-DISTRIBUTION OF THE POPULATION OF ENGLAND AND WALES FROM 1891 TO
+1926. It will be observed that the people of England and Wales have
+been getting steadily older. ]
+
+Statistical statements, however, vary greatly in their value and ease
+of interpretation. The simplest statistical statements with which the
+medical man has to deal are perhaps those which relate to surgical
+operations. The categories in which the patient may be placed are here
+limited; he may die, recover, improve, or get worse. If the operation
+is a quite simple one, and if the surgeon is perfectly honest, and
+also--which is rarer--quite unbiased, a small body of statistics
+may carry immediate conviction as to the value of an operation.
+Thus, Lister’s first results with amputation, as obtained under
+his antiseptic conditions, at once satisfy the mind, although the
+conclusions are based on only forty cases (p. 240). No surgeon at once
+both able and willing to appreciate these results would hesitate to
+adopt the new method.
+
+The operation of amputation is, however, in a statistical sense,
+a particularly simple matter. The patient must either undergo the
+operation or not, and the proportion of cases in which the necessity is
+doubtful is very small. Further, he either recovers or dies--for the
+operation could hardly be in itself unsuccessful, nor the surgeon in
+doubt as to whether the patient had recovered or not. Many operations,
+however, are not of this order. They may be performed for conditions as
+to the exact nature of which the surgeon is uncertain, and for symptoms
+which may be only partially relieved. Thus, the removal of the appendix
+for Appendicitis may be most urgently necessary for the saving of life
+in one case and may be a matter of convenience for the relief of more
+or less indefinite symptoms in another. Further, what one surgeon calls
+appendicitis another may not. One surgeon may have every appendix
+that he removes submitted to skilled pathological examination before
+he accepts the case as one of appendicitis and places it among his
+statistics. Another may be quite content with naked-eye appearances of
+the nature of which he alone is witness, judge, and reporter. It is,
+therefore, clear that any collective statement as to the results of
+such an operation must be cautiously scrutinized before conclusions of
+the slightest scientific value can be drawn from them.
+
+[Illustration:
+
+FIG. 135. DEATH-RATE FROM CANCER OF THE TONGUE. It will be observed
+that it is not a common cause of death till about 45 years of age,
+but that it then increases rapidly to fall again in both sexes in old
+age. These features are clearly related to various factors in the
+causation of the condition. One of these is certainly Syphilis, which
+is most frequently contracted between 20 and 30 and more often by men
+than women. The so-called ‘tertiary’ effects of this condition, some
+of which lead to Cancer of the Tongue, do not usually make themselves
+felt, however, for many years after infection. Contrast Fig. 136 and
+Fig. 137. ]
+
+There is a common and rather foolish saying that ‘Statistics may be
+made to prove anything’. This is true, but it is true only in the sense
+that _evidence_ may be made to prove anything. The matter turns on the
+questions, firstly whether the evidence is of a good or a bad order,
+and secondly whether the investigator is in a good or bad position to
+interpret the evidence. A statistical statement may be well or ill
+founded and well or ill interpreted, but statistical statement is, in
+fact, the only scientific method open to us for presenting long series
+of data. The conclusions to be drawn from those data, though sometimes
+evident and easily elicited, at other times demand specially skilled
+and specially trained interpreters. Moreover, to be of value to others,
+such interpreters must also be skilled in expression, so that the main
+body of those who have no statistical training may be in a position to
+understand the essential elements in their conclusions. In no medical
+department is literary power of greater importance than in that which
+deals with statistics. Thus has arisen the small but highly important
+class of medical statisticians. The rise of medical statistics into a
+vocation places the crown on Medicine _as a science_. It is not given
+to many medical men to be proficient in this department. But the duty
+lies on all medical men, and indeed on all citizens, to appreciate
+the value of this study and to seek to appraise its simpler and more
+established conclusions.
+
+It is remarkable how frequently a straightforward statistical statement
+may remove a false impression, even when the impression is based on
+evidence not of a wholly unscientific character.
+
+[Illustration:
+
+FIG. 136. DEATH-RATE FROM CANCER OF THE LIP. It will be observed that
+this curve resembles in form that of the death-rate from Cerebral
+Haemorrhage as shown in Fig. 137, but differs from that of the
+death-rate from Cancer of the Tongue as shown in Fig. 135. The chances
+of dying from Cancer of the Lip are negligible till middle age is past
+and then increase progressively throughout life. In the causation of
+Cancer of the Lip Syphilis is not an important factor. On the other
+hand the continuous irritation of pipe-smoking, which acts not at one
+age but throughout life, has to be considered as a causative element.
+Hence the resemblance to Fig. 137 rather than to Fig. 135. ]
+
+[Illustration:
+
+FIG. 137. CHART OF DEATH-RATE FROM CEREBRAL HAEMORRHAGE AND ALLIED
+STATES. These conditions are extremely rare in the young, but among
+the commonest causes of death in later life. The liability to them
+increases progressively to extreme old age. This is explained by the
+fact that Cerebral Haemorrhage, etc. follows on the rupture of a
+blood-vessel in the brain and the rupture of the vessel is conditioned
+by the hardness and brittleness of its coat. The hardness of the
+arteries increases progressively in later life, whence the saying ‘a
+man is as old as his arteries’.
+
+]
+
+For example the increase in the incidence of deaths from Cancer has
+often been emphasized. But Cancer is a disease of advancing life. The
+age distribution of the death-rate from many forms of Cancer is closely
+parallel to that of certain other forms of senile disease (Figs.
+136 and 137). Now the age constitution of the population of most civilized
+countries is altering in the sense that the proportion of the elderly
+and aged is constantly increasing (Fig. 134), so that some increase in
+the Cancer incidence must be expected. Moreover the appearance of some
+increase in the incidence of Cancer is due to improved diagnosis. How
+far there is a real increase, when these factors have been taken into
+account, is still somewhat doubtful. It must always be borne in mind
+that a relative decrease in the proportion of deaths from _any_ cause
+must automatically increase the proportion of deaths from other causes.
+
+Again, there is no doubt of the fall in the death-rate in England
+and Wales from ‘Phthisis,’ or pulmonary tuberculosis, during the last
+fifty or sixty years. There is also no doubt of the effect both of
+bad housing and of urban conditions in inducing a susceptibility to
+chest disease in general and to pulmonary tuberculosis in particular.
+Further, there is no doubt that the rural population suffers less
+from pulmonary tuberculosis than the town population. These matters
+of common medical knowledge have naturally led to the conclusion that
+the rise of the great towns has led to a great increase of pulmonary
+tuberculosis, and that this increase has been remedied by the improved
+housing and sanitary conditions of the last generation. A study of the
+statistical evidence, however, negatives this view. The rise in the
+proportion of deaths from pulmonary tuberculosis took place before the
+Industrial Revolution. Moreover, the proportion began to fall long
+before the campaign against tuberculosis could affect the issue. The
+history of pulmonary tuberculosis may, in fact, be regarded as that of
+an ‘epidemic’ outbreak, extending over about 100 years, of a disease
+which has always been endemic and remains so now that the epidemic is
+past.
+
+[Illustration:
+
+FIG. 138. CURVE SHOWING PERCENTAGE OF DEATHS FROM PHTHISIS to total
+deaths from all causes in London over a period of 200 years. It will be
+seen that the percentage begins to rise definitely about 1730 and to
+fall definitely about 1830. This state of affairs may be pictured as an
+epidemic lasting about 100 years. ]
+
+These points are well brought out in the accompanying diagram (Fig.
+138). The fall in the proportion of deaths from Phthisis expressed
+there gives rise to further considerations. It might seem that the
+statement that the proportion of those who died from phthisis was
+diminishing left in itself no doubt that the disease was less prevalent
+than formerly. This, however, is not the case. Phthisis is more liable
+to affect those under forty-five years of age than those who are
+older. Now the proportion of the population that is under forty-five
+is steadily diminishing (Fig. 134). This is one of the results of the
+steadily diminishing general death-rate (Fig. 96, p. 196). Therefore
+the proportion of the more susceptible to the less susceptible is
+diminishing. It might have been the case (though it is not) that the
+ratio (more susceptibles)/(less susceptibles) was not only decreasing
+but was actually decreasing more rapidly than the ratio (total
+deaths)/(deaths from phthisis). Had this been so, the conclusion would
+have been justifiable that the fall in the proportion of deaths from
+the disease did not correspond to any decrease in its infectivity. In
+fact, however, the prolonged high mortality from phthisis and its later
+rate of fall do suggest the former prevalence of a more virulent type
+of the disease over a long period, in other words something of the
+nature of a prolonged epidemic.
+
+This conclusion leads us to the conception of the nature of an
+epidemic. To gain some conception of the ideas involved in that word,
+we must glance back in history.
+
+From the time of Hippocrates onward the subject of Epidemic outbursts
+of disease has drawn the attention of physicians. A writer in the
+_Hippocratic Collection_ thought he could perceive an association
+of symptom-complexes with each other and with the weather. In the
+great work _Epidemics_, to which the name of the Father of Medicine
+is attached, such a view, known as that of ‘Epidemic Constitutions,’
+is set forth. The view was revived by Sydenham in the seventeenth
+century and has given rise to a vast literature extending to our own
+time. In the eighteenth and nineteenth centuries the attempts of the
+investigators of vital statistics to place the leading events of life
+in a form capable of exact analysis (pp. 166-68) focused attention
+on the search for a mathematical expression for the rise and fall of
+epidemic diseases.
+
+The first successful attempt to describe epidemics along these lines
+was made by William Farr (1807-1883), an official in the office of
+the Registrar-General in London, and one of the greatest of all
+epidemiological thinkers. His first publication on the subject was
+in 1840, and had reference to the recent outbreak of small-pox, in
+which more than 30,000 had died in England and Wales. It was his merit
+to observe that the successive decreases in the number of cases in
+successive equal periods during the decline of the epidemic correspond
+to the successive increases in the number of cases during successive
+equal periods of the rise of the epidemic. In other words, he observed
+that the rise and decline of an epidemic tend to be mathematically
+symmetrical.
+
+Farr’s suggestion that epidemics are liable to follow the lines of
+regular mathematical rules drew little attention at the time, but in a
+later year it led to a most remarkable and striking prophecy. At the
+end of 1865 Cattle-plague broke out in England. Week by week the number
+of cases increased. In the fourth week of February 1866 the responsible
+Minister, in a speech in Parliament, gave a very gloomy account of
+the state of affairs, expressing the belief that the devastation
+would be far beyond what had yet been encountered. Farr, however, had
+been watching the returns, and had been applying his rule to them. He
+thereupon made a public pronouncement of his belief that at an early
+date the outbreak would reach its maximum and would then decline. The
+outbreak did, in fact, very closely follow the course which he had
+predicted by reasoned calculation. Farr even prophesied the number of
+cases that would occur week by week. His prophecy was near the truth.
+
+During the years that followed Farr’s prediction his views were applied
+with success to a variety of epidemic conditions. The regular form of
+the development of the epidemic was found to apply in certain outbreaks
+of typhus, measles, and other conditions.
+
+Farr’s law was more exactly expressed by him in 1868. It remained,
+however, simply a mathematical law, a rule of which the underlying
+cause was not apparent. It was soon observed that his law applied to
+many but by no means to all epidemics. Moreover, it was perceived that
+the actual figures which he gave for his epidemic of 1840 resembled
+those of certain other epidemics in that they could be fitted with
+greater or less exactness to a well-known mathematically described
+curve, known as the ‘normal curve of error’. We need not discuss the
+mathematical foundation of this curve, which is shown in two variants
+in Fig. 139. For our immediate purpose it is enough to observe that it
+rises gradually at first, but then more steeply, that the steepness
+decreases after a while, and then the curve begins to decline again, as
+it rose. We note that it is symmetrical.
+
+[Illustration:
+
+FIG. 139. THE NORMAL CURVE OF ERROR, shown in two types made with the
+same formula but with different constants. This curve has been shown
+to be similar to that representing the incidence of cases in some
+Epidemics.
+
+Vertical lines are drawn from two pairs of symmetrical points. The
+continuous lines refer to the higher curve, the broken lines (from the
+points of intersection of the two curves) refer to the lower curve. The
+lines will be seen to divide the curves into three parts. This division
+is of such a character that the sum of the two lateral areas is equal
+to the central area for each case. ]
+
+[Illustration:
+
+FIG. 140. Curve of monthly number of deaths from Small-pox during an
+epidemic at Warrington, Lancashire, in 1743.
+
+FIG. 141. Curve of weekly number of cases of Scarlet Fever registered
+during an epidemic at Glasgow in 1892.
+
+Both curves are fitted to the theoretical epidemic curve, and are
+modified from Brownlee. The curves are in both cases explained on the
+assumption that the infectivity, having reached a high point at the
+beginning of the outbreak, decreases thenceforward in geometrical
+progression. ]
+
+When we are dealing with living beings or are dealing with things that
+may indefinitely approximate to a mathematical rule, but never entirely
+fit it. Especially when the living beings are also human beings, with
+their infinitely complex relationships, various factors are present
+which interfere with the exact application of mathematical findings.
+Nevertheless, the theoretical form of the epidemic is an extremely
+useful framework into which actual epidemics may often be fitted, with
+greater or less exactness. In the accompanying figures (Figs. 140-141)
+are adduced cases of greater exactness. There are, however, many cases
+in which an ‘outbreak’ does not seem to fit the simple theoretical
+curve at all. Examination of such curves has in some cases suggested
+that we have not one epidemic or disease but two or more to deal with.
+In some cases it has been possible to analyze the outbreak on the basis
+of two or more theoretical curves, suggesting in fact two or more
+outbreaks of similar but not identical causation (Fig. 142).
+
+[Illustration:
+
+FIG. 142. THE CURVES OF SOME EPIDEMICS, which do not follow the
+theoretical curve, may be analyzed as compounded of two or more
+epidemics, each of which accords individually to the mathematical rule.
+Thus ‘Summer Diarrhoea’ is a seasonal disease very fatal to infants
+in England during the hot months, July and August. The angular curve
+shows the average daily incidence of deaths from this disease in London
+during the fifty-three years 1850-1903. It can be analyzed into two of
+the theoretical epidemic curves.
+
+Each reading of the curve, calculated from the actual cases of ‘Summer
+Diarrhoea of Infants’, can be divided into two, as indicated in the
+step-like readings, one dotted and the other continuous. These accord
+beautifully with two theoretical curves, thus indicating not one but
+two recurrent epidemics. It thus seems probable that two separate
+sources of infection are confused as ‘Summer Diarrhoea of Infants’.
+
+]
+
+What can be the causative element which constrains the incidence of a
+disease in a population to follow mathematical rules? An answer was
+provided by John Brownlee (1868-1927), the late statistician to the
+Medical Research Council of England. The leading fact about an Epidemic
+is that it rises to a maximum, falls, and then dies out, and that the
+curve representing the number of new cases in a series of equal and
+consecutive periods of time throughout the Epidemic is symmetrical. In
+practice the decline is usually a little slower than the rise. This
+is sometimes, at least, due to better observation and record of the
+later cases. Now why does an Epidemic die out? The possible reasons
+may be reduced to three. Firstly, the end of an Epidemic may be due to
+the exhaustion of susceptible persons in the population. That is to
+say, all the survivors are immune, either being so by nature or having
+become so by having contracted the disease and recovered. Secondly, it
+is conceivable that the liability to the disease should be decreased,
+not by rise in the proportion of immunes, but by externally acting
+causes, as, for instance, by rise of seasonal temperature, which would
+provide conditions under which the organism loses its infectivity.
+Expressed in older language, this is to say that the ‘Epidemic
+Constitution’ (p. 342) has changed. Thirdly, the infecting organisms
+may, of their own inner nature, lose their infectivity. The second
+factor may act in special cases, but may be disregarded except in those
+cases. We are, therefore, left with the first and third.
+
+Now it is possible to construct curves that would correspond to the
+exhaustion of the supply of susceptible persons by continuous increase
+of the proportion of those who become immune either by taking the
+disease or by dying. These curves, however, have the character that
+their descent is more rapid (and neither as rapid nor less rapid) than
+their ascent. It is the merit of Brownlee to have suggested that the
+actual curve of the Epidemic corresponds to a known though very little
+understood biological phenomenon, namely change in the infectivity of
+the invading organisms. The simplest expression of his discovery is
+that the loss of infectivity of these organisms is approximately in the
+ratio given by a geometrical progression. That is, if the infectivity
+of the Epidemic be _m_, and at the end of a unit of time _mg_ (when _g_
+is less than unity), at the end of a second unit of time it will be
+_mg_^2, and at the end of the third _mg_^3, and so on. Assuming this
+to be a fact, the course of Epidemics would follow the curve of normal
+error (Fig. 139).
+
+Of late years it has been possible to institute artificial epidemics in
+a series of animals under control conditions. Such experiments must,
+in the nature of the case, cover a large number of years, but they bid
+fair to throw much light on the nature and progress of human epidemics.
+
+These results seem to show, what was believed on other grounds, that
+in the case of highly infective disease, to which, in any population,
+there are many highly susceptible, isolation of declared cases has
+little or no effect on the course of the Epidemic. Such diseases are
+Scarlet Fever, Measles, Influenza, &c. Moreover, the experimental
+epidemics seem to confirm the conclusions of Brownlee that in some
+cases at least the course of the epidemic is determined by biological
+changes within the parasitic beings that cause it.
+
+Thus in the end our health, our lives, and indeed the continuance
+of our civilization may well depend upon a factor which is outside
+ourselves. For reasons which we know not, the pullulating billions
+of living things which are around us, upon us, within us, take up a
+virulence which before they had not, and after a time they lose that
+virulence to become as they were before. The world is devastated by
+an outbreak of Plague, of Cholera, of Influenza. But how and why
+the organisms that carry these diseases should acquire a new and
+more deadly infectivity lies among the secrets yet locked within the
+living cell. Life--the life of the Cell, of the Bacterium, of Man
+himself--remains among the _Arcana Naturae_. These are the secret
+things that in their essence--which is Life--remain and will remain
+behind the veil. From such cells we came, through such cells we shall
+return. As to what is the force which starts these processes on their
+way, we are as ignorant as children, and must remain so, in essence,
+till we understand the nature of the processes of coming into being and
+passing away. So Medicine must end where she began, quaking before the
+Mystery of Life, a Mystery which could only be resolved if we could
+express Mind in terms simpler than itself. If this could be done the
+veil that is cast over all flesh would indeed be rent. But the author
+of this work believes that the hope of this is vain and that we are
+here in the presence of one of the ultimate things.
+
+
+
+
+EPILOGUE
+
+
+We have now traced various movements in Medicine throughout the ages
+and have seen how all the sciences in turn have been made to bring
+their tribute to the alleviation of suffering. We have seen especially
+how the consideration of disease as a whole, and of the health of
+peoples as a whole, has introduced a new view in the handling of
+disease. Health is a public asset, and its promotion has now been
+recognized as a public duty. There are undeniable disadvantages in
+placing officers of the State in control of the personal liberties of
+its citizens, but, on the whole, the advantages, in matters of health,
+have outweighed the disadvantages. Only a professed pessimist or a
+crotchety reactionary could deny the gains to humanity from the passage
+of preventive measures from private into public hands.
+
+There is another side of the picture which we have need also to
+consider. The advances in Medicine and the advantages that have accrued
+therefrom have been entirely the result of the application of the
+rational method of observation and experiment. To control Nature we
+must above all things understand Nature. Neither the conception of
+Nature as the kind old nurse nor the conception of Nature ravening red
+in tooth and claw will stand. Least of all can we tolerate the picture
+of Nature as a bountiful mother. If we go to her asking something for
+nothing, she (far from bountiful) will give us little but what we have
+given her, and to him who but begs she gives no more than a beggar’s
+portion. It is thus that she has served the magician and the wizard,
+who think they can compel her to give them all things by their paltry
+charms!
+
+The amount of human labor and ingenuity that is now being thrown
+into the investigation of Nature is almost incredible even to men
+of science. Some conception of the enormous and unreadable bulk of
+scientific literature may be gained by a glance at the _International
+Catalogue of Scientific Literature_. This gives the _titles alone_
+of original articles in the various departments of physical science.
+These titles for the year 1914 alone occupied seventeen closely printed
+volumes! The rate of publication has accelerated considerably since
+then. There are now about 25,000 periodicals devoted to scientific
+publications! There are very few departments of science which do not
+have some bearing on Medicine. It is evident that no human mind can
+possibly compass even a year’s output of this material.
+
+And yet it is not the bulk of writing on Science that forms the only
+or even the chief deterrent to the general comprehension of its
+principles. The mass of scientific detail has always been beyond the
+power of one mind to grasp. But as we have traced Rational Medicine
+through its long course in Antiquity and the Middle Ages to its
+debouchment on to our own time, we have found not only a more difficult
+but also a new situation. In approaching our own age we have found ever
+more difficulty in discussing Rational Medicine as a single channel of
+thought. It spreads into a Delta, of which, though the many mouths may
+inosculate, yet the tendency seems to be for an ever wider divergence.
+This diffusion, induced by increased specialization, cannot go on
+for ever without defeating the very objects for which specialism was
+invented.
+
+On the other hand, when we glance at the tasks now being performed by
+the medical man, we cannot fail to be struck by the great increase
+in the number of things that have come to be regarded as within his
+sphere. It is a commonplace that he has in large part taken the place
+of the parson. But he has also made encroachments on the functions of
+the lawyer, the legislator and the judge, of the schoolmaster, the
+architect and the statistician. He has assumed some of the duties of
+the parent and guardian, while even the soldier and the policeman are
+to some degree under his control. In the ordering of their lives,
+and even in the regulation of their vices and the reform of their
+shortcomings, men and women are far more willing to seek the advice and
+help of the medical man than once they were. The reason is, without
+doubt, that his advice is much more worth having than it once was.
+
+The organization of research, the systematized record of experience,
+the improved intercommunications of our time, have combined to
+increase vastly the medical man’s sources of information and to make
+his application of them more accurate and more scientific. Moreover,
+there are factors in our social life itself that have tended not only
+to deepen the physician’s knowledge but to widen his experience. His
+effective working-day has greatly lengthened. No doubt, the motor car
+and railway train are important elements in this extension of the
+doctor’s day, but a far more fundamental element is the advent of the
+skilled nurse. Many tasks which occupied the time of the doctor in the
+old days are now relegated to her. The result is that the doctor sees
+a far greater number of patients and has a much greater experience of
+actual sickness than was formerly possible.
+
+But after we have discussed all those factors which have gone to
+the increase of the power of Physic we have still to consider the
+philosophical basis which has conditioned this increase. Men do not
+willingly accept that in which they do not believe. The shifting of
+men’s trust implies a shifting in their faith. In truth the triumph
+of Physic has underlying it a subtler triumph, that of Scientific
+Determinism. The great increase in the detailed knowledge of Nature has
+led to a great increase in the belief in the Reign of Law. Disease and
+death were once thought to be the special acts of Providence. They are
+now widely held to be illustrations of determined natural laws. Men
+of science in general, and medical men in particular, are not wont to
+profess themselves philosophers, but, in fact, much of their work is
+done in a spirit which would have us believe that these determined laws
+are universal and are wholly outside ourselves. Has there not arisen a
+school that would claim that our thinking is but a seeming, and that
+we do but behave as though we thought? Three centuries ago Descartes
+conceived that the animal might be treated as a machine. If man be
+but an animal, consequences are entailed from which Descartes shrank,
+for the watchword of his philosophy was ‘Cogito, ergo sum’, _I think,
+therefore I am_. There is a newer school whose work is intimately
+bound up with the progress of Medicine that would abandon this basic
+doctrine of the father of modern Philosophy, who is also the founder
+of Physiology, as a separate discipline.
+
+The position as it stands appears as a dilemma. The triumphs of
+Science have been secured by disregarding Mind, and yet they cannot be
+appreciated or advanced without invoking Mind. Unless we accept the
+full conclusions of the Determinist Philosophy, we are forced to the
+conclusion that Mind must do something to the animal body. If Mind
+holds the reins, there must be a point at which Mind pulls the reins.
+The matter ever in dispute is where that point may be. If life and
+growth are bound up with an Entelechy, as seems to the author of this
+work to be the case, there must somewhere and somehow be a level in the
+organism at which the laws of physics and chemistry are transcended by
+some other mode of action.
+
+It is no part of our task to provide a Philosophy which will resolve
+all the problems that our subject raises. Nevertheless, in the presence
+of this dilemma, such a work should not close on too optimistic a note,
+in the department either of medical thought or of its application. Even
+if looked at merely as an interpreter of its own terms, determinist
+thought, which lies at the basis of modern medical developments, has
+not been quite so universally successful as is often supposed, and as
+the preceding pages of this book may lead the reader to think. While
+enormously increasing the sum of our knowledge of Nature, it has also
+tended more and more to separate the parts of that knowledge from each
+other. It is clear that no such way of thinking can ever give us a
+survey of Nature as a whole. It can never enable us to ‘think things
+together’, and without such thinking together our life is and must
+remain a contradiction and a muddle.
+
+For a real survey of Nature we must look to another Philosophy and
+another Method. We are in this matter but just entering on a new era,
+and may it not be that some sort of solution will be provided by a
+better study of the Mind itself? Only by our minds can we know that
+Nature presents us with any order at all. It therefore behoves us to
+search out most diligently all that we can learn about our minds, to
+see whether, on the one hand, this determined order, which has so
+impressed our age, is in any degree within us and part of our observing
+instrument, or whether, on the other hand, it is wholly without us.
+There is much evidence that it is not wholly without us, and that
+Determinism is a habit in our method of thinking on certain topics, and
+that the emphasis on the ‘primary qualities’ (see pages 106-8) which we
+inherit from Galileo is by no means justified. It may be that what we
+think and feel and see is not only as real as what we weigh and count
+and measure, but that weighing, counting, and measuring are but forms
+of thinking, feeling, and seeing. In this connection the reader should
+turn over again in his mind the implications of the ‘Law of Specific
+Nerve Energies’ enunciated by Johannes Müller (see pp. 212-13).
+
+Nor must we end on too optimistic a note as to the actual achievements
+of Science. Advances in our knowledge have certainly been very great,
+but they may be and often are exaggerated. We must always guard
+ourselves against considering mere accumulation of detail as an
+advance. The collection of data is but a means to an end, and if that
+end is not reached they are a very weariness and vexation of the
+philosophic spirit. Real advance in knowledge can only be tested by
+effective advances in theory, and thus judged the cost of progress--the
+cost in the brute accumulation of facts--has increased far more rapidly
+than progress itself. What is wanted is not so much new data as
+correlation in their accumulation. The increase in medical specialism
+is not so much evidence of advance as it is of the heaping up of
+uncoordinated observations.
+
+Works on Medicine intended for popular consumption are often couched
+in the jubilant terms of victory. Yet there are whole departments in
+which no progress whatever has been made. We pride ourselves on the
+advance in knowledge of infectious disease which the germ theory has
+brought us, and yet we are utterly and completely ignorant of the two
+things about infectious disease which are the two things most worth
+knowing on that topic. Firstly, no man has conceived the way in which
+the parasites of disease first fastened themselves on the animal body,
+a specific parasite to a specific animal. In other words, we have not
+the least idea how diseases first begin. Secondly, no man has conceived
+a reason why diseases, distributed over a wide area and in many bodies,
+should vary in virulence from time to time, why, for instance a
+relatively mild condition, such as influenza, should suddenly devastate
+the world. It is easy to say that human resistance varies, but that is
+only to restate the problem in terms of which we know nothing. On these
+high topics of Medicine we know as much and as little as Hippocrates.
+
+Moreover, if we turn to definite diseases, there are many conditions,
+and those among the most important, of which our ignorance is almost
+complete. Thus of the very common and painful diseases, muscular
+rheumatism and rheumatoid arthritis, we know hardly more than
+Hippocrates and our remedies are but little more effective than his.
+The common cold--economically the most important of all diseases, not
+excluding Cancer and Tuberculosis--has a vast literature, but the
+physician is almost helpless in its presence and can but let it run
+its course. Measles, Whooping-cough, and Influenza have become more
+deadly of late years. We have still no clear line of treatment for
+them. Nor have we any real insight into the nature of Cancer. Those
+who reach advanced age have no better chance of life than they had
+two hundred years ago (p. 177). Above all, it must be remembered that
+the great majority of deaths are caused by diseases theoretically
+preventable. There is a natural term to life which it is desirable that
+all should attain. Yet most of us will surely die a violent death as
+truly as though struck down by a felon’s hand. Death from disease is an
+unnatural and a violent death.
+
+Faced by facts of this order there are those who constantly urge
+increased activity in medical ‘research’. But research can only be
+prosecuted by those whose talents specially fit them for the work.
+With reason it may be and is doubted whether there are many in Western
+Europe or America who could profitably be employed on medical research
+who are not already so employed. It is easy to make investigations
+on a certain level, but those best qualified to judge are of opinion
+that the general level of medical research has fallen, not risen, of
+late years. The number of publications has multiplied manyfold, but
+there are those who doubt if there is much increase in investigation of
+the first order. The increase in specialism and the extremely narrow
+outlook of some workers has stultified much investigation, since with
+his decreased range the researcher is often less able to perceive the
+bearings of his own work. Thus he may labor for years elaborating a
+technique by means of which he may collect facts without that guiding
+wisdom or judgment that is the mark of genius. It must ever be borne
+in mind that the object of fact-collecting is the deduction of law.
+Not all facts can be collected, for facts are infinite in number, and
+it is therefore necessary to select. Selection involves _judgment_,
+the final and indefinable property of Mind; for, if from the facts no
+laws emerge, the facts themselves become an obstacle, not an aid, to
+scientific advance.
+
+All who have to read systematically large masses of modern scientific
+literature have been unfavorably impressed by its absence of form. It
+is evident that a large proportion of scientific workers lack adequate
+literary training and never acquire a proper sense of literary form.
+The growing interest in Science has had an unfavorable effect on
+Education in the direction of early and intensive specialization. The
+result is that many scientific publications are but semi-literate,
+they are often incoherent in presentation and even more frequently
+unnecessarily diffuse. Nor is it merely a matter of form. Language is
+but the outward and visible sign of which Thought is the inward and
+spiritual reality. Confused writing usually indicates and always leads
+to confused thinking. Thus the unliterary character of scientific
+writing bids fair to pass from being a mere nuisance to become a great
+scientific evil. Good and effective writing implies a broad and solid
+literary background, just as good and effective scientific research
+implies a broad and solid scientific background. The fact is that the
+Humanities and the Sciences are far from being as independent of each
+other as many suppose. If literary studies lead to clear and effective
+expression and clear and effective thinking in the domain of Science,
+scientific studies ventilate and inform and vitalize Literature. The
+separation of the two disciplines, especially in the adolescent stage
+of mental development, does an injury to both. The concentration of the
+endowments of Learning on the scientific departments and especially on
+the departments of applied science has given rise to a very widespread
+evil which is none the less evil because it is subtle.
+
+Within the sphere of the specifically medical sciences themselves there
+are tendencies which are open to somewhat similar criticism.
+
+The great fallacy from which scientific Medicine has suffered in the
+past, and still to some extent suffers, is the ‘direct attack’. We
+have come to look upon the animal organism as an immeasurably complex
+machine. For its elucidation knowledge from the most diverse quarters
+is therefore demanded. The physical chemist, the organic chemist,
+the physicist, the mathematician, the protozoologist, the systematic
+biologist, the botanist, the spectroscopist, the geologist, and a host
+of others are following callings which have no obvious bearing on the
+study of disease. Yet the results obtained by them, and by men of
+science in many other departments, must be utilized in the study of
+disease. Our knowledge of health and of disease thus depends on the
+sciences as a whole--nay, on Knowledge as a whole. Those who would
+promote the health of mankind would do well if they sought to encourage
+not so much the medical sciences as Science as a whole, or rather
+Learning as a whole, for Science is a way of life which may penetrate
+into all departments of Learning, and is something far greater than
+those discrete accumulations of knowledge that we call ‘the sciences’.
+The Sciences, working out their destiny, must in the end come together
+again.
+
+If that consummation be reached we may expect improvement in health and
+prolongation of life to a degree greater than any previous ages have
+seen. We may indeed expect something yet better, for we may hope for a
+philosophy of the mind that shall make life better worth the living.
+
+Medicine cannot give immortality, but it should enable us all to live
+out our full lives. Death, coming in due and not undue time, is shorn
+of all his terrors, when every man and every woman
+
+    Shall come to his grave in a full age,
+    Like as a shock of corn cometh in, in his season.
+        _Job_ v. 26.
+
+[Illustration: FRIENDLY DEATH]
+
+
+
+
+INDEX
+
+
+  Abdominal Surgery, 243-8
+
+  Achondroplasia, 17
+
+  Adrenals, 325
+
+  Aesculapius (Asklepios), 4, 7, 8, 11, 49, 51
+
+  Ague, _see_ Malaria.
+
+  Air, Nature of, 151-6
+
+  Air-Pump, Boyle’s, 125-6
+
+  Albinus, Bernard Siegfried (1697-1770), 140-1
+
+  Albucasis the Moor (11th cent.), 67, 70
+
+  Alchemy, 122-6
+
+  Alcoholism, 291
+
+  Alexander the Great, 27, 36
+
+  Alexandria, 52
+
+  Alexandrian School, 36-41
+
+  Alkaloids, 325-7
+
+  Almond Oil, 322
+
+  Aloes, 322
+
+  Alum, 322
+
+  American Civil War, 300
+
+  Ammoniacum, 322
+
+  Amputation, 240, 336
+
+  Amyl nitrite, 329
+
+  Anaerobic bacteria, 257
+
+  Anaesthesia, 162, 235-7
+
+  Analgesia, 237
+
+  Anatomy, 122, 138;
+    of Galen, 55-6;
+    Medieval, 72-6;
+    Renaissance, 82-92;
+    earlier 19th cent., 204;
+    Morbid, 156-9
+
+  Anatomy Act (1832), 193
+
+  Aneurysm, 166
+
+  Animal Spirit, 58
+
+  Animism, _see_ Nature-Worship
+
+  Aniseed, 322
+
+  Ann Arbor, 328
+
+  Anthrax, 229-34, 250-1, 261
+
+  Antibodies, 262, 268-9, 330, 333
+
+  Antidiphtheritic serum, 264
+
+  Antirachitics, 312-13
+
+  Antiseptic Surgery, 235, 237-43.
+
+  Antiseptics, 162
+
+  Antitoxins, 264-5, 325
+
+  Antoninus, Emperor, Statute of (160), 46
+
+  Apertorium, the, 164
+
+  Aphorisms, the, 256
+
+  Appendicitis, 336
+
+  Aqueducts, Roman, 46
+
+  Arabic Drugs, 323
+
+  Arabic Medicine, 66-8
+
+  Aricia, 12
+
+  Aristophanes, 29
+
+  Aristotle (384-322 B.C.), 1, 14, 27-35, 37, 69, 86
+
+  Arles, 42
+
+  Arsenic, 331
+
+  Asclepiades of Bithynia (d. _c._ 40 B.C.), 41-2
+
+  Aseptic Surgery, 235, 237-43
+
+  Asklepios, _see_ Aesculapius
+
+  Aspirin, 327
+
+  Assyria, 6;
+    Medical Tablets in, 322
+
+  Astigmatism (Irregular Sight), 317-19
+
+  Astrology, 54
+
+  Astronomy, 103-5, 122, 135-6
+
+  Atomic Structure, 37, 126
+
+  Atropine, 326
+
+  Auenbrugger, Leopold (1722-1809), 160
+
+  Augustus, Emperor (reigned 27 B.C.-A.D. 14), 42
+
+  Aural Surgery, 188
+
+  Avicenna, the Persian (980-1036), 67, 70, 72, 74, 82, 180
+
+  Avignon, 76
+
+
+  Babylonians, the, 6-7
+
+  Bacon, Roger (1214-84), 318
+
+  Bacteria, 120, 121, 227
+
+  Bacteriology, 249-53
+
+  Bacteriolysins, 269
+
+  Baer, Karl Ernst von (1792-1876), 204
+
+  Bagdad, 66
+
+  Baillie, Matthew (1761-1823), 158
+
+  Balfour, Francis Maitland (1851-82), 204
+
+  Bayer, 205, 332
+
+  Beaumont, William (1785-1853), 148
+
+  Bedlam, 286
+
+  Behring, Emil von (1854-1917), 264, 266
+
+  Bell, Sir Charles (1774-1842), 145, 207, 213
+
+  Belladonna, 322
+
+  Bentham, Jeremy (1748-1832), 178, 190-2, 192-3
+
+  Bergmann, Ernst von (1836-1907), 248
+
+  Beri-Beri, 272, 313
+
+  Berlin, 222, 230, 248, 321
+
+  Bernard, Claude (1813-78), 213-15, 229, 326
+
+  Bethlem Hospital, 286
+
+  Biggs, Hermann M., 202
+
+  Binz, Karl (1832-1912), 328
+
+  Biology, 132, 139
+
+  Bismuth, 325
+
+  Bitumen, 322
+
+  Black, Joseph (1728-99), 151-3
+
+  Black Death, the, 80-1
+
+  Blood, Circulation of, 111-20, 146
+
+  Blood-letting, 39
+
+  Blood-poisoning, 239
+
+  Blood-pump, mercurial, 218
+
+  Board of Health, 194-6
+
+  Boerhaave, Hermann (1668-1738), 122, 139-42, 151, 156-7, 169-70
+
+  Bologna, 71-4, 76, 116, 149
+
+  Bonn, 205, 222
+
+  Bordeaux, 42
+
+  Bordet, Jules (1870-), 269
+
+  Borelli, Giovanni Alfonso (1608-79), 39, 129-31
+
+  Boston, Mass., 198
+
+  Botany, 95-6, 138
+
+  Boyle, Robert (1627-91), 35, 101, 124-6, 151
+
+  Brahe, Tycho (1546-1601), 103, 135
+
+  Brain, Aristotle on, 29-30
+
+  Bretonneau, Pierre (1771-1862), 185, 253
+
+  Broca, Paul (1824-80), 211
+
+  Brownlee, John (1868-1927), 348-9
+
+  Bruce, David (1885-), 255
+
+  Bruno, Giordano (1548-1600), 102-3
+
+  Brunton, T. Lauder (1844-1916), 329
+
+  Brussels, 85
+
+  Bubonic Plague, 201
+
+
+  Caesar, Julius (102-44 B.C.), 45, 46
+
+  Caesarean Section, 45
+
+  Caffeine, 326
+
+  Cambridge, 111, 311
+
+  Camomile, 322
+
+  Canada, 290
+
+  Cancers, 223-4, 337-9, 359
+
+  _Cannabis indica_, 322
+
+  Caraway, 322
+
+  Carbohydrates, 311
+
+  Carbolic Acid, 239-40
+
+  Carbon dioxide, 153, 155-6
+
+  Cardamoms, 322
+
+  Carpenter, Mary (1807-77), 300
+
+  Carrel, Alexis (1873-), 248
+
+  Carrier Problem, 269-70
+
+  _Cassia fistula_, 322
+
+  Castor Oil, 322
+
+  Cataract of the Eye, 320-1
+
+  Catechu, 322
+
+  Cattle-plague, 344
+
+  Cavendish, Henry (1731-1810), 153, 156
+
+  Caventou, Joseph (1795-1878), 326
+
+  Cell Theory, 219-24
+
+  Cellular Pathology, 219-24
+
+  Celsus, 43-4, 320
+
+  Census system, 168
+
+  Cerebral Haemorrhage, 338, 340
+
+  Cerebrospinal Meningitis, 269-70
+
+  Chadwick, Edwin (1800-90), 171, 178, 193-6, 202
+
+  Charcot, Jean Marie (1825-93), 211
+
+  Charles V, Emperor, 88
+
+  Chemotherapy, 329-33
+
+  Chester, 182
+
+  Cheyne-Stokes Respiration, 25-6
+
+  Chicago, 248
+
+  Child Life, 18th c., 180-1
+
+  Children in Factories, 191, 194
+
+  Chloroform, 235, 236
+
+  Cholera, 194-5, 198, 201, 234;
+    chicken, 234, 261
+
+  Cholestrol, 312-13
+
+  Christianity, 61-2
+
+  Chyle, 56
+
+  Cinchona, 95, 281-2, 323, 326, 330
+
+  Cinnamon, 323
+
+  Claudius, Emperor (reigned 41-54), 49
+
+  Cleopatra, 36, 41
+
+  Clinical Medicine, 100;
+    Methods and Instruments, 159-61;
+    Teaching, Rise of, 138-42
+
+  Clinical Thermometer, 159
+
+  Cloaca Maxima, 45
+
+  Cnidus, 8
+
+  Cocaine, 236-7, 326
+
+  Coffee, 326
+
+  Cohnheim, Julius (1839-84), 238
+
+  Colchicum, 323
+
+  Colocynth, 323
+
+  Constantine (d. 1087), 64-5
+
+  Constantinople, 183
+
+  Consumption, 234
+
+  Contagious Diseases in 19th cent., 201
+
+  Cook, James (1728-79), 170
+
+  Cope, E. D. (1840-97), 204
+
+  Copernicus, Nicholas (1473-1543), 88, 102
+
+  Coriander, 322
+
+  Corning, J. L. (1855-), 236
+
+  Cos, 8, 14
+
+  Cretinism, 304
+
+  Crile, G. W. (1864-), 237, 310-11
+
+  Crimean War (1854), 298
+
+  Crocus, 323
+
+  Curve of Error, 345-9
+
+  Cushing, Harvey (1869-), 236, 249
+
+  Cushny, A. R. (1866-1926), 329
+
+  Cuvier, Georges (1769-1832), 204
+
+  Cytology, 223
+
+  Cyto-Pathology, 223
+
+
+  Darwin, Charles (1809-82), 204, 227, 293
+
+  _Datura stramonium_, 322
+
+  Daviel, J. (1696-1762), 320
+
+  de Baillou, Guillaume (1538-1616), 96, 98-9
+
+  de Chauliac, Guy (1300-68), 76-7
+
+  Delirium, early case of, 25
+
+  Dementia praecox, 292
+
+  Democritus (_c._ 400 B.C.), 37
+
+  Demography, 188
+
+  de Mondeville, Henri (_c._ 1270-1320), 72, 74
+
+  Dengue, 272
+
+  Derosne, Charles (1780-1846), 326
+
+  Descartes, René (1596-1650), 39, 103-4, 127-9, 207-8, 355
+
+  Diabetes, 306
+
+  Diarrhoea, 347
+
+  Diderot, D. (1713-84), 131
+
+  Digestion, 146-8, 214-15
+
+  Digitalis (Foxglove), 323, 328
+
+  Dill, 322
+
+  Dioscorides, 43, 322
+
+  Diphtheria, 24, 185, 201, 253;
+    immunization, 262-7
+
+  Dispensary Movement, 178, 180
+
+  Dix, Dorothea Lynde (1802-87), 290
+
+  Donders, Frans Cornelis (1818-89), 319, 320
+
+  Dorians, the, 4
+
+  Dorpat, 328
+
+  Drugs, 95, 322-33
+
+  Ductless Glands, 302-8
+
+  Dürer, A., 83
+
+  Düsseldorf, 50
+
+  Dumas, Jean-Baptiste (1800-84), 326
+
+  Dysentery, 271, 330
+
+
+  Eberth, Karl Joseph (1835-1927), 258
+
+  Edinburgh, 235
+
+  Egyptian Civilization, 7
+
+  Egyptian Medical Papyri, 322
+
+  Ehrlich, Paul (1854-1915), 269, 330-1
+
+  Electricity, 149-51
+
+  Elements, the Four, 34, 124
+
+  Embryology, 30-2, 110, 117-18, 120-1, 204
+
+  Emetine, 330, 332
+
+  Emphysema, 158
+
+  _Encyclopédie_ (1751-72), 130
+
+  Endotoxins, 260, 266
+
+  Entelechy, ix, x, 33, 356
+
+  Epicurus (342-270 B.C.), 37
+
+  Epidaurus, 11
+
+  Epidemics, 182-5, 198, 200-1, 342-50
+
+  Epidemiology, 138
+
+  Epileptics, 292
+
+  Erasistratus of Chios (_c._ 300 B.C.), 36, 37-40
+
+  Erysipelas, 239
+
+  Esquirol, Jean Étienne D. (1772-1840), 288-9
+
+  Ether, 235, 237
+
+  Evolution, Organic, 27, 31
+
+  --, theory of, 204
+
+  Exotoxins, 260, 266
+
+  Experimental Medicine, 211-19
+
+  Eye, the, and its Disorders, 313-22
+
+
+  Fabricius, Jerome, of Aquapendente (1537-1619), 109-11
+
+  ‘Far Sight’, 316-18
+
+  Farr, W. (1807-83), 343-5
+
+  Fat, 311
+
+  Federal Health Service, 200
+
+  Fennel, 322
+
+  Fermentation, 225-8, 230, 239
+
+  Ferrier, D. (1843-), 211
+
+  Fevers, 67, 101, 169, 171-2, 174, 185, 194, 200-1, 243, 254-5, 258-9;
+    _see also specific fevers_ (Malaria, Typhoid, Yellow, &c.)
+
+  Fliedner, Frederica (1800-42), 297
+
+  Fliedner, Theodor (1800-64), 297
+
+  Floyer, Sir J. (1649-1734), 159
+
+  Foxglove, _see_ Digitalis
+
+  Fracastoro, Girolamo (1483-1553), 96, 98
+
+  Fractures, 246-8
+
+  Frankfurt, 330
+
+  Franklin, Benjamin (1706-90), 171
+
+  Freud, S. (1856-), 293
+
+  Fry, Elizabeth (1780-1845), 171, 297
+
+
+  Galbanum, 322
+
+  Galen of Pergamum (130-200), 1, 39, 50-3, 320;
+    his Medical System, 53-60;
+    in the Renaissance, 82-90
+
+  Galilei, Galileo (1564-1642), 103, 104-8, 108-9, 115, 135-6, 138,
+        159, 356
+
+  Galls, 323
+
+  Galvani, Luigi (1737-98), 149-51
+
+  Galvanism, 149-51
+
+  Gastric Juice, 148, 303
+
+  Gay-Lussac, Joseph (1778-1850), 326
+
+  Gegenbaur, Karl (1826-1903), 204
+
+  Geneva, 300
+
+  Gengou, O. (1875-), 269
+
+  Gentian, 323
+
+  Gerhard, William (1809-72), 258
+
+  Germ Origin of Disease, 224-37
+
+  Giessen, 205
+
+  Gilbert, W. (1544-1603), 103
+
+  Ginger, 323
+
+  Glands, Ductless, 302-8
+
+  Glasgow, 249
+
+  Glucosides, 327-8
+
+  Glycogen, 214
+
+  Godlee, Rickman (1849-1925), 248
+
+  Goitre, 303-4
+
+  _Golden Bough, The_, 12-13
+
+  Gorgas, William C. (1854-1920), 279
+
+  Gout, 99
+
+  Graefe, Albrecht von (1828-70), 320-1
+
+  Gravity, 136
+
+  Greek Medical Lore, 322
+
+  Greek Medicine, 1-13
+
+  Guayaquil, 273
+
+
+  Haffkine, Waldemar (1860-), 266
+
+  Hales, Stephen (1677-1761), 145-6, 147, 171, 180
+
+  Hall, Marshall (1790-1857), 207, 208
+
+  Haller, Albrecht von (1708-77), 139, 142-5, 151
+
+  Halley, Edmund (1656-1742), 167
+
+  Halsted, W. S. (1852-), 236, 248
+
+  Hartford, Conn., 237
+
+  Harvey, W. (1578-1657), 32, 103, 111-15, 135
+
+  Hashish, 322
+
+  Health of Towns Association (1840), 194
+
+  Heart, Aristotle on, 29, 31
+
+  Heberden, W., the elder (1710-1801), his _Commentaries_, 22
+
+  Helmholtz, Hermann von (1821-94), 213, 319-20
+
+  Herbs, 322-3
+
+  Hering, E. (1834-1918), 212
+
+  Herophilus of Chalcedon (_c._ 300 B.C.), 36-7
+
+  Hippocrates, 1, 8, 14-18, 102, 267, 342, 358-9
+
+  Hippocratic Collection, 9-10, 13-18, 22-3, 26, 95, 256, 342
+
+  _Hippocratic facies_, 26
+
+  Hippocratic Oath, 17-18
+
+  Hippocratic Practice, 18-26
+
+  Hippolytus, 11
+
+  Histology, 219, 222
+
+  Holmes, Oliver Wendell (1809-94), 237, 243
+
+  Hong Kong, 253
+
+  Hopkins, Sir Frederick Gowland, 311
+
+  Hormones, 307-8
+
+  Horsley, V. (1857-1916), 248
+
+  Hospital Gangrene, 239
+
+  Hospitals, 48-50, 77-81, 178-80, 198, 200
+
+  Howard, John (1726-90), 171, 180, 182
+
+  Humors, the Four, 34
+
+  Hunter, John (1728-93), 162, 165-6
+
+  Hunter, William (1718-83), 158, 165
+
+  Hunterian Museum, 166
+
+  Hygiene, 40, 169-72;
+    Roman, 45;
+    Medieval, 77-81;
+    18th cent., 174 sqq.;
+    19th cent., 192-203;
+    Tropical, 270 sqq.
+
+  Hyoscyamus, 323
+
+  Hypodermic Syringe, 329
+
+
+  Iatrochemistry, 127, 131-2
+
+  Iatrophysics, 127-31
+
+  Imhotep, 7, 8
+
+  Immunity, 184, 234, 252, 259-70, 276
+
+  Indian Hemp, 322
+
+  Indian Medicine, Early, 322
+
+  Industrial Revolution, 172-81
+
+  Infantile Paralysis, 270, 274
+
+  Infectious Diseases, 96, 98, 102, 201, 234-5, 358
+
+  Infirmaries, Roman, 49
+
+  Inflammation, 238-9
+
+  Influenza, 270, 280, 349, 359
+
+  Inoculation, 183-4, 261
+
+  Insanity, 286-93
+
+  Insulin, 306
+
+  Internal Medicine, 77, 95-102
+
+  Internal Secretions, 302-8
+
+  International Health Legislation, 193
+
+  International Red Cross Committee, 300
+
+  Invisible College, the, 124
+
+  Ionians, the, 4
+
+  Ipecacuanha, 95, 323, 330
+
+  ‘Irregular Sight’, _see_ Astigmatism
+
+  Isaac of Kairouan (852-952), 67, 70
+
+
+  Jackson, Hughlings (1834-1911), 211
+
+  Jamaica, 278
+
+  Jena, 220
+
+  Jenner, E. (1749-1823), 183
+
+  Johnson, Dr. (1709-84), 158
+
+  Jung, C. G. (1875-), 293-4
+
+  Juniper, 322
+
+  Justinian, Emperor, 46
+
+
+  Kaiserswerth, 297-8
+
+  Kalar-azar, 272
+
+  Kepler, Johannes (1571-1630), 103, 104, 136, 319
+
+  Kitasato, Shibasaburo (_c._ 1860-), 253, 257, 264, 266
+
+  Klebs, E. (1834-1913), 253
+
+  Klebs-Loeffler Bacillus, 253
+
+  Koch, Robert (1843-1910), 184, 202, 229-30, 232, 234, 249-51, 253,
+        321, 330
+
+  Kocher, T. (1841-1917), 303
+
+  Kölliker, Albrecht von (1817-1905), 222
+
+  Koronis, 11
+
+  Kymograph, the, 216-17
+
+
+  Laënnec, René Théophile Hyacinthe (1781-1826), 160-1, 219
+
+  Laughing Gas, 237
+
+  Lavender, 323
+
+  Laveran, A. (1845-), 283
+
+  Lavoisier, Antoine Laurent (1743-94), 155-6, 205
+
+  Law, Reign of, 135-8
+
+  Lazarettos, 182
+
+  Lazear, 279
+
+  Leeuwenhoek, A. von (1632-1723), 39, 118, 120-1
+
+  Leipzig, 215
+
+  Leonardo da Vinci (1452-1518), 83-5
+
+  Leprosy, 78-80, 98, 162, 271
+
+  Lesions, 157, 160
+
+  Licorice, 322
+
+  Liebig, Justus von (1803-73), 205-7, 225, 235, 326
+
+  Lind, James (1716-94), 170-1, 180-1
+
+  Linseed, 323
+
+  Leyden, 131, 139-42
+
+  Lister, Lord (1827-1912), 184, 229, 237-43, 248, 321, 336
+
+  Liverpool, 196
+
+  Lockjaw, _see_ Tetanus, 256-8
+
+  Loeffler, Friedrich (1852-1915), 253
+
+  London Hospital, 178
+
+  Louisiana, 202
+
+  Louvain, 85
+
+  Ludwig, Karl (1816-95), 215-19
+
+  Lyons, 42
+
+
+  Macewen, William (1848-1926), 248-9
+
+  Magendie, François (1783-1855), 238, 326
+
+  Magic, 3, 16
+
+  Malaria, 174, 251, 271, 330;
+    history, 280-6
+
+  Male Fern, 323
+
+  Mallow, 323
+
+  Malpighi, Marcello (1628-94), 114, 116-20, 302
+
+  Malta Fever, 254-6, 268
+
+  Manson, Patrick (1844-1922), 283
+
+  Marburg, 215
+
+  Marine Hospital Service, 200, 201
+
+  Marjoram, 323
+
+  Marseilles, 42, 182
+
+  Massachusetts, 202, 235
+
+  Massage, 247, 248
+
+  Mather, Cotton (1663-1728);
+    Increase (1639-1723), 183
+
+  Mayo, Charles & William, 248
+
+  Mayow John (1645-79), 126, 151-2, 189
+
+  Mead, Dr. Richard (1673-1754), 183
+
+  Measles, 67, 252, 349, 359
+
+  Mechanics, 106, 122, 138
+
+  Medical Theorists in the Renaissance, 126-34
+
+  Medical Research Council, 197, 348
+
+  Medieval Medical Revival, 68-72
+
+  -- Anatomy, &c., 72-7
+
+  -- Hospitals and Hygiene, 77-81
+
+  Mendel, 222
+
+  Mercury, 162, 322, 325, 330
+
+  Mesopotamian peoples, 7
+
+  Metabolism, 107, 108, 220
+
+  Metschnikoff, Élie (1845-1916), 223
+
+  Mezger, Johann (1839-19-), 247
+
+  Michael Scot (d. 1235), 68
+
+  Michelangelo, 83
+
+  Microscope, 105, 115-22, 159
+
+  Microscopic Analysis, 115-22, 138
+
+  Midwives, 295
+
+  Milan, 81
+
+  Military Medicine, 169-70
+
+  Mill, J. S. (1806-73), 191
+
+  Ministry of Health, 197, 291
+
+  Minoans, the, 3-5
+
+  Mint, 322
+
+  Mitchell, S. Weir (1830-1914), 318
+
+  Mohl, Hugo von (1805-72), 220-1
+
+  Moivre, Abraham de (1667-1754), 167
+
+  Mondino di Luzzi (c. 1270-1326), 74, 76
+
+  Montagu, Lady Mary Wortley (1689-1762), 183
+
+  Montpellier, 74, 76
+
+  Morgagni, Giovanni Battista (1682-1771), 157-8
+
+  Morphine, 326
+
+  Morton, William Thomas Green (1819-68), 235
+
+  Mosquito Net, 45
+
+  Mosquitoes, 273-80
+
+  Müller, Johannes (1807-58), 28, 211-13, 356
+
+  Murphy, J. B. (1857-1916), 248
+
+  Mustard, 323
+
+  _Mustelus laevis_, 28-9
+
+  Myrrh, 322
+
+  Myxoedema, 304-5
+
+
+  Nägeli, Karl v. (1817-91), 221-2
+
+  Nature-Worship (Animism), 3, 12, 16
+
+  Natural Spirit, 56
+
+  Naval Medicine, 170-1
+
+  Near Sight, 317, 318
+
+  Nervous Integration, 308-11
+
+  Nestorians, the, 66
+
+  New York, 202, 248
+
+  Newton, Sir Isaac (1642-1727), 104, 136-8, 186
+
+  Nightingale, Florence (1820-1910), 291, 298-301
+
+  Nîmes, 42
+
+  Noguchi, 273-5
+
+  Norfolk, Va., 198
+
+  Nursing, 180, 295-301
+
+  Nutrition, 311-13
+
+  Nux vomica, 322, 326
+
+
+  Obstetrics, 161-6, 236, 243
+
+  Oil of Wintergreen, 327
+
+  ‘Old Sight’, 316, 319
+
+  Ophthalmic Surgery, 320-2
+
+  Ophthalmoscope, 213, 319, 321
+
+  Opium, 326
+
+  Owen, R. (1804-92), 204
+
+  Oxygen, 126, 154, 156, 189
+
+
+  Padua, 75, 86, 108, 110, 139, 157
+
+  Panama, 286
+
+  Pancreas, the, 215, 306, 325
+
+  Paré, Ambroise (1517-90), 92-4, 162, 247
+
+  Paris, 76, 85, 160, 288
+
+  Park, W. H. (1863), 266
+
+  Pasteur, Louis (1822-95), 148, 184, 202, 225-35, 239, 249, 253, 261,
+        321
+
+  Pathology, Medieval, 77;
+    Modern, 301-13;
+    Cellular, 219-24;
+    Comparative, 251-2
+
+  Pavia, 149
+
+  Peel, Sir Robert (1750-1830), 191
+
+  Pelletier, Pierre Joseph (1788-1842), 326
+
+  Percival, Thomas (1740-1804), 170-1, 180
+
+  Percussion, 160
+
+  Pergamum, 52
+
+  Pest Houses, 180, 181
+
+  Petty, Sir William (1623-87), 166-7, 169
+
+  Pflüger, E. F. W. (1829-1910), 205
+
+  Pharmacology, 323, 328-9
+
+  Philadelphia, 171-2, 258
+
+  Philip of Macedon, 27
+
+  Philosopher’s Stone, the, 124
+
+  Phlogiston, 132, 151-4
+
+  Phthisis, 341-3
+
+  Physical Synthesis, 102-8
+
+  Physiological Synthesis, 203-11
+
+  Physiology: of Galen, 56-60;
+    Medieval, 77, 129;
+    Renaissance, 95, 99, 100, 108-15;
+    Earlier 19th cent., &c., 207-19;
+    Modern, 122, 127, 138, 142-51, 301-13
+
+  Pinel, Philippe (1745-1826), 288
+
+  Pisa, 104, 105
+
+  Plague, 80-1, 182, 185, 200-1;
+    Bacilli of, 253-5;
+    Immunization, 266
+
+  Plaster of Paris, 246
+
+  Plato, 14, 27, 29
+
+  Plethora, 39
+
+  Pneumatism, 38, 56, 58
+
+  Political Economy, 166-7
+
+  Polypharmacy, 324
+
+  Poppy, 323
+
+  Population, 176
+
+  Post-mortems, 156-9
+
+  Pravaz, C. (1791-1853), 329
+
+  Preventive Medicine, 192-203
+
+  Priestley, Joseph (1733-1804), 154-5, 189-90
+
+  Pringle, Sir John (1707-82), 169-70, 171, 180
+
+  Prison Medicine, 171-2
+
+  Prophylaxis, 265
+
+  Proteids, 215
+
+  Proteins, 206, 311
+
+  Protoplasm, 221-2
+
+  Prout, W. (1785-1850), 148
+
+  Psyche, the, 31-3, 133
+
+  Psycho-analysis, 293-5
+
+  Psychology, 293-5
+
+  Ptomaine, 259
+
+  Ptolemy, 36, 40
+
+  Public Health, 192-203
+
+  Puerperal Fever, 243
+
+  Pulmonary Tuberculosis, 341-3
+
+  Pulse Watch, 159
+
+  Pulsimeter, 109
+
+  Putrefaction, 225-8, 231-2, 239
+
+  Pyaemia, 239
+
+
+  Qualities, the Four Primary, 33-4
+
+  Quarantine, 173, 182, 194, 197
+
+  Quetelet, Lambert (1796-1874), 168
+
+  Quinine, 281-2, 326, 330, 332
+
+
+  Radcliffe Infirmary, 296
+
+  Radiography, 245
+
+  Ragusa, 81
+
+  Raphael, 83
+
+  Réaumur, René Antoine de (1683-1757), 146-7, 148
+
+  Reed, W. (1851-1902), 279
+
+  Registration Act (1838), 195
+
+  Research, Method and Meaning of, 135
+
+  Respiration, 151-6, 205
+
+  Reymond, E. Du Bois-, (1818-96), 151
+
+  Rhazes of Basra (860-932), 67, 70
+
+  Rheumatism, 98, 358-9
+
+  Rhubarb, 323
+
+  Rickets, 181, 312, 313
+
+  Rochester, Minn., 248
+
+  Röntgen, Wilhelm Conrad (1845-1923), 244-5
+
+  Röntgen Rays, 244-5
+
+  Rokitansky, Karl (1804-78), 158-9
+
+  Roman Empire: Medical Teaching, 41-4;
+    Medical Services, 45-8;
+    Hospitals, 48-50
+
+  Ross, Ronald (1857-), 283
+
+  Roux, Pierre (1853-), 263
+
+  Royal Society, 104, 118, 124, 167
+
+  Rush, Benjamin (1745-1813), 171-2
+
+
+  St. Luke, 63
+
+  St. Bartholomew I., 49, 51
+
+  St. Bartholomew’s Hospital, 178-9
+
+  St. Gall, 50
+
+  St. Thomas’s Hospital, 298
+
+  Salerno, 64-5
+
+  Salicin, 327
+
+  Salts of Copper, 322
+
+  Salts of Lead, 322
+
+  San Francisco, 201
+
+  Sanctorius (1561-1636), 107-9, 159
+
+  Sanitary Commission, 195
+
+  Sanitation, 45, 194
+
+  Saragossa, 42
+
+  Scarlet Fever, 185, 201, 270, 349
+
+  Schaudinn, Fritz (1871-1906), 331-2
+
+  Schick, B., 264
+
+  Schiff, Moritz (1823-90), 304
+
+  Schleiden, Matthias Jakob (1804-81), 219-20
+
+  Schmiedeberg, Oswald (1834-1921), 328
+
+  Schultze, M. (1825-74), 222
+
+  Schwann, T. (1810-82), 220-1
+
+  Scurvy, 170, 181, 313
+
+  Seamen’s Hospital Society, 198
+
+  Secretions, Internal, 302-8
+
+  Semmelweis, Ignaz (1818-65), 243
+
+  Septicaemia, 239
+
+  Serpent, Cult, 4-5, 8, 11
+
+  Sertürner, Adolf (1783-1841), 326
+
+  Sesame, 323
+
+  Sex organs, 306
+
+  Shaftesbury, 7th Earl (1801-85), 290
+
+  Shakespeare, William, 26
+
+  Shattuck, Lemuel (1793-1859), 202
+
+  Sherrington, Sir Charles, 309
+
+  ‘Shock’, Nervous, 310-11
+
+  Sierra Leone, 276, 278
+
+  Sight, Deficient, 316-20
+
+  Simon, Sir John (1816-1904), 196-7
+
+  Simpson, Sir James Young (1811-70), 235
+
+  =606=, 332
+
+  Sleeping Sickness, 234, 272, 332
+
+  Sleepy Sickness, 272
+
+  Small-pox, 182-5, 198, 200, 261, 265, 343
+
+  Smith, Thomas S. (1788-1861), 171, 178, 193-6
+
+  Smyrna, 52
+
+  Spallanzani, Lazaro (1729-99), 147-8
+
+  Specialization, Scientific, 186-92, 359
+
+  Specific Energies, Law of, 212-13
+
+  _Speculum matricis_, 164
+
+  Spencer Wells, _see_ Wells
+
+  Spencer Wells Forceps, 244
+
+  Spinal anaesthesia, 236-7
+
+  _Spirochaeta pallida_, 331-2
+
+  Spotted Fever, 269-70
+
+  Sprue, 272
+
+  Stahl, George Ernest (1660-1734), 132-3, 151, 288
+
+  Starling, E. H. (1866-1927), 308
+
+  Statistics, Medical, 334-50;
+    Vital, 166-8
+
+  Stavesacre, 323
+
+  Stethoscope, the, 160-1
+
+  Stoic Philosophy, 54
+
+  Stomach, Ruminant, 28
+
+  Storax, 323
+
+  Strychnine, 326
+
+  Sublimation, 294-5
+
+  Superstition, 3, 6
+
+  Suprarenal bodies, 306-7
+
+  Surgery: Greek, 49;
+    Medieval, 76-7;
+    Renaissance, 92-4;
+    18th cent., 161-6;
+    Modern, 243-9
+
+  Süssmilch, J. P. (1707-82), 167-8
+
+  Swammerdam, J. J. (1637-80), 39, 121-3, 140, 143
+
+  Switzerland, 303
+
+  Sydenham, Thomas (1624-89), 96, 100-2, 282, 342
+
+  Sylvius, Franciscus (1614-72), 131-2, 139, 148
+
+  Syphilis, 98-9, 162, 251, 269, 291, 330-2, 337
+
+
+  Telescope, the, 105
+
+  Temperaments, Four, 97
+
+  Terebinth, 323
+
+  Tetanus (Lockjaw), 23, 256-8, 260, 264, 265;
+    immunization, 266-7
+
+  Thaddeus of Florence (1223-1303), 72
+
+  Theophrastus (372-287 B.C.), 35
+
+  Thermometer, the, 108-9;
+    clinical, 159
+
+  Theseus, 12
+
+  Thessaly, 14
+
+  Thyroid Gland, 303-6, 325
+
+  Thyroxin, 305
+
+  Tiberius, Emperor (1st c.), 42
+
+  Tobacco, 95, 99, 323
+
+  Toulon, 182
+
+  Tours, 185, 253
+
+  Toxins, 259-60, 262-7, 330-3
+
+  Trachoma, 321-2
+
+  Tragacanth, 323
+
+  Trephining, 18-19, 20, 63, 64, 72
+
+  Tropical Diseases, 198
+
+  Tropical Hygiene and Medicine, 170, 270-86
+
+  Tuberculosis, 234, 250, 330, 359
+
+  Tübingen, 220
+
+  Tuke, W. (1732-1822), 288
+
+  Turpentine, 322
+
+  =205=, 332
+
+  Typhoid Fever, 185, 201, 258-61, 265;
+    immunization, 267-70;
+    death-rate, 271;
+    state, the, 25
+
+  Typhus, 98, 258-9, 271
+
+
+  United States, 171, 290;
+    Preventive Medicine in, 197-203;
+    Public Health Service (1912), 201;
+    Sanitary Commission, 300
+
+  Universities, Medieval, 70-2
+
+  Urea, 205, 214
+
+  Uterus, Aristotle’s nomenclature of, 28, 29
+
+  Utilitarian Philosophy, 190
+
+
+  Vaccination, 184
+
+  Vaccines, 261-2, 265, 266, 268, 325
+
+  Vaso-Motor Mechanism, 215
+
+  Venereal Disease, _see_ Syphilis
+
+  Venice, 81
+
+  Ventilation, 146, 147
+
+  Vesalius, Andreas (1514-64), 85-92, 108, 135, 140
+
+  Vespasian, Emperor (1st cent.), 42
+
+  Victoria, Queen, 195
+
+  Vienna, 158, 160, 215, 236, 243
+
+  Virchow, R. (1821-1902), 222, 238, 253, 258, 264
+
+  Vital Spirit, 58
+
+  Vital Statistics, 166-8
+
+  Vitalism, 127, 132-3
+
+  Vitamins, 311-13
+
+  Volta, Alessandro (1745-1827), 149-50
+
+  Voltaic pile, 149
+
+
+  Waller, A. V. (1816-70), 238
+
+  Wassermann, August von (1866-), 269
+
+  Water, 156
+
+  Water Supply, 178
+
+  Wells, Horace (1815-45), 237
+
+  Wells, Thomas Spencer (1818-97), 243-5
+
+  Whooping Cough, 98
+
+  Widal, F. (1862-), 268
+
+  William of Saliceto (1215?-1280?), 72
+
+  Withering, W. (1741-99), 328
+
+  Wöhler, Friedrich (1800-82), 206, 214, 327
+
+  Wormwood, 323
+
+  Wright, A. (1861-), 223
+
+  Würzburg, 222
+
+
+  X-rays, 244-5, 247
+
+  Xavier, Marie François (1771-1802), 219
+
+
+  Yellow Fever, 172, 194, 198, 200, 201, 272;
+    history of, 273-80
+
+  Yersin, Alexandre (1863-), 253, 263
+
+  York, 288-9
+
+  Young, Thomas (1773-1829), 217, 319-20
+
+
+  Zürich, 215, 253, 294
+
+
+Transcriber’s Notes.
+
+Italic text is indicated with _underscores_, bold text with =equals=.
+Small/mixed capitals have been replaced with ALL CAPITALS.
+
+Evident typographical and punctuation errors have been corrected
+silently. Inconsistent spelling/hyphenation has been normalised.
+
+The usage of "cholestrol" is the author’s.
+
+A half-title and chapter title reiteration have been discarded.
+
+To improve text flow, illustrations have been relocated between
+paragraphs.
+
+Cover art created for this eBook is granted to the public domain.
+
+
+*** END OF THE PROJECT GUTENBERG EBOOK 78966 ***
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+      A short history of medicine | Project Gutenberg
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+
+<body>
+<div style='text-align:center'>*** START OF THE PROJECT GUTENBERG EBOOK 78966 ***</div>
+
+<main>
+
+
+
+
+<p><span class="pagenum"><a id="Page_i"></a><a id="Page_ii"></a><a id="Page_iii"></a><a id="Page_iv"></a>iv</span></p>
+
+<figure class="figcenter illowe30" id="i_f004">
+  <img class="w100" src="images/i_f004.jpg" alt="">
+  <figcaption>
+    <p class="center">HIPPOCRATES<br>
+
+   Ἢν γὰρ παρῇ φιλανθρωπίη πάρεστι καὶ φιλοτεχνίη.<br>
+
+    Where the love of man is, there also is love of this Art.<br></p>
+
+    <p class="right">Παραγγελίαι, i.e. <i>Precepts</i> (Hippocratic Collection), § 6</p>
+  </figcaption>
+</figure>
+
+<p><span class="pagenum" id="Page_v">v</span></p>
+
+
+<h1>
+<span class="sm">A SHORT</span><br>
+HISTORY OF MEDICINE
+</h1>
+
+<p class="center">
+  INTRODUCING MEDICAL PRINCIPLES TO<br>
+  STUDENTS AND NON-MEDICAL READERS<br>
+  <br>
+  <span class="sm">BY</span><br>
+  <br>
+  CHARLES SINGER<br>
+  <span class="xsm">M.A., M.D., D.LITT., OXFORD</span><br>
+  <br>
+  <span class="xsm">FELLOW OF THE ROYAL COLLEGE OF PHYSICIANS OF LONDON<br>
+  LECTURER ON THE HISTORY OF MEDICINE<br>
+  IN THE UNIVERSITY OF LONDON</span>
+</p>
+<p class="center p2 sm">
+  Scire potestates herbarum usumque medendi<br>
+  Maluit et mutas agitare inglorius artes<br>
+  <br>
+  <i>It was his part to learn of the power of Medicine<br>
+  and of the manner of healing and, heedless of<br>
+  glory, to exercise that quiet art.</i><br>
+  Virgil, <i>Aeneid</i> xii, 396-7
+</p>
+<p class="center p4 sm">
+  NEW YORK<br>
+  OXFORD UNIVERSITY PRESS<br>
+  AMERICAN BRANCH<br>
+  1928
+<span class="pagenum" id="Page_vi">vi</span>
+</p>
+<p class="center p4 sm">
+  COPYRIGHT, 1928<br>
+  <span class="smcap">By Oxford University Press</span><br>
+  AMERICAN BRANCH<br>
+  <br>
+  PRINTED IN THE UNITED STATES OF AMERICA
+</p>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_vii">vii</span></p>
+
+
+  <h2 class="nobreak" id="PREFACE">
+    PREFACE
+  </h2>
+</div>
+
+
+<p>The position that Medical Science has now assumed
+in the social polity demands that all educated men
+and women should have some knowledge of the subject,
+whether they have had a medical training or no.
+In these pages the author seeks to place before the
+reader, who is without special knowledge, some account
+of Medicine as a Science. For this purpose the historical
+method is peculiarly suited, since it recapitulates, in
+some measure, the actual stages through which each
+learner must pass. Though the story told here opens
+with Greek times, the narrative of the earlier period is
+so condensed that more than half the book is devoted
+to modern Medicine, which is presented as a natural
+outgrowth of an ancient tradition. An attempt has been
+made to keep the account as simple and as elementary as
+possible and to make the smallest demands on the
+scientific equipment of the reader. The slight divergence,
+in some matters, of the interests of American and
+of English readers, has been held in mind, so that, it is
+hoped, the book may be useful to both classes.</p>
+
+<p>Throughout the work two particular aims have been
+steadily kept in view: first, to stress the principles of
+Medicine rather than the details of practice; second, to
+treat of those principles in as small a space as may be.
+For ‘principles’ the author has substituted at times the
+<span class="pagenum" id="Page_viii">viii</span>word ‘Philosophy.’ He would, however, beseech the
+timid reader to take no alarm at a word, for he employs
+the term ‘Philosophy’ in a time-honored fashion, and
+he undertakes not to plunge deep into the labyrinth of
+Metaphysic. The Philosophy of Medicine stands
+here for the disinterested study of the theory of the
+subject, without reference to its application to particular
+instances.</p>
+
+<p>Certain omissions in the book are justified by the
+author’s forthcoming publication of a history of the
+biological sciences treated along somewhat similar lines.
+It has thus, for example, seemed superfluous to include
+here any but casual references to such highly important
+topics as the study of hereditary characters or the experimental
+investigation of developmental defects. It is,
+however, the duty of the author to direct attention to
+certain other omissions necessitated by the compression
+of the work into a small compass. The history of
+Medicine, as here treated, is essentially a history of
+ideas. The personal element has been kept wholly in
+the background and very little space has been allotted
+to biographical matter. Nor do the limits of the book
+permit any discussion of the status of medical men, and
+very little even of their training. On this account many
+who in their day were remarkable rather for the influence
+they exerted than for the advances in knowledge
+which they initiated find no commemoration here. This
+line of treatment has involved omission of reference to
+<span class="pagenum" id="Page_ix">ix</span>those teachers to whom the author himself owes most,
+Sir William Osler and Sir Clifford Allbutt.</p>
+
+<p>A work on Medicine must be colored, in some degree,
+by its author’s conception of the nature of Life. On
+this theme there are divers views, for the full discussion
+of which there is here no place. The author professes
+himself, however, an adherent of a school of thought
+that is not, at present, greatly in fashion. He ranges
+himself as a vitalist under the banner of Aristotle
+and as a follower in the goodly company of Harvey,
+Hunter and Virchow, of Claude Bernard and Johannes
+Müller. He believes that there is a principle in living
+things that cannot be expressed in chemical or physical
+terms. He believes that this principle works to an
+intelligible end, that it is an <i>Entelechy</i>, an indwelling
+purposiveness, and that it is as real a thing as anything
+that is.</p>
+
+<p><i>They are right who hold ‘soul’ to be not independent of
+body and yet not a kind of body. ‘Soul’ is not body but
+something pertaining to the body and dwelling therein,
+and, what is more, specific to each body. Our forebears
+erred in seeking to fit the ‘soul’ into a body without regard
+to the nature and qualities of the body, for the association of
+‘soul’ and body is by no means thus at random. And so
+indeed we might expect, for the ‘Entelechy’ of each being
+comes naturally to be developed in the potentiality of each
+being, that is to say in the matter proper to it. Whence is
+manifest that the ‘soul’ is a certain ‘Entelechy’, a notion
+<span class="pagenum" id="Page_x">x</span>or form of that which has capacity to be endowed with
+‘soul’.</i> Aristotle, Περὶ Ψυχῆς, <i>II</i>, § 2.</p>
+
+<p>The author is well aware that this conception is
+neither useful nor helpful for physiological research in
+the present state of our knowledge. That is a very good
+reason for excluding it, as the vitalist Claude Bernard
+excluded it, from the physiological laboratory. But it is
+not a good reason for abandoning a point of view which
+does something to make existence intelligible. On the
+contrary, turning from the physiological laboratory to
+the living being as a whole, it is just the indwelling
+purposiveness that is, before all things, most worthy of
+consideration. Every function, every structure, every
+instinct, habit, or reflex, every mental activity that is
+related to health—and which is not?—may throw some
+light thereon. It appears to the author that the scientific
+method is by far the mightiest weapon that has as
+yet come within man’s grasp, for the illumination of
+these multitudinous entities. The searching accuracy
+and power of that superb instrument, wielded by human
+reason in the quest of human health, is the theme of
+this volume. And yet, notwithstanding its triumphs,
+the experimental method, as applied in the separate
+sciences, has, of its nature, certain limitations with reference
+to living beings in general and living human
+beings in particular.</p>
+
+<p>It is the business of each of the sciences—it is indeed
+an essential part of the method of Science—to separate
+<span class="pagenum" id="Page_xi">xi</span>a circumscribed part of the Universe for consideration
+in and for itself. Men of Science must thus perforce
+become Chemists, Physicists, Astronomers, Botanists,
+Cytologists, Statisticians, and the like. In this respect
+modern <i>Science</i> differs most profoundly from medieval
+<i>Scientia</i> and from ancient <i>Philosophia</i>. ‘Specialization’
+follows modern <i>Science</i> as shadow follows substance.
+The new method has triumphed wonderfully in these
+last centuries and it is mere folly and obscurantism to
+seek to place intellectual stumbling-blocks in its path.
+Nor must we be afraid of shadows. The author does
+plead, however, that, while the Man of Science must,
+from the very nature of his method, cut off part of his
+universe of experience from all other parts, he should
+bear in mind, when not employed on his special task,
+that he has so cut off and isolated his special experience,
+of deliberate and set intent. To bear this fact in mind
+should not mean and must not mean that Science fails
+to influence our view of the world as a whole, but it
+should mean and must mean the basing of our view of
+the world as a whole on experience as a whole, and not
+on an artificially separated fragment of experience. For
+Man is neither a walking test-tube, nor a living anatomy,
+nor a colony of cells, nor a self-repairing machine that
+carries its own spare parts, nor a mere summation of
+the factors of heredity and environment, nor, for that
+matter, is he a disembodied spirit. But he is a being
+with a purpose. Of that purpose he, of his nature, can
+<span class="pagenum" id="Page_xii">xii</span>know very little, since it is a part of that through which
+he knows. Yet some glimpse of that purpose, though
+seen through a mist and ever so dimly, we may perhaps
+gain from the view-point on which the stony tracks of
+the separate sciences do ultimately converge. If the
+separate sciences did not so conspire to one end, why
+should we ever bother our heads or weary our limbs
+over their steep ascents? Are there not rosier paths that
+we might tread?</p>
+
+<p>Throughout this book, then, the ideal kept in view
+is the description of Medicine as a Rational Discipline
+involving many and perhaps all the sciences. Medicine
+is not now and never has been followed wholly in the
+scientific spirit. But it is the story of the scientific
+elements in Medicine which is here to be told, and
+other aspects are passed over with a silence which must
+not be interpreted as the silence of contempt.</p>
+
+<p>No two men undertaking the task here outlined would
+make quite the same selections or allot emphasis in
+quite the same manner. Doubtless the author has erred
+by omission and by commission, through ignorance
+and through misconception, but he hopes that he has
+never erred through prejudice. The ideas that he recounts
+are those that present themselves to him as the
+most important and fruitful within the range of scientific
+Medicine, and he is prepared to revise his opinions both
+on matters of fact and on matters of stress. He will therefore
+be very grateful for any corrections or suggestions.</p>
+
+<p><span class="pagenum" id="Page_xiii">xiii</span></p>
+
+<p>The number of names mentioned in the book has
+been reduced to the utmost limit that has seemed feasible.
+In recounting many episodes one name has often been
+taken as an example or type, and thus perhaps sometimes
+an injustice has been done to other workers, no
+less important but perhaps less typical. When modern
+times and living persons are reached the selection becomes
+not only difficult but also delicate, but the reader
+must remember that the names are not always chosen
+for their eminence but sometimes rather as typifying
+the various movements that have to be discussed. There
+is a further complication in that an attempt is here made
+to bring history right up to date. Very few names of
+living men are mentioned, though the work of many
+living men is discussed. Though the author has
+sought to refrain from passing any judgment on such
+latter-day conclusions the value of which does not seem
+to him clearly and firmly established, yet even this course
+in itself implies a judgment, and one in which he is
+even more likely to err than in other topics of which
+the book treats. Nevertheless, some such judgment
+seems necessary to make the book a coherent whole.</p>
+
+<p>There are several from whom the author has had
+help in the writing of this book. Mrs. Singer has
+criticized every detail, and has considerably modified
+its form. No English writer on the History of Medicine
+can fail to refer to the great work of Lt.-Col. Fielding
+H. Garrison of the United States Army and of the
+<span class="pagenum" id="Page_xiv">xiv</span>Library of Congress at Washington. The author of
+this book owes much to Lt.-Col. Garrison’s splendid
+bibliography, but even more to constant correspondence,
+carried on now through a good many years, with
+the man who made it. He owes a similar debt to a very
+old-standing friendship with Dr. E. T. Withington of
+Oxford, to whom he takes the liberty of dedicating this
+book. Professor Graham Wallas, Emeritus Professor
+of Sociology in the University of London, and Professor
+J. C. Drummond, Professor of Biochemistry in the
+University of London, have both read the book in
+proof, and have made a number of suggestions and
+corrections. Help on special points has been given by
+Dr. Clark-Kennedy of Corpus Christi College, Cambridge,
+Dr. Raymond Crawfurd, Registrar of the
+Royal College of Physicians of London, Dr. J. W.
+Eyre, Professor of Bacteriology in the University of
+London, the Rev. Father J. R. Fletcher, who has the
+unusual distinction of being both a Priest and a Physician,
+Dr. K. Franklin of the Pharmacological Laboratory
+in the University of Oxford, and Dr. William
+Robson, Lecturer in Law in the University of London,
+as well as by the author’s pupils Dr. Ivor Hart, Dr. J. F.
+Prendergast, Dr. Dorothy M. Turner and Mr. F.
+Prescott, M.Sc. To all of these the author would tender
+his grateful thanks.</p>
+
+<blockquote>
+<p class="right">
+  CHARLES SINGER.
+</p>
+
+<p class="sm">UNIVERSITY COLLEGE, LONDON.<br>
+<i>January</i>, 1928.</p>
+</blockquote>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_xv">xv</span></p>
+
+
+  <h2 class="nobreak" id="CONTENTS">
+    CONTENTS
+  </h2>
+</div>
+
+
+
+<table class="autotable4">
+<tr>
+<td class="tdl">
+<a href="#PREFACE">PREFACE</a>
+</td>
+<td class="tdr">
+vii-xiv
+</td>
+</tr>
+<tr>
+<td class="tdl">
+<a href="#LIST_OF_ILLUSTRATIONS">LIST OF ILLUSTRATIONS
+</a></td>
+<td class="tdr">
+xix-xxiv
+</td>
+</tr>
+<tr>
+<td class="tdl">
+<a href="#I">I. ANCIENT GREECE</a>, to about 300 <span class="allsmcap">B.C.</span>
+</td>
+<td class="tdr">
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_1_The_Origins">§ 1.</a> Origins of Greek Medicine
+</td>
+<td class="tdr">
+1
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_2_The_Hippocratic_Physician">§ 2.</a> The Hippocratic Physician
+</td>
+<td class="tdr">
+13
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_3_Hippocratic_Practice">§ 3.</a> Hippocratic Practice
+</td>
+<td class="tdr">
+18
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_4_Aristotle">§ 4.</a> Aristotle
+</td>
+<td class="tdr">
+27
+</td>
+</tr>
+<tr>
+<td class="tdl ind1">
+<a href="#II">II. THE HEIRS OF GREECE</a>, from about 300 <span class="allsmcap">B.C.</span> to about <span class="allsmcap">A.D.</span> 200
+</td>
+<td class="tdr">
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#1_The-Alexandrian_School">§ 1.</a> The Alexandrian School
+</td>
+<td class="tdr">
+36
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_2_Medical_Teaching_in_the_Roman_Empire">§ 2.</a> Medical Teaching in the Roman Empire
+</td>
+<td class="tdr">
+41
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_3_Medical_Services_of_the_Roman_Empire">§ 3.</a> Medical Services of the Roman Empire
+</td>
+<td class="tdr">
+45
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_4_Roman_Hospitals">§ 4.</a> Roman Hospitals
+</td>
+<td class="tdr">
+48
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_5_Galen">§ 5.</a> Galen
+</td>
+<td class="tdr">
+50
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_6_The_Final_Medical_Synthesis_of_Antiquity">§ 6.</a> The Final Medical Synthesis of Antiquity
+</td>
+<td class="tdr">
+53
+</td>
+</tr>
+<tr>
+<td class="tdl ind1">
+<a href="#III">III. THE MIDDLE AGES</a>, from about <span class="allsmcap">A.D.</span> 200 to about <span class="allsmcap">A.D.</span> 1500
+</td>
+<td class="tdr">
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#1_period_of_depression">§ 1.</a> The Period of Depression in Europe
+</td>
+<td class="tdr">
+61
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_2_Arabic_Medicine">§ 2.</a> Arabic Medicine
+</td>
+<td class="tdr">
+66
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_3_The_Medieval_Awakening">§ 3.</a> The Medieval Awakening
+</td>
+<td class="tdr">
+68
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_4_The_Universities">§ 4.</a> The Universities
+</td>
+<td class="tdr">
+70
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_5_Medieval_Anatomy_Surgery_and_Internal_Medicine">§ 5.</a> Medieval Anatomy, Surgery, and Internal Medicine
+</td>
+<td class="tdr">
+72
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_6_Medieval_Hospitals_and_Hygiene">§ 6</a>. Medieval Hospitals and Hygiene
+</td>
+<td class="tdr">
+77
+</td>
+</tr>
+<tr>
+<td class="tdl ind1">
+<a href="#IV">IV. THE REBIRTH OF SCIENCE</a>, from about 1500 to about 1700.
+</td>
+<td class="tdr">
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#1_anatomical_awakening">§ 1.</a> The Anatomical Awakening
+</td>
+<td class="tdr">
+82
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_2_The_Anatomical_Reaction_on_Surgery">§ 2.</a> The Anatomical Reaction on Surgery
+</td>
+<td class="tdr">
+92<span class="pagenum" id="Page_xvi">xvi</span>
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_3_The_Renaissance_of_Internal_Medicine">§ 3.</a> The Renaissance of Internal Medicine
+</td>
+<td class="tdr">
+95
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_4_The_First_Physical_Synthesis">§ 4.</a> The First Physical Synthesis
+</td>
+<td class="tdr">
+102
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_5_The_Revival_of_Physiology">§ 5.</a> The Revival of Physiology
+</td>
+<td class="tdr">
+108
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_6_Microscopic_Analysis_of_the_Animal_Body">§ 6.</a> Microscopic Analysis of the Animal Body
+</td>
+<td class="tdr">
+115
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_7_From_Alchemy_to_Chemistry">§ 7.</a> From Alchemy to Chemistry
+</td>
+<td class="tdr">
+122
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_8_The_Medical_Theorists">§ 8.</a> The Medical Theorists
+</td>
+<td class="tdr">
+126
+</td>
+</tr>
+<tr>
+<td class="tdl ind1">
+<a href="#V">V. THE PERIOD OF CONSOLIDATION</a>, from about 1700 to about 1825.
+</td>
+<td class="tdr">
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#1_reign_of_law">§ 1.</a> The Reign of Law
+</td>
+<td class="tdr">
+135
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_2_The_Rise_of_Clinical_Teaching">§ 2.</a> The Rise of Clinical Teaching
+</td>
+<td class="tdr">
+138
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_3_Physiology_passes_to_the_Modern_Stage">§ 3.</a> Physiology passes to the Modern Stage
+</td>
+<td class="tdr">
+142
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_4_Some_Physiological_Advances">§ 4.</a> Some Physiological Advances
+</td>
+<td class="tdr">
+145
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_5_Discovery_of_the_Nature_of_the_Air">§ 5.</a> Discovery of the Nature of the Air
+</td>
+<td class="tdr">
+151
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_6_Morbid_Anatomy_becomes_a_Science">§ 6.</a> Morbid Anatomy becomes a Science
+</td>
+<td class="tdr">
+156
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_7_Clinical_Methods_and_Instruments">§ 7.</a> Clinical Methods and Instruments
+</td>
+<td class="tdr">
+159
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_8_Surgery_and_Obstetrics">§ 8.</a> Surgery and Obstetrics
+</td>
+<td class="tdr">
+161
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_9_The_Beginnings_of_the_Science_of_Vital_Statistics">§ 9.</a> The Beginnings of the Science of Vital Statistics
+</td>
+<td class="tdr">
+166
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_10_Military_Naval_and_Prison_Medicine">§ 10.</a> Military, Naval, and Prison Medicine
+</td>
+<td class="tdr">
+169
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_11_The_Industrial_Revolution">§ 11.</a> The Industrial Revolution
+</td>
+<td class="tdr">
+172
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#12_control_and_recognition">§ 12.</a> Control and Recognition of Epidemic Diseases
+</td>
+<td class="tdr">
+182
+</td>
+</tr>
+<tr>
+<td class="tdl ind1">
+<a href="#VI">VI. PERIOD OF SCIENTIFIC SUBDIVISION</a>, from about 1825 onwards.
+</td>
+<td class="tdr">
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#1_origins_and_implications">§ 1.</a> Origins and Implications of Scientific Specialization
+</td>
+<td class="tdr">
+186
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_2_The_Revolution_in_Preventive_Medicine">§ 2.</a> The Revolution in Preventive Medicine
+</td>
+<td class="tdr">
+192
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#a_Preventive_Medicine_in_Britain">(<i>a</i>)</a> Preventive Medicine in Britain
+</td>
+<td class="tdr">
+193
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#b_Preventive_Medicine_in_the_United_States">(<i>b</i>)</a> Preventive Medicine in U. S. A.
+</td>
+<td class="tdr">
+197<span class="pagenum" id="Page_xvii">xvii</span>
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_3_The_Transition_to_a_Physiological_Synthesis">§ 3.</a> The Transition to a Physiological Synthesis
+</td>
+<td class="tdr">
+203
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#a_Anatomy_and_Embryology">(<i>a</i>)</a> Anatomy and Embryology in the Earlier Nineteenth Century
+</td>
+<td class="tdr">
+204
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#b_Chemical_Physiology_in_the_Earlier_Nineteenth_Century">(<i>b</i>)</a> Chemical Physiology in the Earlier Nineteenth Century
+</td>
+<td class="tdr">
+205
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#c_Nervous_Physiology_in_the_Earlier_Nineteenth_Century">(<i>c</i>)</a> Nervous Physiology in the Earlier Nineteenth Century
+</td>
+<td class="tdr">
+207
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_4_The_Experimental_Foundations_of_Modern_Medicine">§ 4.</a> The Experimental Foundations of Modern Medicine
+</td>
+<td class="tdr">
+211
+</td>
+</tr>
+<tr>
+
+<td class="tdl ind3">
+<a href="#a_The_Work_of_Johannes_Muller">(<i>a</i>)</a> The Work of Johannes Müller
+</td>
+<td class="tdr">
+211
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#b_The_Work_of_Claude_Bernard">(<i>b</i>)</a> The Work of Claude Bernard
+</td>
+<td class="tdr">
+213
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#c_The_Work_of_Karl_Ludwig">(<i>c</i>)</a> The Work of Karl Ludwig
+</td>
+<td class="tdr">
+215
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_5_The_Cell_Theory_and_Cellular_Pathology">§ 5.</a> The Cell Theory and Cellular Pathology
+</td>
+<td class="tdr">
+219
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#6_establishment">§ 6.</a> Establishment of the Doctrine of the Germ Origin of Disease
+</td>
+<td class="tdr">
+224
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_7_Anaesthesia">§ 7.</a> Anaesthesia
+</td>
+<td class="tdr">
+235
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_8_The_Revolution_in_Surgery">§ 8.</a> The Revolution in Surgery
+</td>
+<td class="tdr">
+237
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_9_Some_Modern_Surgical_Advances">§ 9.</a> Some Modern Surgical Advances
+</td>
+<td class="tdr">
+243
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_10_Bacteriology_becomes_a_special_Science">§ 10.</a> Bacteriology becomes a Special Science
+</td>
+<td class="tdr">
+249
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_11_Some_Important_Bacteriological_Results">§ 11.</a> Some Important Bacteriological Results
+</td>
+<td class="tdr">
+253
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_12_The_Study_of_Immunity">§ 12.</a> The Study of Immunity
+</td>
+<td class="tdr">
+259
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_13_Some_Practical_Applications_of_Immunity">§ 13.</a> Some Practical Applications of Immunity
+</td>
+<td class="tdr">
+263
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_14_The_Conquest_of_the_Tropics">§ 14.</a> The Conquest of the Tropics
+</td>
+<td class="tdr">
+271
+</td>
+</tr>
+<tr>
+<td class="tdl ind3"><a href="#a_Yellow_Fever">(<i>a</i>)</a> Yellow Fever
+</td>
+<td class="tdr">
+273
+</td>
+</tr>
+<tr>
+<td class="tdl ind3"><a href="#b_Malaria">(<i>b</i>)</a> Malaria
+</td>
+<td class="tdr">
+280
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_15_The_Changed_View_of_Insanity">§ 15.</a> The Changed View of Insanity
+</td>
+<td class="tdr">
+286
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_16_The_New_Movement_in_Psychology">§ 16.</a> The New Movement in Psychology
+</td>
+<td class="tdr">
+293
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_17_The_Revolution_in_Nursing">§ 17.</a> The Revolution in Nursing
+</td>
+<td class="tdr">
+295<span class="pagenum" id="Page_xviii">xviii</span>
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#18_some_modern">§ 18.</a> Some Modern Physiological Concepts of Clinical Import
+</td>
+<td class="tdr">
+301
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#a_Ductless_Glands_and_Internal_Secretions">(<i>a</i>)</a> Ductless Glands and Internal Secretions
+</td>
+<td class="tdr">
+302
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#b_Nervous_Integration">(<i>b</i>)</a> Nervous Integration
+</td>
+<td class="tdr">
+308
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#c_Vitamins">(<i>c</i>)</a> Vitamins
+</td>
+<td class="tdr">
+311
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_19_Knowledge_of_the_Eye_and_its_Disorders">§ 19.</a> Knowledge of the Eye and its Disorders
+</td>
+<td class="tdr">
+313
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_20_Investigation_of_the_Nature_and_Action_of_Drugs">§ 20.</a> Investigation of the Nature and Action of Drugs
+</td>
+<td class="tdr">
+322
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#a_Entry_of_Vegetable_Drugs_into_the_Pharmacopoeia">(<i>a</i>)</a> Entry of Vegetable Drugs into the Pharmacopoeia
+</td>
+<td class="tdr">
+322
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#b_Active_Principles">(<i>b</i>)</a> Active Principles
+</td>
+<td class="tdr">
+323
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#c_The_Alkaloids">(<i>c</i>)</a> The Alkaloids
+</td>
+<td class="tdr">
+325
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#d_The_Glucosides">(<i>d</i>)</a> The Glucosides
+</td>
+<td class="tdr">
+327
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#e_The_Study_of_Pharmacology">(<i>e</i>)</a> The Study of Pharmacology
+</td>
+<td class="tdr">
+328
+</td>
+</tr>
+<tr>
+<td class="tdl ind3">
+<a href="#f_Chemotherapy">(<i>f</i>)</a> Chemotherapy
+</td>
+<td class="tdr">
+329
+</td>
+</tr>
+<tr>
+<td class="tdl ind2">
+<a href="#_21_Interpretation_of_Collective_Medical_Data">§ 21.</a> Interpretation of Collective Medical Data
+</td>
+<td class="tdr">
+333
+</td>
+</tr>
+<tr>
+<td class="tdl">
+<a href="#EPILOGUE">EPILOGUE</a>
+</td>
+<td class="tdr">
+351
+</td>
+</tr>
+<tr>
+<td class="tdl">
+<a href="#INDEX">INDEX</a>
+</td>
+<td class="tdr">
+364
+</td>
+</tr>
+</table>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_xix">xix</span></p>
+
+
+  <h2 class="nobreak" id="LIST_OF_ILLUSTRATIONS">
+    LIST OF ILLUSTRATIONS
+  </h2>
+</div>
+
+
+
+<table class="autotable5">
+<tr>
+<td class="tdr vtop">
+1.
+</td>
+<td class="tdl">
+Hippocrates. British Museum, second or third century <span class="allsmcap">B.C.</span>
+</td>
+<td class="tdr vbottom">
+<a href="#i_f004"><i>Frontispiece</i></a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+2.
+</td>
+<td class="tdl">
+Ivory and gold Minoan statuette of a votaress in a state of ecstasy. By kind permission of the Museum of Fine Arts, Boston, U.S.A.
+</td>
+<td class="tdr vbottom">
+<a href="#i005">5</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+3.
+</td>
+<td class="tdl">
+Surgical instruments recovered from Babylonian sites. Reproduced by kind permission of Professor Meyer-Steineg of Jena
+</td>
+<td class="tdr vbottom">
+<a href="#i005">5</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+4.
+</td>
+<td class="tdl">
+Clay model of sheep’s liver used for instruction in divination in a Babylonian temple school. Drawn from the object in the British Museum
+</td>
+<td class="tdr vbottom">
+<a href="#i006">6</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+5.
+</td>
+<td class="tdl">
+Imhotep. From a statuette in the British Museum
+</td>
+<td class="tdr vbottom">
+<a href="#i008">8</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+6.
+</td>
+<td class="tdl">
+Aesculapius. Photograph Anderson
+</td>
+<td class="tdr vbottom">
+<a href="#i008">8</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+7.
+</td>
+<td class="tdl">
+Scheme illustrating some of the sources of Hippocratic Medicine
+</td>
+<td class="tdr vbottom">
+<a href="#i009">9</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+8.
+</td>
+<td class="tdl">
+A Greek clinic of about 400 <span class="allsmcap">B.C.</span> From a vase painting
+</td>
+<td class="tdr vbottom">
+<a href="#i017a">17</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+9.
+</td>
+<td class="tdl">
+Instruments used by Greek surgeons
+</td>
+<td class="tdr vbottom">
+<a href="#i020">20</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+10.
+</td>
+<td class="tdl">
+The <i>Ladder of Nature</i> according to Aristotle
+</td>
+<td class="tdr vbottom">
+<a href="#i028">28</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+11.
+</td>
+<td class="tdl">
+The womb with the names of its parts as given by Aristotle
+</td>
+<td class="tdr vbottom">
+<a href="#i029">29</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+12.
+</td>
+<td class="tdl">
+Embryo dogfish, <i>Mustelus laevis</i>, after Johannes Müller
+</td>
+<td class="tdr vbottom">
+<a href="#i029">29</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+13.
+</td>
+<td class="tdl">
+The four <i>Elements</i> in association with the four <i>Humours</i> and the four <i>Qualities</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i034">34</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+14.
+</td>
+<td class="tdl">
+Inscribed tablet of about 100 <span class="allsmcap">B.C.</span> from the wall of the temple of Kom-Ombos in Upper Egypt
+</td>
+<td class="tdr vbottom">
+<a href="#i040">40</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+15.
+</td>
+<td class="tdl">
+Roman surgical instruments of the first century <span class="allsmcap">A.D.</span> found at Pompeii
+</td>
+<td class="tdr vbottom">
+<a href="#i044">44</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+16.
+</td>
+<td class="tdl">
+Aqueduct of Nero from an engraving by Piranesi
+</td>
+<td class="tdr vbottom">
+<a href="#i047">47</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+17.
+</td>
+<td class="tdl">
+Roman advanced dressing-station. From Trajan’s column
+</td>
+<td class="tdr vbottom">
+<a href="#i048">48</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+18.
+</td>
+<td class="tdl">
+Island of St. Bartholomew in the Tiber at Rome. From an engraving by Piranesi
+</td>
+<td class="tdr vbottom">
+<a href="#i051">51</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+19.
+</td>
+<td class="tdl">
+Dissection of the hand of a man
+</td>
+<td class="tdr vbottom">
+<a href="#i057">57</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+20.
+</td>
+<td class="tdl">
+Dissection of the hand of a Barbary ape
+</td>
+<td class="tdr vbottom">
+<a href="#i057">57</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+21.
+</td>
+<td class="tdl">
+Galen’s Physiological System
+</td>
+<td class="tdr vbottom">
+<a href="#i059">59</a><span class="pagenum" id="Page_xx">xx</span>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+22.
+</td>
+<td class="tdl">
+The earliest known representation of St. Luke as a Physician
+</td>
+<td class="tdr vbottom">
+<a href="#i063">63</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+23.
+</td>
+<td class="tdl">
+Picture of Trephining, from a thirteenth-century manuscript
+</td>
+<td class="tdr vbottom">
+<a href="#i063">63</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+24.
+</td>
+<td class="tdl">
+Illustrating the mode of action of the trephining instrument used by the surgeon in Fig. 23
+</td>
+<td class="tdr vbottom">
+<a href="#i064">64</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+25.
+</td>
+<td class="tdl">
+Scene at a siege of Salerno, from a manuscript prepared in South Italy early in the thirteenth century
+</td>
+<td class="tdr vbottom">
+<a href="#i065">65</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+26.
+</td>
+<td class="tdl">
+A Jewish translator receiving an Arabic medical volume from an Eastern potentate (right) and handing it, translated into Latin, to a Western monarch (left)
+</td>
+<td class="tdr vbottom">
+<a href="#i069">69</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+27.
+</td>
+<td class="tdl">
+Medieval Bologna, from a mural painting of about 1500 in the town-hall of the city
+</td>
+<td class="tdr vbottom">
+<a href="#i073">73</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+28.
+</td>
+<td class="tdl">
+An anatomical lecture at Padua in the fifteenth century, from a contemporary Italian woodcut
+</td>
+<td class="tdr vbottom">
+<a href="#i075">75</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+29.
+</td>
+<td class="tdl">
+A ward in a hospital at Paris in the sixteenth century. Reproduced, by kind permission of M. Édouard Champion, from D. L. MacKay, <i>Les hôpitaux et la Charité à Paris au XIII<sup>e</sup> siècle</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i079">79</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+30.
+</td>
+<td class="tdl">
+Drawing of Dissection of the Heart by Leonardo da Vinci
+</td>
+<td class="tdr vbottom">
+<a href="#i085">85</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+31.
+</td>
+<td class="tdl">
+Title-page of the work <i>On the Fabric of the Human Body</i>, by Vesalius, published in 1543
+</td>
+<td class="tdr vbottom">
+<a href="#i087">87</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+32.
+</td>
+<td class="tdl">
+Skeleton from the anatomical work of Vesalius
+</td>
+<td class="tdr vbottom">
+<a href="#i091">91</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+33.
+</td>
+<td class="tdl">
+Artificial arms and hands, designed and figured by Ambroise Paré
+</td>
+<td class="tdr vbottom">
+<a href="#i093">93</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+34.
+</td>
+<td class="tdl">
+The ‘Four Temperaments’, from the Guild Book of the Barber-Surgeons of York
+</td>
+<td class="tdr vbottom">
+<a href="#i097">97</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+35.
+</td>
+<td class="tdl">
+Earliest picture showing the use of Tobacco
+</td>
+<td class="tdr vbottom">
+<a href="#i099">99</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+36.
+</td>
+<td class="tdl">
+Allegorical picture illustrating the venereal plague
+</td>
+<td class="tdr vbottom">
+<a href="#i101">101</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+37.
+</td>
+<td class="tdl">
+Sanctorius in his balance
+</td>
+<td class="tdr vbottom">
+<a href="#i107">107</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+38.
+</td>
+<td class="tdl">
+The principle of Galileo’s thermometer
+</td>
+<td class="tdr vbottom">
+<a href="#i109">109</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+39.
+</td>
+<td class="tdl">
+The application of the system shown in Fig. 38 by Sanctorius, who used a curved tube
+</td>
+<td class="tdr vbottom">
+<a href="#i109">109</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+40.
+</td>
+<td class="tdl">
+The adaptation of the instrument, shown in Fig. 39, as a clinical thermometer
+</td>
+<td class="tdr vbottom">
+<a href="#i109">109</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+41.
+</td>
+<td class="tdl">
+Galileo’s ‘pulsimeter’
+</td>
+<td class="tdr vbottom">
+<a href="#i109">109</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+42.
+</td>
+<td class="tdl">
+Dissection of a vein in the thigh and leg, from Fabricius
+</td>
+<td class="tdr vbottom">
+<a href="#i111">111</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+43.
+</td>
+<td class="tdl">
+The circulation of the blood
+</td>
+<td class="tdr vbottom">
+<a href="#i113">113</a><span class="pagenum" id="Page_xxi">xxi</span>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+44.
+</td>
+<td class="tdl">
+The superficial veins, from William Harvey
+</td>
+<td class="tdr vbottom">
+<a href="#i114">114</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+45.
+</td>
+<td class="tdl">
+Lungs of a frog, showing the capillary vessels, from Malpighi
+</td>
+<td class="tdr vbottom">
+<a href="#i116">116</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+46-9.
+</td>
+<td class="tdl">
+Stages in the formation of the chick, from Malpighi
+</td>
+<td class="tdr vbottom">
+<a href="#i117">117</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+49a.
+</td>
+<td class="tdl">
+One of Leeuwenhoek’s microscopes. Reproduced, by the permission of Mrs. George Martin, from <i>The Asclepiad</i>, II
+</td>
+<td class="tdr vbottom">
+<a href="#i118">118</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+50-3.
+</td>
+<td class="tdl">
+Illustrating the blood corpuscles and circulation after Leeuwenhoek
+</td>
+<td class="tdr vbottom">
+<a href="#i119">119</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+54.
+</td>
+<td class="tdl">
+The first representation of Bacteria
+</td>
+<td class="tdr vbottom">
+<a href="#i120">120</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+55-56a.
+</td>
+<td class="tdl">
+Drawings by Leeuwenhoek of the structure of muscle
+</td>
+<td class="tdr vbottom">
+<a href="#i121">121</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+57-60.
+</td>
+<td class="tdl">
+Experiments by Swammerdam
+</td>
+<td class="tdr vbottom">
+<a href="#i123">123</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+61.
+</td>
+<td class="tdl">
+Boyle’s Air-pump
+</td>
+<td class="tdr vbottom">
+<a href="#i125">125</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+62.
+</td>
+<td class="tdl">
+Descartes’ conception of the relation of a sensory impression and a motor impulse
+</td>
+<td class="tdr vbottom">
+<a href="#i128">128</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+63.
+</td>
+<td class="tdl">
+Diagram of Descartes, to illustrate nervous action
+</td>
+<td class="tdr vbottom">
+<a href="#i129">129</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+64.
+</td>
+<td class="tdl">
+Diagrams from Borelli, to illustrate movements of muscles
+</td>
+<td class="tdr vbottom">
+<a href="#i130">130</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+65.
+</td>
+<td class="tdl">
+Diagram of muscular action
+</td>
+<td class="tdr vbottom">
+<a href="#i131">131</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+66.
+</td>
+<td class="tdl">
+Two Plates from Bernard Siegfried Albinus’ <i>Anatomical Plates of the Muscles of Man</i>, Leyden, 1747
+</td>
+<td class="tdr vbottom">
+<a href="#i141">141</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+67.
+</td>
+<td class="tdl">
+Windmill ventilator designed by the Rev. Stephen Hales. From a print in the British Museum
+</td>
+<td class="tdr vbottom">
+<a href="#i147">147</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+68-70.
+</td>
+<td class="tdl">
+Experiments illustrating the effects of metallic contacts on the nerves and muscles of frogs’ legs. From A. Galvani, <i>On Electric Forces</i>, 1792
+</td>
+<td class="tdr vbottom">
+<a href="#i149">149</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+71-3.
+</td>
+<td class="tdl">
+Volta’s figures of the electric pile and crown of cups
+</td>
+<td class="tdr vbottom">
+<a href="#i150">150</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+74-5.
+</td>
+<td class="tdl">
+Illustrating the chemistry of burning and breathing, from a work issued by Mayow in 1674
+</td>
+<td class="tdr vbottom">
+<a href="#i152">152</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+76.
+</td>
+<td class="tdl">
+Apparatus from Joseph Priestley’s <i>Experiments and Observations on different Kinds of Air</i>, 1774
+</td>
+<td class="tdr vbottom">
+<a href="#i154">154</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+77.
+</td>
+<td class="tdl">
+Lavoisier in his laboratory making experiments on breathing. From a contemporary sketch
+</td>
+<td class="tdr vbottom">
+<a href="#i155">155</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+78.
+</td>
+<td class="tdl">
+Part of the lung of Dr. Samuel Johnson, from a drawing published by Matthew Baillie
+</td>
+<td class="tdr vbottom">
+<a href="#i158">158</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+79-82.
+</td>
+<td class="tdl">
+Laënnec’s wooden stethoscope, from the first edition of his work <i>On Instrumental Auscultation</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i161">161</a><span class="pagenum" id="Page_xxii">xxii</span>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+83.
+</td>
+<td class="tdl">
+Lying-in scene in the sixteenth century, from a contemporary work on Midwifery
+</td>
+<td class="tdr vbottom">
+<a href="#i163">163</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+84-6.
+</td>
+<td class="tdl">
+Early obstetric instruments
+</td>
+<td class="tdr vbottom">
+<a href="#i164">164</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+87.
+</td>
+<td class="tdl">
+John Hunter’s country house at Earl’s Court, Kensington, before its demolition in 1886. Reproduced, by the kind permission of Mrs. George Martin, from <i>The Asclepiad</i>, VIII
+</td>
+<td class="tdr vbottom">
+<a href="#i165">165</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+88.
+</td>
+<td class="tdl">
+An eighteenth-century Quarantine station (Naples)
+</td>
+<td class="tdr vbottom">
+<a href="#i173">173</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+89-90.
+</td>
+<td class="tdl">
+Illustrating the textile trade from home industry to factory work with the consequent break-up of the family as the labour unit. The upper picture from a drawing by George Walker, the lower from <i>Economic Botany: The Cotton Manufacture</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i175">175</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+91.
+</td>
+<td class="tdl">
+Graph showing approximate growth of population in England and Wales 1670-1830
+</td>
+<td class="tdr vbottom">
+<a href="#i176">176</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+91a.
+</td>
+<td class="tdl">
+Tables illustrating vital conditions in the eighteenth century
+</td>
+<td class="tdr vbottom">
+<a href="#captioned_tables">177</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+92.
+</td>
+<td class="tdl">
+St. Bartholomew’s Hospital at Smithfield, London, in 1720. From Strype’s edition of Stow’s <i>Survey</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i179">179</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+93.
+</td>
+<td class="tdl">
+The Pest House in Tothill Fields, London, in 1796. From a print in the British Museum
+</td>
+<td class="tdr vbottom">
+<a href="#i181">181</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+94.
+</td>
+<td class="tdl">
+Hand of Dairymaid infected with cow-pox, from figure by Jenner
+</td>
+<td class="tdr vbottom">
+<a href="#i184">184</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+95.
+</td>
+<td class="tdl">
+A cartoon by Robert Cruikshank
+</td>
+<td class="tdr vbottom">
+<a href="#i191">191</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+96.
+</td>
+<td class="tdl">
+Annual death-rate in London per thousand living over 85 years
+</td>
+<td class="tdr vbottom">
+<a href="#i196">196</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+97.
+</td>
+<td class="tdl">
+The Old <i>Dreadnought</i> Hospital Ship
+</td>
+<td class="tdr vbottom">
+<a href="#i199">199</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+98.
+</td>
+<td class="tdl">
+Diagram of Transverse section of the Spinal Cord, &amp;c.
+</td>
+<td class="tdr vbottom">
+<a href="#i208">208</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+99.
+</td>
+<td class="tdl">
+Diagram to illustrate Reflex
+</td>
+<td class="tdr vbottom">
+<a href="#i209">209</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+100.
+</td>
+<td class="tdl">
+Diagram to illustrate Cerebral localization
+</td>
+<td class="tdr vbottom">
+<a href="#i210">210</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+101.
+</td>
+<td class="tdl">
+Thomas Young’s Kymograph
+</td>
+<td class="tdr vbottom">
+<a href="#i217">217</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+102-5.
+</td>
+<td class="tdl">
+Drawings by Theodor Schwann to illustrate cells
+</td>
+<td class="tdr vbottom">
+<a href="#i221">221</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+106.
+</td>
+<td class="tdl">
+Organisms of Fermentation, from Pasteur
+</td>
+<td class="tdr vbottom">
+<a href="#i226">226</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+107.
+</td>
+<td class="tdl">
+Pasteur’s experiment to prove that fermentation is the result of air-borne organisms
+</td>
+<td class="tdr vbottom">
+<a href="#i228">228</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+108.
+</td>
+<td class="tdl">
+Bacilli of Anthrax
+</td>
+<td class="tdr vbottom">
+<a href="#i231">231</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+108a.
+</td>
+<td class="tdl">
+Screw used in the eighteenth and the early nineteenth century to secure analgesia. Reproduced, by the kind permission of Mrs. George Martin, from <i>The Asclepiad</i>, VII
+</td>
+<td class="tdr vbottom">
+<a href="#i236">236</a><span class="pagenum" id="Page_xxiii">xxiii</span>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+109.
+</td>
+<td class="tdl">
+The ‘Donkey Engine’ designed by Lord Lister. Now in the Royal College of Surgeons of England
+</td>
+<td class="tdr vbottom">
+<a href="#i241">241</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+109a.
+</td>
+<td class="tdl">
+Operating table used by Lord Lister in the Glasgow Royal Infirmary. Reproduced, by kind permission of Messrs. Jackson, Wylie &amp; Co., from <i>Lister and the Lister Ward in the Royal Infirmary of Glasgow</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i242">242</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+110.
+</td>
+<td class="tdl">
+‘Spencer Wells Forceps’
+</td>
+<td class="tdr vbottom">
+<a href="#i244">244</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+111.
+</td>
+<td class="tdl">
+Spencer Wells performing an abdominal operation
+</td>
+<td class="tdr vbottom">
+<a href="#i245">245</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+112.
+</td>
+<td class="tdl">
+An operation in the sixteenth century
+</td>
+<td class="tdr vbottom">
+<a href="#i246">246</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+113.
+</td>
+<td class="tdl">
+An abdominal operation under modern conditions. Reproduced, by kind permission of W. B. Saunders’ Company, Philadelphia, from <i>The Operating Room, St. Mary’s Hospital, Rochester, Minnesota</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i247">247</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+114.
+</td>
+<td class="tdl">
+Bacilli of Diphtheria
+</td>
+<td class="tdr vbottom">
+<a href="#i254">254</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+115.
+</td>
+<td class="tdl">
+Bacilli of Plague
+</td>
+<td class="tdr vbottom">
+<a href="#i255">255</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+116.
+</td>
+<td class="tdl">
+Diagram showing the Incidence of Malta fever
+</td>
+<td class="tdr vbottom">
+<a href="#i256">256</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+117.
+</td>
+<td class="tdl">
+Bacilli of Tetanus
+</td>
+<td class="tdr vbottom">
+<a href="#i257">257</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+118.
+</td>
+<td class="tdl">
+Bacilli of Typhoid Fever
+</td>
+<td class="tdr vbottom">
+<a href="#i258">258</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+119.
+</td>
+<td class="tdl">
+Death-rate of cases of Laryngeal Diphtheria
+</td>
+<td class="tdr vbottom">
+<a href="#i263">263</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+120-1.
+</td>
+<td class="tdl">
+A common Malaria-carrying mosquito and a Yellow Fever-carrying mosquito. Reproduced, by kind permission of the British Museum (Natural History), from Edwards, <i>Mosquitoes and their Relation to Disease</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i272">272</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+122.
+</td>
+<td class="tdl">
+Distribution of Malaria in England and Wales
+</td>
+<td class="tdr vbottom">
+<a href="#i281">281</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+123.
+</td>
+<td class="tdl">
+The Life-History of the Parasite of Malaria. Reproduced, by kind permission of Messrs. Baillière, Tindall &amp; Cox, from C. M. Wenyon’s <i>Protozoology</i>, vol. II
+</td>
+<td class="tdr vbottom">
+<a href="#i285">285</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+124-5.
+</td>
+<td class="tdl">
+A Malaria-carrying mosquito and a common gnat. Reproduced, by kind permission of the British Museum (Natural History), from Edwards, <i>Mosquitoes and their Relation to Disease</i>
+</td>
+<td class="tdr vbottom">
+<a href="#i287a">287</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+126.
+</td>
+<td class="tdl">
+Chart of cases of Malaria reported in Italy in recent years
+</td>
+<td class="tdr vbottom">
+<a href="#i287b">287</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+127.
+</td>
+<td class="tdl">
+‘The Retreat’ near York. Reproduced, by permission of Messrs. Kegan Paul, Trench, Trubner &amp; Co., from Tuke, <i>Chapters in the History of the Insane in the British Isles</i>, 1882
+</td>
+<td class="tdr vbottom">
+<a href="#i289">289</a><span class="pagenum" id="Page_xxiv">xxiv</span>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+128.
+</td>
+<td class="tdl">
+Florence Nightingale at Scutari. Photograph, Rischgitz Collection
+</td>
+<td class="tdr vbottom">
+<a href="#i299">299</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+129-30.
+</td>
+<td class="tdl">
+Cretinous infant before and after thyroid treatment. Reproduced by kind permission of the Royal College of Surgeons
+</td>
+<td class="tdr vbottom">
+<a href="#i305">305</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+131.
+</td>
+<td class="tdl">
+Diagram to show the structure of the eye
+</td>
+<td class="tdr vbottom">
+<a href="#i314">314</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+132.
+</td>
+<td class="tdl">
+Diagram to show the nature of accommodation of the eye
+</td>
+<td class="tdr vbottom">
+<a href="#i317">317</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+133.
+</td>
+<td class="tdl">
+The Organisms of Syphilis in a smear from the Local Infection
+</td>
+<td class="tdr vbottom">
+<a href="#i331">331</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+134.
+</td>
+<td class="tdl">
+Diagram illustrating alteration in Age-distribution of the population of England and Wales. Reproduced, by kind permission of the authors, from Carr-Saunders &amp; Caradog Jones, <i>Social Structure of England and Wales</i> (Clarendon Press)
+</td>
+<td class="tdr vbottom">
+<a href="#i335">335</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+135.
+</td>
+<td class="tdl">
+Death-rate from Cancer of the Tongue. Reproduced, by kind permission of the Editors, from <i>The Quarterly journal of Medicine</i>, vol. v, No. 5
+</td>
+<td class="tdr vbottom">
+<a href="#i337">337</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+136.
+</td>
+<td class="tdl">
+Death-rate from Cancer of the Lip. Reproduced, by kind permission of the Editors, from <i>The Quarterly Journal of Medicine</i>, vol. v, No. 5
+</td>
+<td class="tdr vbottom">
+<a href="#i338">338</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+137.
+</td>
+<td class="tdl">
+Death-rate from Cerebral Haemorrhage. Reproduced, by kind permission of the Editors, from <i>The Quarterly Journal of Medicine</i>, vol. v, No. 5
+</td>
+<td class="tdr vbottom">
+<a href="#i340">340</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+138.
+</td>
+<td class="tdl">
+Curve showing percentage of deaths from Phthisis to total deaths
+</td>
+<td class="tdr vbottom">
+<a href="#i343">343</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+139.
+</td>
+<td class="tdl">
+The normal curve of error
+</td>
+<td class="tdr vbottom">
+<a href="#i345">345</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+140.
+</td>
+<td class="tdl">
+Curve of monthly number of deaths from Small-pox during an epidemic at Warrington, Lancashire, in 1743
+</td>
+<td class="tdr vbottom">
+<a href="#i346">346</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+141.
+</td>
+<td class="tdl">
+Curve of weekly number of cases of Scarlet Fever during an epidemic at Glasgow in 1892
+</td>
+<td class="tdr vbottom">
+<a href="#i346">346</a>
+</td>
+</tr>
+<tr>
+<td class="tdr vtop">
+142.
+</td>
+<td class="tdl">
+Analysis of curve representing death-rates from Summer Diarrhoea in London over a long period of years
+</td>
+<td class="tdr vbottom">
+<a href="#i347">347</a>
+</td>
+</tr>
+</table>
+
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_1">1</span></p>
+
+
+  <h2 class="nobreak" id="I">
+    I
+    <br>
+    ANCIENT GREECE
+    <br>
+    <span class="sm">(TO ABOUT 300 B.C.)</span>
+  </h2>
+</div>
+
+
+<h3 id="_1_The_Origins">§ 1. <i>Origins of Greek Medicine.</i></h3>
+
+<p>Scientific Medicine began with the Greeks. The
+Greeks not only started scientific Medicine upon its
+course, but also provided the substantial basic elements
+of our anatomy, physiology and pathology, and above
+all, perhaps, our conception of the bodily ‘constitution’,
+‘habit’ or ‘temperament’. It is from the Greeks that
+we derive almost all our medical nomenclature. When
+to this we add that our medical traditions are inherited
+through a direct and continuous chain from the Greek
+practitioners, it becomes evident that the debt that
+Medicine owes to this marvellous people is great indeed.</p>
+
+<p>Now this debt has become associated with two or
+three great figures. The names Hippocrates, Aristotle,
+Galen, are familiar to all. Yet it is not always
+recognized that these men were but the representatives
+of a widely extended and long-lasting system. Greek
+Medicine was, in fact, like modern Medicine, the
+result of centuries of carefully recorded, collated and
+progressive research. Greek Medicine first assumed a
+scientific aspect with the Ionian and Italo-Greek philosophers
+at the very beginning of the sixth century <span class="allsmcap">B.C.</span>
+It continued to make important advances until the
+death of Galen at the very end of the second century
+of the Christian era. Thus the life-span of progressive
+and scientific Medicine among the Greeks was no less
+than eight hundred years. With the most tolerant use
+<span class="pagenum" id="Page_2">2</span>of the words ‘scientific’ and ‘progressive’, we can hardly
+place the beginnings of modern Medicine in Europe
+before the end of the fifteenth century. Thus our own
+system has only been developing its characteristic
+features for some four and a half centuries, which is but
+little more than half the course that Greek science ran.</p>
+
+<p>It is evident, therefore, that we may have much to
+learn from the Greeks, not indeed in matters of actual
+fact or observation—for nearly all that is <i>directly</i> useful
+in their writings has been absorbed long ago into our
+medical literature—but in spirit and method. From
+a study of the character and course of Greek medical
+science we can gain hints of the snares and pitfalls and
+catastrophes into which the Art of Medicine may at
+times be led. Further, by study of the practice of
+Medicine under conditions so different from ours, we
+learn something of what is truly permanent in the Art of
+Healing. Lastly, by tracing the growth of the Science
+of Medicine, as it arose among the Greeks and as it
+died in the hands of their less worthy descendants, we
+may take alike example and warning. We may learn
+to distinguish the healthy and vigorous growth of a
+science from the stunted and deformed products that
+are often acclaimed, even in our own times, as Wisdom’s
+final word to Man.</p>
+
+<p>It has been said that, ‘save the blind forces of Nature,
+nothing lives or moves which is not Greek in origin’.
+The saying needs modification, for there is a thing
+which still lives and moves that is not Greek in origin,
+a blind force which is not a blind force of Nature. It
+is the force of Superstition, of that age-old belief that
+Nature will give us something for nothing, which is
+<span class="pagenum" id="Page_3">3</span>expressed by the word ‘Magic’. The Greeks were no
+more free from that contemptible fallacy than are the
+men of our own days. But the greatest of the Greeks
+stood wholly above such folly, and we can watch the
+Greek mind gradually lifting itself from that primeval
+mental attitude which is older than any known culture,
+older perhaps than any known race, the attitude of
+Nature-Worship, or ‘Animism’. To give an idea of
+how the ‘sweet reasonableness’ of the Greek mind
+gradually dissipated the animistic fog, a few words
+must be said about the history of the Greeks. Without
+that amount of history it would seem a miracle that
+Man ever became reasonable at all.</p>
+
+<p>The Medicine we call Greek might be described as
+the system which prevailed in ancient times in that half
+of the Mediterranean area which lies east and south of
+the Italian Peninsula.</p>
+
+<p>Up to about 1000 <span class="allsmcap">B.C.</span> most of the coast-lands of
+this Mediterranean area were inhabited by that very
+remarkable people, the Minoans. These have left some
+extraordinary remains, the full significance of which has
+not yet been revealed. The general development of the
+Minoan civilization has, however, been clearly outlined
+by modern archaeological investigation. This has
+resulted in an entirely new interpretation of the story
+which Homer tells in the <i>Iliad</i>. The siege of Troy represents
+an attack by the invading Greeks on one of the
+last Minoan strongholds. About 1000 <span class="allsmcap">B.C.</span> the whole
+Eastern Mediterranean basin was being overrun by the
+Greek tribes coming in from the north. These Greeks
+were no pure race, but a mixed multitude of invaders
+who came along several lines of advance. As always
+<span class="pagenum" id="Page_4">4</span>happens in such invasions, the conquered were not exterminated,
+but mingled with the invaders. Thus the
+Greeks, as they advanced, absorbed much of the culture
+and outlook of the civilization that they submerged.</p>
+
+<p>In considering the history of Rational Medicine we
+are concerned chiefly with two main invading streams
+of Greek tribes: that of the Dorians, who passed towards
+Crete and towards the Island of Cos and the
+opposite peninsula of Cnidus, and that of the Ionians,
+who colonized most of the remaining part of western
+Asia Minor. These two peoples were, between them,
+responsible for the main intellectual output of the
+Greeks of those early days. The medical system which
+they initiated first took shape in western Asia Minor,
+and thence became diffused over the whole of the Greek
+world. The Greek system of Medicine which thus
+arose in Asia Minor had various roots, as indeed the
+Medicine of a mixed people, living under very complex
+social conditions, was bound to have.</p>
+
+<p>Firstly, there was the submerged civilization of the
+conquered Minoan folk. It is probable that the cult
+of the serpent—so constantly associated with Aesculapius
+and still used as a medical emblem—was of
+Minoan origin, for the serpent was a symbol much
+used in the Minoan religion (<a href="#i005">Fig. 2</a>). It is probable
+too that some of the hygienic ideas of the Greeks were
+derived from the same source, for the Minoans had
+an excellent system of drainage. We can, however, say
+little on this head because the interpretation of the
+Minoan records is still hidden from us.</p>
+
+<figure class="figcenter illowe30" id="i005">
+  <img class="w100" src="images/i005.jpg" alt="figures 2 and 3">
+  <figcaption>
+    <p><span class="smcap">Fig. 2.</span> IVORY AND GOLD MINOAN STATUETTE of a votaress
+    in a state of ecstasy. In either hand she holds a serpent, illustrating the
+    importance attached to this animal in the Minoan cult. From the Museum
+    of Fine Arts, Boston, U.S.A.</p>
+    <p><span class="smcap">Fig. 3.</span> SURGICAL INSTRUMENTS recovered from Babylonian
+    sites. There are here represented three knives, a saw and a trephine.
+    These instruments, which illustrate the state of surgery in the ancient
+    Mesopotamian civilization, are in the possession of Professor Meyer-Steineg
+    of Jena, by whose permission they are here reproduced.</p>
+  </figcaption>
+</figure>
+
+<p>Secondly, we have to remember that the shores of
+Asia Minor lie on the outskirts of the great civilization
+<span class="pagenum" id="Page_5">5</span>which had grown up in the valley of the Tigris
+and the Euphrates. The Greeks drew from that source
+much of their more superstitious beliefs, as well as
+some, at least, of their scientific method. On the one
+hand, the demoniac theories that bulk so largely in
+<span class="pagenum" id="Page_6">6</span>later Greek medicine doubtless came from Assyria and
+Babylonia. The Medicine of the New Testament, for
+instance, with its casting out of devils, is of Mesopotamian
+origin. But, on the other hand, the Mesopotamian
+peoples had for long ages laid up a great
+treasury of observation, notably of astronomical data
+which were often applied to astrological ends. There
+was also some knowledge of anatomy derived from the
+entrails of animals used in divination (<a href="#i006">Fig. 4</a>). Working
+<span class="pagenum" id="Page_7">7</span>on the basis of these records, the Greeks were able to
+erect a scientific method which appears as a prominent
+feature in their intellectual life in later centuries. Moreover,
+there was in Mesopotamia a standardization of
+both medical and surgical procedure which the nimble-witted
+Greeks were quick to adopt (<a href="#i005">Fig. 3</a>). On its
+lower and less intelligent side, however, the Mesopotamian
+material was made to minister to Greek superstition
+and especially to astrological belief.</p>
+
+<figure class="figcenter illowe30" id="i006">
+  <img class="w100" src="images/i006.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 4.</span> CLAY MODEL OF SHEEP’S LIVER used for instruction
+    in divination in a Babylonian temple school. The object is now in the
+    British Museum. It is covered with cuneiform writing, the nature and
+    contents of which fix its date as about 2000 <span class="allsmcap">B.C.</span> The writing is here omitted
+    for the sake of simplicity.</p>
+    <p>Various parts of the liver have their Babylonian technical terms and can
+    be identified with parts recognized by modern anatomists. Some of these
+    modern terms are written on our drawing.</p>
+    <p>To each hole in the original model an inscription containing a forecast is
+    assigned. The diviner made his forecast by comparing an actual liver with
+    this clay model at each point corresponding to a hole. His forecast was
+    elaborated according to the state of the liver at all these points.</p>
+  </figcaption>
+</figure>
+
+<p>Thirdly, to the Egyptian civilization the Greek debt
+was also considerable. Many drugs were derived from
+Egypt and others were suggested by Egyptian practice.
+The basis of Greek medical ethics, too, can be
+traced to Egypt. Some of the practical devices of Greek
+Medicine, such as the forms of the surgical instruments,
+were of Egyptian origin. Nor can we neglect the statement
+made by the Greeks themselves, that mathematical
+knowledge—the test and index of all scientific
+growth—came to them first from Egypt. Lastly, we
+note that the Egyptians deified a physician, Imhotep
+(<a href="#i008">Fig. 5</a>), in exactly the way that the Greeks deified their
+physician Aesculapius (<a href="#i008">Fig. 6</a>). Both Imhotep and
+Aesculapius were, in fact, historic personages, and their
+evolution into gods presents many interesting parallels.</p>
+
+<figure class="figcenter illowe30" id="i008">
+  <img class="w100" src="images/i008.jpg" alt="figures 5 and 6">
+  <figcaption>
+    <p><span class="smcap">Fig. 5.</span> IMHOTEP, originally a physician, subsequently deified as an
+    Egyptian god of Medicine. From a statuette in the British Museum.</p>
+    <p><span class="smcap">Fig. 6.</span> AESCULAPIUS, originally a physician, subsequently deified
+    as a Greek god of Medicine. He holds a staff, around which a serpent
+    twines. From a statue in the Capitoline Museum at Rome.</p>
+  </figcaption>
+</figure>
+
+<p>The Greeks of western Asia Minor, thus drawing
+material from many sources, came to develop, towards
+the end of the seventh century B.C., a philosophical
+system from which the whole of their Science may be
+said to be a natural growth. Factors in this development
+were the medical schools of Cos, where Hippocrates
+was born, and of the opposite peninsula, Cnidus.
+These schools were in active operation by the sixth
+<span class="pagenum" id="Page_8">8</span>century <span class="allsmcap">B.C.</span> By the middle of the fifth century they
+were important elements in the growing complexity of
+Greek life. Much of the so-called <i>Hippocratic Collection</i>,
+which contains the earliest Greek medical writings that
+have survived, must have been put together somewhere
+in the fourth century <span class="allsmcap">B.C.</span>, though its final recension is
+certainly later (<a href="#i009">Fig. 7</a>). In that final recension Persian
+and Indian elements were also included, though to what
+degree is still very uncertain.</p>
+
+<p><span class="pagenum" id="Page_9">9</span></p>
+
+<figure class="figcenter illowe30" id="i009">
+  <img class="w100" src="images/i009.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 7.</span> SCHEME ILLUSTRATING SOME OF THE SOURCES OF
+    HIPPOCRATIC MEDICINE
+  </figcaption>
+</figure>
+
+<p><span class="pagenum" id="Page_10">10</span></p>
+
+<p>But the picture of the development of Greek Medicine
+is not yet complete. Although we inherit the
+scientific spirit from the Greeks, and although they set
+a standard for all time of the purest and most disinterested
+type of medical practice, they are also in part
+responsible for some of the basest forms of medical
+jugglery that have afflicted and still afflict mankind.
+The medicine of the physicians was only one of their
+medical systems. There was a far lower form which
+gradually passed into the hands of the priests. The
+temple jugglery of Greece is ancestor, both by imitation
+and by direct tradition, of much medieval and modern
+medical miracle-mongering.</p>
+
+<p>Furthermore, in ancient as in modern times, all
+medical men were not equally pure in aim or scientific
+in method. The practice of some Greek physicians was
+more than flavored with magic. In justice, also, it
+must be said that not all priests were mere charlatans,
+and that there are traces of scientific method in the
+treatment of patients in the temples. There was,
+indeed, a relation between the practice of some of the
+physicians among the Greeks and that of some of their
+priestly magicians. We shall not attempt to determine
+the actual extent and nature of this relationship. For
+our purpose it is enough that the two systems were
+quite distinct in their most typical developments.</p>
+
+<p>The temple system of Greek Medicine was associated
+from an early date with a deity, Asklepios, or, to give
+him his better-known Latin name, Aesculapius. Numerous
+representations of him have come down to us, and
+in them we see him gradually molded to a particular
+type. He becomes at last an aged man of noble,
+<span class="pagenum" id="Page_11">11</span>benevolent and dreamy aspect, holding in his hand
+a staff around which a serpent twines (<a href="#i008">Fig. 6</a>). The
+cult of the god Aesculapius was carried on at numerous
+sites. The best known, both from literature and excavation,
+is Epidaurus. The conditions there are typical
+of those in other Aesculapian centers.</p>
+
+<p>Epidaurus is about thirty miles from Athens. It lies
+between two considerable ranges of hills, and the
+country bears still, in its customs and place-names, some
+remnants of the ancient cult. One tradition tells that
+a certain maiden, Koronis, being with child by Apollo,
+brought forth the infant Aesculapius on the mountain
+above Epidaurus. There is still a village named Koroni
+hard by. She fled to conceal her shame and left the
+child on the mountain, where it was tended by a goat
+and watched over by a dog. The infant performed
+various miracles which we need not pursue, though the
+temple arose on the site where he is said to have wrought
+them. One of his miracles, however, has a wider interest
+and is worth recounting. A certain Hippolytus,
+falsely accused of impure relations with his stepmother,
+was slain by the gods in answer to the curses of his
+father, Theseus. Raised from the dead by the wonder-working
+Aesculapius, he reappears in legend at the
+Arician grove in Italy. ‘There’, says a Greek chronicler
+of the second century <span class="allsmcap">A.D.</span>, ‘he became a king and
+devoted a precinct to Artemis, where, down to my
+time, the prize for the victor in single combat was the
+priesthood of the goddess. The contest was open to
+no freeman, but only to runaway slaves.’</p>
+
+<p>The son slain by his father and then rising from the
+dead; the runaway slave seeking sanctuary with Artemis
+<span class="pagenum" id="Page_12">12</span>in her grove, allowed his liberty and elevated to
+the priesthood there; the priesthood held only so long as
+the priest can guard it in mortal combat against the
+next runaway slave; this succession of slave kings and
+priestly murders has touched the imagination of the
+poets and artists in ancient and in modern times. The
+sacred grove of Artemis stood by the side of the lake
+of Nemi:</p>
+
+<div class="poetry-container">
+  <div class="poetry">
+    <div class="stanza">
+      <div class="verse indent0">The still glassy lake that sleeps</div>
+      <div class="verse indent0">Beneath Aricia’s trees—</div>
+      <div class="verse indent0">Those trees in whose dim shadow</div>
+      <div class="verse indent0">The ghastly priest doth reign,</div>
+      <div class="verse indent0">The priest who slew the slayer</div>
+      <div class="verse indent0">And shall himself be slain.</div>
+    </div>
+  </div>
+</div>
+
+<p>It is a picture utterly out of accord with the general
+trend of classical mythology. Long ago scholars saw
+therein a remnant of a submerged faith, that ancient
+‘Nature worship’ which survived among the Greeks,
+and survives with us. From this incident is named
+the great classical work of Anthropology, <i>The Golden
+Bough</i>. By this story and by all that it implies, by all
+that learning has drawn out of it and associated with
+it, the history of Medicine comes into contact with the
+brooding spirit of savage man. Into that dark realm we
+shall not enter in this volume.</p>
+
+<p>History is the tale of the spirit of Man unfolding
+itself. This process is always slow, often imperceptible,
+sometimes retrograde, yet over long periods of time it
+is sure. Where no evolution of the spirit can be traced
+true history cannot be written, wherefore no man can
+write a history of human folly. Irrational man, driven
+by disease and fear of death, exhibits the same follies
+<span class="pagenum" id="Page_13">13</span>in all ages. The medical follies and superstitions of our
+own days are as in those when Aesculapius claimed
+men’s allegiance. His garments and his names are
+changed, his temples are transformed, his priests assume
+other titles, but his face is the same, and he works
+the same wonders with about the same frequency. It is
+of Rational Medicine that we have henceforth to speak.</p>
+
+
+<h3 id="_2_The_Hippocratic_Physician">
+  § 2. <i>The Hippocratic Physician.</i>
+</h3>
+
+<p>We turn to the other side of the picture. Nothing
+could be in greater contrast to the orgies of the savage,
+the dark ways of the magician, or the charlatanry of the
+priests, than the serene spirit of wisdom which pervades
+the best Greek Medicine. The finest presentation
+of that system is to be found in a group of about
+a hundred works that have been associated together
+since antiquity under the name of Hippocrates. It is
+known as the <i>Hippocratic Collection</i>.</p>
+
+<p>It will naturally be asked, ‘Which of these works is
+by the man whose name they bear?’ To that question,
+alas, no definite answer can be given. There is no single
+work which we can state with certainty to be the composition
+of the Father of Medicine. The books of which
+the <i>Collection</i> is composed are the work of a number of
+authors, belonging to different schools, holding various
+and often contradictory views, living in widely separated
+parts of the Greek world and writing at dates
+divided from each other, in the most extreme cases, by
+perhaps five or six centuries. Of the finest books of
+this collection we can but say that they contain nothing
+inconsistent with a Hippocratic origin, that their
+ethical standpoint is in accord with the Hippocratic
+<span class="pagenum" id="Page_14">14</span>ideal, and that they are the work of physicians of great
+intellectual power and experience.</p>
+
+<p>If we ask what is known about Hippocrates himself,
+and if we seek information rather than entertainment,
+our answer will be almost as meager. Hippocrates is
+no mythical figure, for he is mentioned with high
+respect by his younger contemporary, Plato. He was
+the son of a physician, and was born at Cos about
+460 <span class="allsmcap">B.C.</span> The most active period of his life thus
+began about 420 <span class="allsmcap">B.C.</span> His death is placed between
+377 and 359—the latter would make him 101, an
+appropriate age for a great physician. He led a wandering
+life, and is heard of at Cos, Thasos, Athens, in
+Thrace and elsewhere, and lastly in Thessaly, where his
+grave was long shown. Among his pupils were his two
+sons, and his son-in-law. Of the work of the latter we
+have a fragment preserved both by Aristotle and in
+the <i>Hippocratic Collection</i> itself.</p>
+
+<p>That is all that is known about the Father of Medicine.
+We have not even his portrait. Yet we have
+something far better; we have an idealized representation
+of what the Greek would wish his physician to be.
+It is a noble bust to which the name of Hippocrates was
+early attached. Many copies exist (see <a href="#i_f004">Frontispiece</a>).
+The calm, righteous and dignified presence which it
+portrays has stamped itself on the consciousness and
+conscience of those who follow the Art of Healing. To
+that gracious figure the medical man will continue to
+pay homage.</p>
+
+<p>If critical examination has dealt thus hardly with the
+Hippocratic writings and with Hippocrates himself,
+what has been left which we may surely derive from the
+<span class="pagenum" id="Page_15">15</span>Greek medical system? The answer is that Medicine
+has from the Greeks two great things: the picture of
+a man and the institution of a method.</p>
+
+<p>The man is Hippocrates himself. His figure, gaining
+in dignity what it loses in clearness, stands for all time
+as that of the ideal physician, for the ideal is there and
+is clearly set forth in these great writings, whether we
+discern the details of his earthly features or no. Calm
+and effective, humane and observant, prompt and
+cautious, at once learned and willing to learn, eager
+alike to get and give knowledge, unmoved save by the
+fear lest his knowledge may fail to benefit others—both
+the sick and their servants the physicians,—incorruptible
+and pure in mind and body, the figure of the
+greatest of physicians has gained, not lost, by time. In
+all ages he has been held by medical men in a reverence
+comparable only to that which has been felt towards
+the founders of the great religions by their followers.
+The figure of the Hippocratic physician has been of
+incalculable spiritual value to the medical profession in
+the twenty-three centuries that have passed since his
+death.</p>
+
+<p>So much for the man. We turn now to the method.</p>
+
+<p>The <i>method</i> of Hippocratic medicine is that known
+to-day as the <i>experimental</i> or better <i>experiential</i>. It was
+employed among the Greeks for centuries after the
+death of Hippocrates. Then came a time when a social
+and philosophical upheaval prevented its further prosecution.
+For the thousand years that followed the break-up
+of the Roman Empire the medical practice of Europe
+was at best a corrupted imitation and misunderstanding
+of the Hippocratic teaching; at worst it descended to a
+<span class="pagenum" id="Page_16">16</span>low level of Animism and Magic. Then there was
+a rally. Slowly—very slowly at first—the foundations
+of Modern Science were laboriously laid. Among
+the first elements in this scientific Renaissance was the
+recovery of the Hippocratic works.</p>
+
+<p>In the centuries that followed this Renaissance the
+very words of the <i>Hippocratic Collection</i> were taught in
+the medical schools in a spirit that was anything but
+that of Hippocrates. Gradually, however, a better
+understanding crept into men’s minds. The spirit of
+those writings and their methods and observations
+came now rightly to be exalted above the works themselves.
+The works themselves were wisely dropped
+from the medical curriculum. They are no longer used
+in any medical school. But if we turn again to contemplate
+the Hippocratic treatises, we may recognize in
+them the modern process of careful record of data and
+cautious inference from them—that collation of experience
+from various sources obtained by various methods
+with which we are now so familiar. We may even see
+in full force the actual process of case-taking, bed
+side instruction and clinical lecture. These methods
+are practised much in the way in which we know them,
+and are set forth with a conciseness and beauty of
+language and a loftiness of ethical tone which have not
+since been surpassed. To such a collection medical
+men must always return. No part of it is more impressive
+than the so-called <i>Hippocratic Oath</i>.</p>
+
+<figure class="figcenter illowe30" id="i017a">
+  <img class="w100" src="images/i017a.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 8.</span> A GREEK CLINIC OF ABOUT 400 <span class="allsmcap">B.C.</span>, when Hippocrates
+    was in his prime.<br>From a vase painting.</p>
+    <p>The physician sits in the center. He holds a lancet in his right hand, seizes
+    the patient’s right arm with his left and is bleeding him from a vein at the
+    bend of the elbow. The blood falls into a large basin on the floor. Above
+    the physician’s head are suspended three cupping vessels, shaped thus: <img class="picalign"
+    src="images/i017b.jpg" width="20" alt="diagram showing shape of cupping vessel"></p>
+
+    <p>To the right sits a patient awaiting his turn to interview the physician.
+    His left arm is bandaged. Behind this patient stands a figure smelling a flower
+    as a preventive against infection. Behind the physician stands a man
+    wounded in the left leg, which is bandaged. Back to back to this last figure
+    is a dwarf with a disproportionately large head. His body exhibits deformities
+    typical of the developmental disease now known as <i>Achondroplasia</i>. In
+    addition to his other deformities, we note that his muscular body is hairy,
+    and that the bridge of his nose is sunken. On his back he carries a hare
+    which is almost as tall as himself. Talking to the dwarf is a man leaning on
+    a long staff, who has the remains of a bandage round his chest.</p>
+  </figcaption>
+</figure>
+
+<p>The <i>Hippocratic Oath</i>, in its present form, is of
+very much later date than Hippocrates. Yet parts of it
+may be even earlier than he, and some suggestion of
+the Oath is, perhaps, to be seen in the contents of
+<span class="pagenum" id="Page_17">17</span>Egyptian papyri of the second millennium <span class="allsmcap">B.C.</span> It need
+hardly be said that the late date of the <i>Oath</i> by no
+means removes the interest of this grand ethical monument.
+No passage better reflects the spirit of the
+Hippocratic physicians. The oath is clearly designed
+for a youth entering on his apprenticeship to such a one.</p>
+
+<blockquote>
+<p>‘I swear by Apollo the healer, invoking all the gods and goddesses
+to be my witnesses, that I will fulfil this Oath and this
+written Covenant to the best of my ability and judgement.</p>
+
+<p>‘I will look upon him who shall have taught me this Art even
+as one of my own parents. I will share my substance with him,
+and I will supply his necessities, if he be in need. I will regard
+<span class="pagenum" id="Page_18">18</span>his offspring even as my own brethren, and I will teach them this
+Art, if they would learn it, without fee or covenant. I will impart
+this Art by precept, by lecture and by every mode of teaching,
+not only to my own sons but to the sons of him who has taught
+me, and to disciples bound by covenant and oath, according to the
+Law of Medicine.</p>
+
+<p>‘The regimen I adopt shall be for the benefit of the patients
+according to my ability and judgement, and not for their hurt or
+for any wrong. I will give no deadly drug to any, though it be
+asked of me, nor will I counsel such, and especially I will not
+aid a woman to procure abortion. Whatsoever house I enter,
+there will I go for the benefit of the sick, refraining from all
+wrongdoing or corruption, and especially from any act of seduction,
+of male or female, of bond or free. Whatsoever things I see
+or hear concerning the life of men, in my attendance on the sick
+or even apart therefrom, which ought not to be noised abroad, I
+will keep silence thereon, counting such things to be as sacred
+secrets. Pure and holy will I keep my Life and my Art.</p>
+
+<p>‘If I fulfil this Oath and confound it not, be it mine to enjoy
+Life and Art alike, with good repute among all men at all
+times. If I transgress and violate my oath, may the reverse be
+my lot.’</p>
+</blockquote>
+
+
+<h3 id="_3_Hippocratic_Practice">
+  § 3. <i>Hippocratic Practice.</i>
+</h3>
+
+<p>Among the most remarkable features of the <i>Hippocratic
+Collection</i> is the feeling of contact with the patient
+which most of its works convey. This is naturally a
+special characteristic of the surgical works. One treatise,
+which bears the title <i>On wounds of the head</i>, has always
+drawn attention as bespeaking especial ingenuity and
+experience. The description of trephining is of peculiar
+interest, because the practice was known in prehistoric
+times and is still employed by savage and semi-civilized
+peoples. The process recommended for cases of fracture
+of the skull and injury to the underlying structures
+<span class="pagenum" id="Page_19">19</span>resembles, in many details, the modern surgical procedure.</p>
+
+<blockquote>
+<p>‘When it is necessary to trephine a patient, make up your mind
+and judge as follows. If you have had charge of the case from the
+first, do not trephine the bone down to the membrane at once,
+for it is not desirable that the membrane be long exposed, lest
+it end by becoming rotten and fungous. There is also another
+danger, to wit that you wound the membrane with the saw
+during the operation, if you try to remove the bone by trephining
+immediately down to the membrane. Therefore, when the bone
+is almost sawn through and is already loose, cease trephining
+and allow the bone to come away of itself. While trephining,
+often remove the instrument and dip it in cold water. If you
+do not do this, the trephine, becoming heated by the circular
+motion and heating and drying the bone, may burn it and cause
+an unduly large piece of the bone round the sawing to come
+away.’</p>
+</blockquote>
+
+<figure class="figcenter illowe30" id="i020">
+  <img class="w100" src="images/i020.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 9.</span> INSTRUMENTS USED BY GREEK SURGEONS.</p>
+    <p><i>a</i> Simplest form of trephine. It has central pin and serrated edge. The
+    point is held against the skull and the staff twirled between the hands.
+    (Cf. <a href="#i246">Fig. 112</a>.) It could also be rotated by a crosspiece and thong, as in
+    <a href="#i063">Fig. 22</a>. <i>b</i> Case of scalpels from a bas-relief in the temple of Aesculapius on
+    the Acropolis at Athens. <i>c</i> Trephining instrument of type still in use. The
+    carpenter’s ‘center bit’ was known in antiquity, and was probably adapted
+    to the trephine. <i>a</i> and <i>c</i> represent sixteenth-century instruments of ancient
+    type. No ancient trephines of Greek origin are known, though a specimen
+    has come down to us from Mesopotamia, see <a href="#i005">Fig. 3</a>.</p>
+  </figcaption>
+</figure>
+
+<p>So much for a normal case which comes to the physician’s
+hands directly after the accident. But in less
+fortunate cases he is not called in so early, and the
+wound suppurates before he can bring his Art to bear
+upon it. In such a case he is advised:</p>
+
+<blockquote>
+<p>‘Saw the bone immediately to the membrane with a serrated
+trephine (<a href="#i020">Fig. 9</a>, <i>a</i> and <i>c</i>), frequently removing the trephine and
+testing with the probe all round along the track, for the bone is sawn
+through much more quickly if it is already suppurating and penetrated
+by the pus. The bone, however, often happens to be thin
+in places. Therefore be on your guard not to apply the trephine
+at random, but fix it in the bone where it appears thickest, frequently
+making an examination and trying to raise the bone by
+moving it. And after removing it, continue such treatment as may
+appear advantageous to the wound, according to circumstances.’</p>
+</blockquote>
+
+<p>Among the works of the <i>Hippocratic Collection</i> is
+a lecture note-book known by the title <i>Concerning the
+<span class="pagenum" id="Page_20">20</span>things in the Surgery</i>. It is written in very abbreviated
+style and consists of mere headings. Nevertheless, our
+attention is arrested by its startling modernness, when
+we read such a category as this:</p>
+
+<blockquote>
+<p>‘Operative requisites in the surgery: the patient; the operator;
+assistants; instruments; the light, where and how placed; the
+<span class="pagenum" id="Page_21">21</span>patient’s person and apparatus. The operator, whether seated or
+standing, should be placed conveniently to the part being
+operated upon and to the light. Each of the two kinds of
+light, ordinary or artificial, may be used in two ways, direct or
+oblique.’</p>
+</blockquote>
+
+<p>Or again, such details as:</p>
+
+<blockquote>
+<p>‘The nails [of the operator] neither to exceed nor come short
+of the finger-tips. Practise using the finger-ends. Practise all
+operations with each hand and with both together, your object
+being to attain ability, speed, painlessness, elegance and readiness.
+Let those who look after the patient present the part for operation
+as you want it, and hold fast the rest of the body so as to be
+all steady, keeping silence and obeying their superior.’</p>
+</blockquote>
+
+<p>Are we not here reminded of an up-to-date operator
+and operating theater?</p>
+
+<p>In the <i>Hippocratic Collection</i> the physician attends
+cases of every type, and does not refuse to do his best
+for a case because the use of an instrument is demanded.
+He is thus no ‘specialist’. But the mass of his practice
+lay with cases to which instrumental treatment was inapplicable.
+In cases in which surgical intervention was
+not justified the Hippocratic physician adopted for the
+most part what is called an ‘expectant’ line of treatment.
+Realizing that, in general, the tendency of the
+body is to recover, he contented himself with ‘waiting on
+Nature’. This does not by any means imply that he
+was helpless, for much could be done by nursing, regimen
+and diet to aid the patient in that conflict which he
+alone must fight out. For the conduct of that great
+battle wise and useful directions are recorded. But believing
+in <i>the healing power of Nature</i>—the famous
+phrase is used in the Hippocratic writings—the physician
+was none too eager to administer drugs. In the
+<span class="pagenum" id="Page_22">22</span>state of knowledge of the day this reluctance was well-judged.
+Nevertheless the Hippocratic drugs, though
+neither numerous nor complex, were some of them very
+efficient, and their judicious if reluctant use at the right
+juncture saved many a life.</p>
+
+<p><i>The Aphorisms</i> is the most famous book with which
+the name of Hippocrates is associated, and is as likely
+as any of the Collection to be by Hippocrates himself.
+It consists of a series of very brief generalizations.
+Many of these have been confirmed by the clinical
+experience of later ages. Some have passed into medical
+commonplaces, others have become popular proverbs.
+The style of the work suggests an aged physician reflecting
+on the experience of a lifetime. Among modern
+medical writings its closest analogue is perhaps the
+<i>Commentaries</i> of the great English physician, William
+Heberden the elder (1710-1801), which was commenced
+by him after the age of seventy, occupied the
+last twenty years of his life, contained a summary of the
+whole of his vast experience, and was published by his
+son after his death. If the <i>Aphorisms</i> is similarly a work
+of the old age of Hippocrates it may be dated about
+380 <span class="allsmcap">B.C.</span> A few extracts give a good idea of the nature
+of the book.</p>
+
+<blockquote>
+<p>‘Life is short and Art is long; the Crisis is fleeting, Experiment
+risky, Decision difficult. Not only must the physician be ready
+to do his duty, but the patient, the attendants, the external circumstances
+must conduce to the cure.’</p>
+
+<p>‘Old persons bear fasting most readily, next adults, and young
+people yet less; least of all children, and of these least again those
+who are particularly lively.’</p>
+
+<p>‘If in any illness sleep does harm, it is a symptom of deadly
+import.’</p>
+
+<p><span class="pagenum" id="Page_23">23</span></p>
+
+<p>‘When sleep puts an end to delirium, it is a good sign.’</p>
+
+<p>‘Weariness without cause indicates disease.’</p>
+
+<p>‘If there be a painful affection in any part of the body, and
+yet no suffering, there is mental disorder.’</p>
+
+<p>‘To eat heartily after a long illness without putting on flesh is
+a bad portent.’</p>
+
+<p>‘Food or drink slightly inferior in itself, but more pleasant,
+should be preferred to that better itself, but less pleasant.’</p>
+
+<p>‘The old have fewer illnesses than the young, but if any become
+chronic with them they generally carry it with them to the grave.’</p>
+
+<p>‘Those naturally very fat are more liable to sudden death than
+the thin.’</p>
+
+<p>‘The dry seasons are more healthy than the rainy, and attended
+by less mortality.’</p>
+
+<p>‘Cold sweats in conjunction with an acute fever indicate death,
+but with a milder fever only prolonged sickness.’</p>
+
+<p>‘Convulsions supervening on a wound are deadly.’ (Tetanus,
+cp. <a href="#Page_267">p. 267</a>.)</p>
+
+<p>‘Those attacked by tetanus either die within four days, or if
+they get through these they recover’ (compare pp. <a href="#Page_257">257</a> and <a href="#Page_267">267</a>).</p>
+
+<p>‘Phthisis comes on mostly from eighteen to thirty-five years
+of age.’</p>
+
+<p>‘It is fatal for a woman in pregnancy to be attacked by one
+of the acute diseases.’</p>
+
+<p>‘In cases of jaundice, hardening of the liver is a bad sign.’</p>
+
+<p>‘We should observe the appearance of the eyes in sleep. If any
+of the white show through the eyelids when closing, this is a bad
+sign and very dangerous, unless it be due to diarrhoea or taking
+a purgative.’</p>
+
+<p>‘An attack of delirium with laughter is less dangerous than
+with despondency.’</p>
+
+<p>‘Apoplexy is commonest between the ages of forty and sixty.’</p>
+
+<p>‘If you give the same nutriment to a patient in a fever and to
+a person in health, the patient’s disease is aggravated by what
+adds strength to the healthy man.’</p>
+</blockquote>
+
+<p>The chief clinical achievement of the <i>Hippocratic
+Collection</i> lies in the descriptions of actual cases. These
+<span class="pagenum" id="Page_24">24</span>descriptions are not only without parallel during nearly
+2,000 years, but they are models of what succinct clinical
+records should be. They are clear and short, they give
+all the leading features and yet they show no attempt
+to prejudge the importance of any particular feature.
+The records of these cases illustrate the Greek genius
+for seizing the essential. The writer does not betray the
+least wish to exalt his own skill. He seeks merely to
+put the data before the reader for his guidance under
+like circumstances. It is a reflex of the spirit of honesty
+in which these men worked that in the great majority
+of the cases they record death ensued. Two of these
+remarkable descriptions may be given:</p>
+
+<blockquote>
+<p>‘The woman with quinsy, who lodged with Aristion; her
+complaint began in the tongue; voice inarticulate; tongue red
+and parched. <i>First day</i>, shivered, then became heated. <i>Third
+day</i>, rigor, acute fever; reddish and hard swelling on both sides
+of neck and chest; extremities cold and livid; respiration elevated;
+drink returned by the nose; she could not swallow; alvine and
+urinary discharges suppressed. <i>Fourth day</i>, all symptoms exacerbated.
+<i>Fifth day</i>, died.’</p>
+</blockquote>
+
+<p>This was a case of Diphtheria. The quinsy, the paralysis
+of the palate leading to return of the food through
+the nose, and the difficulty with speech and swallowing
+are typical results of this affection which was here complicated
+by a spread of the septic processes into the neck
+and chest, a not uncommon event in the disease. The
+rapid onset of the conditions is rather unusual, but may
+be explained if we regard the case as a mild and unnoticed
+diphtheria, subsequently complicated by paralysis
+and by secondary septic infection, for which reason
+she came under observation.</p>
+
+<p><span class="pagenum" id="Page_25">25</span></p>
+
+<blockquote>
+<p>‘In Thasos, the wife of Delearces, who lodged on the plain,
+through sorrow was seized with an acute and shivering fever.
+From first to last she always wrapped herself up in her bedclothes;
+kept silent, fumbled, picked, bored, and gathered hairs
+[from the clothes]; tears and again laughter; no sleep; bowels
+irritable but passed nothing; when urged drank a little; urine
+thin and scanty; to the touch the fever was slight; coldness of the
+extremities. <i>Ninth day</i>, talked much incoherently, and again
+sank into silence. <i>Fourteenth day</i>, breathing rare, large and
+spaced, and again hurried. <i>Seventeenth day</i>, after stimulation of
+the bowels she passed even drinks, nor could retain anything;
+totally insensible; skin parched and tense. <i>Twentieth day</i>, much
+talk, and again became composed, then voiceless; respiration
+hurried. <i>Twenty-first day</i>, died. Her respiration throughout was
+rare and large; she was totally insensible; always wrapped up in
+her bedclothes; throughout either much talk, or complete silence.’</p>
+</blockquote>
+
+<p>We have here a description of low muttering delirium,
+a common end of continued fevers, as, for instance,
+Typhoid. It resembles the condition known to physicians
+as the ‘typhoid state’. Incidentally the case contains
+a reference to a type of breathing common among
+the dying. The respiration becomes deep and slow, as it
+sinks gradually into quietude and becomes rarer and
+rarer until it seems to cease altogether, and then it
+slowly becomes more rapid and so on alternately. This
+type of breathing is known to physicians as ‘Cheyne-Stokes’
+respiration, in commemoration of two distinguished
+Irish physicians of the last century who brought
+it to the attention of medical men. In our own time
+it has been partially explained on a physiological basis.</p>
+
+<p>We may note that there is another and even better
+pen-picture of Cheyne-Stokes respiration in the <i>Hippocratic
+Collection</i>. We read of one ‘Philescos who lived by
+the wall and who took to his bed on the first day of acute
+<span class="pagenum" id="Page_26">26</span>fever.’ About the middle of the sixth day he died, and
+the physician notes that ‘the respiration throughout was
+<i>like that of a person recollecting himself</i> and was large and
+rare’. Cheyne-Stokes breathing is admirably described
+as ‘that of a person recollecting himself’.</p>
+
+<p>Immense and, as some may think, overwhelming importance
+is laid by the Hippocratic writings upon the art
+of ‘Prognosis’, that is of predicting the course which the
+disease will take. The work to which the title <i>Prognostics</i>
+is attached represents a very lofty standard of practice.
+We quote from it a description of the signs of death
+to which the name of <i>Hippocratic facies</i> has become attached.
+It is imitated by Shakespeare in his description
+of the death of Falstaff in Henry V (<i>Act II, Scene 3</i>).</p>
+
+<blockquote>
+<p>‘You should observe thus in acute diseases; first the countenance
+of the patient, if it be like those of persons in health, and
+especially if it be like itself, for this is best of all. But the opposite
+are the worst, such as these: a sharp nose, hollow eyes,
+collapsed temples; the ears cold, contracted, and their lobes
+turned out; the skin about the forehead rough, stretched and
+parched; the colour of the face greenish, dusky, livid or leaden.</p>
+
+<p>‘If the countenance be such at the beginning of the disease, and
+if this cannot be accounted for by the symptoms, inquiry
+must be made whether the patient has been sleepless, whether his
+bowels have been very loose, or whether he has wanted food.
+If any of these be confessed, the danger is to be reckoned so far
+the less, and it will become obvious in a day and night whether or
+no the appearance come of these. But if no such cause exist
+and if the symptoms do not subside in this time, be it known for
+certain that the end is at hand.’</p>
+</blockquote>
+
+<p>These glimpses will give some idea of Rational Medicine
+in the making. In the fourth century <span class="allsmcap">B.C.</span> Medicine
+emerges as a definite part of the scientific consciousness.
+Rational Medicine is now in being.</p>
+
+<p><span class="pagenum" id="Page_27">27</span></p>
+
+
+<h3 id="_4_Aristotle">
+  § 4. <i>Aristotle.</i>
+</h3>
+
+<p>During the fourth century <span class="allsmcap">B.C.</span> there lived and worked
+one whose thought has stamped itself on the whole
+subsequent course of the biological and medical sciences,
+and indeed of all Science.</p>
+
+<p>Aristotle (384-322 <span class="allsmcap">B.C.</span>) was a provincial Greek and
+son of a Macedonian physician. At seventeen he became
+a pupil of Plato at Athens. After Plato’s death in
+347 Aristotle crossed the Aegean to reside in Asia
+Minor. The main part of his biological observations
+was made during his stay there. In 342 <span class="allsmcap">B.C.</span>, at the
+request of King Philip of Macedon, Aristotle became
+tutor to Philip’s son, Alexander the Great. He remained
+in Macedon for seven years. About 336, when
+Alexander departed for the invasion of Asia, Aristotle returned
+to Athens, where he taught for the rest of his
+life. He died in 322 <span class="allsmcap">B.C.</span>, a few months after his pupil
+Alexander.</p>
+
+<p>Aristotle was the great codifier of ancient Science.
+On him all subsequent biological development, including
+that of modern times, is surely based. In his wonderful
+biological works, which are still read by naturalists,
+he discusses many problems current to this very day.
+He laid the basis of the doctrine of Organic Evolution
+in his teaching concerning the <i>Scala Naturae</i> ‘Ladder
+of Nature’ (<a href="#i028">Fig. 10</a>). He developed coherent theories
+of Generation and Heredity. He founded Comparative
+Anatomy and he dissected many animals. He did not,
+however, anatomize the human body.</p>
+
+<figure class="figcenter illowe30" id="i028">
+  <img class="w100" src="images/i028.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 10.</span> The <i>Ladder of Nature</i> according to Aristotle.
+  </figcaption>
+</figure>
+
+<p>Aristotle gave good descriptions of some organs, regarded
+from the standpoint of Comparative Anatomy.
+These descriptions he sometimes illustrated by drawings,</p>
+
+<p><span class="pagenum" id="Page_28">28</span></p>
+
+<p>the first anatomical figures of which we have a
+record. In some cases these drawings can be restored
+with confidence. Thus, he gave an account of the
+uterus, the nomenclature of which has been retained in
+more or less modified form to our own time (<a href="#i029">Fig. 11</a>).
+Among the best anatomical descriptions given by Aristotle
+is that of the ruminant stomach. Perhaps his most
+extraordinary anatomical feat is his account of the development
+of the dogfish <i>Mustelus laevis</i>, which he
+showed was attached to its mother’s womb in a way very
+similar to the embryo of a mammal (<a href="#i029">Fig. 12</a>). This
+raised the admiration of the greatest modern morphologist,
+Johannes Müller (1807-58, <a href="#Page_211">pp. 211-13</a>), and would
+in itself be sufficient to establish the claim of Aristotle
+to a place in the front rank of observing naturalists.
+Aristotle gave fairly accurate descriptions of the
+<span class="pagenum" id="Page_29">29</span>branches of the great veins and of the superficial vessels
+of the arm of mammals. He realized that the arteries
+are usually accompanied by veins. He described the
+generative and digestive organs of cephalopod Molluscs,
+and many other parts of many other animals.</p>
+
+<figure class="figcenter illowe30" id="i029">
+  <img class="w100" src="images/i029.jpg" alt="figures 11 and 12">
+  <figcaption>
+    <p><span class="smcap">Fig. 11.</span> The womb with the names of its parts as given by Aristotle.
+    These names remain, in various forms, in modern anatomy.</p>
+    <p><span class="smcap">Fig. 12.</span> Embryo dogfish, <i>Mustelus laevis</i>, after Johannes Müller. The
+    little creature is shown attached to the wall of its mother’s womb, somewhat
+    after the manner of a mammal.</p>
+  </figcaption>
+</figure>
+
+<p>Something should be said of the errors of Aristotle.
+Though an excellent Naturalist, he was in general much
+weaker in Physiology. Thus, he made no proper distinction
+between arteries and veins. He failed to trace
+any adequate relations between the sense organs, the
+nerves, and the brain. His refusal to attach great importance
+to the brain is remarkable. Primacy he placed
+with the heart, which he regarded also as the seat of the
+intelligence. This was contrary not only to the medical
+opinion of his day, but also to the popular view, voiced,
+for instance, by Aristophanes in his play <i>The Clouds</i>,
+written about 400 <span class="allsmcap">B.C.</span>, where we read of a man who
+had <i>concussion of the brain</i>. Moreover, Aristotle’s
+teacher Plato placed the seat of thought and feeling in
+<span class="pagenum" id="Page_30">30</span>the brain. From all we know of Aristotle, it seems probable
+that he did not take up this attitude without evidence.
+It seems likely that he had experimented on the
+brain and found it devoid of sensation. Hence his view,
+opposed to current belief, that it is not associated with
+thought. Aristotle regarded the brain simply as an
+agent for cooling the heart, and preventing it from
+being over-heated. This cooling process, he considered,
+was effected by the secretion of <i>phlegm</i> (<i>pituita</i>), an
+idea still preserved in our anatomical term the <i>pituitary
+body</i>.</p>
+
+<p>The views of Aristotle have had a vast influence in
+determining the direction of medical thought. For
+more than two thousand years Aristotelian philosophy,
+in more or less corrupted form, constituted the main
+intellectual food of mankind. Without some knowledge
+of the biological verdicts of Aristotle, it is impossible to
+understand the course taken by Rational Medicine.
+The influence of Aristotle is specially evident in certain
+basic biological conceptions.</p>
+
+<p>The problem of the nature of Generation is one in
+which Aristotle never ceased to take an interest.
+Among the methods by which he sought to solve it was
+embryological investigation. His most important embryological
+researches were made upon the chick. His
+choice was most fortunate, and the chick has remained,
+to this day, the classical subject of embryological research.
+Aristotle asserts that the first signs of life in
+the hen’s egg are noticeable on the third day, the heart
+being visible as a palpitating blood-spot. As it develops,
+two meandering blood-vessels extend to the surrounding
+tunics. A little later, he observes, the body becomes
+<span class="pagenum" id="Page_31">31</span>distinguishable, at first very small and white, the head
+being clearly distinguished and the eyes very large
+(<a href="#i117">Figs. 46-7</a>, p. 117). To follow the main features of
+the later stages was a comparatively easy task.</p>
+
+<p>Aristotle was greatly impressed by these phenomena.
+He lays stress on the early appearance of the heart in
+the embryo. Corresponding to the general gradational
+view that he had formed of Nature, he held that the
+most primitive and fundamentally important organs
+make their appearance before the others. Among the
+organs all give place to the heart, which he considered
+the first to live and the last to die. In the heart, as we
+have seen, he placed the seat of the intelligence.</p>
+
+<p>Thus, not only in his account of the ‘Ladder of
+Nature’, but also in his theories of individual development,
+Aristotle exhibits some approach to evolutionary
+doctrine. This is somewhat obscured, however, by his
+peculiar view of the nature of procreation. On this
+topic his general conclusion is that the material substance
+of the embryo is contributed by the female, but
+that this is mere passive formable material, almost as
+though it were the soil in which the embryo grows. The
+male, by giving the principle of life, the <i>soul</i> (<i>psyche</i>),
+contributes the essential generative agency. But this
+<i>soul</i> is not material, and it is not, therefore, theoretically
+necessary for anything material to pass from male to
+female. The material which does in fact pass with the
+semen of the male is, as the older philosophers would
+have said, an <i>accident</i>, not an <i>essential</i>. The essential
+contribution of the male is not matter but <i>form</i> and
+<i>principle</i>.</p>
+
+<p>The female then only provides the <i>material</i>, the male
+<span class="pagenum" id="Page_32">32</span>the <i>soul</i>, the form, the principle, that which makes life.
+Aristotle was thus prepared to accept instances of fertilization
+without material contact, i.e., in effect, <i>parthenogenesis</i>
+or ‘virgin birth’. In the centuries that
+came after him such instances were not infrequently
+adduced, and this doctrine was given a special turn by
+Christian theologians. Belief in the ‘accidental’ character
+of the material contribution of the male was common
+among men of science till the nineteenth century. The
+general attitude as to the nature of fertilization set
+forth, for instance, by William Harvey (1578-1657,
+<a href="#Page_111">pp. 111-14</a>) in his book, <i>On the Generation of Animals</i>,
+published in London in <span class="allsmcap">A.D.</span> 1651, is practically identical
+with the views of Aristotle published in Athens about
+350 <span class="allsmcap">B.C.</span>, just 2,000 years earlier. It is of great interest
+to note that very recent embryological research goes
+some way to confirm this view of Aristotle. Without
+any intervention of the male sexual element, it is possible
+so to stimulate the egg mechanically as to produce
+a perfect animal which is thus fatherless from the first.
+The male element is indeed unnecessary and, in fact,
+transmits only hereditary characters.</p>
+
+<p>We must say something concerning Aristotle’s conceptions
+of the nature of Life itself. He was before all
+things a ‘vitalist’. For him the distinction between
+living and not-living substance is to be sought not in
+material constitution, but in the presence or absence
+of something that he calls <i>psyche</i>, which we may translate
+‘Soul’. His teaching on this topic had the
+profoundest influence on subsequent anatomical and
+physiological thought.</p>
+
+<p>Aristotle’s theory as to the relation of this Soul to
+<span class="pagenum" id="Page_33">33</span>material things is a difficult and complicated subject.
+Its adequate discussion would take us beyond our
+theme. He holds, however, that the Soul is related to
+the idea of <i>form</i>. In living things the soul is that which
+gives form. It is the pervasion by the soul that leads to
+the determinate development of the body and its parts.
+This activity of the Soul, under the Aristotelian term
+<i>Entelechy</i> (which we may perhaps translate ‘the indwelling
+perfectability’ or ‘purposiveness’, see <i>Preface</i>),
+has an important place in modern biological theory,
+which has, indeed, swung definitely in the direction
+of the Aristotelian position.</p>
+
+<p>Aristotle defines Life, existing in Matter, as ‘the
+power of self-nourishment and of independent growth
+and decay’. Of the Soul, the principle of Life, he distinguishes
+three orders or types, the lowest <i>vegetative</i>,
+or nutritive and reproductive, next the <i>animal</i> or sensitive,
+and highest the <i>rational</i> or intellectual soul. The
+last, he at first held, was peculiar to man, but later he
+modified this view.</p>
+
+<figure class="figcenter illowe30" id="i034">
+  <img class="w100" src="images/i034.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 13.</span> The four <i>Elements</i> in association with the four <i>Humors</i>
+    and the four <i>Qualities</i>.
+  </figcaption>
+</figure>
+
+<p>The history of the reception of Aristotle’s science
+by later ages is very strange to modern eyes. Of all
+Aristotle’s scientific teachings, men clung most firmly
+for many centuries not to his finely thought-out biological
+conceptions, but to a doctrine of the constitution of
+matter of which the modern student hears nothing.
+Aristotle, following more ancient writers, held that
+there were four primary and opposite fundamental
+<i>Qualities</i>, the <i>hot</i> and the <i>cold</i>, the <i>wet</i> and the <i>dry</i>.
+These met in binary combination to constitute the
+four Essences or Existences which entered in varying
+proportions into the constitution of all Matter. The
+<span class="pagenum" id="Page_34">34</span>four Essences, or, to give them their usual name, <i>Elements</i>,
+were <i>earth</i>, <i>air</i>, <i>fire</i>, and <i>water</i>. Thus, water was
+wet and cold, fire hot and dry, and so forth. With this
+theory later writers combined the somewhat similar
+Hippocratic doctrine which held that the body was
+composed of the four ‘Humors’ or liquids: <i>blood</i>, <i>phlegm</i>,
+<i>black bile</i> (melancholy), and <i>yellow bile</i> (choler). Some
+of the Hippocratic physicians had associated excess of
+the Humors with various types of bodily constitution.
+Their followers made much of the ‘temperaments’ resulting
+therefrom, and according to the prevailing
+humor they distinguished the sanguine, phlegmatic,
+melancholy or choleric temperament (<a href="#i097">Fig. 34</a>, p. 97).</p>
+
+<p>These conceptions, now departed altogether from
+our scientific discipline, still persist embedded in our
+language. Poetry still uses such ideas as the ‘raging of
+<span class="pagenum" id="Page_35">35</span>the elements’ and ‘elemental forces’. We may yet
+speak of a ‘fiery nature’ or an ‘aerial spirit’. We know
+what is meant by a <i>sanguine</i> or a <i>phlegmatic</i> temperament,
+and a <i>melancholy</i> or <i>choleric</i> disposition, and such
+words conjure up real pictures in our minds (<a href="#i097">Fig. 34</a>).
+Until it began to be undermined by Robert Boyle
+(1627-91) and others in the seventeenth century, the
+doctrine of the four elements persisted in its entirety,
+while ideas and terms derived from the old humoral
+pathology can, in fact, be traced in the medicine of the
+twentieth century.</p>
+
+<p>The biological activity of the school of Aristotle was
+continued after his death by his pupil Theophrastus
+(372-287 <span class="allsmcap">B.C.</span>). Especially the writings on plants of
+Theophrastus are instinct with a thoroughly scientific
+spirit, and are rightly regarded as the basic documents
+of the science of Botany. Nevertheless, his works had
+little effect or influence on his contemporaries and
+successors. With Theophrastus the purely biological
+school of Aristotle may be said to come to an end. The
+biological sciences ceased, for many centuries, to be
+studied for their own sake and became mere handmaidens
+of Medicine. Neither mistress nor servant was
+the better for the change.</p>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_36">36</span></p>
+
+
+  <h2 class="nobreak" id="II">
+    II
+    <br>
+    THE HEIRS OF GREECE
+    <br>
+    <span class="sm">(300 B.C. TO A.D. 200.)</span>
+  </h2>
+</div>
+
+
+<h3 id="1_The-Alexandrian_School">§ 1. <i>The Alexandrian School.</i></h3>
+
+<p>Soon after Aristotle, about 300 <span class="allsmcap">B.C.</span>, a great medical
+school was founded at Alexandria in Egypt. That
+country had been conquered by Alexander the Great,
+after whom the town was named. On Alexander’s
+death, Egypt came under the rule of one of his generals,
+Ptolemy, who established a dynasty which became
+extinct with the famous Queen Cleopatra, thirty years
+before the Christian era. Alexandria was a favorite
+residence of this Greek dynasty and became more
+Greek than Egyptian. Ptolemy and his successors
+were patrons of learning, and at the Alexandrian school
+remarkable anatomical and physiological researches
+were made. These were the work of Greek physicians
+who, in the tradition of their people, were only too
+wont to associate their discoveries with sweeping
+theoretical generalizations, often on very inadequate
+bases.</p>
+
+<p>The two earliest medical teachers at Alexandria were
+also the greatest, Herophilus of Chalcedon, who
+flourished about 300 <span class="allsmcap">B.C.</span>, and his slightly younger
+contemporary Erasistratus of Chios. Herophilus may
+be regarded as the father of Anatomy, Erasistratus as
+the father of Physiology.</p>
+
+<p>Herophilus was probably the first to dissect the
+human body in public. He recognized the brain as the
+<span class="pagenum" id="Page_37">37</span>central organ of the nervous system and regarded it as
+the seat of the intelligence, thus reversing the verdict of
+Aristotle on the primacy of the heart. He was the first
+to grasp the nature of the nerves, which he distinguished
+as connected with motion and sensation (<a href="#i208">Fig. 98</a>),
+though he did not separate them clearly from tendons
+and sinews. He greatly extended the knowledge of the
+parts of the brain. Certain parts of the brain still bear
+titles which are translations of those which he gave
+them. He also made the first clear distinction between
+arteries and veins.</p>
+
+<p>At the time of the institution of the Alexandrian
+medical school, and for long after, there flourished that
+view of the structure of the world known as <i>atomic</i>,
+propounded by the philosopher Democritus (<i>c.</i> 400 <span class="allsmcap">B.C.</span>).
+The chief exponent of the theory was Epicurus (342-270),
+whose philosophy was of the order which we
+should now call ‘materialistic’. For it the only ultimate
+realities were atoms and ‘the void’, and everything was
+ultimately expressible in these terms. Epicurean philosophy
+was not without its reactions on Medicine at
+Alexandria, where its leading exponent was Erasistratus
+of Chios.</p>
+
+<p>Erasistratus was essentially a rationalist and professed
+himself a foe to all mysticism. In the last resort,
+however, he had to invoke the idea of Nature as a great
+artist acting as an external power, shaping the body
+according to the ends to which it must act. This is in
+contrast with Aristotle’s view of the ‘soul’ as an
+<i>Entelechy</i> (p. 33), an innate and inherent factor. Erasistratus
+sought to express his views in atomic terms,
+but, to make physiology intelligible, he added a conception,
+<span class="pagenum" id="Page_38">38</span><i>Pneumatism</i>, found also among older thinkers.
+Pneumatism is the belief that the phenomena of life
+are associated with the existence of a subtle vapor,
+‘pneuma’ or spirit, which permeates the organism, and
+causes its movements. This subtle vapor is held to
+have some affinities with the air we breathe. Pneumatism
+is, in fact, a primitive attempt to explain the
+phenomena of respiration.</p>
+
+<p>Erasistratus observed that every organ is equipped
+with a threefold system of ‘vessels’, vein, artery, and
+nerve, which divide to the very limits of vision, and he
+considered that the process of division continues beyond
+those limits. The minute divisions of these vessels,
+plaited together, he believed to make up the tissues.
+Veins, arteries, and nerves are, for him, made of minute
+tubes of the same nature as themselves, through which
+they are nourished. Blood and two kinds of pneuma
+are the essential sources of nourishment and movement.
+The blood is carried by veins. Air, on the other
+hand, is taken in by the lungs and passes to the heart,
+where it becomes changed into a peculiar pneuma, the
+<i>Vital Spirit</i>, which is sent to the various parts of the
+body by the arteries. This spirit is carried to the brain,
+in the cavities or ‘ventricles’ of which it is further
+changed to a second kind of pneuma, the <i>Animal Spirit</i>.
+The animal spirit is conveyed to different parts of the
+body by the nerves, which are hollow.</p>
+
+<p>In the brain Erasistratus observed the convolutions,
+noted that they were more elaborate in man than in
+animals, and associated this complexity with the higher
+intelligence of man. He distinguished between the
+main parts of the brain, the ‘cerebrum’ and ‘cerebellum’
+<span class="pagenum" id="Page_39">39</span>(<a href="#i210">Fig. 100</a>, p. 210), and gave a detailed description of
+the ‘cerebral ventricles’ or cavities within the brain and
+of the ‘meninges’ or membranes that cover the brain.
+He considered that the cerebral ventricles were filled
+with <i>Animal Spirit</i>. (Compare Galen’s scheme, <a href="#Page_58">p. 58</a>.)</p>
+
+<p>Erasistratus attained to a clear view of the action
+of muscles in producing movement. He regarded the
+shortening of muscles as due to distension by <i>Animal
+Spirit</i> conveyed to the muscles by the nerves. We may
+note that similar theories as to the nature of muscular
+action were again set forth, on theoretical grounds, in
+the seventeenth century by Descartes (1596-1650,
+<a href="#Page_127">pp. 127-8</a>) and by Borelli (1608-79, <a href="#Page_129">pp. 129-30</a>), but
+were rebutted by the experiments of Swammerdam
+(1637-80, <a href="#Page_123">p. 123</a>). We may recall that we are still
+in the dark as to the mechanism of contraction of
+muscle fiber, the structure of which was first revealed
+by Leeuwenhoek (1632-1723, <a href="#i121">Figs. 55-56</a><span class="allsmcap">A</span>, p. 121).</p>
+
+<p>Erasistratus considered the chief cause of disease to be
+excess of blood or <i>Plethora</i>. Diseases thus caused differ
+according to their site. Among them are coughing of
+blood, epilepsy, pneumonia, tonsillitis, &amp;c. Most of
+these diseases could be treated by diminishing the local
+supply of blood by starvation. Among his contemporaries
+and successors blood-letting was an habitual
+practice applied to almost every condition. Erasistratus
+employed it but rarely, and his followers banned
+it altogether. He was consistently opposed to violent
+remedies. Among the therapeutic measures which
+he favored were regulated exercise, diet, and the
+vapor bath.</p>
+
+<p>Erasistratus complained that many physicians of his
+<span class="pagenum" id="Page_40">40</span>time were not interested in Hygiene. He therefore
+wrote a treatise on the subject. Though he regarded
+Hygiene as a means of substituting prevention for cure,
+this did not prevent him from being extremely careful
+and precise in his treatment of cases.</p>
+
+<p>After the first generation or two, the activity of the
+Alexandrian medical school flagged, though the city
+long remained a great teaching center, and minor
+<span class="pagenum" id="Page_41">41</span>medical advances were made. Surgery (cf. <a href="#i040">Fig. 14</a>)
+seems to have languished less than Medicine. The stagnation
+in medical matters at Alexandria is in contrast to
+the continued activity there in Mathematics, Astronomy,
+Mechanics and Geography.</p>
+
+<p>With the absorption of Egypt into the Roman
+Empire in 50 <span class="allsmcap">B.C.</span> and the extinction of the Ptolemaic
+dynasty by the death of Cleopatra in 30 <span class="allsmcap">B.C.</span>, Alexandria
+ceased to have great scientific importance. The
+school continued for centuries with restricted activity
+and devoid of all originality. Intellectually, it had become
+subordinate to the Metropolis. Rome was now
+mistress of the world and the future of Medicine must be
+considered from the point of view of the Roman Empire.</p>
+
+<figure class="figcenter illowe30" id="i040">
+  <img class="w100" src="images/i040.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 14.</span> INSCRIBED TABLET OF ABOUT 100 <span class="allsmcap">B.C.</span> from the
+    wall of the temple of Kom-Ombos in Upper Egypt. The temple itself was
+    built by Ptolemy VII (181-146 <span class="allsmcap">B.C.</span>), but the carving is later. It is
+    divided into four partitions. These illustrate the surgical instruments in
+    use in Egypt during Alexandrian times.</p>
+    <p>In the partition to the extreme left can be seen two cupping-glasses
+    (cf. <a href="#i017a">Fig. 8</a>), a case of instruments (cf. <a href="#i044">Fig. 15</a>), a pair of shears, a sponge,
+    a probe, a pair of fine forceps, and two knives (cf. <a href="#i020">Fig. 9</a>).</p>
+    <p>In the next partition to the right can be seen two large forceps, two bags
+    or flasks, a strigil, two magic eyes, a pair of scales, and two growing plants.</p>
+    <p>In the next partition to the right can be seen several hooks of different
+    forms, several knives, and two or three pairs of forceps.</p>
+    <p>In the partition to the extreme right can be seen a bifid probe, a pair of
+    tongs, a long-bladed knife, probes, a double hook, a saw, a cautery, and
+    several objects probably intended to represent bandages.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_2_Medical_Teaching_in_the_Roman_Empire">
+  § 2. <i>Medical Teaching in the Roman Empire.</i>
+</h3>
+
+<p>The original native Roman medical system was quite
+devoid of scientific elements and was that of a people of
+the lower culture. Interwoven, as is all primitive Medicine,
+with ideas that trespass on the domains of religion
+and magic, it possessed that multitude of ‘specialist
+deities’ which was so characteristic of the Roman cults.
+The entire external aspect of Roman medicine was
+changed by the advent of Greek science. Yet, notwithstanding
+the large medical field that the Western
+Empire provided, and the wide acceptance of Greek
+medicine by the upper classes, it is remarkable that the
+Latin-speaking peoples produced no eminent physician.</p>
+
+<p>At first scientific medical education at Rome was
+entirely a matter of private teaching. The earliest important
+scientific teacher there was the Greek Asclepiades
+of Bithynia (died <i>c.</i> 40 <span class="allsmcap">B.C.</span>), a contemporary of
+<span class="pagenum" id="Page_42">42</span>the poet Lucretius and, like him, an Epicurean. Asclepiades,
+like Erasistratus, imported the atomic view of
+Democritus into Medicine. He deeply influenced the
+course of later medical thought, ridiculed the Hippocratic
+attitude of relying on the ‘healing power of nature’
+which he regarded as a mere ‘meditation on death’,
+and urged that active measures were needed for the process
+of cure to be ‘seemly, swift and sure’. He founded
+a regular school at Rome which continued after him.</p>
+
+<p>At first the school was the mere personal following of
+the physician, who took his pupils and apprentices
+round with him on his visits. At a later stage such
+groups combined to form societies or colleges, where
+problems of the art were debated. Towards the end of
+the reign of Augustus (27 <span class="allsmcap">B.C.</span>-14 <span class="allsmcap">A.D.</span>) or the beginning
+of that of Tiberius (14 <span class="allsmcap">A.D.</span>-37 <span class="allsmcap">A.D.</span>), these societies constructed
+for themselves a meeting-place on the Esquiline
+Hill. Finally the emperors built halls or <i>auditoria</i> for
+the teaching of Medicine. The professors at first received
+only the pupils’ fees. It was not until the time
+of the Emperor Vespasian (reigned <span class="allsmcap">A.D.</span> 70-9) that
+medical teachers were given a salary at the public
+expense. The system was extended by later emperors.</p>
+
+<p>Thus Rome became a center of medical instruction.
+After a time subsidiary centers were established in
+other Italian towns. From Italy the custom spread
+and we meet traces of such schools at the half-Greek
+Marseilles as well as at Bordeaux, Arles, Nîmes, Lyons,
+and Saragossa. For the most part these provincial
+schools produced workaday medical men, few of whose
+writings have come down to us. They were perhaps
+largely training-places for the army surgeons. That
+<span class="pagenum" id="Page_43">43</span>class seldom had scientific interests, though Dioscorides,
+one of the most prominent physicians of
+antiquity, one who earned the respect of Galen and
+has deeply influenced the modern pharmacopoeia,
+served in the army under Nero. His book is, in fact,
+an extremely useful though ill-arranged compendium
+of drugs. Dioscorides wrote in Greek, and his work
+was not translated into Latin until the sixth century
+of our era.</p>
+
+<p>The earliest scientific medical work in Latin is the
+<i>De re medica</i> of Celsus, which was prepared about
+<span class="allsmcap">A.D.</span> 30. It is in many ways the most readable and well-arranged
+ancient medical work that we have. It is,
+however, not an original work but a compilation from
+the Greek, and the sole surviving part of a complete
+encyclopaedia of knowledge. Many of its phrases are
+closely reminiscent of the <i>Hippocratic Collection</i>. The
+ethical tone is high and the general line of treatment
+sensible and humane. Celsus, though almost forgotten
+in the Middle Ages, was the first classical medical
+writer to be printed (<span class="allsmcap">A.D.</span> 1476).</p>
+
+<p>The treatise of Celsus opens with an interesting
+account of the History of Medicine. It then passes on
+to deal with diet and the general principles of therapeutics
+and pathology, next it discusses internal disease,
+and then turns to external diseases. The last part of
+the work is devoted to surgery, and is perhaps the most
+valuable of the whole.</p>
+
+<p>Celsus professes himself a follower of Asclepiades of
+Bithynia (p. 41), but, unlike his master, he by no means
+despises the Hippocratic <i>expectant</i> method of ‘waiting
+on the disease’. In many matters we are struck with</p>
+
+<p><span class="pagenum" id="Page_44">44</span></p>
+
+<p>his boldness as a surgeon. Thus he describes plastic
+operations on the face and mouth, and the removal of
+polypus from the nose. He tells too of the very dangerous
+operation for extirpating a goiter (p. 303), and
+of cutting for stone. He gives an excellent account of
+what might be thought the modern operation for
+removal of tonsils. Noteworthy also is his description
+of dental practice which includes the wiring of loose
+teeth and an account of a dental mirror. An idea of
+the surgical instruments in use in his time can be obtained
+from those recovered from Pompeii (<a href="#i044">Fig. 15</a>).</p>
+
+<figure class="figcenter illowe30" id="i044">
+  <img class="w100" src="images/i044.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 15.</span> ROMAN SURGICAL INSTRUMENTS of the first
+    century <span class="allsmcap">A.D.</span> found at Pompeii.</p>
+    <p><i>a.</i> Forceps, probably for extracting teeth.</p>
+    <p><i>b.</i> Small pocket-case of instruments containing sharp spoon, probe, &amp;c.</p>
+    <p><i>c.</i> Fine-toothed forceps.</p>
+    <p><i>d.</i> Trocar and cannula for tapping fluids confined in cavities.</p>
+    <p><i>e.</i> Speculum for examining orifices and cavities.</p>
+    <p><i>f.</i> Instrument for dilating wounds that they may be more fully examined.</p>
+  </figcaption>
+</figure>
+
+<p><span class="pagenum" id="Page_45">45</span></p>
+
+
+<h3 id="_3_Medical_Services_of_the_Roman_Empire">
+  § 3. <i>Medical Services of the Roman Empire.</i>
+</h3>
+
+<p>If, in Medicine itself, the Roman achieved but few
+advances, in the organization of medical service, and
+especially in the department which deals with public
+health, his position is far more noteworthy. All Latin
+writers on architecture give much attention to the
+orientation, position and drainage of buildings. From
+an early date sanitation and public health drew the
+attention of statesmen. Considering the dread of the
+neighborhood of marshes on the part of these practical
+sanitarians of Ancient Rome, and in view of modern
+knowledge of the mosquito-borne character of Malaria
+(<a href="#Page_284">pp. 284-5</a>), it entertaining to find the mosquito net
+ridiculed by the poets Horace, Juvenal and Propertius!</p>
+
+<p>Sanitation was a feature of Roman life. Rome was
+already provided with <i>cloacae</i> or subterranean sewers in
+the age of the Tarquins (6th cent. <span class="allsmcap">B.C.</span>). The <i>Cloaca
+Maxima</i> itself, the main drain of Rome, which is still
+in use, dates back to that period.</p>
+
+<p>The antiquity of hygienic ideas is seen in an interdict,
+by a law of about 450 <span class="allsmcap">B.C.</span>, against burials within the
+city walls and in the instructions issued to the town
+officials to attend to the cleanliness of the streets and to
+the distribution of water. Among these ancient laws
+we may note one attributed to the first king of Rome,
+which directed the opening of the body in the hope of
+extracting a living child in the case of a woman dying in
+pregnancy. It is the origin of the so-called ‘Caesarean
+section’ on the living mother, the method by which
+Caesar himself is said to have been brought into the
+world. At the date of these decrees physicians in Rome
+<span class="pagenum" id="Page_46">46</span>were either slaves or in an entirely subordinate position.
+Their status was improved by Julius Caesar (102-44
+<span class="allsmcap">B.C.</span>), who conferred citizenship on all who practised
+Medicine at Rome, in order to induce physicians to
+settle there.</p>
+
+<figure class="figcenter illowe40" id="i047">
+  <img class="w100" src="images/i047.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 16.</span> AQUEDUCT OF NERO. This structure, when complete, conveyed part of the water-supply of Rome.<br>
+
+    (<i>From an engraving by Piranesi.</i>)
+  </figcaption>
+</figure>
+
+<p>The finest monument to the Roman care for the
+public health stands yet for all to see in the remains
+of the fourteen great aqueducts which supplied the city
+with 300,000,000 gallons of potable water daily. No
+modern city is better equipped (<a href="#i047">Fig. 16</a>).</p>
+
+<p>Under the early Empire a definite public medical
+service was constituted. Public physicians were appointed
+to the various towns and institutions. A statute
+of the Emperor Antoninus of about the year <span class="allsmcap">A.D.</span> 160
+regulates the appointment of these physicians, whose
+main duty was to attend to the poor. In the code of the
+Emperor Justinian (<span class="allsmcap">A.D.</span> 533) is an article urging them
+to give this service cheerfully rather than the more
+subservient attendance on the wealthy. Their salaries
+were fixed by the municipal councillors. They were
+encouraged to undertake the training of pupils. Inscriptions
+attest the respect in which these state physicians
+were held in many towns.</p>
+
+<p>It is in connection with the army that we see the
+Roman medical system at its best. There was an adequate
+supply of military medical attendants who were
+well organized (<a href="#i048">Fig. 17</a>). The defects of the Roman
+army medical system were, however, absence of any
+elastic scheme for the ranking of medical officers, and
+complete subordination of the medical to the combatant
+officer. These facts are of a piece with the general
+Roman indifference to theoretical science, and explain</p>
+
+<p><span class="pagenum"><a id="Page_47"></a><a id="Page_48"></a>48</span></p>
+
+<p>why the Roman army surgeons made no additions to
+knowledge. The social status of the medical staff in
+the Roman military hierarchy was that of the non-commissioned
+personnel, which included accountants,
+registrars and secretaries.</p>
+
+<figure class="figcenter illowe30" id="i048">
+  <img class="w100" src="images/i048.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 17.</span> ROMAN ADVANCED DRESSING-STATION.<br>
+    (<i>From Trajan’s column.</i>)</p>
+    <p>To the left two Roman soldiers assist a wounded comrade. To the right a
+    Roman military surgeon bandages the wounded thigh of a friendly ally.
+    The costume of the surgeon is almost identical with that of the soldiers,
+    though he carries a case for ‘first aid’ slung over his shoulder.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_4_Roman_Hospitals">
+  § 4. <i>Roman Hospitals.</i>
+</h3>
+
+<p>The great contribution of Rome to Medicine—and
+it is a very great one—is the hospital system. It is a
+scheme that naturally arose out of the Roman genius for
+<span class="pagenum" id="Page_49">49</span>organization and is connected with the Roman military
+system. Among the Greeks, <i>iatreia</i>, ‘surgeries’, were
+well known; they were, however, the private property
+of the medical man. Larger institutions were connected
+with Aesculapian temples and there is evidence of some
+degree of scientific medical treatment in these places.
+In the Republican period the Romans were no better off
+and, despite the vast numbers of slaves, there was no
+provision for them when sick. A temple to Aesculapius
+had been established on an island of the Tiber in
+Republican times. It became the custom to expose the
+sick and worn-out slaves on this island of Aesculapius,
+to avoid the trouble of treating them. The Emperor
+Claudius (<span class="allsmcap">A.D.</span> 41-54) decreed that such slaves were
+free, and that, if they recovered, they need not return to
+the control of their masters. Thus, the island became
+a place of refuge for the sick poor. We may regard it
+as an early form of public hospital (<a href="#i051">Fig. 18</a>).</p>
+
+<p>Later writers speak of <i>valetudinaria</i>, ‘infirmaries’, for
+such persons, and give humane directions for their
+management. Such valetudinaria were in use even by
+free Romans. The excavations at Pompeii show that
+a physician’s house might even be built somewhat on
+the lines of a modern ‘nursing home’. It was probably
+in the provinces that private institutions first developed
+into subventioned public hospitals.</p>
+
+<p>This development of public hospitals naturally early
+affected military life. At first, sick soldiers had been
+sent home for treatment. As the Roman frontiers
+spread ever wider this became impossible and military
+hospitals were founded at important strategic points.
+The sites of several such military hospitals have been
+<span class="pagenum" id="Page_50">50</span>excavated. The best explored is near Düsseldorf and
+was founded about <span class="allsmcap">A.D.</span> 100.</p>
+
+<p>From the military valetudinarium it was no great
+step to the construction of similar institutions for the
+numerous Imperial officials and their families in the
+provincial towns. Motives of benevolence, too, gradually
+came in, and public hospitals were founded in many
+localities. The idea passed on to Christian times, and
+the pious foundation of hospitals for the sick and outcast
+in the Middle Ages is to be traced back to these Roman
+valetudinaria. The first charitable institution of this
+kind, concerning which we have clear information, was
+established at Rome in the fourth century by a Christian
+lady of whom we learn from St. Jerome. The plan of
+such a hospital projected at St. Gall in the early years of
+the ninth century has survived. It reminds us, in many
+respects, of the early Roman military hospitals. These
+medieval hospitals for the sick must naturally be distinguished
+from the even more numerous ‘spitals’ for
+travellers and pilgrims, the idea of which may perhaps
+be traced back to the rest-houses along the strategic
+roads of the Empire.</p>
+
+<figure class="figcenter illowe40" id="i051">
+  <img class="w100" src="images/i051.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 18.</span> ISLAND OF ST. BARTHOLOMEW IN THE TIBER AT ROME.<br>(<i>From an engraving by Piranesi.</i>)</p>
+    <p>The island was the site of a temple to Aesculapius used as a refuge for worn-out slaves. It is the first known public hospital.
+    The entire island is carved in the form of a ship. On its prow can be discerned the head of Aesculapius and his staff and serpent.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_5_Galen">
+  § 5. <i>Galen.</i>
+</h3>
+
+<p>The Latin culture, as we have seen, did not adapt
+itself easily to the prosecution of scientific Medicine.
+Long after Greece had ceased to exist as an independent
+state such medical writings as appeared were usually
+in the Greek rather than in the Latin language. This is
+true to the end, and the end came, so far as creative
+science is concerned, with the second half of the second
+century. The scene is then, and for centuries to come,
+<span class="pagenum"><a id="Page_51"></a><a id="Page_52"></a>52</span>mainly occupied by the huge overshadowing figure of
+Galen.</p>
+
+<p>Galen of Pergamum (<span class="allsmcap">A.D.</span> 130-200) devoted himself
+to medicine from an early age, and in his twenty-first
+year we hear of him studying anatomy at Smyrna. To
+extend his knowledge of drugs he made long journeys
+to Asia Minor. Later he proceeded to Alexandria,
+where he improved his anatomical equipment, and
+here, he tells us, he examined a human skeleton. His
+direct practical acquaintance with human anatomy was
+limited to that skeleton, for dissection of the human
+body was no longer carried on in his time. Thus, his
+physiology and anatomy were derived mainly from
+animal sources.</p>
+
+<p>The general medical standpoint of the Galenic is not
+unlike that of the Hippocratic writings, but the noble
+vision of the lofty-minded, pure-souled physician has
+utterly passed away. In its place we have an acute,
+contentious fellow of prodigious industry, who is frequently
+satisfied with a purely verbal explanation. Yet
+he is an ingenious physiologist, acquainted with the
+internal parts, so far as this is possible from a devotion
+to dissection of animals, equipped with all the learning
+of the schools of Pergamum, Smyrna and Alexandria,
+and rich with the experience of a vast practice at Rome.
+Galen is essentially an ‘efficient’ man. He has the grace
+to acknowledge constantly his indebtedness to the
+Hippocratic writings.</p>
+
+<p>Some of Galen’s works are, however, mere drug-lists,
+little superior to those of Dioscorides (p. 43). With the
+depression of the intelligence that corresponded with
+the break-up of the Roman Empire, it was these that
+<span class="pagenum" id="Page_53">53</span>were chiefly studied and distributed in the West.
+The Greek medical writers after Galen were but his
+imitators and abstractors, and they usually imitated and
+abstracted Galen at his worst. Through some of them
+Galen’s works reached the West at a very early period
+in the Middle Ages.</p>
+
+
+<h3 id="_6_The_Final_Medical_Synthesis_of_Antiquity">
+  § 6. <i>The Final Medical Synthesis of Antiquity.</i>
+</h3>
+
+<p>We now turn to the theoretical content of the vast
+mass of Galenic writings. These set forth a medical
+system of which the substance is based on the <i>Hippocratic
+Collection</i> and the form derived from Aristotle.
+This synthesis, in more or less corrupted form, provided
+the theoretical basis of medical practice for the
+next fifteen hundred years. Galen’s view of the human
+body may be examined under two aspects, which we
+describe as (<i>a</i>) philosophical and (<i>b</i>) descriptive.</p>
+
+<p>First as to the philosophical aspect. Galen’s voluminous
+works are saturated with the theory that all structures
+in the body have been formed by the Creator for
+a known and intelligible end. In the anatomical works,
+masses of explanation, based on this view, dilute the
+often imperfect accounts of structures. Thus, following
+the Aristotelian principle that Nature makes nought
+in vain, Galen seeks to justify, the form and structure
+of every organ—nay, of every part of every organ—with
+reference to the functions for which he believes
+it is destined. To do this is to claim that in every
+work of Creation—of which Man’s body is a type—and
+in every detail of such work, we can demonstrate
+God’s design along known principles. It is to claim,
+in fact, a complete knowledge of the Laws of Nature.
+<span class="pagenum" id="Page_54">54</span>No modern man of science, however intoxicated with
+his own achievements, has as yet arrogated such powers
+to himself. To conceive that such claims should be
+made by a pious, theistically minded author, the reader
+must think himself back into a very different philosophical
+environment from that to which we are nowadays
+accustomed.</p>
+
+<p>The prevailing philosophy of Galen’s world was the
+Stoic. Now in the world of the Stoic philosopher all
+things were determinate, and they were determined by
+forces acting wholly outside Man. The type and origin
+of that determination the Stoic sought in the heavens,
+and found in the majestic and overwhelming procession
+of the stars. The recurring phenomena of the spheres
+typified, foreshadowed, nay, exhibited and controlled,
+the cycle of man’s life. Man dwelt in a finite world,
+bounded by a definite frontier—the sphere of the fixed
+stars. Within that spherical frontier all things worked
+by rule—and that rule was the rule of the heavenly
+bodies. Astrology had become one of the dogmas of
+the Stoic creed.</p>
+
+<p>To such a world Galen’s determination was in itself
+no strange thought. Yet Galen’s view was far from
+being wholly in accord with Stoicism. Though a determinism,
+it was a determinism of perfection in which all
+was fixed by a wise and far-seeing God, and was a
+reflection of His perfection. Now such a scheme did
+not ill fit the new creed which was just beginning to
+raise its head and was destined to replace Stoicism and
+all the other pagan schemes. Galen’s thought, in fact,
+made a special appeal to the Christian point of view,
+and this is, doubtless, the reason that his works have
+<span class="pagenum" id="Page_55">55</span>been preserved in larger bulk than those of any other
+pagan writer. The Galenic standpoint appealed equally
+to the theological bias of Islam, whose medical knowledge
+was based almost entirely on Galen.</p>
+
+<p>We may now turn from the philosophical to the descriptive
+bases of Galen’s medical system, namely to
+his Anatomy and Physiology.</p>
+
+<p>We may begin with the bones. These Galen had
+studied on an actual human skeleton at Alexandria.
+He divided them into long bones with a central canal
+and flat bones without such a canal. He had a fairly
+good idea of the bones of the skull. He regarded
+the teeth as bones, and he gives a good description of
+their origin. He recognized twenty-four vertebrae terminated
+by the <i>sacrum</i>. Galen gives accurate elementary
+descriptions of the vertebrae, of the ribs, of the
+breastbone, of the collar-bone, and of the bones of the
+limbs. He divides joints or junctions of bones into
+two main orders, those with movement and those without
+movement, and the titles that he gives to his main
+divisions have survived in our modern nomenclature.</p>
+
+<p>As regards the muscular system there can be little
+doubt that Galen’s work was in large part of a really
+pioneer character. Throughout his works the muscles
+are perhaps the structures that he describes most accurately.
+His writings contain frequent references to form
+and function of muscles of various animals. Thus, the
+dissection of the muscles of the orbit and larynx was
+performed on the ox, and the muscles of the tongue
+are described from the ape. Occasionally he indicates
+that he is aware of the differences between certain of the
+muscles he is describing from those of man. For his
+<span class="pagenum" id="Page_56">56</span>investigation of muscles Galen used particularly the
+Barbary ape (<i>Macacus inuus</i>), a creature anatomically
+near enough to man for a knowledge of its detailed
+structure to be applicable to human Surgery. (<a href="#i057">Figs. 19 and 20.</a>)</p>
+
+<figure class="figcenter illowe40" id="i057">
+  <img class="w100" src="images/i057.jpg" alt="figures 19 and 20">
+  <figcaption>
+<div class="column">
+    <p class="center"><span class="smcap">Fig. 19.</span> DISSECTION OF HAND OF MAN.</p>
+</div>
+<div class="column">
+<p class="center">
+<span class="smcap">Fig. 20.</span> DISSECTION OF HAND OF BARBARY APE.</p>
+</div>
+    <p>
+    The ape’s hand shows all the main muscular and tendinous structures present in the human hand, though the proportional
+    development differs somewhat. The same is true of other parts of the body. Galen’s anatomy, drawn
+    from the Barbary ape, was thus quite serviceable for many surgical procedures. Apart from proportion, the most
+    obvious anatomical difference in the hands of the two species is the position of attachment of the small severed
+    muscle indicated by the asterisk in both cases.</p>
+  </figcaption>
+</figure>
+
+<p>Galen’s description of the brain and of the vascular
+system is inferior to his account of the bones and
+muscles. His account of the nervous system, other
+than the brain, occupies an intermediate position. His
+account of the origin of nerves from the brain has left
+its traces even in modern descriptive anatomy.</p>
+
+<p>Finally we may turn to Galen’s theory of the working
+of the human body, that is to his Physiology.</p>
+
+<p>The basic principle of life in the Galenic physiology
+was a <i>spirit</i> or <i>pneuma</i> drawn from the general World-spirit
+in the act of breathing. It entered the body
+through the windpipe or <i>trachea</i> and so passed to the
+lung and thence, through the <i>arteria venalis</i>—which we
+now call the ‘pulmonary vein’—to the left ventricle of
+the heart, where it encountered the blood (<a href="#i059">Fig. 21</a>). But
+what was the origin of the blood? To this question his
+answer was ingenious, and the errors that it involved
+remained till the time of Harvey (<a href="#i113">Fig. 43</a>, p. 113).</p>
+
+<p>Galen believed that food-substance from the intestines
+was carried as ‘Chyle’ by the portal vein to the
+liver. There it was converted into blood and endowed
+with a particular pneuma, the <i>Natural Spirit</i>, which
+bestowed the power of growth and nutrition. Part of
+this lower-grade blood was carried from the liver to the
+right ventricle, where it gave off impurities by way of
+the <i>vena arterialis</i>, our ‘pulmonary artery,’ to the lungs,
+whence they were exhaled in the breath. The venous
+<span class="pagenum"><a id="Page_57"></a><a id="Page_58"></a>58</span>blood, thus continuously purified, ebbed to and fro in
+the veins for purposes of ordinary nutrition. A very
+small part of this venous blood passed through invisible
+pores in the muscular septum to the left ventricle.
+There it mixed with air drawn in from the lung
+by way of the <i>arteria venalis</i>, our ‘pulmonary vein’.
+From this mixture was produced a higher-grade blood,
+the arterial blood, instinct with the principle of life and
+charged with a second kind of pneuma, the <i>Vital Spirit</i>.
+Blood containing this second kind of pneuma ebbed to
+and fro in the arteries endowing the various organs with
+function. Such as reached the brain became there
+charged with the noblest essence of all, the third
+pneuma, the <i>Animal Spirit</i> or breath of the soul. The
+<i>Animal Spirit</i> was carried from the brain by the nerves—believed
+to be hollow—and through them initiated
+the higher functions of the organism, including motion
+and sensation (<a href="#i059">Fig. 21</a>).</p>
+
+<p>Among Galen’s most remarkable efforts are the investigations
+he made of the physiology of the nervous
+system. He tells of his experiments on the spinal cord.
+Injury to the cord between the first and second vertebrae
+caused, he observed, instantaneous death. Section
+between the third and fourth produced arrest of
+breathing. Below the sixth vertebra it gave rise to paralysis
+of the chest muscles, breathing being then carried
+on only by the diaphragm. If the lesion was lower the
+paralysis was confined to the lower limbs, bladder, and
+intestines. The physiology of the spinal cord is worked
+out most ably and in very considerable detail.</p>
+
+<p>Galen established no school, nor had he any definite
+followers. His self-satisfaction and love of controversy
+<span class="pagenum"><a id="Page_59"></a><a id="Page_60"></a>60</span>were not of the kind that would endear him to disciples.
+On his death in <span class="allsmcap">A.D.</span> 200 the active prosecution of anatomical
+and physiological inquiry ceased absolutely.
+The curtain descends at once, and, for the subject we
+are discussing, the Dark Ages have begun.</p>
+
+<p>Rational medicine in the pagan world descends into
+darkness as surely and even more abruptly than Philosophy.
+The whole system is soon to be overwhelmed.
+Alexandria has long been in decline. A mob, fanatically
+Christian, has destroyed her school and library, with
+all the hoarded wisdom of the pagan past. Men of the
+new faith fix their eyes on the wrath to come and the
+glory after it. In the race for salvation, who will pause
+to consider this miserable tenement of clay? Antiquity
+is no more. A new age has begun.</p>
+
+<figure class="figcenter illowe30" id="i059">
+  <img class="w100" src="images/i059.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 21.</span> GALEN’S PHYSIOLOGICAL SYSTEM.
+  </figcaption>
+</figure>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_61">61</span></p>
+
+
+  <h2 class="nobreak" id="III">
+    III
+    <br>
+    THE MIDDLE AGES
+    <br>
+    <span class="sm">(FROM ABOUT A.D. 200 TO ABOUT A.D. 1500.)</span>
+  </h2>
+</div>
+
+
+<h3 id="1_period_of_depression">§ 1. <i>The Period of Depression in Europe.</i></h3>
+
+<p>The observational period of Antiquity closed with
+Galen. The centuries that follow exhibit progressive
+deterioration of the intellect. For that deterioration
+many causes have been assigned. An important factor
+was certainly the philosophical outlook of later paganism.
+Men lacked a motive for living. Their view of
+the World was dreary and without hope. It is sometimes
+alleged that the advent of Christianity was a
+factor in the decay of Science, but Science was, in fact,
+in headlong decay before Christianity was in a position
+to have any real effect on pagan thought.</p>
+
+<p>Christianity came to the ancient world as a protest
+and a revulsion against the prevailing and extremely
+pessimistic pagan outlook. Christianity brought men
+something for which to live. It was natural that it
+should oppose the philosophical basis of pagan thought.
+In this sense Christianity was certainly anti-scientific.
+Early Christian thought exhibits an aversion to the view
+which places the whole of man’s fate under the dominion,
+the inescapable tyranny, of Natural Law. It
+is, however, essential to remember that the early
+Church, in developing this opposition, was not dealing
+with living observational Science. The conflict was
+simply with a philosophical tradition which contained
+dead, non-progressive and misunderstood scientific
+elements.</p>
+
+<p><span class="pagenum" id="Page_62">62</span></p>
+
+<p>For some eight centuries from the time that Christianity
+finally replaced Paganism in the Roman Empire—from
+about <span class="allsmcap">A.D.</span> 400 to about <span class="allsmcap">A.D.</span> 1200—such remains
+of classical learning and classical science as survived
+were in monastic keeping. It was only in the
+monasteries that there were any who cared at all for
+these things, and it was only in the monasteries that
+manuscripts could be either written or preserved. We
+cannot be sufficiently grateful to the monks for having
+succeeded in preserving even as much as they did.
+Nevertheless, whether we consider what they saved or
+what they lost of medical literature, we can express no
+high opinion of either monastic taste or monastic judgment.</p>
+
+<p>The curse of the Science of Medicine, as of all
+sciences, has always been the so-called ‘practical man’,
+who will consider only the immediate end of his art,
+without regard to the knowledge on which it is based.
+Monkish medicine had no thought save for the immediate
+relief of the patient. All theoretical knowledge
+was permitted to lapse. Anatomy and Physiology
+perished. Prognosis was reduced to an absurd rule
+of thumb. Botany became a drug-list. Superstitious
+practices crept in, and Medicine deteriorated into a
+collection of formulae, punctuated by incantations,
+which became less understood and further removed
+from their originals at each copying. Medicine remained
+surrounded by sacred associations (<a href="#i063">Fig. 22</a>),
+but the scientific stream, which is its life-blood, was
+dried up at its source.</p>
+
+<figure class="figcenter illowe30" id="i063">
+  <img class="w100" src="images/i063.jpg" alt="figures 22 and 23">
+  <figcaption>
+    <p><span class="smcap">Fig. 22.</span> EARLIEST KNOWN REPRESENTATION OF ST.
+    LUKE AS A PHYSICIAN. From a seventh-century painting in the
+    underground basilica of Saints Felix and ‘Adauctus’ at Rome. St. Luke,
+    as an Evangelist, holds a scroll between his hands; as a Physician he carries
+    suspended from his left arm a bag containing four instruments, one of
+    which is a lancet. The head is tonsured like a monk’s. By courtesy of Rev.
+    Father J. R. Fletcher.</p>
+    <p><span class="smcap">Fig. 23.</span> PICTURE OF TREPHINING from a thirteenth-century
+    manuscript. The surgeon is using a well-known and primitive form of
+    drill, the mode of action of which will be understood by the accompanying
+    diagram, shown as <a href="#i064">Fig. 24</a>.</p>
+  </figcaption>
+</figure>
+
+<p>There was just one area in the Latin West where a
+slightly higher standard prevailed. In the South of
+<span class="pagenum" id="Page_63">63</span>Italy the Greek tongue still continued for centuries to
+be spoken and written. Though civilization had sadly
+deteriorated with the disorders of the times, yet there
+remained here and there in that region a slightly higher
+intellectual standard than prevailed elsewhere in
+Europe. Moreover, about the same time as the Norman
+Conquest in England, there was a Norman Conquest
+<span class="pagenum" id="Page_64">64</span>of South Italy also. The strong arm of the Norman
+administrator might wield the weapon of a tyrant, but
+at least it brought order where there had been anarchy.
+Learning under the Normans could lift a timid head.
+Notably at the town of Salerno, not far from Naples,
+there arose something resembling a medical school. At
+Salerno in the eleventh century there was a certain
+amount of translation of medical works from Greek into
+Latin. The choice of works for translation was very
+poor, but it was something that enough mental energy
+existed for the effort.</p>
+
+<figure class="figcenter illowe30" id="i064">
+  <img class="w100" src="images/i064.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 24.</span> Figure to illustrate the mode of action of the instrument used
+    by the surgeon in <a href="#i063">Fig. 23</a>. The twist of the thong causes rapid rotation of
+    the axis. The rotating point is pressed on the skull and gradually penetrates
+    it. From a drawing of the sixteenth century.</p>
+  </figcaption>
+</figure>
+
+<p>Salerno differed too from other centers of learning of
+the time in that instruction was not entirely under
+monastic auspices (<a href="#i065">Fig. 25</a>). Some, at least, of the Salernitan
+physicians were laymen. At the time of the
+Norman conquest of Salerno, the school was stimulated
+by the advent of a wanderer from the East, Constantine
+by name (died 1087). This man brought with him medical
+works in Arabic which he was able to translate into
+rude Latin. The Latin versions prepared by Constantine,
+<span class="pagenum" id="Page_65">65</span>corrupt, confused, barbarous, often almost incomprehensible,
+were yet a better intellectual fare than that
+on which the torpid mind of Europe had long fed.
+The Salernitan medical writings of the eleventh and
+twelfth centuries exhibit some faint-hearted attempts
+to return to Nature. Constantine was but the harbinger
+of the great ‘Arabian revival’ the further origins of
+which we must now seek to trace.</p>
+
+<figure class="figcenter illowe30" id="i065">
+  <img class="w100" src="images/i065.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 25.</span> SCENE AT A SIEGE OF SALERNO from a manuscript
+    prepared in South Italy early in the thirteenth century. An archer transfixes
+    two of the defenders through the cheeks. A <i>medicus</i> is aiding one of
+    them. Two nurses, bearing drugs and dressings, attend the medicus. It
+    illustrates the existence of lay physicians at Salerno at this date. The
+    medicus is not tonsured.</p>
+  </figcaption>
+</figure>
+
+<p><span class="pagenum" id="Page_66">66</span></p>
+
+
+<h3 id="_2_Arabic_Medicine">
+  § 2. <i>Arabic Medicine.</i>
+</h3>
+
+<p>Barbarian incursions sapped and finally destroyed
+the Western Roman Empire. The influence of those
+incursions on the Eastern Empire was less dramatic.
+It is true that the intellectual outlook of the East
+Roman or Byzantine Empire was no less modified, in
+the course of time, than was that of the West. In the
+absence, however, of any collapse of the system of
+government, the ancient Greek learning or rather the
+documentary casing in which it was enshrined, was
+better preserved than were the Latin traditions. Men
+in the Eastern Empire could still read the ancient
+Greek medical works in the language in which they
+had been written, and, if their reading was unintelligent,
+it was at least persistent. Moreover, heretical Christian
+sects on the confines of the East Roman Empire prepared
+for themselves translations of many of the ancient
+Greek authors. One of these heretical sects, the Nestorians,
+exhibited great missionary activity. It was
+perhaps on this account that the Nestorians prepared
+translations of many Greek medical works into their
+own language, Syriac.</p>
+
+<p>In the seventh century, Islam arose and soon swept
+over vast areas that had erstwhile belonged to the
+Emperor of the East. The territory occupied by the
+Nestorians in the Near East came early under Moslem
+rule. The Moslems, at first indifferent to infidel learning,
+came gradually to appreciate it. In the ninth century
+a great and united Moslem Empire was established
+with its center at Bagdad. The need for translation of
+Greek scientific works into Arabic, the common language
+<span class="pagenum" id="Page_67">67</span>of Islam, now asserted itself. One after another
+the medical writings that had been turned into Syriac
+were translated into Arabic, and Greek Science in
+general and Greek Medicine in particular were thus
+spread far and wide in the Moslem world.</p>
+
+<p>Greek science in the Arabic version came in time
+to be better understood by Arabic-speaking students
+than it had been by any since Galen. Nor were the
+Arabic-speaking peoples content to rest on the texts
+that had thus descended to them from antiquity. A
+considerable number of Arabic writers produced works
+of their own, some not wholly devoid of originality.
+Unfortunately these men were without effective anatomical
+or physiological basis for their medical knowledge,
+though many of them were acute clinical observers,
+and, even from the modern point of view, some of
+their works are not wholly contemptible. Thus Rhazes
+(860-932), a native of Basra on the Persian Gulf, wrote
+a work containing the first known description of
+Measles, which he carefully distinguishes from Small-pox.
+The Persian Avicenna (980-1036) composed a
+vast encyclopaedia of medical knowledge, the so-called
+<i>Canon</i>, which served as the main text-book of Medicine
+both among the Arabic-speaking peoples and in the
+Latin West until the seventeenth century. The Jew,
+Isaac of Kairouan (852-952), composed a treatise on
+fevers which was the best account of the subject available
+in Europe during the entire Middle Ages. The
+Moor, Albucasis (11th cent.), left a text-book of surgery
+which was an important element in the revival of the
+subject in Italy and France.</p>
+
+<p>These are only prominent members of a vast school
+<span class="pagenum" id="Page_68">68</span>of writers who flourished in Arabic-speaking countries
+between the ninth and thirteenth centuries. The bulk
+and number of their writings is portentous. Many of
+their works were translated into Latin, often by Jewish
+translators (<a href="#i069">Fig. 26</a>). These Latin translations caused
+a reawakening of the intellect of Europe, and provided
+the staple reading in the medieval universities throughout
+the Middle Ages.</p>
+
+<figure class="figcenter illowe30" id="i069">
+  <img class="w100" src="images/i069.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 26.</span> A JEWISH TRANSLATOR receiving an Arabic medica
+    volume from an Eastern potentate (right) and handing it, translated into
+    Latin, to a Western monarch (left). From a thirteenth-century manuscript.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_3_The_Medieval_Awakening">
+  § 3. <i>The Medieval Awakening.</i>
+</h3>
+
+<p>The Spanish peninsula had been inundated by the
+Islamic tide as early as the eighth century. After a
+while the waters began to recede. The speech and culture
+of Islam had become stamped upon the natives of
+the peninsula, and were only gradually replaced by the
+Latin civilization and dialect which we now call Spanish.
+During the centuries of Islamic retreat, there was thus
+a bilingual population in the peninsula, so that access
+to the Arabic learning became possible. The translations
+that were to have influence on Europe were always
+into Latin. To make or to obtain such translations
+many adventurous spirits journeyed from Christian
+Europe into Spain, or sometimes into Sicily where conditions
+were very similar. These men were aided in
+their work by native Jews or by Mohammedans. The
+heretical company which they kept, together with the
+strange and mysterious material which they brought
+back with them, earned them a reputation as magicians.
+The memory, for instance, of Michael Scot is connected
+with the Black Art, and has been presented by Sir
+Walter Scott in his poem <i>The Lay of the Last Minstrel</i>.</p>
+
+<p>The wizard Michael Scot (died 1235) journeyed in
+<span class="pagenum" id="Page_69">69</span>both Spain and Sicily, learned Arabic and Hebrew, and
+had commerce with Mohammedans and Jews. He
+turned a number of Arabic works into Latin, and, in
+particular, he prepared versions of the biological works
+of Aristotle (<a href="#Page_28">pp. 28-33</a>) which, though corrupt and
+second-hand, had much influence in determining the
+direction of medical thought during the Middle Ages.</p>
+
+<p>There was a large class of such translators and commentators
+who made Arabic Medicine accessible to the
+West. This Arabic-Latin literature is generally characterized
+by the qualities most often associated with the
+words <i>medieval</i> and <i>scholastic</i>. It is extremely verbose
+and almost wholly devoid of the literary graces. An
+immense amount of attention is paid to the mere arrangement
+of the material, which often occupies its authors
+more than the ideas that are to be conveyed.
+Great stress is laid on argument, especially in the form of
+<span class="pagenum" id="Page_70">70</span>the syllogism, while observation of Nature is entirely in
+the background. Above all, there is a constant appeal to
+the authority of the ancient masters, especially Aristotle
+and Galen. Lip service is often paid to Hippocrates,
+but his spirit is absent from these windy discussions.</p>
+
+<p>When the Latin translations from the Arabic reached
+the readers for whom they were intended, they were
+eagerly studied. The texts were, however, by no means
+permitted to remain in their pristine state, but were
+submitted to exactly the same process to which their
+Arabic authors had themselves subjected their Aristotelian
+and Galenic models. The Christian writers of
+the West treated the Latin translations of Rhazes, of
+Avicenna, of Isaac and of Albucasis (p. 67), as subjects
+for commentary. Their works were expanded,
+annotated, castigated again and again, and without any
+new inflow of ideas. The result is a progressive elaboration
+of form and deterioration of content throughout
+the centuries. Vast masses of argument, rebuttal, refutation
+and confirmation drowned again the human
+spirit which hardly recovered from its submersion until
+the sixteenth century.</p>
+
+
+<h3 id="_4_The_Universities">
+  § 4. <i>The Universities.</i>
+</h3>
+
+<p>Nevertheless, when these translations were new to
+Europe, and especially in the thirteenth century, they
+caused much stir. In this awakening a large part was
+played by the Universities. These were established in
+numbers during the thirteenth and the following centuries.
+University life gradually came to exercise a
+profound effect on social, political and intellectual
+conditions. In most of the Universities Medical
+<span class="pagenum" id="Page_71">71</span>Faculties grew up. The medical teaching was entirely
+theoretical and there was no clinical instruction, though
+at the beginning of the fourteenth century some advance
+was made by the introduction of brief and superficial
+anatomical demonstrations (p. 74).</p>
+
+<p>As a type of Medieval University, we may take
+Bologna, which was an important center of learning
+from a very early date (<a href="#i073">Fig. 27</a>). As the Universities
+multiplied, they began to some extent to ‘specialize’.
+Bologna had appeared first as a Law School and continued
+to develop along the same line. In the second half
+of the thirteenth century it was by far the most important
+seat of legal learning in Europe.</p>
+
+<p>An organized Medical Faculty existed there as far
+back as 1156. The teaching at Bologna, as in other
+medical schools, consisted entirely of readings of Latin
+translations from Arabic which were becoming ever
+more accessible. Yet it was at Bologna that public dissection
+was first practised. The early advent of dissection
+has often impressed the historian. There was still
+no botany worthy of the name, no zoology, hardly any
+naturalistic art, no experimental science, no systematic
+record of observation in any department. Yet dissection
+had become recognized at Bologna by the end of
+the first quarter of the fourteenth century. The question
+is why men, so little interested in Nature and
+Nature’s ways, should have lent themselves to so repellent
+a process as dissection of the human body? The
+answer is that the earliest reason for examining the
+human body was simply the gathering of evidence for
+legal processes. As time went on, post-mortem examination
+passed into anatomical study. But still dissection
+<span class="pagenum" id="Page_72">72</span>did no more, and was asked to do no more, than verify
+Avicenna—whom nobody doubted. It was, in fact,
+little but an aid to the memory of students.</p>
+
+<p>At Bologna we can trace the rise of a surgical school
+beginning about the end of the twelfth century.
+Prominent among its early surgeons was William of
+Saliceto (1215?-1280?). He wrote a very able treatise
+on Surgery, containing a section on Anatomy. The
+anatomical portion is borrowed from the current
+Arabian anatomies, but contains some evidence of direct
+access to the dead human body. He includes in his
+work a good description of trephining the skull (<a href="#i063">Fig. 23</a>).</p>
+
+<p>A most interesting contemporary of William of
+Saliceto was Thaddeus of Florence (1223-1303), who
+also taught at Bologna. This man perceived the importance
+of access to Greek sources, as distinct from
+Graeco-Arabic, and he encouraged the preparation of
+good Latin translations of medical works direct from
+the Greek. He stamped his personality on the whole
+development of Medicine at Bologna, and he is bound
+up with the beginning of dissection. But if Medicine
+owed a debt to Thaddeus for introducing better texts
+and better Anatomy, he did grave harm to the subject
+in another direction. The scholastic and argumentative
+form assumed by medieval Medicine is largely due to
+him, and it is to the assumption of this form that we
+owe the almost complete absence of scientific advance
+between the thirteenth and sixteenth centuries.</p>
+
+<figure class="figcenter illowe40" id="i073">
+  <img class="w100" src="images/i073.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 27.</span> MEDIEVAL BOLOGNA, from a mural painting of about 1500 in the town-hall of the city.
+    The city contained a number of towers, nearly all of which have now been destroyed.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_5_Medieval_Anatomy_Surgery_and_Internal_Medicine">
+  § 5. <i>Medieval Anatomy, Surgery and Internal Medicine.</i>
+</h3>
+
+<p>At the very end of the thirteenth century there came
+to Bologna a Norman student, Henri de Mondeville
+<span class="pagenum"><a id="Page_73"></a><a id="Page_74"></a>74</span>(about 1270-1320). In 1301 he settled at the famous
+Medical School at Montpellier in Southern France,
+and thus transplanted to France the medical, surgical
+and anatomical traditions of Bologna. Those
+traditions were of Arabic origin, and mainly borrowed
+from Avicenna.</p>
+
+<p>Contemporary with de Mondeville was one whose
+method of teaching shines as a good deed in a naughty
+world. Mondino di Luzzi (<i>c.</i> 1270-1326) was a pupil
+of Thaddeus and a fellow-student of Henri de Mondeville.
+He worked systematically at Anatomy and dissected
+the human body in public. His treatise on
+Anatomy, written in 1316, is the first modern work
+on the subject. Those who preceded him incorporated
+their anatomical work in larger treatises on Surgery,
+and do not refer directly to their own anatomical experiences.
+With Mondino this is changed. His work
+is essentially a practical manual of the subject and he is
+with justice called the ‘Restorer of Anatomy’. He had
+read widely among the Arabian anatomists, and naturally
+borrowed from them. Nevertheless, his work contains
+a considerable number of references to actual
+anatomical procedure. Moreover, he deals not only
+with Anatomy in our modern sense, but also includes
+Physiology and much discussion of the application of
+anatomical and physiological principles to Medicine
+<span class="pagenum"><a id="Page_75"></a><a id="Page_76"></a>76</span>and Surgery. His book thus gives a good deal of insight
+into the scientific knowledge of the day.</p>
+
+<figure class="figcenter illowe30" id="i075">
+  <img class="w100" src="images/i075.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 28.</span> AN ANATOMICAL LECTURE AT PADUA in the fifteenth
+    century, from a contemporary Italian woodcut.</p>
+    <p>The professor stands in his ‘chair’, a great pulpit or ‘cathedra’, reading
+    from his book—hence the English academic titles ‘Reader’ and ‘Lecturer’
+    or ‘Lector’ (that is, ‘one who reads’). The body is dissected by a menial,
+    whose work is guided by an assistant, who, with wand, points out (Latin
+    <i>demonstrat</i>, hence our modern title <i>Demonstrator</i>) the lines of incision.
+    Students in academic dress stand around, but do not themselves dissect.</p>
+  </figcaption>
+</figure>
+
+<p>We would emphasize the fact that Mondino dissected
+<i>in person</i>. In this respect he was wiser than his
+successors until the time of Vesalius. As dissection
+gained formal inclusion in the curriculum, the professor
+became more haughty, further removed from the object
+of his study. Leaving his position by the body, where
+he might demonstrate to his students, he ascended his
+high professorial chair, a great elevated structure provided
+with steps and a reading-desk. From there he
+read from his text-book while a junior colleague pointed
+out the line of incision and a menial performed the actual
+dissection (<a href="#i075">Fig. 28</a>). All was thus done at third-hand
+and according to the written word. We are in the
+scholastic period, and must not expect any frequent appeal
+to Nature. Having once got into his chair, it took
+a good deal to persuade the professor to descend from
+that dignified position. Thus, it is saying much for
+Mondino that he was his own demonstrator. He took
+the first and perhaps the greatest step. It was two
+centuries and more before the next step was taken.</p>
+
+<p>Most typical of medieval surgeons was Guy de
+Chauliac (1300-68), who studied at Montpellier, Paris,
+and Bologna, and practised at Montpellier and afterwards
+at Avignon, where he was a member of the
+Papal Court. He was a man of much learning, and
+his <i>Great Surgery</i> became the standard treatise on the
+subject during the later Middle Ages. It fixed medieval
+practice. It is to be found in scores of manuscripts and
+was frequently translated and printed. Among the
+good points of his practice is his acceptance of responsibility
+<span class="pagenum" id="Page_77">77</span>for certain operations, such as those for rupture
+and for cataract, which at that time were usually left
+to wandering charlatans who regarded themselves as
+specialists. A famous passage in his work describes
+the use of a narcotic inhalation frequently used during
+the Middle Ages and into modern times. Of such a
+narcotic it is written that:</p>
+
+<div class="poetry-container">
+  <div class="poetry">
+    <div class="stanza">
+      <div class="verse indent0">I’ll imitate the pities of old surgeons</div>
+      <div class="verse indent0">To this lost limb, who, ere they show their art,</div>
+      <div class="verse indent0">Cast one asleep, then cut the diseased part.</div>
+   </div>
+<div class="attrib">(Thomas Middleton, <i>Women beware women</i>. First acted 1622.)</div>
+  </div>
+</div>
+
+<p>The general character of Internal Medicine during the
+later Middle Ages was below that of Surgery. Modern
+clinical Medicine is firmly based on such sciences as
+Physiology, Pharmacology, Pathology, Biochemistry
+and Epidemiology. In the Middle Ages and far
+beyond, Physiology was still that of Galen, which had
+lost in exactness what it had gained in bulk from the
+Arabic and Latin commentators. Pathology was still
+that of the four humors. The knowledge of drugs
+was empirical, and the sciences of Pharmacology and
+Biochemistry as yet were not; while the medieval conception
+of the nature of epidemics was the very perversion
+of reason and common sense. Nevertheless, as
+we shall see, the Middle Ages ultimately succeeded in
+instituting a limited number of effective preventive
+measures.</p>
+
+
+<h3 id="_6_Medieval_Hospitals_and_Hygiene">
+  § 6. <i>Medieval Hospitals and Hygiene.</i>
+</h3>
+
+<p>Undoubtedly an important development of medieval
+Medicine is its hospital system. The public hospital
+arose in pagan antiquity out of the Temples of Aesculapius
+<span class="pagenum" id="Page_78">78</span>and the military valetudinaria (p. 49). The conception
+was seized on by Christianity and developed
+beyond all knowledge. In the early Christian centuries,
+<i>hospitalia</i>, ‘guest chambers’ or ‘guest houses’, were set
+aside for the numerous <i>hospites</i>, or ‘pilgrims’. Similar
+buildings under the same title came to be instituted
+for the care of orphans, the aged, the blind, and other
+victims of fortune. Thus arose the medieval hospital
+system, of which ours is the direct outgrowth.</p>
+
+<p>In matters of Hygiene the Middle Ages are a byword.
+The health conditions of a medieval town were
+far below those of the same town under the Roman
+Empire. Water-supply was deficient, drains were
+absent, streets and houses filthy and overcrowded,
+rooms unventilated. Nevertheless, there is one important
+hygienic conception for which our own age
+owes a considerable debt to that which preceded it.
+Despite their scientific acumen in many departments,
+it is yet true to say that among the physicians of classical
+antiquity we find no consistent view of the transmission
+of infection by contact. Indeed the whole idea of infection
+was effectively absent from them, so that preventive
+measures based upon it could not be developed.
+It was reserved for the Middle Ages to conceive serious
+official measures against the spread of epidemics.
+These measures were consciously derived from the leper
+ritual of the Bible with its fundamental concept of
+isolation.</p>
+
+<figure class="figcenter illowe30" id="i079">
+  <img class="w100" src="images/i079.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 29.</span> A HOSPITAL WARD in sixteenth century Paris.
+    In the left aisle, a nun folds the hands of a dying patient, while a
+    priest gives the Sacrament to another in the same bed. In front,
+    nuns sew shrouds. The right aisle is more cheerful. Nuns minister
+    to two patients in one bed, while a convalescent, fortunate
+    in having a bed to himself, vigorously takes nourishment. In
+    the centre nuns receive postulants and a royal founder kneels in
+    prayer.</p>
+  </figcaption>
+</figure>
+
+<p>During the early centuries of the Christian era,
+Leprosy, which had till then been confined to the East,
+crept along the Mediterranean littoral and thence northward
+throughout Europe. The disease was from the
+<span class="pagenum" id="Page_79">79</span>first regarded as contagious, and various regulations
+were introduced to isolate and separate the unfortunate
+sufferers. The medieval treatment of lepers is one of
+the dark incidents of man’s inhumanity to man. The
+leper was banished from human society. He was
+declared legally dead. He was excluded even from
+church or allowed to attend only in special seats where
+a special basin of holy water was assigned to him. How
+rigorously this segregation from the ranks of free
+people was carried out by law is well known. The cruel
+edicts were, however, effective. In the course of centuries
+<span class="pagenum" id="Page_80">80</span>it freed Europe from Leprosy, of which it is
+said there were at one time some 20,000 cases in
+France alone. Thus about one person in 200 would
+have been a leper, and the burden of the leper on the
+community was comparable to that, let us say, of the
+feeble-minded and insane with us.</p>
+
+<p>Leper inspection, the regular examination of all suspects
+and carriers of leprosy, became a most elaborate
+business. It was entrusted to a special branch of the
+civil service and was gradually freed from ecclesiastical
+control.</p>
+
+<p>This preventive method of combating a chronic
+disease, which, as we know now, has a very low infectivity,
+had a peculiar and unlooked-for result. The
+meticulous system of warding off the contagion of
+leprosy so occupied the attention of physicians that
+they came to see allied conditions in the same light. So
+it was that in the thirteenth century the general concept
+became current of disease as contagious. A number
+of other diseases besides leprosy were recognized
+as infectious. Among these were Plague, fevers with
+obvious rashes, Phthisis, Granular Conjunctivitis, the
+Itch and Erysipelas. Municipal authorities were from
+time to time ordered to put patients suffering from one
+or other such diseases outside the city gates. They
+were forbidden to traffic in articles of food and drink
+and were placed under restrictions not unlike those of
+lepers. The devastating epidemic of the Black Death
+of 1347-8 brought restrictions of this order into special
+force. Thus the Black Death had somewhat the same
+effect on the health administration of the day that the
+Cholera outbreaks of the thirties of the nineteenth century
+<span class="pagenum" id="Page_81">81</span>had upon modern Europe. The health service
+began to be put into more efficient order.</p>
+
+<p>In the later Middle Ages there were actually instances
+in which the Pest was averted or successfully
+combated by these means. This seems to have been
+the case of Milan and Venice between the years 1370
+and 1374. At that time the Plague was again advancing
+through Europe. The most drastic regulations were
+invoked to prevent infected persons from entering the
+cities, and these regulations came into force well in
+advance of the disease.</p>
+
+<p>There is one incident in this medieval attempt to
+prevent Plague that has left a mark on our language.
+The Republic of Ragusa, on the eastern side of the
+Adriatic, adopted and extended the regulations that had
+been so successful at Venice. A landing-station was
+established far from the city and the harbor. There
+incoming suspects had to spend thirty days in the open
+air and sunlight, and any who had traffic with them
+were isolated. The period of thirty days was spoken
+of as the <i>Trentina</i>. Later this was found to be not long
+enough. The thirty days became forty days, the <i>Quarantina</i>,
+whence we have the word <i>Quarantine</i>. The
+system of quarantine gradually spread through Europe.
+It was accompanied by very drastic destruction, by
+burning, of all goods belonging to the infected.</p>
+
+<p>These attempts to arrest epidemic disease were
+sometimes successful and the elaboration of quarantine
+measures was among the few advances with which we
+may credit the Middle Ages. The fact that we can now
+dispense with quarantine must not blind us to its value
+in conditions other than our own.</p>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_82">82</span></p>
+
+
+  <h2 class="nobreak" id="IV">
+    IV
+    <br>
+    THE REBIRTH OF SCIENCE
+    <br>
+    <span class="sm">(FROM ABOUT 1500 TO ABOUT 1700)</span>
+  </h2>
+</div>
+
+
+<h3 id="1_anatomical_awakening">§ 1. <i>The Anatomical Awakening.</i></h3>
+
+<p>During the Middle Ages beliefs about physiology
+were always based on Galen. They were frequently
+confused and often the result of a misunderstanding of
+his work. In the fifteenth century, however, took place
+the so-called <i>Renaissance</i> or <i>Revival of Learning</i>.
+Greek works which had been trickling in since the
+thirteenth century began to be recovered more rapidly,
+and to be more accurately studied. The first step towards
+any improvement on the views of Galen was
+naturally a proper understanding of what he had really
+said. For that there was needed a better knowledge of
+Greek than had been possessed by the Middle Ages.
+In the fifteenth century Greek scholarship made great
+advances and there was enthusiasm for classical learning.
+Accurate translations of the Greek works of Galen
+were made. The printing press was invented about
+the middle of the fifteenth century. Towards its end
+printed copies of the improved translations began to
+appear. So it came about that the Revival of Learning
+produced a revival of the ancient scientific knowledge.</p>
+
+<p>This scientific revival led to a new interest in Anatomy.
+During the Middle Ages the occasional dissections
+at the Universities were merely supposed
+to illustrate Avicenna and Galen (<a href="#i075">Fig. 28</a> and <a href="#Page_72">p. 72</a>).
+Dissection became much more widely practised in
+the fifteenth century, but it was nearly the middle of the
+<span class="pagenum" id="Page_83">83</span>sixteenth century before any real and open discussion
+of Galen’s views took place in the Universities.</p>
+
+<p>There were, moreover, other influences at work.
+Along with the revival of learning there was also a
+renaissance of art. Some of the great Renaissance artists—Michelangelo,
+Raphael and Dürer among them—began
+to study the human form very closely. They
+soon found that to represent it accurately some knowledge
+of Anatomy, and especially of the bones and
+muscles, was needed. The artists, therefore, began also
+to dissect. Among these great artists were some who
+took more than a purely artistic interest in the structure
+and workings of the body. Of these the most important
+for us was Leonardo da Vinci (1452-1518). He was
+a man of enormously powerful and inquiring mind,
+and his achievements in science are at least as remarkable
+as his works of art. He had determined to write
+a text-book of anatomy and physiology. Though he did
+not publish it, many of his beautifully illustrated note-books
+on these subjects have survived.</p>
+
+<p>Leonardo was the first to question the views of
+Galen. He made careful first-hand investigations on
+the bodies of men and animals, and performed many
+physiological experiments. Though a man of the most
+lofty genius, centuries ahead of his time, yet his outlook
+is, in many respects, typical of his age. His interest
+in anatomical investigation is therefore not surprising,
+for such inquiries were then astir. It happened that he
+was particularly interested in the heart and blood-vessels.
+He reached the correct conclusion that, contrary
+to Galen, the branches of the air-tubes in the lungs
+do not come into relation with the heart, but, after
+<span class="pagenum" id="Page_84">84</span>branching and gradually diminishing in size, they finally
+end <i>blindly</i>. He inflated the lungs with air and found
+that, whatever the force used, air could not be driven
+from the air-tubes into the heart. He therefore inferred
+quite correctly that Galen’s <i>arteria venalis</i> (our ‘pulmonary
+vein’) did not convey air to the heart, as the followers
+of Galen believed.</p>
+
+<p>Leonardo then turned to examine the structure and
+form of the heart itself. He prepared more accurate
+drawings of it than had been made by any before him,
+making sections and dissections and examining its
+valves (<a href="#i085">Fig. 30</a>). Ultimately he succeeded in grasping
+the nature and action of the valves at the root of the
+great arteries as they arise from the heart, and he verified
+his view by remarkable experiments. He proved
+that the valves allowed the blood to pass in only one direction,
+and prevented its regurgitation. Yet Leonardo
+gives no complete or clear description of the action of the
+heart. He could not emancipate himself from the old
+idea of the passage of the blood from the right ventricle
+through the septum into the left ventricle (<a href="#i059">Fig. 21</a>),
+though he sometimes seems doubtful about it.</p>
+
+<figure class="figcenter illowe30" id="i085">
+  <img class="w100" src="images/i085.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 30.</span> DRAWING OF DISSECTION OF THE HEART by
+    Leonardo da Vinci. The modern names of some of the more important
+    parts have been added.</p>
+  </figcaption>
+</figure>
+
+<p>It must be remembered that Leonardo did not publish
+his researches. It is only recently that his note-books
+have become fully accessible. But although Leonardo’s
+work remained in manuscript, it must not be assumed
+that his views were wholly without effect on his contemporaries.
+At any rate, soon after his time the questions
+that he had raised concerning the heart and
+blood-vessels were attracting others and were generally
+regarded as forming an important problem needing
+solution.</p>
+
+<p><span class="pagenum" id="Page_85">85</span></p>
+
+<p>The task of writing an anatomical text-book based
+on direct observation, to which Leonardo did but put
+his hand, was achieved by one who was only four years
+old at the time when the great artist died. The central
+place in the unfolding drama is occupied by Andreas
+Vesalius of Brussels (1514-64). This extraordinary
+man studied first at the University of Louvain and
+afterwards at Paris. Anatomical instruction at these
+Universities had not improved much, if at all, on that
+of the Middle Ages. Vesalius soon tired of hearing
+long passages of Galen read out by the professor. He
+<span class="pagenum" id="Page_86">86</span>therefore resolved to go to northern Italy, where newer
+methods were being practised. Padua was the place
+of his choice. He immediately made his mark there,
+and was himself appointed professor when only twenty-four
+years of age. He established a scientific tradition
+at Padua which that University has retained to this day.</p>
+
+<p>No sooner was Vesalius settled at Padua than he
+applied himself with unparalleled diligence to lecturing
+and research. Students crowded to hear him (<a href="#i087">Fig. 31</a>).
+To aid them he issued, in 1538, a short guide to anatomy
+and physiology. An examination of this shows
+that his physiological views were still those of Galen
+and Aristotle. After its issue Vesalius found that
+Galen and Aristotle were by no means always to be
+trusted. The realization of this led him constantly to
+doubt any statement by them. His scepticism was
+sometimes excessive, but it led him to put every statement
+made by his predecessors to the test of experience.
+This gives his later work an epoch-making value.</p>
+
+<figure class="figcenter illowe30" id="i087">
+  <img class="w100" src="images/i087.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 31.</span> TITLE-PAGE of the work <i>On the Fabric of the Human Body</i>,
+    by Vesalius, published in 1543.</p>
+    <p>It shows a dissection scene at Padua. In the center stands Vesalius dissecting
+    a female body. At the head of the table stands an articulated skeleton.
+    At its foot are dissecting instruments. Eager students throng around. In the
+    foreground attendants are squabbling. On one side an attendant holds a monkey,
+    one on the other a dog, for Vesalius had often to resort to animal in lieu
+    of human anatomy. Shut off by a bar are members of the lay public. Gallants,
+    grey-bearded scholars, monks, and an enthusiastic bookworm may be
+    discerned among them. Other observers crowd in from every vantage point,
+    even from the windows in the roof. The naked man to the left has been
+    used by Vesalius to demonstrate the surface markings of the underlying
+    organs. The whole scene is busy and vigorous in the extreme. It should
+    be contrasted with the academic calm of <a href="#i075">Fig. 28</a> drawn fifty years earlier.</p>
+  </figcaption>
+</figure>
+
+<p>During the next four years Vesalius had ampler
+opportunities to dissect than he had yet encountered.
+He devoted a fiery energy to the preparation of his
+<span class="pagenum"><a id="Page_87"></a><a id="Page_88"></a>88</span>great work. <i>The Fabric</i> (that is ‘workings’, compare
+German ‘Fabrik’) <i>of the Human Body</i> was printed in
+1543, a magnificent and beautifully illustrated volume.
+It is a landmark in the History of Science, and a wonderfully
+full record of a prodigious number of accurately
+recorded discoveries and investigations made by a single
+observer.</p>
+
+<p>The masterpiece of Vesalius is not only the foundation
+of modern Medicine as a science, but the first
+great positive achievement of Science itself in modern
+times. As such it ranks with another work that appeared
+in the same year, the treatise of Nicholas Copernicus,
+<i>On the Revolutions of the Celestial Spheres</i>. The
+work of Copernicus removed the Earth from the center
+of the Universe; that of Vesalius revealed the real
+structure of man’s body. Between the two they destroyed
+for ever the medieval theories on the subjects
+of which they treat. But the work of Copernicus is
+one of close and subtle reasoning, still retaining many
+medieval elements, and is hardly a great exposition of
+what we now call the ‘Experimental Method’. The
+work of Vesalius far more nearly resembles a modern
+scientific monograph than does the treatise of Copernicus.</p>
+
+<p>The achievement of Vesalius was very well received
+by the scientific world. Nevertheless, soon after its
+publication, Vesalius resigned his professorship to take
+up the position of a court physician to the Emperor
+Charles V, the great monarch of the age. He was then
+only twenty-nine years old, but his scientific career was
+closed.</p>
+
+<p>The edition of the <i>Fabric</i> was soon exhausted, and
+<span class="pagenum" id="Page_89">89</span>the demand for more copies was met by imitations of
+the work by other hands. At last, in 1555, Vesalius
+was induced to issue a second edition. This contains
+certain changes in point of view that are important
+for the subsequent development of physiology. Vesalius
+now no longer merely hints his doubts as to the
+character of Galen’s physiology; he openly asserts that
+he is unable to verify its fundamental bases.</p>
+
+<p>We may take a single instance of this new outspokenness.
+In his description of the septum of the
+heart, he had written in the first edition:</p>
+
+<blockquote>
+<p>‘The septum of the ventricles of the heart is very dense. It
+abounds with pits on both sides. Of these pits none, so far as the
+senses can perceive, penetrate from the right to the left ventricle.
+We are thus forced to wonder at the art of the Creator, by which
+the blood passes from right to left ventricle through pores which
+elude the sight.’ (Compare <a href="#i059">Fig. 21</a>, p. 59.)</p>
+</blockquote>
+
+<p>This passage is altered to something quite different in
+the second edition, where he writes:</p>
+
+<blockquote>
+<p>‘Although sometimes these pits are conspicuous, yet none, so
+far as the senses can perceive, passes from the right to the left
+ventricle. I have not come across even the most hidden channels
+by which the septum of the ventricles is pierced. Yet such channels
+are described by teachers of Anatomy, who have absolutely
+decided that the blood is taken from the right to the left ventricle.
+I, however, am in great doubt as to the action of the heart in this
+part.’</p>
+</blockquote>
+
+<p>He further sets forth his whole policy with reference
+to Galen’s view in the following interesting passage:</p>
+
+<blockquote>
+<p>‘In considering the structure of the heart and the use of its
+parts, I bring my words for the most part into agreement with
+the teachings of Galen; not because I think these on every point
+in harmony with the truth, but because, in referring at times to
+<span class="pagenum" id="Page_90">90</span>new uses and purposes for the parts, I still distrust myself. Not
+long ago I would not have dared to diverge a hair’s breadth from
+Galen’s opinion. But the septum is as thick, dense and compact
+as the rest of the heart. I do not, therefore, see how even the
+smallest particle can be transferred from the right to the left
+ventricle through it. When these and other facts are considered,
+many doubtful matters arise concerning the blood-vessels.’</p>
+</blockquote>
+
+<p>The work terminates with a little chapter <i>On the
+dissection of living animals</i>. We note that this, while
+dealing skilfully with the methods of physiological
+experiment, does not exhibit any very marked advance
+on the views of Galen.</p>
+
+<p>Among the experiments on living animals that Vesalius
+enumerates are excision of the spleen, the loss of
+which he showed was consistent with life; and the cutting
+of the nerves that supply the organ of voice, with
+resultant loss of that faculty. He demonstrated that
+longitudinal section of a muscle interferes little with its
+function, but cross section produces disability in proportion
+to the injury. Such experiments had been performed
+by Galen, who had also reached the same conclusion
+as Vesalius, that it is through the spinal cord that
+the brain acts on the various muscles of the limbs and
+trunk. Vesalius repeated Galen’s experiments on section
+of the spinal cord (p. 58). The most striking of his
+<span class="pagenum"><a id="Page_91"></a><a id="Page_92"></a>92</span>experiments were those on respiration. Here he showed
+that, even though the chest-wall be pierced, the animal
+may be kept alive if the lungs are continuously aerated
+by means of a bellows, and that a flagging heart may be
+revived by similar means.</p>
+
+<p>The work of Vesalius at once placed the knowledge
+of the human body in a new position. It cannot be said
+that he completed the task of describing the naked-eye
+structure of the human body. Yet he went so far towards
+this that no dramatic improvement has since
+been made upon his methods. It is a fair statement that
+the whole of modern Descriptive Anatomy may be
+treated as a comment and correction and amplification
+of Vesalius. His work moreover stimulated a host of
+investigators.</p>
+
+<figure class="figcenter illowe30" id="i091">
+  <img class="w100" src="images/i091.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 32.</span> SKELETON from the anatomical work of
+    Vesalius, 1543.</p>
+    <p>It is beautifully and dramatically posed, and the drawing is remarkably
+    accurate. The figure leans against a tomb, contemplating a skull. In the
+    front left-hand corner of the top of the tomb is a part of the bony structure
+    which supports the organ of voice (<span class="allsmcap">H</span>).</p>
+    <p>The inscription on the tomb may be translated ‘Man’s spirit lives. The
+    rest is Death’s portion’.</p>
+    <p>The inscription at the top may be translated: ‘A delineation from the
+    side of the bones of the human body, freed from the other structures which
+    they support and placed in their correct positions.’</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_2_The_Anatomical_Reaction_on_Surgery">
+  § 2. <i>The Anatomical Reaction on Surgery.</i>
+</h3>
+
+<p>The immediate effect of the new knowledge of
+Anatomy was an improvement in Surgery. The Wars
+of Religion of the sixteenth and seventeenth centuries
+were fierce and prolonged, and the army surgeons of
+the time had much experience of the treatment of
+wounds. The most prominent of the military practitioners
+was the Frenchman, Ambroise Paré (1517-90).
+He perceived the importance of anatomical knowledge
+and adapted his discoveries to the needs of Surgery.
+Paré did much to elevate the surgeon’s profession from
+a despised handicraft to a position equal to that of other
+branches of the healing art.</p>
+
+<p>Apart from the introduction of anatomical discipline
+into Surgery, Paré’s four contributions to the surgical
+art were, firstly, his discovery that gunshot wounds are
+<span class="pagenum" id="Page_93">93</span>not ‘poisonous’ as had theretofore been thought, and
+that therefore they do not require the application of
+boiling oil, but are best healed by soothing applications;
+secondly, the cognate doctrine that bleeding
+after amputations should be arrested, not by the terrible
+method of indiscriminate use of the red-hot cautery,
+but by simple ligature; thirdly, his advocacy of the
+method of turning the child in its mother’s womb
+before delivery in certain abnormal cases; and fourthly,
+his ingenious devising of artificial limbs (<a href="#i093">Fig. 33</a>).
+None of these four was without precedent. Nevertheless,
+the eminence, skill, and wide experience of Paré
+<span class="pagenum" id="Page_94">94</span>were the main factor in the spread of these practices.
+But the greatest of all Paré’s contributions to surgery
+was the service of his own personality, the example of his
+steadfast efforts to increase his knowledge of human
+anatomy and his skill in the art, and his constant
+emphasis on the surgeon’s duty to exert his utmost
+efforts to avoid or relieve the patient’s suffering.</p>
+
+<figure class="figcenter illowe30" id="i093">
+  <img class="w100" src="images/i093.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 33.</span> ARTIFICIAL ARMS AND HANDS, designed and figured
+    by Ambroise Paré, and used by him for wounded soldiers from about 1560
+    onwards.</p>
+  </figcaption>
+</figure>
+
+<p>In a famous passage Paré describes how he, a ‘freshwater
+soldier’, on his first campaign, watched the other
+surgeons following the old rule of treating all gunshot
+wounds with boiling oil. At first he formed his practice
+on theirs. The theory was that gunshot wounds contained
+a poison, which the boiling oil was believed to
+drive out. Paré tells of his agitation when one evening,
+his supplies having run out, men had to be treated without
+the boiling oil. Next morning he was astonished
+to find that every man whose wounds had been treated
+only with a salve had rested fairly comfortably, while all
+who had undergone the customary treatment were, as
+we may well believe, in great pain. ‘Then I resolved
+within myself never so cruelly to burn poor wounded
+men.’ Another saying of the shrewd old surgeon is
+the famous adage ‘I dressed him and God cured him.’</p>
+
+<p>Paré’s works were frequently reprinted and translated
+into various European languages, including
+English. They exercised the widest influence on surgical
+craft in the sixteenth and seventeenth centuries.
+Like Vesalius, he is an example and type of a large
+class. In every country surgeons arose who made an
+effort to utilize the new anatomical knowledge.</p>
+
+<p><span class="pagenum" id="Page_95">95</span></p>
+
+
+<h3 id="_3_The_Renaissance_of_Internal_Medicine">
+  § 3. <i>The Renaissance of Internal Medicine.</i>
+</h3>
+
+<p>Internal Medicine lagged behind Surgery at this
+period. The anatomical reforms of Vesalius were unaccompanied
+by any commensurate advance in physiological
+knowledge, and without a scientific Physiology
+there can be no science of Internal Medicine. The
+practice of the physicians thus remained in effect that
+of the Middle Ages. The ruling idea was still that of
+the ‘four humors’ corresponding to the four ‘temperaments’
+(<a href="#i034">Fig. 13</a>, p. 34, and compare <a href="#i097">Fig. 34</a>, p. 97).</p>
+
+<p>There are, however, three respects in which we see
+an improvement of the physician’s art during the sixteenth
+and first half of the seventeenth century.</p>
+
+<p>Firstly, there was some improvement in the medical
+texts that were habitually read. More reliable translations
+were now available. Notably the great Hippocratic
+works became more widely disseminated. They
+formed a substitute for the old texts translated or mistranslated
+from the Arabic.</p>
+
+<p>Secondly, the extension of geographical knowledge
+and the formation of settlements and colonies brought
+new drugs upon the market. These were often a mixed
+blessing, for some of the drugs were useless and others
+dangerous. Nevertheless, to this process Medicine owes
+several important contributions, among them Ipecacuanha,
+Cinchona (p. 326), and, by no means least,
+Tobacco (<a href="#i099">Fig. 35</a>). Apart from the amenities introduced
+by Tobacco, it was for long of great value as a
+narcotic drug. Moreover, there was a corresponding
+advance in Botany. The movement was cursed with
+the ‘practical’ spirit, and only those plants thought to
+<span class="pagenum" id="Page_96">96</span>have an application as drugs were exactly figured and
+described. Nevertheless, the beautifully illustrated
+herbals of the sixteenth and seventeenth centuries
+exercised, by the care and accuracy of their execution,
+an exemplary influence on the development of Biological
+Science in general and of Medical Science in
+particular.</p>
+
+<p>Thirdly, there was some advance in the knowledge
+of the natural history of infectious disease. A rational
+theory of the nature of infection was placed before the
+public as early as 1546 by the Veronese physician,
+Girolamo Fracastoro (1483-1553). He regarded infection
+as due to the passage of minute bodies from the
+infector to the infected. These hypothetical minute
+bodies had the power of self-multiplication. The conception
+bore a superficial resemblance to the modern
+germ theory of disease. An important contribution to
+the conception of epidemics was also made by the
+French physician Guillaume de Baillou (1538-1616),
+who reintroduced the old Hippocratic idea of ‘Epidemic
+Constitution’, i.e. that particular seasons and
+particular years are of their nature subject to particular
+diseases. The idea was extended and developed by the
+English physician Thomas Sydenham (1624-89), and
+it still has its value.</p>
+
+<figure class="figcenter illowe30" id="i097">
+  <img class="w100" src="images/i097.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 34.</span> FIGURE ILLUSTRATING THE ‘FOUR TEMPERAMENTS’,
+    from the Guild Book of the Barber-Surgeons of York, now in
+    the British Museum. The figure was prepared about 1500. Above, to the left,
+    is the <i>Melancholy</i> man, and to the right the <i>Sanguine</i>. Below to the left is
+    the <i>Choleric</i> man, and to the right the <i>Phlegmatic</i>. On the scroll work is
+    written in English ‘Ther ar the iiij umors, thath ar oderwysse calde the iiij
+    complecconis thath ar resceuid un to the iiij elementis, Hafyng the kynd of
+    humors’, which may be rendered ‘There are the 4 humors, that are otherwise
+    called the 4 complexions, that are received unto the 4 elements, having
+    the nature of humors’. For the theory compare <a href="#i034">Fig. 13</a>, p. 34.</p>
+  </figcaption>
+</figure>
+
+<p>In connection with their epidemiological work these
+three men, Fracastoro, de Baillou, and Sydenham, made
+significant additions to the knowledge of particular
+infectious conditions. Thus, during the sixteenth and
+seventeenth centuries there arose an exact body of
+teaching concerning acute infectious diseases which was
+the necessary prelude to the introduction of more effective
+<span class="pagenum"><a id="Page_97"></a><a id="Page_98"></a>98</span>preventive measures at a later date. To one infectious
+disease we may refer more particularly.</p>
+
+<p>During the Middle Ages there had smouldered in
+various districts an obscure disease, sometimes more or
+less dimly distinguished under various specific names,
+but most frequently confused with Leprosy. Towards
+the end of the fifteenth century this disease, which was
+still imperfectly distinguished in men’s minds from
+Leprosy, broke out in epidemic and virulent form all
+over Europe. It caused great destruction of life and
+developed everywhere as a problem of national importance.
+Various titles were given it, such as ‘pox,’
+‘the French disease’, ‘the Spanish disorder’. Only
+tardily was it recognized that the disease was usually of
+venereal origin. Not till 1530, on the suggestion of
+Fracastoro, did it receive its modern cognomen <i>Syphilis</i>.
+From the time of its recognition, Syphilis has been
+pursued by a portentous mass of literature, the mere
+sifting and verification of which is a formidable task.
+Alarm, misunderstanding, religious feeling, false modesty,
+wilful misrepresentation, and change in type
+of the disease itself have all contributed their quota of
+obscurantism and fable to a naturally difficult subject
+(Figs. <a href="#i099">35</a> and <a href="#i101">36</a>). Fracastoro did something to bring
+order out of the confusion. To him also we owe the first
+good scientific descriptions of several other destructive
+diseases, among which Typhus fever, now known to be
+conveyed by lice (p. 258), takes a prominent place.</p>
+
+<figure class="figcenter illowe30" id="i099">
+  <img class="w100" src="images/i099.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 35.</span> THE EARLIEST PICTURE showing the use of Tobacco.
+    From a work on Brazil, printed in Paris in 1558. In the center of a native
+    hut stands an Indian suffering from Syphilis. Behind him, on the left, a
+    man smokes a huge cigar over him as a curative measure. Right and
+    left his arms are held by two figures who seek to suck the poison out of him.
+    Another offers him a curative plant. Behind him is a ‘hammock’—the word
+    is of American-Indian origin and means ‘tobacco-bed’. Above his head
+    are a monkey, a parrot, and a bale of tobacco.</p>
+  </figcaption>
+</figure>
+
+<p>De Baillou (1538-1616) first described Whooping
+Cough, and was the first to use the word <i>Rheumatism</i>
+in the modern sense. He was moreover the first, since
+Hippocrates, to distinguish between Rheumatism and
+<span class="pagenum" id="Page_99">99</span>Gout. De Baillou’s works deeply influenced Sydenham,
+who held very similar epidemiological views, and uses a
+somewhat similar vocabulary (p. 100).</p>
+
+<p>We have seen how the knowledge of Anatomy forwarded
+Surgery, while, with the lag in Physiology,
+Internal Medicine remained in a backward state. It is
+well to recall however that a knowledge of Anatomy
+and Physiology will not, of themselves, make a man a
+<span class="pagenum" id="Page_100">100</span>scientific physician. The object which presents itself
+to a physician is neither a living anatomy nor a physiological
+model. It is a sick and suffering patient. The
+physician’s first task is to examine exactly the phenomena
+of sickness and suffering, and in doing this the
+first demand on his knowledge will be the history and
+fate of others who have endured like sickness and
+suffering. When he has ranged these instances in his
+mind he may turn, for explanation and relief, to the
+resources suggested by other sciences, Anatomy and
+Physiology among them. But all the Anatomy and
+Physiology in the world will not aid the practitioner
+who is unacquainted with the natural history of disease.
+This is the truth that was firmly seized by Thomas
+Sydenham.</p>
+
+<p>The Natural History of Disease was a subject which
+Sydenham pursued with lifelong devotion. Before
+his time the phenomena of disease had been classified,
+subdivided, discussed, and treated with all the
+subtlety and skill of scholastic thought. Men had now
+and again shaken themselves free from the shackles of
+the medieval system, and had here and there corrected
+the views of Galen or amplified the limited achievements
+of their predecessors. Yet none before Sydenham
+had set himself to consider all the actual cases of
+disease that lay before him as a subject of scientific
+description and analysis. That was the great achievement
+of the ‘English Hippocrates’. We should not find
+it easy to point to any important discovery to associate
+with his name. But he did more than discover. He
+initiated a new mode of approach. He was the founder
+of modern Clinical Medicine.</p>
+
+<p><span class="pagenum" id="Page_101">101</span></p>
+
+<p>In 1666 Thomas Sydenham published his classic work,
+<i>The Method of Treating Fevers</i>, dedicated to his friend
+Robert Boyle, ‘the Father of Chemistry’ (<a href="#Page_124">pp. 124-6</a>).
+The book opens with the almost Hippocratic phrase
+‘A disease, in my opinion, how prejudicial soever its
+cause may be to the body, is no more than a vigorous
+effort of Nature to throw off the morbific matter, and
+thus recover the patient’. We have here the <i>healing
+<span class="pagenum" id="Page_102">102</span>power of Nature</i> of Hippocrates (p. 21), which had
+been obscured and overlaid in the twenty centuries
+which lay between the two great physicians. The works
+of Sydenham may reasonably be regarded as the first
+great commentary on the Hippocratic theme. Sydenham
+set well on its way the conception of infectious
+conditions as specific entities, a conception which has
+since been illuminated by the germ theory of disease
+(p. 224 ff.).</p>
+
+<figure class="figcenter illowe30" id="i101">
+  <img class="w100" src="images/i101.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 36.</span> Allegorical picture illustrating the venereal plague Syphilis.</p>
+    <p>From a work printed in Germany in 1496. The Virgin sits enthroned
+    on clouds, crowning a crusader, who kneels at her right hand. The Holy
+    Child on her knee sends forth the plague of Syphilis as a scourge on mankind.
+    Two women, spotted with the rash of the disease, kneel in supplication
+    before her on her left. In the foreground of the picture lies a corpse dead
+    of the disease, the speckled ravages of which may be seen upon it.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_4_The_First_Physical_Synthesis">
+  § 4. <i>The First Physical Synthesis.</i>
+</h3>
+
+<p>Manifestations of the Human Spirit are not accustomed
+to confine themselves exactly within the convenient
+limits of the centuries. Nevertheless, it happens
+that in the History of Science the year 1600 does, in
+fact, correspond to something of the character of a real
+change in the current attitude to Nature. That year
+really ushers in the era of physical experiment. The
+last of the great transitional thinkers who mark the
+waning of Renaissance philosophy was Giordano
+Bruno, the martyr of science.</p>
+
+<p>Giordano Bruno (1548-1600), who was no practical
+scientist, had eagerly incorporated into his often fantastic
+philosophy the ill-worked-out conclusions of
+Copernicus (p. 88). Nominally adopting the Copernican
+theory, he modified it fundamentally. Copernicus,
+having placed the Sun at the center of the World,
+and made the Earth and other planets circle round it,
+had still left the stars at a fixed and definite distance, as
+had the ancient astronomers. The limitation of the
+sphere of the fixed stars was obnoxious to Giordano,
+and he removed the boundaries of the Universe to an
+<span class="pagenum" id="Page_103">103</span>infinite distance, in accordance with the principles of his
+philosophy. The change may seem unimportant save
+for astronomy, but, in fact, it came to influence every
+department of scientific thought, for the endlessness
+of Nature is implicit in the modern scientific attitude.</p>
+
+<p>Giordano was burned at the stake at Rome, after
+seven years’ imprisonment, in 1600. In the same year
+the experimental era was ushered in with the work of
+William Gilbert (1544-1603), <i>On the Magnet</i>, in which
+he not only demonstrates experimentally the properties
+of magnets but also shows that the Earth itself is a
+magnet. In the same year, too, Tycho Brahe (1546-1601)
+handed over the torch to Johannes Kepler.
+Tycho was the last of the older astronomers who
+worked on the Aristotelian view of circular and uniform
+movements of heavenly bodies. Kepler was the
+real founder of the modern astronomical system. The
+period from 1600 onward lies with new men, Galileo
+(1564-1642) and Kepler (1571-1630) among astronomers
+and physicists, Harvey (1578-1657) among
+biologists, Descartes (1596-1650) among philosophers.</p>
+
+<p>The seventeenth century opened with an extraordinary
+wealth of scientific discovery. As we glance
+at the mass of fundamental work produced during that
+period, we perceive the major departments of Science,
+as we know them to-day, becoming clearly differentiated.
+The acceptance of Observation and Experiment
+as the only method of eliciting the Laws of Nature
+reaches an ever-widening circle. Even to enumerate
+the names of the seventeenth-century pioneers would
+be a formidable task. The sciences penetrated to the
+Universities and influenced the curricula. The number
+<span class="pagenum" id="Page_104">104</span>of scientific men became so large and so influential that
+separate organizations were formed by them in the
+interests of their studies. It is the age of the foundation
+of the ‘Academies’, of which the English Royal Society
+is a type.</p>
+
+<p>From the multitude of workers on these subjects we
+can but select a few names. In the first half of the century
+Galileo and Kepler are the main exponents of
+natural law. Descartes takes his place here as the first
+since antiquity who sought to explain the phenomenal
+universe on a unitary basis. In the second half of the
+period comes the mighty figure of Newton, whose researches
+ushered in that phase in our story in which we
+live to-day.</p>
+
+<p>The early training of Galileo Galilei had been
+scholastic and Aristotelian. By 1590, however, he had
+begun to doubt, and was making experiments on the
+rate of acceleration of falling bodies. His conclusions
+were demonstrated in 1591 from the leaning tower of
+Pisa. By that famous experiment he showed, in the
+most public manner, the error of the Aristotelian view
+that the rate of fall was a function not of the weight of
+the object but of the period of fall. Revolutionary also
+was Galileo’s work of 1604. In that year a new star
+appeared in the constellation <i>Serpentarius</i>. He demonstrated
+that this star was situated beyond the planets
+and among the remote heavenly bodies. Now this
+remote region was regarded in the Aristotelian scheme
+as absolutely changeless. Although new stars had been
+previously noticed, they had been considered to belong
+to the lower and less perfect regions nearer to earth.
+To the same lower region, according to the then
+<span class="pagenum" id="Page_105">105</span>current theory, belonged such temporary and rapidly
+changing bodies as meteors and comets. But Galileo
+had attacked the incorruptible and unchangeable
+heavens.</p>
+
+<p>In 1609 Galileo made accessible two instruments
+that were to have a deep influence on the subsequent
+development of Science, the Telescope and Microscope.
+It is with the former instrument that his name is most
+frequently associated. His first discoveries made by
+means of the Telescope were issued in 1610. That year
+was crowded with important observations especially on
+the inner planets and notably on Venus. It had been
+rightly claimed in criticizing the Copernican hypothesis
+that, if the planets resemble the Earth in revolving
+round the Sun, only such parts of them should be luminous
+as are exposed to the Sun’s rays. In other words,
+they should exhibit phases like the Moon. Such phases
+in Venus were now actually observed by Galileo. In the
+following year he described sunspots and traced them
+round the Sun’s disk.</p>
+
+<p>We need not follow the further astronomical observations
+of Galileo, nor need we discuss the contest with
+the older school on which he embarked. It is sufficient
+to remind ourselves that the appearance of a new star,
+the behavior of the rings of Saturn, the observations of
+the phases of Venus and of the Sun’s spots, struck a
+blow at the Aristotelian astronomy comparable to that
+delivered against the Aristotelian physics by the falling
+weights from the leaning tower of Pisa. Aristotelian
+astronomy demanded heavens eternally changeless.
+Here were changes and new appearances in the heavens,
+clearly visible to all who would see.</p>
+
+<p><span class="pagenum" id="Page_106">106</span></p>
+
+<p>During these years too, Galileo was laying firm the
+foundations of the science of Mechanics. Out of his
+mechanical researches came a new way of looking at
+the objects of Nature which has profoundly influenced
+the entire subsequent course of science. That way is
+best expressed in Galileo’s own words, which place him
+among the philosophers whose thought influences all
+those who deal with scientific themes.</p>
+
+<blockquote>
+<p>‘As soon as I form a conception of a material or corporeal substance,
+I simultaneously feel the necessity of conceiving that it
+has boundaries and is of some shape or other; that relatively to
+others it is great or small; that it is in this or that place, in this or
+that time; that it is in motion or at rest; that it touches, or does
+not touch, another body; that it is unique, rare, or common; nor
+can I, by any act of imagination, disjoin it from these qualities.
+But I do not find myself absolutely compelled to apprehend it as
+necessarily accompanied by such conditions as that it must be
+white or red, bitter or sweet, sonorous or silent, smelling sweetly
+or disagreeably; and if the senses had not pointed out these
+qualities language and imagination alone could never have
+arrived at them. Therefore I think that these tastes, smells,
+colors, &amp;c., with regard to the object in which they appear to
+reside, are nothing more than mere names. They exist only in
+the sensitive body, for when the living creature is removed all
+these qualities are carried off and annihilated, although we have
+imposed particular names upon them, and would fain persuade
+ourselves that they truly and in fact exist. I do not believe that
+there exists anything in external bodies for exciting tastes, smells
+and sounds, &amp;c., except size, shape, quantity, and motion. If
+ears, tongues, and noses were removed, I am of opinion that
+shape, quantity, and motion would remain, but there would be
+an end of smells, tastes, and sounds, which abstractedly from
+the living creature I take to be mere words.’</p>
+</blockquote>
+
+<p>This passage is a veritable Charter of Science. From
+Galileo’s day to ours, men of science have occupied</p>
+
+<p><span class="pagenum" id="Page_107">107</span></p>
+
+<p>themselves in measuring size, shape, quantity, and
+motion, the ‘primary qualities’, and expressing their
+knowledge in that measured form. They have relegated
+colors, smells, tastes, sounds, and other sense-impressions
+to the position of ‘secondary qualities’, and
+have tried to express them, when they express them at
+<span class="pagenum" id="Page_108">108</span>all, in terms of the primary qualities. We need not
+enter on the philosophical discussion as to how far the
+primary qualities are in truth more real than the secondary,
+but it is a fact that, since the time of Galileo,
+Science has come to be regarded more and more widely
+as an exact process. <i>Science is Measurement.</i> It is a
+conception that has affected the medical no less than
+the other sciences, and it is a conception that Medicine,
+for good or ill, owes to Galileo.</p>
+
+<figure class="figcenter illowe30" id="i107">
+  <img class="w100" src="images/i107.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 37.</span> SANCTORIUS IN HIS BALANCE. Sanctorius was able to
+    eat and even to sleep in his balance, counterpoised by a weight working on
+    the principle of the steelyard. He was thus able to test his weight under
+    various conditions, and notably to estimate the amount of the ‘insensible’
+    perspiration. His were the first experiments on ‘Metabolism’ (see <a href="#Page_108">p. 108</a>).</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_5_The_Revival_of_Physiology">
+  § 5. <i>The Revival of Physiology.</i>
+</h3>
+
+<p>The first to apply Galilean principles of measurement
+to biological matters was Sanctorius (1561-1636),
+a professor at Padua. He described a thermometer
+for use in taking the temperature of the human body
+(<a href="#i109">Figs. 39 and 40</a>), and an apparatus for comparing the
+rate of pulse beats (<a href="#i109">Fig. 41</a>). Both these he modified
+from devices suggested by Galileo (<a href="#i109">Fig. 38</a>). It is an
+indication of the transitional character of the Science
+of the time that he describes these instruments in a
+commentary on a medieval translation of the <i>Canon</i> of
+Avicenna (p. 67). He also sought to compare the
+weight of the body at different times and in different
+circumstances. In the process of doing this, he demonstrated
+that the body loses weight by mere exposure,
+a process which he ascribed to ‘insensible perspiration’
+(<a href="#i107">Fig. 37</a>). By these experiments he laid the foundation
+of the modern study of ‘Metabolism’ (p. 220).</p>
+
+<figure class="figcenter illowe30" id="i109">
+  <img class="w100" src="images/i109.jpg" alt="figures 38 to 41">
+  <figcaption>
+    <p><span class="smcap">Fig. 38.</span> The principle of Galileo’s thermometer. A tube ending in
+    a bulb <span class="allsmcap">A</span> is inverted over a mercury bath <span class="allsmcap">B</span>. If the temperature fall the air
+    in <span class="allsmcap">A</span> will contract and mercury be drawn up into the tube. If the temperature
+    rise the air in <span class="allsmcap">A</span> will expand and mercury be driven out of the tube. The
+    height of the mercury can be read on the scale <span class="allsmcap">SS</span>. The reading will not be
+    accurate because the instrument is, in fact, also a barometer, since the
+    mercury in <span class="allsmcap">B</span> is exposed to the atmospheric pressure, which will therefore
+    affect the rise in the tube.</p>
+    <p><span class="smcap">Fig. 39.</span> The application of the same system by Sanctorius who used
+    a curved tube.</p>
+    <p><span class="smcap">Fig. 40</span> is not, as might be thought, a man trying to swallow a centipede,
+    but the adaptation of the instrument of Sanctorius as a clinical thermometer.</p>
+    <p><span class="smcap">Fig. 41.</span> Galileo’s simple and effective ‘pulsimeter’. It consists only
+    of a weight suspended on a thread. This thread is held in the hand and
+    the weight made to oscillate as a pendulum. As the thread is shortened
+    the oscillations increase in frequency. The process is continued until the
+    pendulum oscillates to time with the pulse. The length of the free thread
+    is then read off on the accompanying scale. It was used by Sanctorius.</p>
+  </figcaption>
+</figure>
+
+<p>While Sanctorius was engaged in this pioneer work
+at Padua, the movement that Vesalius had inaugurated
+there was making further conquests in the purely biological
+line. Vesalius had been succeeded at Padua by
+<span class="pagenum" id="Page_109">109</span>a series of anatomists of great eminence. Perhaps the
+most prominent among these was Jerome Fabricius
+(1537-1619), usually called ‘of Aquapendente’, after
+the small Tuscan village where he was born. This
+<span class="pagenum" id="Page_110">110</span>Fabricius of Aquapendente taught at Padua for over
+fifty years, from 1565 till his death at eighty-two in
+1619. He made many contributions to the advancement
+of anatomy, most of which had physiological
+bearings. Thus, he was the effective founder of modern
+embryology and the author of the first illustrated work
+on that subject, in which he describes the formation
+of the chick in the egg. He was the first to give accurate
+figures of the structure of the eye. He developed the
+mechanics of muscular motion. He added to his qualities
+as an observer the power of attracting younger men.</p>
+
+<p>In spite of all his powers, however, Fabricius never
+shook himself free from ancient views, and especially
+he was steeped in the theories of Aristotle and Galen.
+This backward-looking habit prevented his work from
+being as important as it might otherwise have been. In
+connection with the circulation, for instance, he made
+a striking discovery, but wholly failed to draw out its
+most important lesson.</p>
+
+<figure class="figcenter illowe30" id="i111">
+  <img class="w100" src="images/i111.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 42.</span> DISSECTION OF A VEIN in the thigh and leg from a work
+    <i>On the Valves of the Veins</i>, published by Fabricius in 1603 at Padua. These
+    valves prevent the passage of the blood in any direction except toward the
+    heart. They may be seen at the points <span class="allsmcap">P</span>, <span class="allsmcap">Q</span>, <span class="allsmcap">R</span>, <span class="allsmcap">S</span>,
+    and <span class="allsmcap">T</span>.</p>
+  </figcaption>
+</figure>
+
+<p>In 1600 he published his book, <i>On the Valves of the
+Veins</i>. In it he says that these structures are so placed
+that their mouths are always directed <i>toward</i> the heart
+(<a href="#i111">Fig. 42</a>), yet he never gets an inkling that the effect of
+these valves must be to prevent blood flowing into the
+veins except toward the heart. He is too set on the
+old Galenic physiology to permit such a revolutionary
+thought. The real importance of Fabricius is, therefore,
+not so much as an investigator but rather as a teacher,
+a capacity in which he shone above all other physiologists
+for generations to come. He would deserve our
+remembrance if only as the master of the discoverer of
+the circulation of the blood, William Harvey.</p>
+
+<p><span class="pagenum" id="Page_111">111</span></p>
+
+<p>The Englishman, William Harvey (1578-1657),
+after education at Cambridge, went to Padua in 1599,
+when Fabricius was at the height of his powers. Returning
+to England in 1602, he set up in practice
+in London. During the years which followed, he was
+dissecting and experimenting very industriously, and
+by 1615 had reached a clear conception of the circulation
+of the blood (<a href="#i113">Fig. 43</a>), though he did not publish
+his discovery till some thirteen years later.</p>
+
+<p>To discuss the actual steps by which Harvey made
+his discovery would be beyond our scope. He had,
+however, been well trained in experimenting on living
+animals by Fabricius, and had read widely in anatomical
+literature. He was of a contemplative turn of mind and
+his quiet and cautious temper, united with his enthusiasm
+and skill as an experimenter, provided a superb
+mental equipment for a life of scientific investigation.</p>
+
+<p><span class="pagenum" id="Page_112">112</span></p>
+
+<p>Harvey, early in his work, reached two fundamental
+conceptions concerning the vascular system. He perceived
+that the valves in the veins would permit the
+blood to pass only towards the heart (<a href="#i113">Fig. 43</a>), while
+those in the great arteries arising from the heart would
+permit the blood to pass only away from the heart. In
+connection with the movement of the blood, Harvey’s
+crucial point is that it must be <i>continuous</i>, and <i>always
+in one direction</i>. This really clinches the matter, for
+consider the capacity of the heart. Let us suppose that
+either ventricle holds but 2 ounces of blood. The pulse
+beats 72 times a minute and 72 × 60 times an hour.
+In the course of one hour, therefore, the left ventricle
+will throw into the aorta, or the right ventricle into
+the pulmonary artery, no less than 72 × 60 × 2 = 8,640
+ounces = 38 stones 8 lb. In other words, in one hour
+the ventricle will throw into the great artery more than
+three times the body weight of a heavy man. Where
+can all this blood come from? Whither can it all go?
+It cannot come from the ingested food and drink, for
+no one could consume so much in one hour! It cannot
+reach and remain in the tissues, for they would
+soon all burst and ooze with blood! The solution of
+the puzzle, Harvey came to see, is that it is the same
+blood that is always being pumped into the arteries,
+and the same blood that is always coming back through
+the veins. In other words the blood <i>circulates</i>, a fact
+which Harvey proceeded to demonstrate with convincing
+thoroughness (<a href="#i113">Fig. 43</a>).</p>
+
+<figure class="figcenter illowe30" id="i113">
+  <img class="w100" src="images/i113.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 43.</span> DIAGRAM TO ILLUSTRATE THE NATURE OF THE
+    CIRCULATION OF THE BLOOD. Leaving the <i>left ventricle</i>, when the
+    walls of that cavity contract, the blood is forced through the valves into the
+    great artery known as the <i>aorta</i>. From the aorta it passes into smaller and ever
+    smaller arteries, finally reaching the <i>systemic capillaries</i> or the <i>portal capillaries</i>.
+    After travelling through one or other capillary network it enters a vein.
+    Thence it passes into larger and ever larger veins, until it ultimately enters
+    the great vein known as the <i>vena cava</i> that opens into the <i>right auricle</i>. It has
+    now completed the Greater Circulation. As the right auricle contracts the
+    blood passes through the valves between the right auricle and right ventricle
+    into the <i>right ventricle</i>. From there it enters the Lesser Circulation, passing
+    into the great <i>pulmonary artery</i>, which conducts it to the lung. In the lung
+    the pulmonary artery breaks up into branches and finally into capillaries.
+    Through these the blood travels until it reaches a tributary of the <i>pulmonary
+    vein</i> and finally the pulmonary vein itself. The pulmonary vein empties its
+    blood into the <i>left auricle</i>. From the left auricle the blood passes at last into
+    the left ventricle from which it started, having traversed both the Greater
+    and the Lesser Circulations.</p>
+    <p>To understand the change which Harvey wrought in the conception of
+    the workings of the body, this description and diagram should be compared
+    with the description and diagram on pages 56-59.</p>
+  </figcaption>
+</figure>
+
+<p>We may note that, though Harvey demonstrated
+the existence of the circulation, he was never able to
+follow it throughout, for he did not see the capillary
+<span class="pagenum"><a id="Page_113"></a><a id="Page_114"></a>114</span>vessels by which the blood is conveyed from the terminal
+branches of the arteries to the smallest tributaries
+of the veins. These were first demonstrated by Malpighi
+(p. 116).</p>
+
+<p>The knowledge of the circulation of the blood has
+been the basis of the whole of modern Physiology and
+with it of the whole of modern rational Medicine. The
+attitude of Galen and Aristotle towards the heart and
+the great vessels passed into the shadow. The blood,
+it was seen, is a carrier always going round and round
+<span class="pagenum" id="Page_115">115</span>on the same beat. What it carries, and why, how and
+where it takes up its loads, and how, where, and why it
+parts with them, these are questions the answering of
+which has been the main task of Physiology in the centuries
+that have followed. As each of the questions has
+obtained a more and more rational answer, so clinical
+Medicine has always made a step forward, and has come
+to approach more nearly to a true science. Thus it is
+that the work of Harvey lies at the back of almost every
+important medical advance.</p>
+
+<figure class="figcenter illowe30" id="i114">
+  <img class="w100" src="images/i114.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 44.</span> THE VALVES in the superficial veins as seen in the bandaged
+    arms of living men, from William Harvey’s great work on the <i>Circulation
+    of the Blood</i>, printed in 1628. The bandage is seen on the upper arm in each
+    case, and the valves are indicated, as in life, by nodes or swellings in the
+    veins. If a finger is pressed along the vein from one valve to another
+    as from node <span class="allsmcap">O</span> to node <span class="allsmcap">H</span> in a direction away from the heart, the vein from
+    <span class="allsmcap">O</span> to <span class="allsmcap">H</span> will be emptied of blood. It will remain empty, since the valve at <span class="allsmcap">O</span>
+    does not permit the passage of blood away from the heart, but only towards
+    it. This observation was Harvey’s starting point for his great discovery.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_6_Microscopic_Analysis_of_the_Animal_Body">
+  § 6. <i>Microscopic Analysis of the Animal Body.</i>
+</h3>
+
+<p>The compound microscope was first made into an
+effective instrument by Galileo. It was, as it were, a
+<i>by-product</i> of his invention of the telescope. With that
+instrument he had seen enough to convince himself
+that the movement of the Sun round the Earth was but
+an appearance. At the very time that Harvey was giving
+his first course of lectures securely in London, Galileo’s
+teaching was attracting the unwelcome attention
+of the Inquisition in Rome.</p>
+
+<p>Galileo’s microscopes, however, were far less satisfactory
+than his telescopes. For optical reasons which
+we need not discuss, these early compound microscopes
+failed to give a clear picture. With any high degree of
+magnification, the image was always blurred and distorted.
+More than three centuries were to pass before
+a better compound system was introduced. But about
+1650 a way was found of constructing and mounting
+simple lenses of very high power. Many of the most
+important microscopical discoveries of the second half
+of the seventeenth century were, therefore, made with
+<span class="pagenum" id="Page_116">116</span>a simple lens. This was notably the case with much of
+the work of the great investigators Malpighi and
+Leeuwenhoek (<a href="#i118">Fig. 49 <span class="allsmcap">A</span></a>).</p>
+
+<figure class="figcenter illowe30" id="i116">
+  <img class="w100" src="images/i116.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 45.</span> LUNGS OF FROG, showing the capillary vessels from a figure
+    by Malpighi in the rare first edition of his work <i>On the Lungs</i>, published
+    at Bologna in 1661. <span class="allsmcap">A</span> is the part of the larynx, <span class="allsmcap">B</span> is the opening of the larynx
+    into the trachea or air-tube leading to the lung. The letters <span class="allsmcap">EEE</span> represent
+    the outer surface of the lung and exhibit the network of capillary vessels.
+    On the other side the sack-like lung has been laid open, and is viewed from
+    the inside. The letters <span class="allsmcap">HHH</span> are placed upon veins on the inner surface of
+    the lung. These arise from capillaries which are indicated between the veins.</p>
+  </figcaption>
+</figure>
+
+<p>Marcello Malpighi (1628-94) was born in the year
+in which Harvey’s work was published. He became
+a professor at Bologna, having early developed great
+skill in minute investigation. His first work, which
+appeared in 1661, supplied the element missing in the
+investigations of Harvey, for he describes the actual
+passage of blood from the arteries to the veins through
+<span class="pagenum" id="Page_117">117</span>the ‘capillary’ blood-vessels (<a href="#i116">Fig. 45</a>). Harvey, who did
+not use a microscope, knew nothing of the capillaries.
+The object which yielded up the secret was the lung of
+the frog. This organ in the frog happens to be almost
+<span class="pagenum" id="Page_118">118</span>transparent, is very simple in structure, and is furnished
+on its surface with particularly conspicuous capillary
+vessels. Malpighi could hardly have selected an object
+better suited for this particular research. This important
+discovery of his drew the attention of scientific
+men in England. The Royal Society soon entered
+into correspondence with him, and during the remainder
+of his life undertook the publication of his researches.</p>
+
+<figure class="figcenter illowe30" id="i117">
+  <img class="w100" src="images/i117.jpg" alt="figures 46 to 49">
+  <figcaption>
+    <p class="big">In 1673 Malpighi published in London his work <i>On the Formation
+    of the Chick in the Egg</i>. Thirteen years later, in 1686, he published
+    extensions and corrections of this work. Our figures are taken from
+    the later work.</p>
+    <p><span class="smcap">Fig. 46</span> is the whole embryonic area, at about the end of the second day
+    of incubation. The embryo itself is seen with its large head containing the
+    three ‘cerebral vesicles’ (which are the rudiments of the brain), the large
+    eye, the protuberant coiled heart (<span class="allsmcap">NM</span>), from which vessels pass to the
+    ‘vascular area’. The segmented vertebral column is well seen, as well as the
+    vessels forming a network as they meander over the vascular area.</p>
+    <p><span class="smcap">Fig. 47</span> exhibits the embryo more enlarged and in greater detail.</p>
+    <p><span class="smcap">Fig. 48</span> is an enlarged figure of the heart; the part <span class="allsmcap">D</span> will ultimately
+    form the ventricle, <span class="allsmcap">B</span> the auricle, and <span class="allsmcap">A</span> the vena cava. At <span class="allsmcap">F</span> the aorta sends
+    forth three branches which unite again. The nature of these branches was not
+    understood in Malpighi’s time. They have been explained in modern times
+    by embryologists working under the inspiration of evolutionary theory as
+    having once furnished the blood-supply to the gills of a fish-like ancestor.</p>
+    <p><span class="smcap">Fig. 49</span> is a part of the segmented vertebral column still more enlarged.</p>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i118">
+  <img class="w100" src="images/i118.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 49a.</span> ONE OF LEEUWENHOEK’S MICROSCOPES. To understand
+    the figure turn the book at right angles to the line of print. The object
+    to be examined—here the tail of a small eel—is placed in water in the test-tube
+    <span class="allsmcap">B</span>. This test-tube is held firmly by two springs in the frame <span class="allsmcap">A</span>. The
+    microscope itself is simply a flat metal plate <span class="allsmcap">D</span>, into which is let a very minute
+    lens, the setting of which is shown above the letter <span class="allsmcap">D</span> (when the head of the
+    eel is downwards). The lens is focused by means of a fine screw which moves
+    the whole plate.</p>
+  </figcaption>
+</figure>
+
+<p>The contributions of Malpighi to biological knowledge
+were very numerous and important. The study of
+early development, embryology as it is now called, was
+greatly extended by him. The later stages of embryological
+development had been investigated by Fabricius
+(p. 110) and some additions to the subject had been
+made by Harvey. Malpighi, applying his microscope
+to the earlier germ of the animal body, described in detail
+the development of the organs, notably of the heart
+and the nervous system (<a href="#i117">Figs. 46-49</a>). He also demonstrated
+<span class="pagenum" id="Page_119">119</span>the minute structure of the skin, spleen and liver,
+in all of which there are anatomical structures that still
+bear his name. He investigated microscopically the
+structure and physiology of insects and plants, and his
+figures of the cell-walls of the latter are good and clear.</p>
+
+<figure class="figcenter illowe30" id="i119">
+  <img class="w100" src="images/i119.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Figs. 50-53</span> illustrate the blood corpuscles and circulation after
+    Leeuwenhoek.</p>
+    <p><span class="smcap">Fig. 50.</span> Oval blood corpuscles of salmon showing nuclei.</p>
+    <p><span class="smcap">Fig. 51.</span> Human red blood corpuscles.</p>
+    <p><span class="smcap">Fig. 52.</span> Drawing of human red blood corpuscles for comparison with
+    Leeuwenhoek’s figures.</p>
+    <p><span class="smcap">Fig. 53.</span> Capillary network in web of frog’s foot. <span class="allsmcap">A</span>, <span class="allsmcap">C</span> and <span class="allsmcap">E</span> are arterioles,
+    <span class="allsmcap">B</span>, <span class="allsmcap">D</span> and <span class="allsmcap">F</span> are venules.</p>
+  </figcaption>
+</figure>
+
+<p><span class="pagenum" id="Page_120">120</span></p>
+
+<p>A most remarkable contemporary microscopist was
+the Dutchman, Anthony van Leeuwenhoek (1632-1723).
+Without medical or scientific training, desultory
+and secretive in his mode of working, he was
+withal an observer of genius and a very shrewd investigator.
+During his long and industrious life he
+made a series of disconnected discoveries which for
+originality and importance have been surpassed by no
+other microscopic observer. He improved and extended
+the knowledge of the capillary circulation of which
+Malpighi was the discoverer (<a href="#i119">Fig. 53</a>), he gave figures of
+the blood corpuscles (<a href="#i119">Figs. 50-1</a>), of spermatozoa and of
+fibres of muscles (<a href="#i121">Figs. 55-56a</a>), and advanced the knowledge
+of embryology. He always worked with a simple
+microscope, using lenses of exceedingly short focal
+length (<a href="#i118">Fig. 49<span class="allsmcap">A</span></a>). It is astounding that, with such
+<span class="pagenum" id="Page_121">121</span>an instrument, he saw and figured bacteria as early as
+1683 (<a href="#i120">Fig. 54</a>).</p>
+
+<figure class="figcenter illowe30" id="i120">
+  <img class="w100" src="images/i120.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 54.</span> THE FIRST REPRESENTATION OF BACTERIA. They
+    were figured by Leeuwenhoek in the <i>Philosophical Transactions of the Royal
+    Society</i> of London in 1683.</p>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i121">
+  <img class="w100" src="images/i121.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Figs. 55-56</span><span class="allsmcap">A.</span> Drawings of the structure of muscle
+    made about 1682 by Leeuwenhoek.</p>
+    <p><span class="smcap">Fig. 55</span> shows a muscle teased up into bundles of fibres, magnified.</p>
+    <p><span class="smcap">Fig. 56</span> is a more magnified view of a bundle of fibres. The cut fibres are
+    shown at the end.</p>
+    <p><span class="smcap">Fig. 56</span><span class="allsmcap">A</span> is a very highly magnified view of a single fibre showing very
+    clearly the striations that are very characteristic of voluntary muscle.</p>
+  </figcaption>
+</figure>
+
+<p>The short life of a second Dutch microscopist of
+the seventeenth century, Jan Jacobz Swammerdam
+(1637-80), was abbreviated yet further, as regards
+scientific achievement, by his insanity. In his brief
+working period he produced his <i>Bible of Nature</i> which,
+alone of the scientific writings of his age, is still consulted
+by modern naturalists for the unique beauty and accuracy
+of its figures. He extended the knowledge of embryology
+and he made a series of physiological experiments
+which involved the very modern physiological
+device known as the ‘nerve-muscle preparation’. He is
+thus the founder of an important department of Physiology.
+Swammerdam showed that, during contraction,
+a muscle does not increase in bulk, and that therefore
+the nerve brings nothing to it in the way of the hypothetical
+‘nervous fluid’ in which many then believed
+<span class="pagenum" id="Page_122">122</span>(<a href="#i129">Fig. 63</a>). He applied the same reasoning to the heart
+(<a href="#i123">Figs. 57-60</a>). Swammerdam was perhaps the first to see
+the blood corpuscles. Like several of his contemporaries
+and followers, he made injection preparations of much
+beauty and delicacy. His great work was not published
+till after his death. The copper plates that he had prepared
+for it were found and purchased by Boerhaave
+(p. 140), who produced them at his own expense.</p>
+
+<p>These microscopists and several others in the seventeenth
+century did much to explore the minute structure
+of the animal body. Their revelations showed at
+once an unexpected complexity of all the parts, and an
+unexpected resemblance of some of those parts which
+appear diverse to the naked eye. Thus, the structure of
+the body came to be subjected to a process that we may
+call ‘microscopic analysis’. For long after the time of
+these classical microscopists no effective improvements
+were made in the microscope, and the progress of microscopic
+analysis lay almost dormant. With the improvements
+in the microscope of the nineteenth century, the
+method was taken up again with triumphant results.</p>
+
+<figure class="figcenter illowe30" id="i123">
+  <img class="w100" src="images/i123.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Figs. 57-60.</span> Experiments by Swammerdam to illustrate
+    the nature of muscular contraction.</p>
+    <p><span class="smcap">Fig. 57</span> is the simplest form of what physiologists call a ‘nerve-muscle
+    preparation’. It is merely a living muscle dissected away from the body,
+    but with its nerve still attached. In the experiment the two tendons of the
+    muscle are held by the two hands. An assistant pinches the nerve with
+    forceps. The muscle thereon contracts and draws the two hands together.</p>
+    <p><span class="smcap">Fig. 58</span> shows the muscle passed through a glass tube. Its two tendons are
+    fastened by two pins. When the nerve is pinched the pins are drawn towards
+    each other, and the muscle, in contracting, fills the middle of the tube.</p>
+    <p><span class="smcap">Fig. 59</span> shows the nerve-muscle preparation enclosed within a tube. This
+    tube has a narrow neck in which, at <i>e</i>, is a drop of water. The other end of
+    the tube is closed by a cork. The nerve may be squeezed by pulling the
+    thread <i>c c</i>, which passes through the cork and drags the nerve into a narrow
+    wire loop.</p>
+    <p><span class="smcap">Fig. 60</span> is a similar experiment with the heart, which contracts and
+    expands spontaneously and needs no irritation.</p>
+    <p>The experiments 59 and 60 show that during ‘contraction’ no new
+    substance passes into the muscle, since it does not then increase in size. This
+    gives the death-blow to the conception of a ‘nervous fluid’ passing into the
+    muscle to cause contraction by distending it.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_7_From_Alchemy_to_Chemistry">
+  § 7. <i>From Alchemy to Chemistry.</i>
+</h3>
+
+<p>During the sixteenth and the first part of the seventeenth
+century the basic science of Mechanics had
+been placed on a firm footing by Galileo. Astronomy,
+with Galileo and Kepler, had made the great break with
+the past. Anatomy and Physiology had put on their
+modern dress. Chemical knowledge, however, remained
+peculiarly backward. Many advances, it is true,
+had been made in technical processes, but investigations
+designed to throw light on theory were mostly
+<span class="pagenum"><a id="Page_123"></a><a id="Page_124"></a>124</span>prosecuted by the band of dupes and charlatans who,
+since the Middle Ages, had been seeking the Philosopher’s
+Stone. The old theory of the four elements,
+earth, air, fire, and water (p. 34), formed an ill basis
+for experiment. Some philosophers, it is true, had put
+forward crude atomic theories, but they had little experimental
+evidence to adduce. Nevertheless even the
+alchemists had made some advance and had, for instance,
+perfected a system of weighing.</p>
+
+<p>The great defect of the ancient view of matter was
+that it contained no definite conception of the nature
+of a <i>pure</i> substance. Metals, for instance, were regarded,
+like other substances, as a mixture in certain
+proportions of the four elements of Aristotle (p. 34).
+Thus, the transmutation of one metal or one substance
+into another by distillation did not seem an absurdity,
+or even a task of special theoretical difficulty.</p>
+
+<p>The main agent in changing the chemical outlook
+was Robert Boyle (1627-91). He was a member of
+a small association of scientific men, the <i>Invisible College</i>,
+which met first in London, then in Oxford, and
+finally in 1663 was incorporated by Royal Charter as
+the <i>Royal Society</i>. These men were satisfied that the
+only way to learn anything effective about Nature was
+by observation and experiment. From their discussions
+all purely speculative views were excluded. They
+agreed to meet together solely to compare experiences,
+to demonstrate experiments, and to draw immediate
+deductions. None of them was more active in these
+matters than Boyle.</p>
+
+<p>The actual chemical and physical discoveries of
+Boyle were very numerous, but his great achievement,
+<span class="pagenum" id="Page_125">125</span>the real service he rendered to learning in general and
+to medicine in particular, was his introduction of a new
+spirit into Chemistry. Under him that study was no
+longer prosecuted for purely practical ends; it was set
+free from the mystic factor in Alchemy and it was
+loosed from the chains which bound it to Medicine, to
+the disadvantage of both. Chemistry thus became an
+independent science, the principles of which were to be
+ascertained by experiment, and its truths pursued for
+their own sake.</p>
+
+<p>Boyle demonstrated that the air is a material substance
+and has weight. By means of his air-pump, he
+<span class="pagenum" id="Page_126">126</span>proved clearly that this substance is necessary for the
+support of respiration (<a href="#i129">Fig. 63</a>). The law of the compressibility
+of gases is still known by his name. Most
+important of all Boyle’s contributions to chemical theory
+was his adumbration of the conception of a chemical
+element in our modern sense, and his view, which he
+borrowed from another philosopher, of the atomic
+structure of matter.</p>
+
+<p>Under the inspiration of Boyle and his colleagues,
+chemical works of the second half of the seventeenth
+century exhibit in general a positive, cautious, experimental
+spirit, and show a great contrast to the mystical
+and obscure writings of the first half of the century,
+which have much affinity with Alchemy. A fine exponent
+of this new spirit was John Mayow (1645-79),
+who was prevented by an early death from fulfilling
+all his promise. He was the first to recognize clearly
+that there is a substance or principle in air which is
+concerned at once with combustion, respiration, and
+the conversion of venous into arterial blood. In this
+sense he was the discoverer of Oxygen (<a href="#i152">Figs. 74 and 75</a>).</p>
+
+<figure class="figcenter illowe30" id="i125">
+  <img class="w100" src="images/i125.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 61.</span> ONE OF ROBERT BOYLE’S AIR-PUMPS. A cat has
+    been placed in the receiver. It shows signs of asphyxia as soon as the air is
+    exhausted by the pump.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_8_The_Medical_Theorists">
+  § 8. <i>The Medical Theorists.</i>
+</h3>
+
+<p>The great advances in the physical and biological
+sciences, instituted during the sixteenth and seventeenth
+century, left the old medical theories derelict. We have
+already traced the wrecking of the Galenic physiology.
+With its destruction, the old ideas concerning the three
+types of spirit, natural, vital, and animal, went by the
+board. The doctrine of the circulation of the blood
+(p. 113) and the investigations of the new Chemistry
+accorded ill with the old humoral pathology, which
+<span class="pagenum" id="Page_127">127</span>ascribed all disease to excess or defect of one of the
+four humors, blood, phlegm, bile, and melancholy
+(p. 34). Numerous fresh theories arose, of which the
+more important can be classed under the three headings
+<i>Iatrophysics</i>, <i>Iatrochemistry</i>, and <i>Vitalism</i>.</p>
+
+
+<h4 id="a_Iatrophysics">
+  (<i>a</i>) <i>Iatrophysics.</i>
+</h4>
+
+<p>The physical discoveries of Galileo and the demonstrations
+of Sanctorius (p. 108) and of Harvey (p. 111)
+gave a great impetus to the attempt to explain the
+workings of the animal body on purely mechanical
+grounds. The writers who took this point of view are
+known as the <i>Iatrophysicists</i>. One of the earliest and
+most impressive exponents of physiological theory along
+these lines was the French philosopher René Descartes
+(1596-1650). His work on the subject appeared posthumously
+in 1662. It is important as the first modern
+book entirely devoted to the subject of Physiology.</p>
+
+<p>Descartes had not himself any extensive practical
+knowledge of the subject with which he was dealing.
+On theoretical grounds he set forth a very complicated
+apparatus which he believes to be a model of animal
+structure. Subsequent investigation failed to confirm
+his findings, and his work soon passed into oblivion.
+For a time, however, it attracted much attention and
+many followers. A strong point in his theory is the great
+stress laid upon the nervous system, and its power of co-ordinating
+the different bodily activities. Thus stated,
+his view may seem not far from the modern standpoint,
+though in fact he was grotesquely wrong in detail. An
+important part of his theory is the complete separation
+of Man from all the other animals. Man, according to
+<span class="pagenum" id="Page_128">128</span>him, differs from all other animals by his possession of
+a soul, which is situated in a structure in the brain
+known to physiologists as the ‘pineal body’! Animals,
+he held, have no soul, and all their actions and movements,
+even those which seem to express pain or fear, are
+<span class="pagenum" id="Page_129">129</span>purely automatic. It is the modern theory of ‘behaviorism’
+with man excluded! (Figs. <a href="#i128">62</a> and <a href="#i129">63</a>.)</p>
+
+<figure class="figcenter illowe30" id="i128">
+  <img class="w100" src="images/i128.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 62.</span> DESCARTES’ conception of the relation of a sensory impression
+    and a motor impulse. The image of the object <span class="allsmcap">ABC</span> passes to the eye and
+    is formed on the retina. Owing to the optical properties of the eye, it is there
+    inverted. The image is inverted yet again within the brain, where it passes
+    to the pineal gland <span class="allsmcap">H</span> at the point <i>b</i>. The position and character of the image
+    formed on the retina determines the nature and distribution of its effect on
+    the pineal body. According to the nature and distribution of that effect is
+    the result on the nerve, and through it, by the passage of nervous fluid, on the
+    muscles. The movement in the nerve is initiated at the point <i>c</i>. The relation
+    between <i>b</i> and <i>c</i> is an insoluble mystery in which is wrapped up the very
+    nature of the soul. (From the posthumous work of Descartes on Physiology.)</p>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i129">
+  <img class="w100" src="images/i129.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 63.</span> DIAGRAM OF DESCARTES to illustrate his theory of
+    nervous action. <span class="allsmcap">P R</span> and <i>q s</i> are nerves which supply the muscles of the
+    eye <span class="allsmcap">T</span> and <span class="allsmcap">V V</span>. Descartes held that these nerves were hollow and provided
+    with valves, which can be seen at the point at which the <span class="allsmcap">P R</span> and <i>q s</i>
+    first branch. These valves were partly controlled by little fibrils (which can
+    be seen in the main stems of <span class="allsmcap">P R</span> and <i>q s</i> and in certain of their branches).
+    These valves control the movement of the fluid within the hollow spaces of
+    the nerves. Additional complication is lent to the scheme by the fact that
+    <span class="allsmcap">P R</span> and <i>q s</i> intercommunicate at certain points. The view of Descartes,
+    and all such theories of nervous fluid, were destroyed by the experiment of
+    Swammerdam (<a href="#i123">Figs. 57-60</a>), which, however, long remained unpublished.</p>
+  </figcaption>
+</figure>
+
+<p>More lasting was the achievement of Giovanni Alfonso
+Borelli (1608-79), an eminent mathematician
+who was professor at several Italian universities and
+the friend of Galileo and Malpighi. Stirred, like
+Descartes, by the success of Galileo in giving a mathematical
+expression to mechanical events, Borelli attempted
+to do the same with the animal body. In this
+undertaking he was, in fact, very successful. That department
+of Physiology which treats of muscular movement
+on mechanical principles was effectively founded
+and largely developed by him. Here his mathematical
+<span class="pagenum" id="Page_130">130</span>and physical training was specially useful. He endeavored,
+with some success, to extend mechanical
+principles to such movements as the flight of birds and
+the swimming of fish. When he came to an analysis
+of some of the other activities of the body, such as
+the action of the heart, or the movements of the intestines,
+he was less successful, and he naturally failed
+altogether in his attempt to introduce mechanical ideas
+in explanation of what we now know to be chemical
+processes, such as digestion in the stomach.</p>
+
+<p>Undeterred by Borelli’s failure, other writers sought
+to find mechanical explanations of physical processes.
+As is usual in such cases, the amount of theory was
+inversely proportional to the amount of knowledge.
+The views of some of the later ‘Iatrophysicists’ became
+<span class="pagenum" id="Page_131">131</span>very fantastic. Belated representatives of the school are
+the writers of the great French <i>Encyclopédie</i> (1751-72),
+and notably its main author, the man of letters, Denis
+Diderot (1713-84).</p>
+
+<figure class="figcenter illowe30" id="i130">
+  <img class="w100" src="images/i130.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 64.</span> DIAGRAMS FROM BORELLI, showing one of his attempts
+    to analyse the movements of the muscles, in this case of the arm, according
+    to the principles of the science of Mechanics as expounded by Galileo. The
+    figure should be considered in conjunction with <a href="#i131">Fig. 65</a> opposite.</p>
+  </figcaption>
+</figure>
+
+
+<h4 id="b_Iatrochemistry">
+  (<i>b</i>) <i>Iatrochemistry.</i>
+</h4>
+
+<p>Just as there were some who sought to explain all
+animal activity on a mechanical basis so others resorted
+to chemical interpretation. These may be termed
+<i>Iatrochemists</i>. The most prominent was Franciscus
+Sylvius (1614-72), professor of Medicine at Leyden.
+That university had become, in the second half of the
+seventeenth century, the most progressive scientific
+center north of the Alps. It was the seat of the first University
+laboratory, built at the instigation of Sylvius.</p>
+
+<p>Sylvius devoted much attention to the study of
+salts. He recognized that they were the result of the
+<span class="pagenum" id="Page_132">132</span>union of acids and bases, and he attained to the idea of
+chemical affinity—an important advance. He looked
+at the phenomena of life also from the chemical point
+of view. Well abreast of the anatomical knowledge of
+his day, and accepting the broader lines of mechanistic
+advance in Biology, such as the circulation of the blood
+and the mechanics of muscular motion, Sylvius sought
+to interpret other activities in chemical terms. His
+position and abilities as a teacher gave his views wide
+currency and he and his pupils occupy a large part of
+the field of medical theory until well into the eighteenth
+century.</p>
+
+<p>Under the influence of this school, almost all forms
+of vital activity were expressed in terms of ‘acid
+and alkali’ and of ‘fermentation’. The latter process
+was assumed to be of a chemical order, and no clear distinction
+was made between changes that are brought
+about by ‘unorganized’ ferments, such as gastric juice
+or rennet, and changes that are brought about by the
+action of micro-organisms, such as alcoholic fermentation
+or leavening by yeast. Nevertheless, the school
+of Sylvius and its immediate successors added considerably
+to our knowledge of physiological processes,
+notably by their examination of the body fluids, especially
+the digestive fluids such as the saliva, and the
+secretions of the stomach and of the pancreas.</p>
+
+<figure class="figcenter illowe30" id="i131">
+  <img class="w100" src="images/i131.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 65.</span> DIAGRAM OF MUSCULAR ACTION involved in lifting
+    a weight in the hand. It illustrates how muscular movement may sometimes
+    be resolved into terms of the lever. In practice, however, it is usually necessary
+    to involve a whole system of levers, pulleys, resistances, &amp;c., as Borelli
+    clearly perceived. (Compare <a href="#i130">Fig. 64</a>.)</p>
+  </figcaption>
+</figure>
+
+
+<h4 id="c_Vitalism">
+  (<i>c</i>) <i>Vitalism.</i>
+</h4>
+
+<p>Yet another school of medical theorists arose under
+the leadership of the German chemist and physician,
+George Ernest Stahl (1660-1734). Stahl is best remembered
+as the author of the famous theory of
+<span class="pagenum" id="Page_133">133</span><i>phlogiston</i>, a hypothetical substance with which bodies
+were supposed to part during the process of burning
+(p. 151). He is important in the history of science for
+his success in grouping chemical phenomena and therefore
+in systematizing the study of the subject. For
+our purpose, however, Stahl stands as the protagonist
+of that view of the nature of the organism which now
+goes under the term <i>Vitalism</i>. Though expressed by
+him in obscure and mystical language, it is, in effect, a
+return to the Aristotelian position and a denial of the
+view of Descartes. To Descartes the animal body was a
+machine. To Stahl the word <i>machine</i> expressed exactly
+what the animal body was not. The phenomena characteristic
+of the living body are, he considered, not
+governed by physical and chemical laws, but by laws
+of a wholly different kind. These laws are the laws of
+the <i>sensitive soul</i>. The <i>sensitive soul</i> of Stahl is, in its
+ultimate analysis, not dissimilar to the <i>psyche</i> of Aristotle
+(p. 32). Stahl held that the immediate instruments,
+the natural slaves of this sensitive soul, were
+chemical processes and his Physiology develops along
+lines of which Aristotle could know nothing. This does
+not, however, alter the fact of his hypothesis being an
+essentially vitalistic one of Aristotelian origin.</p>
+
+<hr class="tb">
+
+<p>The language and the theories of the Iatrophysicists,
+the Iatrochemists, and the Vitalists of the seventeenth
+and eighteenth centuries have long been discarded by
+men of science in the form in which they were originally
+propounded. Nevertheless, they represent three
+attitudes to the activities of living things which have
+present and current meaning. Each seems to present
+<span class="pagenum" id="Page_134">134</span>some aspect of truth. Whether some physiological
+thinker will combine all three aspects into one coherent
+whole, it is for the future to decide. Yet it is certain
+that all three lines of approach remain of value, and the
+stimulus provided by each of the three inspires investigation
+at the present day. In this sense we enter on the
+period of modern Medicine in the seventeenth century.
+In this sense the foundations of modern rational
+Medicine may be said to have been laid by Borelli,
+Sylvius and Stahl, with Galileo, Boyle and Harvey
+standing behind them.</p>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_135">135</span></p>
+
+
+  <h2 class="nobreak" id="V">
+    V
+    <br>
+    THE PERIOD OF CONSOLIDATION
+    <br>
+    <span class="sm">(FROM ABOUT 1700 TO ABOUT 1825)</span>
+  </h2>
+</div>
+
+
+<h3 id="1_reign_of_law">§ 1. <i>The Reign of Law.</i></h3>
+
+<p>During the sixteenth and seventeenth centuries the
+human mind cast off its medieval vestments and, having
+refreshed itself at the spring of Antiquity, turned to array
+itself in the garments of the New Philosophy. The
+advent of new ideas and new knowledge had been very
+rapid. The <i>method</i> of Research had been determined by
+Galileo at the beginning of the seventeenth century. The
+<i>meaning</i> of Research was determined by a second great
+investigator, Newton, at the end of the same century.</p>
+
+<p>The change wrought in the thought of their time
+by Vesalius, Galileo, Harvey and their like was quantitative
+rather than qualitative. They discovered new
+laws of Nature, but the discovery of such new laws was
+hardly unprecedented. Law had been traced in the
+heavens from of old. The rules of planetary and stellar
+motion had been gradually developed from the simple
+astronomical theories of the ancients. The great astronomers
+of the sixteenth and seventeenth centuries did
+not hesitate to appeal to the records and doctrines of
+medieval writers, for new mathematical relationships
+of the heavenly bodies had been elicited even during
+the Middle Ages. In the sixteenth century Astronomy
+under Tycho (died 1601) put her house in order for
+the ‘Great Instauration’ of the coming age. And then
+Galileo startled the world (1604) with that new star
+<span class="pagenum" id="Page_136">136</span>of his (p. 104), among the most remote heavenly bodies
+in the very region held by the Aristotelian and Platonic
+schemes to be utterly changeless. The Revolution in
+Thought had begun, though no new order had been
+established.</p>
+
+<p>By 1618 Kepler had enunciated his ‘three laws of
+planetary motion’, bringing these movements into an
+intelligible relation with each other. Then the experimental
+philosophers set forth to establish terrestrial
+mechanics. They determined the mode of action of
+gravitation, and Galileo came near to the ‘three laws
+of motion’ which we call Newton’s. But it was Newton
+who first affirmed them clearly and succeeded in linking
+them with Kepler’s laws of planetary motion. Before
+Newton, no man had shown or perceived that rule by
+which the natural succession of earthly phenomena is
+in relation to that of the heavenly bodies. Nay, Faith
+and Reason alike would have been against such a view.
+To prove that the relationship amounted to identity,
+to move men’s minds to see that the force that causes
+the stone to fall is that which keeps the planets in their
+path, this was Newton’s unique achievement. It was
+Newton who first enunciated a law whose writ ran alike
+in the Heavens and on the Earth. With Newton the
+Universe acquired an independent rationality, and
+the whole cosmology of Aristotle, of Galen, and of
+the Middle Ages lay in the dust.</p>
+
+<p>When Newton had completed his work, the Gravitation
+of the Earth and of the Heavens was seen to be
+one, and all the Mechanism of the Universe lay spread
+before him. The vision was set forth in his <i>Principia</i>
+(1687). It established a view of the structure and
+<span class="pagenum" id="Page_137">137</span>working of the Universe which has survived to our
+own generation.</p>
+
+<p>And now as to the change wrought in men’s minds.
+It was something more than a Revolution. It was the
+establishment of a New Order. Newton conceived a
+working Universe wholly independent of the Spiritual
+Order. As to how far his vision is philosophically
+tenable and as to how far he realized its nature, these
+are matters which we need not discuss here. There can,
+however, be no doubt that Newton utterly destroyed the
+very foundations of medieval thought. With Newton
+there sets in the last stage of ‘scientific determinism’.</p>
+
+<p>During the two centuries and a half since the <i>Principia</i>
+appeared, Science has developed prodigiously
+along the lines into which Newton led her. In reliance
+on the universality of Natural Law, the stars in their
+courses have been paced, weighed, measured, analysed.
+The same process, directed to our own planet, has
+traced its history, determined its composition, demonstrated
+its relation to other bodies. Physicist and
+chemist have suggested a structure in terrestrial matter
+similar to that of the stars and suns. The world has
+been reduced to a unitary system. Wherever men have
+sought Law, they have found Law. With search skilful
+enough and patient enough, Law has ever emerged. It
+has been <i>the Age of the Reign of Law</i>.</p>
+
+<p>It is true that in our own time philosophers in general
+have come to see that these Laws of Nature are within
+us as much as without; that they are, in part at least,
+the result of the structure of our minds. This is a point
+of view, however, which has not affected, and perhaps
+will not affect, the working man of science. His constant
+<span class="pagenum" id="Page_138">138</span>occupation, since the days of Newton, has been
+the pursuit of Law, and he has always been satisfied
+that Law has only to be sought in order to be found.
+This conception has affected the medical and biological
+sciences very deeply. Thus the influence of the Newtonian
+philosophy is as traceable in them as it is in the
+astronomical and physical sciences. Galileo showed
+men of science that weighing and measuring are worth
+while. Newton convinced a large proportion of them
+that weighing and measuring are the <i>only</i> investigations
+that are worth while. The question as to whether
+this view is ultimately true or philosophically justifiable
+does not need discussion at the moment. The point,
+for our immediate purpose, is that the view has been
+and is very widely held.</p>
+
+
+<h3 id="_2_The_Rise_of_Clinical_Teaching">
+  § 2. <i>The Rise of Clinical Teaching.</i>
+</h3>
+
+<p>The eighteenth century dawned with the refreshing
+breeze of Newtonian philosophy blowing through it.
+During the previous two hundred years there had been
+an immense amount of new and fruitful research along
+diverse lines. Chemistry and Mechanics, Botany and
+Comparative Anatomy, Descriptive Anatomy and
+Experimental Physiology, Epidemiology and Microscopic
+Analysis, all had yielded startling results. The
+new generation was bewildered with the very mass and
+novelty of the material. The Biologists of the time
+must have been well nigh hopeless of reducing their
+vast accumulations to order, when they contemplated
+the beauty and symmetry of the mathematical relations
+that Newton and his followers had introduced into
+Cosmic conceptions. Thus the eighteenth century is
+<span class="pagenum" id="Page_139">139</span>a period for Biology of pause and consolidation during
+which attempts were made to introduce unitary conceptions
+into the mass of accumulated material. It
+was, moreover, a period of consolidation not only of
+ideas but also of teaching. These tasks at first turned
+men’s minds away from the immediate accumulation
+of further knowledge. So it is that the first half of
+the eighteenth century exhibits something of a gap in
+the progress of Research. The medical field is largely
+filled by two great figures, Boerhaave and Haller.</p>
+
+<p>Until the seventeenth century there was no systematic
+clinical teaching. The Universities gave medical
+degrees on the basis of a spoken disputation. No contact
+with the patient was demanded. The first effective
+attempt to change this was at Leyden, where about
+1636 clinical teaching was instituted. Owing to this,
+and to the fact that, as at Padua, students of every
+religious denomination were accepted, Leyden became
+much frequented by foreign and especially by Protestant
+students. The attractions of the place were increased
+by Sylvius (<a href="#Page_131">pp. 131-2</a>) who, in the second half
+of the seventeenth century, added laboratory instruction
+to his clinical teaching. Leyden had several eminent
+anatomists, while its botanic garden and museums
+added to the practical character of the medical instruction
+that it offered.</p>
+
+<p>Hermann Boerhaave (1668-1738) was first appointed
+as a teacher at Leyden in 1701. At once the medical
+school attained a front rank reputation which rapidly
+came to surpass even that of Padua. Boerhaave had
+very few beds at his disposal, but never did man
+make better use of his opportunities. Besides clinical,
+<span class="pagenum" id="Page_140">140</span>chemical, botanical and anatomical instruction he
+followed such of his patients as died into the post-mortem
+room and there demonstrated to his students
+the relation of lesions to symptoms. He is thus the
+introducer of the method of medical instruction still
+in vogue in our modern medical schools.</p>
+
+<p>Boerhaave was a man of wide culture. He rescued
+and published the plates of the priceless <i>Bible of Nature</i>
+of Swammerdam (p. 121). He brought to Leyden the
+best anatomist of his age, Bernard Siegfried Albinus
+(1697-1770). With him Boerhaave edited in superb
+form the collected works of Vesalius (1725, <a href="#Page_85">p. 85</a> ff.).
+The edition exhibits remarkable prevision of the
+scientific needs of the scholarship of our own time. To
+Albinus, and indirectly to Boerhaave, we owe the most
+beautiful of all works on muscular anatomy (1747), a
+book still in current use (<a href="#i141">Fig. 66</a>). Apart from his
+clinical ability and acumen Boerhaave was a skilled
+chemist, botanist, and anatomist.</p>
+
+<p>With all these accomplishments Boerhaave was
+better able than any man of his time to achieve something
+like a medical synthesis, to bring all the sciences
+to the service of the patient. Taking one thing with
+another, considering his influence as a teacher, his
+clinical acumen, his power of inspiring younger workers,
+his wide learning, his balanced vision, his eagerness for
+new knowledge, his sanity, his humanity, his generosity,
+and his prophetic power, Boerhaave must be
+regarded as the greatest physician of modern times.
+To him the debt of British Medicine, and through it
+of British well-being, is quite incalculable. Through
+his pupils he is the real founder of the Edinburgh
+<span class="pagenum"><a id="Page_141"></a><a id="Page_142"></a>142</span>Medical School, and through it of the best medical
+teaching in the English-speaking countries of the
+world. The success of the Edinburgh school, founded
+while the great Leyden professor was still in his prime,
+can be ascribed to two causes which are perhaps
+reducible to one—the inspiration of Boerhaave.
+These two causes are, firstly, the enthusiasm of its
+early teachers, and, secondly, the concentration of all
+the medical teaching, both clinical and subsidiary, in
+one great university school.</p>
+
+<figure class="figcenter illowe40" id="i141">
+  <img class="w100" src="images/i141.jpg" alt="">
+  <figcaption class="center"
+>
+    <span class="smcap">Fig. 66.</span> TWO PLATES FROM BERNARD SIEGFRIED ALBINUS.<br><i>Anatomical Plates
+    of the Muscles of Man</i>, Leyden, 1747.<br>These are the most beautiful and among the most accurate
+    anatomical figures ever published.
+  </figcaption>
+</figure>
+
+
+<h3 id="_3_Physiology_passes_to_the_Modern_Stage">
+  § 3. <i>Physiology passes to the Modern Stage.</i>
+</h3>
+
+<p>The only figure in the eighteenth century whose
+influence is comparable to that of Boerhaave is his pupil,
+the Swiss Albrecht von Haller (1708-77), one of the
+most accomplished men of all time. In actual scientific
+achievement Haller stands, indeed, far above his
+master. He achieved distinction as poet, botanist, anatomist,
+and novelist, carried on a prodigious correspondence,
+was an exceedingly learned bibliographer, and
+perhaps the most voluminous of all scientific authors.
+His special distinction, however, is as a physiologist.</p>
+
+<p>Haller’s great work, <i>Elements of the Physiology of the
+Human Body</i> (1759-66), marks the modernization of
+the subject of which it treats. Of the highest importance
+were his researches on the Mechanics of Respiration,
+on the formation of bone, and on the development
+of the embryo. He did good work on the action of the
+digestive juices. His most important contributions,
+however, are his conceptions of the nature of living
+substance and of the action of the nervous system.
+These conceptions formed the main background of
+<span class="pagenum" id="Page_143">143</span>biological thinking for a hundred years, and are still
+integral parts of physiological doctrine.</p>
+
+<p>All departments of Medicine must be influenced by
+the views we may hold on the nature and action of the
+nervous system, just as all parts of the body are influenced
+and indeed are linked together by that system.
+Thus the growth in knowledge of the physiology of the
+nervous system is extremely important to us if we would
+gain a true idea of the progress of Rational Medicine.</p>
+
+<p>When we look into the history of nervous Physiology
+before Haller, we shall be struck by the smallness
+of the observational foundation of a vast speculative
+structure. That we may be the more charitable in our
+judgment of such fanciful developments, we may recall
+that the Mind is so constructed that it can take little
+interest in the accumulation of instances unless it can
+adduce general laws therefrom. Theory is thus as
+necessary to practice as practice to theory. The earlier
+doctrines of the nature of nervous action are, however,
+so unlike those we now hold that we can afford to pass
+over them lightly. They consist of speculations on
+the topic of the seat of the soul, together with explanations
+which suppose the passage either of a fluid
+or of some chemical change down the nerves. Haller
+was the first to construct a theory of the nervous
+system that has an appearance of modernity.</p>
+
+<p>During the seventeenth century the favorite doctrine
+of nervous action supposed the existence of a nervous
+fluid. This, it was held, passed down the nerves to
+inflate or extend the muscle fibers. Inflation was supposed
+to shorten the fibers and so the muscle came to
+contract. An exquisite experiment by Swammerdam
+<span class="pagenum" id="Page_144">144</span>with his nerve-muscle preparation had disproved this
+(p. 123). But Swammerdam’s work was unknown till
+published by Boerhaave in 1736, and so the matter
+stood till Haller’s time.</p>
+
+<p>Haller concentrated the problem on an investigation
+of the fibers. A muscle fiber, he pointed out, had in
+itself a tendency to shorten with any stimulus, and
+afterward to expand again to its normal length. This
+capacity for contraction Haller, following a predecessor,
+called <i>irritability</i>. He recognized the existence of
+‘irritability’ as an element in the movement of the
+viscera, and notably of the heart, and of the intestines.
+The feature of ‘irritability’ is that a very slight stimulus
+produces a movement altogether out of proportion to
+itself, and that it would continue to do this repeatedly
+so long as the fiber remained alive.</p>
+
+<p>But besides the force inherent in a muscle fiber
+Haller showed that there was another force which comes
+to it from without, is carried from the central nervous
+system by the nerves, and is the power by which
+muscles are normally called into action. This force, like
+that of irritability, is independent of the will, and like
+it can be called into action after the death of the animal.
+Haller thus distinguished the <i>inherent muscular force</i>
+from the <i>nerve force</i>. Both these forces he further distinguished
+from the natural tendency to contraction
+and expansion, under changing conditions of humidity,
+pressure and so on, of all tissues, living or dead.</p>
+
+<p>Haller, having dealt with the question of movement,
+turned to that of feeling. He was able to show that the
+tissues are not themselves capable of sensation, but that
+the nerves are the sole channels or instruments of this
+<span class="pagenum" id="Page_145">145</span>process. He showed how all the nerves are gathered
+together into the brain, and he believed that they
+tended to its central part. These views he supported
+by experiments and observations involving injuries or
+stimulation to the nerves and different parts of the
+brain. He ascribed special importance to the cortex, but
+the central parts of the brain he regarded as the essential
+seat of the living principle, the Soul.</p>
+
+<p>Throughout his discussion Haller never falters in
+his display of the rational spirit. He develops no mystical
+or obscure themes, and, although his view of the
+nature of Soul may lack clarity, he separates such conceptions
+sharply from those which he is able to deduce
+from actual experience. He is essentially a modern
+physiological thinker, and certain of his themes were
+developed by workers who come on the frontiers of
+what we have called the ‘period of consolidation’.</p>
+
+<p>Among these workers we would select the Scottish
+surgeon Sir Charles Bell (1774-1842), who in 1811
+showed that of the two roots from the spinal cord by
+which all the nerves of the body arise one root conveys
+only sensory elements while the other conveys only
+motor elements (<a href="#i208">Fig. 98</a>, p. 208). By this discovery
+Bell not only completed the views of Haller on the
+central nervous system, but also brought them within
+the range of practical Medicine.</p>
+
+
+<h3 id="_4_Some_Physiological_Advances">
+  § 4. <i>Some Physiological Advances.</i>
+</h3>
+
+<p>Haller provided a philosophical basis to physiological
+conceptions. There were, however, other
+workers of the time who added to the knowledge of
+actual workings of the animal body. First among these,
+<span class="pagenum" id="Page_146">146</span>both in time and eminence, stands the English country
+clergyman Stephen Hales.</p>
+
+<p>The Rev. Stephen Hales (1677-1761) was by temper
+a biologist, but he had received a training in Mathematics
+and Physics. With this ideal equipment, he proceeded
+to investigate the Dynamics of the Circulation.
+His method consisted in applying the principle of the
+pressure gauge or manometer to living things. By
+tying tubes into the arteries and veins of animals, he was
+able to record and measure the blood-pressure. He
+thus laid the foundation of an important mode of studying
+the diagnosing disease. He extended his exact
+investigations into most of the mechanical aspects of
+the circulation. He computed the circulation rate and
+he estimated the actual velocity of the blood in veins,
+arteries, and capillary vessels. He made a very important
+contribution by showing that the capillary vessels
+are liable to constriction and dilatation, a knowledge
+that has since become not only important for physiological
+theory but of primary significance to the practising
+physician (p. 309). He began to explore the wonderful
+mechanism of the heart by which that organ adjusts
+itself to its needs of output. He exhibited his versatility
+by important contributions to many other departments,
+as, for instance, his discoveries on Respiration, his improvements
+in Ventilation (<a href="#i147">Fig. 67</a>), and his campaign
+for Temperance. All his work is characterized by simplicity
+and directness, the supreme marks of his genius.</p>
+
+<figure class="figcenter illowe30" id="i147">
+  <img class="w100" src="images/i147.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 67.</span> WINDMILL VENTILATOR designed by the Rev. Stephen
+    Hales, and erected by order of the Aldermen of the City of London, in 1752,
+    on the roof of Dick Whittington’s Gate at Newgate Prison. From a print
+    in the British Museum.</p>
+  </figcaption>
+</figure>
+
+<p>In the meantime considerable progress was made in
+the knowledge of the digestive processes. The French
+naturalist, René Antoine de Réaumur (1683-1757),
+best remembered for his thermometer (1731) and for
+<span class="pagenum" id="Page_147">147</span>his superb work on insects (1734-42), made a series of
+experiments on gastric digestion in birds (1752). By an
+ingenious contrivance he succeeded in obtaining gastric
+juice in a pure state. He was able to demonstrate its
+power to dissolve food substances in a test-tube kept at
+body temperature. This was important, since many
+believed that the process of solution was the result of a
+churning process induced mechanically by the muscles of
+the stomach-wall. Réaumur thus gave the death-blow
+to the Iatrophysical conception of digestion (p. 130).</p>
+
+
+<p><span class="pagenum" id="Page_148">148</span></p>
+<p>The investigation of gastric digestion was further
+pursued by a versatile Italian, the Abbé Lazaro Spallanzani
+(1729-99), who showed that the churning action
+is an aid, but not an essential, to the process of digestion
+(1782). He proved that digestion was not of the nature
+of putrefaction and differed essentially from the fermentation
+of wine. Spallanzani thus improved on the view
+of Sylvius (p. 132), and took a step towards that solution
+of the natures of putrefaction, fermentation, and digestion
+which was finally provided by Pasteur (p. 225).
+He showed that the gastric juice was secreted by the
+stomach itself, and not introduced into it from other
+organs. A suspicion that the gastric juice contained a
+free acid crossed his mind. He observed that it curdled
+milk and so began our knowledge of a separate ferment,
+that of ‘rennet’. Spallanzani’s results may be summarized
+by saying that he showed that gastric juice had a solvent
+power <i>sui generis</i>, and that this power or faculty was of a
+different order from putrefaction or vinous fermentation.</p>
+
+<p>The phase of digestive physiology represented by
+Réaumur and Spallanzani was brought to a close by
+the English physician William Prout (1785-1850), who
+demonstrated in 1823 the existence of free Hydrochloric
+Acid in the stomach. He showed that the presence
+of this acid was necessary for gastric digestion,
+but that the actual process of solution of food was the
+work of another agent. The matter was at last brought
+into the range of medical practice by an American
+Army Surgeon, William Beaumont (1785-1853), who,
+in the ten years ending 1833, had the opportunity to
+investigate gastric juice in a man who, having been
+shot in the stomach, had a permanent fistula. Through
+<span class="pagenum" id="Page_149">149</span>this the juice could be obtained and the lining membrane
+of the stomach examined at will.</p>
+
+<figure class="figcenter illowe30" id="i149">
+  <img class="w100" src="images/i149.jpg" alt="figures 68 to 70">
+  <figcaption>
+    <p>Experiments illustrating the effects of metallic contacts on the nerves
+    and muscles of frogs’ legs. From A. Galvani, <i>On Electric Forces</i>, 1792.</p>
+    <p><span class="smcap">Fig. 68.</span> Contact is established between water in two dishes. In one lies
+    the end of the nerve with the spinal cord and vertebral column attached. In
+    the other are the feet of the frog.</p>
+    <p><span class="smcap">Fig. 69</span> shows contact by a metal bar with two damp mats on one of which
+    lies the spinal cord and on the other are the feet.</p>
+    <p><span class="smcap">Fig. 70</span> shows a broken contact which can be completed by bringing the
+    metal rods together.</p>
+  </figcaption>
+</figure>
+
+<p>An important department of Physiology was opened
+by the extension of the knowledge of electric phenomena
+to the living body. Static electricity had been
+studied since the beginning of the seventeenth century.
+Luigi Galvani (1737-98) of Bologna, while investigating
+the susceptibility of nerves to irritation, showed
+that nervous action could be induced by electrical
+phenomena (1791). He was, as a matter of fact, producing
+an electrical current. Many thought at the time
+that a new kind of ‘animal electricity’ had been produced
+and they dubbed it ‘galvanism’.</p>
+
+<p>Alessandro Volta (1745-1827) of Pavia, deviser of
+the ‘Voltaic pile’ (<a href="#i150">Figs. 71-3</a>), had long been working
+at electricity. He was able to demonstrate (1800) that
+<span class="pagenum" id="Page_150">150</span>galvanism is without any essential animal relationship,
+and showed that a muscle can be thrown into continuous
+contraction by repeating electric stimulations.</p>
+
+<p>Humbug and misunderstanding in connection with
+the electrical relations of living tissues were rife, and it
+was not till after the period we are now considering that
+electricity came to take a place in rational Medicine.
+<span class="pagenum" id="Page_151">151</span>The change came with E. Du Bois-Reymond (1818-96),
+who took the matter up scientifically about the
+middle of the nineteenth century (1843 onwards). He
+showed that a nervous impulse is accompanied by the
+passage along the nerve of a change of electrical
+potential. It should be added that, despite all the work
+since done upon the nervous system, this is still the
+only physical accompaniment of a nerve impulse that
+has been detected.</p>
+
+<figure class="figcenter illowe30" id="i150">
+  <img class="w100" src="images/i150.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Figs.</span> 71, 72, and 73. From an article by Volta, <i>On the Electricity
+    excited by the mere Contact of Substances of different kinds</i>, published
+    in 1800.</p>
+    <p><span class="smcap">Fig. 71</span> is the famous ‘Couronne de tasses’. It consists of a series of vessels
+    containing salt water, in which are steeped plates of alternate silver <span class="allsmcap">A</span> and zinc
+    <span class="allsmcap">Z</span>. The plates are connected by strips of metal <i>a</i> <i>a</i> <i>a</i>. If the first and the last
+    cup be connected by a conductor, a current flows from one to the other.</p>
+    <p><span class="smcap">Fig. 72</span> is a simple voltaic pile, consisting of alternate disks of silver and
+    zinc, sandwiched between wet strips of leather. The pile is held by glass
+    rods <i>m</i> <i>m</i> <i>m</i>. From the lowermost disk a strip of metal passes to a vessel
+    containing salt water. A current will pass from the uppermost disk to the
+    vessel if the two are connected by a conductor.</p>
+    <p><span class="smcap">Fig. 73</span> is a similar apparatus with two piles connected by a metal plate <i>c c</i>,
+    and two vessels <i>b</i> <i>b</i>. A current will pass between the two vessels <i>b</i> <i>b</i> if they
+    are joined by a conductor.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_5_Discovery_of_the_Nature_of_the_Air">
+  § 5. <i>Discovery of the Nature of the Air.</i>
+</h3>
+
+<p>The seventeenth century saw advances in the knowledge
+of the air. Boyle (1654, <a href="#Page_124">p. 124</a>) had shown by
+means of his air-pump that air was a material substance
+and could be weighed. By exhausting the air from a
+vessel in which an animal had been placed, he showed
+that it was this material substance and no ether, spirit,
+or other mysterious entity which supported respiration.
+Mayow (1668, <a href="#Page_126">p. 126</a>) proved that a part only of the air
+was necessary for life, and later that this same part was
+removed equally by respiration and combustion (<a href="#i152">Figs. 74-5</a>).
+His work was forgotten for a hundred years.
+The great theorists, Stahl, Boerhaave and Haller, knew
+him not, and Stahl’s doctrine of <i>phlogiston</i> set back the
+hands of the clock. No advance was made till the work
+of Joseph Black (1728-99) which appeared soon after
+the middle of the eighteenth century.</p>
+
+<figure class="figcenter illowe30" id="i152">
+  <img class="w100" src="images/i152.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Figs.</span> 74 and 75, illustrating the chemistry of burning and breathing,
+    from a work issued by Mayow in 1674. The experiments show the essential
+    similarity of the two processes in their effect upon the air.</p>
+    <p><span class="smcap">Fig. 74.</span> A candle is burning and a piece of inflammable material is being
+    ignited in a glass vial by a burning-glass, the mouth of which is under the
+    surface of the water. The air can, if desired, be changed or sampled through
+    the attached tube.</p>
+    <p><span class="smcap">Fig. 75.</span> A mouse confined under a glass cover. The air under this cover
+    communicates with that in the vessel below, and can be cut off more or less
+    completely by means of a more or less porous diaphragm.</p>
+  </figcaption>
+</figure>
+
+<p>Black was a cautious investigator and his success was
+due to the accuracy of his measurements. He was aware
+of the fact that chalk, when heated, is transformed into
+quicklime (equation 1, <a href="#Page_152">p. 152</a>), thereby losing its power
+of effervescing with acids, but gaining the power of
+<span class="pagenum" id="Page_152">152</span>absorbing water (equation 2). In modern nomenclature,
+the changes are:</p>
+
+<p class="center">
+  (1) CaCO<sub>3</sub> = CaO + CO<br>
+  (2) CaO + HO = Ca(OH)<sub>2</sub>
+</p>
+
+<p>The first achievement of Black was to show that in
+the process of heating the chalk lost weight (equation 1).
+This was a blow at the phlogiston theory, for it had
+been supposed that quicklime consisted of chalk <i>plus</i>
+phlogiston, and that the phlogiston was conveyed to
+it during the heating. Black now showed that if slaked
+<span class="pagenum" id="Page_153">153</span>lime be treated with a mild alkali, such as the carbonate
+of sodium, it is changed back to the state in which it
+was before heating, in fact into chalk, while the mild
+alkali is converted into a caustic alkali. As we now
+express it:</p>
+
+<p class="center">
+  (3) Ca(OH)<sub>2</sub> + Na<sub>2</sub>CO<sub>3</sub>  = CaCO<sub>3</sub> + 2NaOH
+</p>
+
+<p>Black’s triumph consisted essentially in showing
+that reactions (1) and (3) were indefinitely reversible
+and that the same amount of CaCO<sub>3</sub> could always be extracted
+from (3) as was put into (1). Moreover, he
+showed that a definite amount of chalk, whether heated
+into quicklime or not, neutralized an equal weight of
+acid, the only difference being that the neutralization
+took place with effervescence and loss of weight if the
+chalk were unheated, and without effervescence or loss
+of weight if the chalk were first heated into quicklime.
+Thus:</p>
+
+<p class="center">
+  (4) <i>Unheated</i> CaCO<sub>3</sub> + 2HCl = CaCl<sub>2</sub> + H<sub>2</sub>O + CO<sub>2</sub><br>
+  (5) <i>Heated</i> CaO + 2HCl = CaCl<sub>2</sub> + H<sub>2</sub>O
+</p>
+
+<p>The substance given off by the chalk in (1), absorbed
+by it in (3), and produced by the reaction (4), he named
+<i>fixed air</i>. We now call it <i>Carbon dioxide</i>. The conversion
+of caustic lime into ordinary chalk by exposure,
+CaO + CO<sub>2</sub> = CaCO<sub>3</sub>, proves that Carbon dioxide is a
+normal constituent of the atmosphere. Black learned
+something of its properties, and his work is also of
+very great importance as the first detailed quantitative
+study of a chemical reaction and its reversal. The
+properties of Carbon dioxide were further investigated
+(1766) by Henry Cavendish (1731-1810).</p>
+
+<p>The next advance in the chemistry of the air was
+<span class="pagenum" id="Page_154">154</span>made by the English Unitarian Divine, Joseph Priestley
+(1733-1804). A series of important observations was
+made by him in the seventies and eighties of the eighteenth
+century. He showed that green growing plants
+would make respired air again respirable, and that they
+gave off a respirable gas. In 1774 he prepared Oxygen
+by heating certain oxides, though, still hampered by
+the phlogiston theory, he failed to recognize the nature
+of the oxygen he had produced. The conclusions of his
+<span class="pagenum" id="Page_155">155</span>striking experiments on blood, which he showed to
+depend on this same agent for its changes from venous
+to arterial, were similarly vitiated.</p>
+
+<figure class="figcenter illowe30" id="i154">
+  <img class="w100" src="images/i154.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 76.</span> APPARATUS from Joseph Priestley’s <i>Experiments and Observations
+    on different Kinds of Air</i>, Birmingham, 1774. In the background
+    can be seen an experiment on the effect of combustion on confined air.
+    There are also two cylinders inverted over water in which green plants are
+    growing. In one of them the growing plant has given off a gas (oxygen)
+    which Priestley showed could support both combustion and respiration.
+    In the foreground under a bell-jar are some mice on which Priestley performed
+    respiratory experiments.</p>
+  </figcaption>
+</figure>
+
+<p>The real passage to the modern point of view in our
+knowledge of the air was made by the brilliant French
+chemist Antoine Laurent Lavoisier (1743-94). He
+made an extensive quantitative investigation of the
+changes during breathing (<a href="#i155">Fig. 77</a>), burning, and
+calcination. In the course of these he discovered the
+true composition of respired air, and showed how both
+Carbon dioxide and water are normal products of the
+act of breathing. If clear grasp of the implication of
+<span class="pagenum" id="Page_156">156</span>discovery be made the test, Lavoisier must be regarded
+as the discoverer of Oxygen.</p>
+
+<p>Cavendish (1731-1810) had already discovered the
+composition of water (1785). Lavoisier concluded that
+water and Carbon dioxide are produced by the process
+of oxidation in the lungs, and that it is this oxidization
+process, and not any innate quality of a mysterious
+character in the body or in the blood, that is responsible
+for the bodily heat. Lavoisier introduced much of the
+chemical nomenclature that we still employ. So far
+as respiration is concerned, subsequent research has
+added much to his standpoint. In the purely chemical
+aspect, however, it has altered little, though we now
+know that the tissues and not the lungs are the seat
+of oxidation.</p>
+
+<figure class="figcenter illowe30" id="i155">
+  <img class="w100" src="images/i155.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 77.</span> LAVOISIER in his laboratory making experiments on breathing.
+    To the right Madame Lavoisier sits at a table, taking notes. Lavoisier stands
+    behind, directing. To the left is the subject of the experiment. His face is
+    covered with a mask provided with a valve. He is breathing into the
+    apparatus. An assistant feels his pulse while a second assistant collects the
+    respired air in a bell-jar inverted over a trough.</p>
+    <p class="center">From a contemporary sketch.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_6_Morbid_Anatomy_becomes_a_Science">
+  § 6. <i>Morbid Anatomy becomes a Science.</i>
+</h3>
+
+<p>The main intellectual movement of the seventeenth
+and eighteenth centuries had been focused, so far as
+Medicine was concerned, on the manner of working
+of the animal body, the department that we now term
+Physiology. It was necessary to obtain clear concepts
+of the action of the body in health before venturing
+into discussion of its action in disease. Towards the
+end of the seventeenth century, an industrious compiler
+had put together all the then published records of post-mortem
+examinations up to his time. During the first
+part of the eighteenth century many practitioners in
+Physic and in Surgery published isolated cases or
+groups of cases connected with particular diseases.
+Boerhaave regularly attended post-mortem examinations
+(p. 140). No general pathological principles had,
+<span class="pagenum" id="Page_157">157</span>however, yet been elicited on a scientific basis. The
+theories of disease such as those of Boerhaave were
+perforce still mainly speculative, for there were no extensive
+records of the correlation of symptoms during
+life with the appearances of the organs of the body after
+death, the subject we now call ‘Morbid Anatomy’.
+This gap was first effectively bridged by Morgagni.</p>
+
+<p>Giovanni Battista Morgagni (1682-1771) was professor
+at Padua for no less than fifty-six years. During
+this time he performed an enormous number of post-mortem
+examinations, and made important contributions
+to Descriptive Anatomy. In his seventy-ninth
+year, eleven years before his death, there emerged
+from his enormous experience his work <i>On the sites
+and causes of disease</i>. This classical treatise may still
+be read with profit. Its leading feature is the very
+careful way in which actual cases are recorded. The
+life-history of the patient, the history of his disease, the
+events in connection with his final illness and death, are
+all recounted with detail and care. The condition of
+the organs at the post-mortem examination is minutely
+described and an attempt is made to explain how the
+symptoms were the result of the lesions. Morgagni
+is justly said to have introduced the ‘anatomical concept’
+into the practice of medicine. This concept is one
+of the main elements in modern diagnosis, and a modern
+physician, in reflecting on a case, considers first whether
+he is able to express the symptoms in terms of lesion.
+There are many lesions of great importance and frequent
+occurrence which Morgagni was the first to
+describe.</p>
+
+<p>The task which Morgagni had undertaken was
+<span class="pagenum" id="Page_158">158</span>worthily continued by the Scot, Matthew Baillie (1761-1823),
+nephew, pupil, and heir of William Hunter
+(p. 165). Baillie was a successful London practitioner.
+He followed a new and convenient method in arranging
+his work according to organs instead of by symptoms,
+as Morgagni had done. Baillie performed post-mortem
+examinations on several men of eminence, among them
+Dr. Johnson, whose lung he describes (see <a href="#i158">Fig. 78</a>).</p>
+
+<p>The task of naked-eye pathological anatomy, effectively
+begun by Morgagni, was effectively completed
+by Karl Rokitansky of Vienna (1804-78). His work
+(1842-6) was based on an experience extending over
+<span class="pagenum" id="Page_159">159</span>30,000 post-mortems! Though disfigured by a bizarre
+theory, it left but few gaps for subsequent workers.
+From now on, the science of Pathology was to be
+prosecuted in a new spirit and with new instruments.
+Even in his own day Rokitansky was something of an
+anachronism, with his pure naked-eye anatomy hardly
+ever involving experimental evidence on the one hand
+or the findings of the microscope on the other.</p>
+
+<figure class="figcenter illowe30" id="i158">
+  <img class="w100" src="images/i158.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 78.</span> PART OF THE LUNG OF DR. SAMUEL JOHNSON,
+    from a drawing published by Matthew Baillie. Johnson was a fat, unwieldy
+    man, with a great barrel chest, who suffered for many years from shortness
+    of breath. These are common associations with the pathological condition
+    known as <i>Emphysema</i>, in which the lungs, which are normally of fine
+    spongy texture, become full of abnormally large cavities, so that, as Baillie
+    remarks, they come ‘to resemble the air cells of the lungs of amphibious
+    animals’ (cf. <a href="#i116">Fig. 45</a>, p. 116). In the figure <span class="allsmcap">B</span> represents the external part of
+    the lung and <span class="allsmcap">A</span> its cut surface. On the cut surface the large cellular structure
+    can be seen. The very dark points are the orifices of cut branches of the
+    pulmonary vessels.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_7_Clinical_Methods_and_Instruments">
+  § 7. <i>Clinical Methods and Instruments.</i>
+</h3>
+
+<p>The great teachers of the earlier eighteenth century,
+though better equipped as regards knowledge than
+their predecessors, had hardly any better means of
+diagnosis. Pulse-measurers and thermometers such as
+those of Sanctorius and Galileo (p. 109) had proved
+impracticable by the bedside. The microscope had not
+yet entered into Clinical Medicine. Chemical analysis
+as applied to disease had proved, as yet, of little value.</p>
+
+<p>The first efficient instrument of precision to merit
+clinical adoption was the ‘pulse watch’, by Sir John
+Floyer (1649-1734), an English provincial physician. It
+was introduced as early as 1707 as a ‘Physician’s Pulse
+Watch’ and was an instrument constructed to go for just
+one minute. At that time the making of a twenty-four
+hours watch with a seconds-hand presented great
+mechanical difficulties. Floyer’s invention was not
+widely adopted at the time. Attempts were also made
+to introduce a thermometer into practice, but again the
+construction of suitable instruments proved impossible.</p>
+
+<p>Effective pulse watches and clinical thermometers
+did not penetrate into the general practice of Medicine
+till well into the nineteenth century. Two instrumental
+<span class="pagenum" id="Page_160">160</span>advances of first-class importance to Medicine
+were, however, introduced during the later eighteenth
+century. These were the methods of Percussion and
+Stethoscopy.</p>
+
+<p>Percussion of the surface of the body yields notes
+of varying degrees of resonance. Its application has
+proved of great value to the physician in outlining the
+position of the organs and of lesions, especially those
+of the chest. It was invented by Leopold Auenbrugger
+(1722-1809), a Viennese physician who first introduced
+it in 1761. Like the thermometer, it was very
+slow in entering the general practice of Medicine.</p>
+
+<p>Auenbrugger deserves great credit for his invention,
+but he did not work out its application with anything
+like the completeness that the Breton physician, René
+Théophile Hyacinthe Laënnec (1781-1826), applied to
+his ‘stethoscope’ (1819). Laënnec’s instrument was of
+the uni-tubular type that is now seldom seen. At first,
+indeed, he used a mere roll of paper. His idea was
+rapidly diffused into every country.</p>
+
+<p>But Laënnec did far more than introduce a useful
+and convenient device into Medicine. He explored
+with extraordinary skill the physical signs in the chest
+which correspond to a large number of diseases. The
+major part of our chest-lore and much of the technique
+and nomenclature of chest examination come direct
+from him. Despite continual bad health and the shortness
+of his life, Laënnec’s brilliance and devotion to
+duty at a hospital in Paris enabled him to transmit
+his views and methods to many other physicians,
+both French and foreign. He is unquestionably among
+the greatest physicians of all time. Clinical medicine
+<span class="pagenum" id="Page_161">161</span>assumes with him a completely modern aspect. In
+reading his work one feels that, had he been called in
+consultation by a medical man of our own day, the two
+would have been able to understand each other perfectly,
+after only a little adjustment and explanation.</p>
+
+<figure class="figcenter illowe30" id="i161">
+  <img class="w100" src="images/i161.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Figs. 79-82.</span> LAËNNEC’S WOODEN STETHOSCOPE,
+    from his work of 1819, <i>On Instrumental Auscultation</i>.</p>
+    <p><span class="smcap">Fig. 79</span> is the complete instrument.</p>
+    <p><span class="smcap">Fig. 80</span> is the instrument in section.</p>
+    <p><span class="smcap">Fig. 81</span> is the ear-piece unscrewed.</p>
+    <p><span class="smcap">Fig. 82</span> is the detachable chest-piece terminating in a thin metal tube.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_8_Surgery_and_Obstetrics">
+  § 8. <i>Surgery and Obstetrics.</i>
+</h3>
+
+<p>During the eighteenth century the improved knowledge
+of Normal and Pathological Anatomy was a great
+aid to the surgeon. The technique of Surgery was certainly
+improved. Operations were now being performed
+with success that could not before have been attempted.
+Nevertheless few important new principles were introduced
+until long after the nineteenth century had
+dawned. It is indeed probable that as a means of life-saving
+<span class="pagenum" id="Page_162">162</span>Surgery had an almost inappreciable effect on
+vital statistics until the advent of Anaesthesia and Antiseptics.
+Even the greatest surgeon of the eighteenth
+century, John Hunter, introduced no fundamental new
+surgical principles. True, the names of many surgeons
+of the period have become associated with operations
+invented or introduced by them, but it was not till
+after the advent of antiseptic methods that these were
+practised with full success. There are but two surgical
+matters in which advances of great significance can be
+said to have been made. These were the treatment of
+Venereal Disease and the treatment of Labor.</p>
+
+<p>Syphilis, which existed in Europe in the later Middle
+Ages, had usually been confused with Leprosy and
+other conditions (p. 98). Its treatment by Mercury had
+been practised at least as early as the fifteenth century,
+perhaps as an inheritance from the Arabic-speaking
+physicians. During the sixteenth and seventeenth
+centuries various other remedies were tried (<a href="#i093">Fig. 33</a>);
+much quackery arose around them. In the eighteenth
+century the accumulated experience of generations
+returned again to Mercury. Satisfactory methods of
+administration were evolved and the treatment became
+standardized. It hardly changed until the twentieth
+century.</p>
+
+<figure class="figcenter illowe30" id="i163">
+  <img class="w100" src="images/i163.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 83.</span> LYING-IN SCENE in the sixteenth century from a contemporary
+    work on midwifery. Drinking and feasting is going on in the room
+    where, in addition to the patient, there are two men, five women, and two
+    children. A dog chews a bone on the floor, cooking is in progress in the
+    adjoining room. Food and drink is being forced on the unfortunate patient
+    herself. The whole scene, which is intended to portray an upper-class
+    household, suggests carousal, disorder, and dirt, as well as ignorance of the
+    most elementary principles of hygiene.</p>
+  </figcaption>
+</figure>
+
+<p>The treatment and care of women in Labor made
+considerable progress during the period of which we
+are treating. We have seen how there were advances
+even during the sixteenth century (p. 93) by such
+a writer as Paré. Works on obstetrics intended for
+women were often printed in the sixteenth century in
+France, England and Germany. Scientific obstetric</p>
+
+<p><span class="pagenum" id="Page_163">163</span></p>
+
+<p>works were produced especially in France in the second
+half of the seventeenth century. The obstetric forceps
+was known, but was still a family secret. At the time
+and for long after, there was a great objection on the
+part of pregnant women to treatment by men. The
+midwives were for the most part ignorant, dirty, unskilful
+and superstitious, and the loss of life and health
+<span class="pagenum" id="Page_164">164</span>that resulted from their mishandling was enormous.
+The objection to the ‘man midwife’ was only gradually
+overcome, though his advent was unquestionably
+attended by a fall in the mortality. About the middle
+of the eighteenth century, moreover, the obstetric
+forceps came into wider use. One of the ablest and
+most successful of the obstetric physicians was
+<span class="pagenum" id="Page_165">165</span>William Hunter (1718-83), the brother of John
+Hunter.</p>
+
+<figure class="figcenter illowe30" id="i164">
+  <img class="w100" src="images/i164.jpg" alt="">
+  <figcaption>
+    <p class="center">Early obstetric instruments.</p>
+    <p><span class="smcap">Fig. 84</span> is the very dangerous and brutal <i>Speculum matricis</i> used to force
+    open the mouth of the womb in cases of difficult labor. A similar instrument
+    has been used since antiquity to dilate wounds.</p>
+    <p><span class="smcap">Fig. 85</span> is an even more terrible and powerful instrument, the <i>Apertorium</i>,
+    provided with a sharp edge by means of which the mouth of the womb
+    was violently cut or torn.</p>
+    <p>In the seventeenth century less heroic measures began to be used, and the
+    obstetric forceps was introduced.</p>
+    <p><span class="smcap">Fig. 86</span> shows a pair of obstetric forceps as used in the seventeenth century.
+    The instrument is the direct ancestor of that now in use, which, however,
+    is a vast improvement upon it. The obstetric forceps was invented by
+    a member of an hereditary family of man midwives, at the beginning of the
+    seventeenth century. The nature of the instrument was long kept a secret.
+    This particular instrument was found by accident in 1813, having been
+    hidden under the floor by a member of the family of the inventor.</p>
+  </figcaption>
+</figure>
+
+<p>Despite the absence of any great new principle in the
+surgery of the period, there can be no doubt that a
+new spirit was introduced by John Hunter (1728-93).
+His complex and interesting character demands
+better treatment than it has yet received. As an
+investigator his powers were superb, but, like Leonardo,
+he was handicapped at every turn by literary
+incoherence. Nevertheless, with him Surgery begins
+to appear, at last, as a real Science and not as a mere
+applied Art. Hunter brought to bear on the subject
+a mind stored with ideas drawn from Comparative
+Anatomy and Pathology. Quick to detect analogy,
+shrewd in his scientific judgments, tireless and unsparing
+of himself in his pursuit of truth, a victim of
+disease self-inflicted in the service of science to which
+<span class="pagenum" id="Page_166">166</span>he was tragically a martyr in his death, he shows as a
+heroic figure, rendered no less heroic by some very human
+failings. Fully to appreciate so incoherent a writer,
+it is unfortunately necessary to wade through many
+works written in his own clumsy and ill-arranged manner.
+To gain any real idea of this great personality we
+must consult the writings of his contemporary colleagues.</p>
+
+<p>So far as actual advances are concerned, two may be
+connected with Hunter’s name. Firstly, in the treatment
+of the deadly condition known as ‘Aneurysm’ he
+introduced a method of operation which is still in
+vogue. Secondly, he enormously improved the method
+of making and ordering a museum. His monument
+is the Hunterian Museum in London, based on his
+specimens of which many may still be seen there.
+The museums of Natural History, as now constituted
+in all civilized countries, have been influenced by,
+if they have not been derived from, that which he literally
+gave his life’s blood to found. He was right when
+he said musingly in his illness, ‘You will not easily
+find another John Hunter.’</p>
+
+<figure class="figcenter illowe30" id="i165">
+  <img class="w100" src="images/i165.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 87.</span> JOHN HUNTER’S COUNTRY HOUSE at Earl’s Court,
+    Kensington, before its demolition in 1886. This house was in the country
+    in Hunter’s day, though its site is now a busy part of London. For many
+    years he used it as a laboratory and menagerie, and much of his best work
+    was done there.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_9_The_Beginnings_of_the_Science_of_Vital_Statistics">
+  § 9. <i>The Beginnings of the Science of Vital Statistics.</i>
+</h3>
+
+<p>Attempts to combat widespread disease and to improve
+the public health are to be found in the history
+of all civilizations, both ancient and modern. Nevertheless,
+the rational method cannot come into operation
+until it has exact data upon which to work. Such data
+may be numerically expressed, a fact first appreciated
+by the versatile English physician and inventor, Sir
+William Petty (1623-87), who is usually regarded as
+the father of the science of Political Economy. In 1662,
+<span class="pagenum" id="Page_167">167</span>and on many subsequent occasions, he joined a friend in
+issuing <i>Natural and Political Observations upon the Bills
+of Mortality</i> of London. In this work he endeavored
+to deduce population, death-rates, disease prevalence,
+and other matters of vital statistics from the crude
+figures of the day. He was fully aware of the imperfection
+of his materials, and on this account he urged the
+necessity of providing a system and a government
+department for the collection of trustworthy statistics.
+In his <i>Political Arithmetick</i> (1683), the basic work of
+modern Economics, he displays ideas of a very modern
+character. Among these is his view that the true wealth
+of a country is to be sought in its efficient man power.</p>
+
+<p>A number of Petty’s fellow members of the Royal
+Society began to take interest in statistics. Chief
+among these was Edmund Halley, the astronomer
+(1656-1742). Toward the end of the century (1693)
+Halley produced a mass of statistics on the chances of
+life at various ages, designed for the estimation of the
+price of annuities. During the eighteenth century
+numerous writers devoted themselves to similar investigations.
+An important contributor to the mathematical
+basis of vital statistics was the French Huguenot and
+friend of Newton, Abraham de Moivre (1667-1754).
+His <i>Doctrine of Chances</i> (1715) and his <i>Annuities upon
+Lives</i> (1725) are important contributions to the subject.
+His celebrated hypothesis that among a body
+of persons over a certain age the successive annual decrease
+by death may be esteemed as nearly equal (that
+‘the decrements of life are in arithmetical progression’)
+was under discussion for a century, but is now accepted.</p>
+
+<p>In 1761 a Prussian clergyman, J. P. Süssmilch
+<span class="pagenum" id="Page_168">168</span>(1707-82), produced an extraordinary theological
+work, <i>The Divine Ordinance manifested in the Human
+Race through Birth, Death, and Propagation</i>. Its object
+was to exhibit God’s design in the constancy of the
+numerical relationships of vital statistics. Despite the
+motive—somewhat unpromising for a scientific treatise—the
+work is of great historic and scientific importance,
+for it was based upon a vast mass of statistics and
+showed a great advance in method. It stressed the importance
+of accurate data and the necessity for numerous
+observations, if reliable conclusions were to be
+drawn. From the time of the publication of the work of
+Süssmilch, the statistical study of population advanced
+rapidly. The basis of statistics was greatly improved by
+the introduction of the census system which was put into
+action in England in 1801.</p>
+
+<p>The science of vital statistics was placed on a firm
+foundation by the Belgian astronomer Lambert Quetelet
+(1796-1874). His principal work, <i>On Man and on
+the Development of his Faculties, An Essay on Social
+Physics</i>, contains an account of his statistical researches
+on the development of the physical and intellectual
+qualities of man and on the ‘average man’ both physically
+and intellectually considered. He followed this
+in 1848 by his treatise, <i>On the Social System and the Laws
+which govern it</i>. In it he shows how the numbers representing
+the individual qualities of man may be grouped
+round the numbers referring to the average man in a
+way corresponding to the principles of the theory of
+probabilities. This conception, elaborated and further
+analyzed, has formed the basis of all subsequent researches
+in vital statistics.</p>
+
+<p><span class="pagenum" id="Page_169">169</span></p>
+
+
+<h3 id="_10_Military_Naval_and_Prison_Medicine">
+  § 10. <i>Military, Naval, and Prison Medicine.</i>
+</h3>
+
+<p>The eighteenth century saw some of Petty’s principles
+put into practice. There was, as yet, but one
+section of public life in which scientific principles of
+preventive medicine could be applied. Only in the
+Army and Navy were the sufferers from disease under
+adequate control and observation, and only there were
+proper statistics of sickness and health available. Thus,
+many of the most important movements in Preventive
+Medicine during the eighteenth century, both in
+England and other countries, were initiated by naval
+and military surgeons.</p>
+
+<p>Among military medical reformers an important
+place is taken by a Scottish pupil of Boerhaave, Sir John
+Pringle (1707-82). He had a large military experience
+in the British army, occupied a position of great influence,
+and was able to get many of his views and reforms
+generally accepted. Pringle was among the first to see
+the importance of ordinary putrefactive processes in the
+production of disease, and quite the first to apply these
+principles in hospitals and camps. Important conclusions
+on these matters were published in his <i>Experiments
+upon Septic and Antiseptic Substances, with Remarks
+relating to their Use in the Theory of Medicine</i>,
+which appeared in 1750. He identified ‘gaol fever’ or
+typhus with ‘hospital fever’. He laid down important
+rules for the hygiene of camps which involved avoidance
+of marshes, proper drainage, and adequate latrines.
+His most permanent service was probably his suggestion
+that army hospitals should be regarded as neutral, and
+be mutually protected by belligerents. This great
+<span class="pagenum" id="Page_170">170</span>physician is a good illustration of the ‘new humanity’
+which came into public life in the eighteenth century.
+In much of that movement one may feel the influence
+of that most humane of physicians, Hermann Boerhaave
+(<a href="#Page_140">pp. 140-1</a>).</p>
+
+<p>Hardly less important than the work of Pringle for
+the Army was that of his brother Scot, James Lind
+(1716-94), for the Navy. Lind was a pupil’s pupil of
+Boerhaave. He had a long naval experience and in
+1753 wrote an important work on Scurvy, then a very
+common and fatal disease at sea. He demonstrated how
+this might be prevented by the adequate use of fresh
+fruit or, when this was not available, of lemon juice.
+Fresh water had always been a difficulty of sea voyages.
+Lind arranged for sea-water to be distilled for the purpose.
+He introduced rules for the prevention of typhus
+on ships, and made great improvements in naval
+hygiene. His essay of 1757 <i>On the most effectual means
+of preserving the Health of Seamen</i> is a classic. He also
+wrote an important <i>Essay on Diseases of Europeans in
+Hot Climates</i>, which opened the campaign for the conquest
+of the tropics (p. 270).</p>
+
+<p>Lind, like Pringle, is one of a type that is very fully
+represented in the eighteenth century. A worthy representative
+of that school was Captain James Cook (1728-79),
+the explorer, who adopted Lind’s principles. He
+established a record in one of his voyages to the South
+Seas. The voyage lasted three and a half years, and
+many hardships had to be endured, but out of 118 men
+only one died, and he was consumptive when he embarked
+from England. Of a different type was the Manchester
+health reformer, Thomas Percival (1740-1804),
+<span class="pagenum" id="Page_171">171</span>who worked to introduce the reforms of Pringle and Lind
+into civilian life. The work of Percival leads on naturally
+to Southwood Smith and Chadwick (<a href="#Page_193">pp. 193-5</a>).</p>
+
+<p>The eighteenth century was essentially a period of
+individual effort. The time was not yet ripe for public
+action on a large scale in matters of Hygiene. Pringle,
+Lind, and Percival had, however, their humanitarian
+parallels among prison reformers. Scientific attempts to
+improve the ventilation and sanitation of prisons had
+been instituted by the Rev. Stephen Hales (<a href="#Page_146">pp. 146-7</a>).
+None brought greater devotion to the task than John
+Howard (1726-90), a native of London who spent
+his vigorous powers in investigating the prison system.
+His researches extended to the hospital, quarantine and
+prison systems of France, Flanders, Holland, Germany,
+Italy, Greece and Turkey (<a href="#i173">Fig. 88</a>). His reports were
+directly instrumental in the improvement of the hygiene
+both of prisons and hospitals, as well as in the institution
+of special fever hospitals in many countries. Some
+aspects of Howard’s work were carried on by the great
+Quaker philanthropist Elizabeth Fry (1780-1845),
+others came within the field of activity of Southwood
+Smith and Chadwick (<a href="#Page_193">pp. 193-5</a>).</p>
+
+<p>The eighteenth-century humanitarian movement was
+active and had many able representatives in the United
+States. Foremost among them was Benjamin Franklin
+(1706-90), while in the ranks of Medicine none takes
+a higher place than Benjamin Rush of Philadelphia
+(1745-1813). Rush was particularly revolted by public
+punishments, to the abolition of which he devoted much
+energy. In matters of Hygiene Rush was ahead of
+his time. He wrote on the hygiene of troops and laid
+<span class="pagenum" id="Page_172">172</span>special stress on fresh air and cleanliness of body and
+mind as an aid to health. He had a peculiar horror and
+repulsion for alcoholic intemperance. He was responsible
+for the first systematic work on insanity published
+in America. He left a fine account of a Yellow Fever
+epidemic at Philadelphia, and he approached the truth
+in his view that the disease arose in Philadelphia itself
+and was not brought as an infection from without.</p>
+
+<figure class="figcenter illowe40" id="i173">
+  <img class="w100" src="images/i173.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 88.</span> AN EIGHTEENTH-CENTURY QUARANTINE STATION (Naples).<br>
+
+    From John Howard’s <i>An Account of the principal Lazarettos in Europe</i>, Warrington, 1789.
+  </figcaption>
+</figure>
+
+
+<h3 id="_11_The_Industrial_Revolution">
+  § 11. <i>The Industrial Revolution.</i>
+</h3>
+
+<p>During the eighteenth century the character of
+English civilization became modified by a factor which
+has since profoundly influenced all civilized countries.
+There was a rapid increase in the number and size of
+the towns. The main cause of this was the transformation
+of Industry by the use of mechanical power. The
+change that resulted in the life and outlook of the
+people was very profound. These changes and the
+causes that gave rise to them are usually spoken of
+as the ‘Industrial Revolution’. That revolution had
+effects that were both wider and deeper than followed
+any other such single upheaval in history. With the
+mechanical elements that were at the back of the
+Industrial Revolution, such as the improvements in
+transport, the invention of industrial machinery (<a href="#i175">Fig. 90</a>),
+the enclosure of common land, the new position
+of agriculture, we are not here directly concerned.
+What does affect our story is the increasing urbanization
+of the population, which began early in the
+eighteenth century, increased rapidly soon after the
+middle of the eighteenth century, and has progressed
+continuously ever since. In this matter England is but
+<span class="pagenum"><a id="Page_173"></a><a id="Page_174"></a>174</span>a type, for all other civilized countries followed in her
+wake, though at a somewhat later date.</p>
+
+<p>Along with the growth of towns and the increased
+population there was an increased demand for food.
+The country became better cultivated and better
+drained, and there were many improvements in agriculture.
+Thus, certain diseases began to diminish,
+notably Malaria, essentially a disease of undrained and
+ill-cultivated lands. The expulsion of this disease, as of
+Typhus, was the work of the nineteenth century (p. 283).</p>
+
+<p>It is often assumed that the physical evils of life became
+accentuated by the rise of the great towns. Nevertheless,
+investigation shows that the opposite has been
+the case. During the eighteenth century men and women
+began to crowd into the great towns from the country.
+They were, in fact, right in their choice, for their
+chances of life there were greater than upon the land.
+In the rural districts infamous housing conditions,
+an overcrowding beyond anything which we now
+encounter, exposure to weather, uncertainty and fluctuation
+in the prices of commodities, low wages, unpassability
+of roads in winter time, inaccessibility of medical
+aids, combined to render life, and especially child life,
+more precarious than in urban areas.</p>
+
+<figure class="figcenter illowe30" id="i175">
+  <img class="w100" src="images/i175.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Figs.</span> 89 and 90 illustrate the passage of the textile trade from home
+    industry to factory work with the consequent break-up of the family as the
+    labor unit. Textiles were the first important articles of commerce to be
+    thus affected, but others rapidly followed. The pictures are typical of the
+    Industrial Revolution.</p>
+  </figcaption>
+</figure>
+
+<p>The improvement of hygienic conditions in the
+towns began in England soon after the middle of the
+eighteenth century. Westminster obtained an Improvement
+Act in 1762, Birmingham in 1765, the City
+of London in 1766, Manchester in 1776, and most of the
+other provincial towns soon followed. As a result of
+such Acts noisome streams which were but open drains
+were covered in, the streets were paved and lighted, and
+<span class="pagenum"><a id="Page_175"></a><a id="Page_176"></a>176</span>the sewers improved. There were still many glaring
+defects of sanitation which have occupied and still
+occupy reformers, but by the end of the eighteenth
+century the general appearance of a street in one of
+the more advanced cities was much what it now is. The
+change from the medieval conditions of a century before
+was at least as great as the changes that have since taken
+place.</p>
+
+<figure class="figcenter illowe30" id="i176">
+  <img class="w100" src="images/i176.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 91</span> shows how the population of England and Wales started to
+    increase rapidly about 1750, with the beginning of the Industrial Revolution.
+    The chart covers a period in which statistics were not exact. The figures
+    for it have had to be estimated, but they are probably accurate as round
+    numbers. The census returns are available from 1801.</p>
+  </figcaption>
+</figure>
+
+<figure id="captioned_tables">
+<table class="autotable3">
+<tr>
+<td class="tdr" colspan="8">
+</td>
+<td class="tdc" colspan="2">
+1910-12
+</td>
+
+</tr>
+<tr>
+<td class="tdr">
+<i>Age</i>
+</td>
+<td class="tdr">
+1730-9
+</td>
+<td class="tdr">
+1740-9
+</td>
+<td class="tdr">
+1750-9
+</td>
+<td class="tdr">
+1760-9
+</td>
+<td class="tdr">
+1770-9
+</td>
+<td class="tdr">
+1780-9
+</td>
+<td class="tdr">
+1790-9
+</td>
+<td class="tdr">
+<i>Males</i>
+</td>
+<td class="tdr">
+<i>Females</i>
+</td>
+</tr>
+<tr>
+<td class="tdr">
+10
+</td>
+<td class="tdr">
+36·9
+</td>
+<td class="tdr">
+37·0
+</td>
+<td class="tdr">
+37·3
+</td>
+<td class="tdr">
+36·9
+</td>
+<td class="tdr">
+36·7
+</td>
+<td class="tdr">
+37·5
+</td>
+<td class="tdr">
+38·2
+</td>
+<td class="tdr">
+—
+</td>
+<td class="tdr">
+—
+</td>
+</tr>
+<tr>
+<td class="tdr">
+20
+</td>
+<td class="tdr">
+29·1
+</td>
+<td class="tdr">
+28·9
+</td>
+<td class="tdr">
+29·2
+</td>
+<td class="tdr">
+29·3
+</td>
+<td class="tdr">
+29·4
+</td>
+<td class="tdr">
+29·9
+</td>
+<td class="tdr">
+28·4
+</td>
+<td class="tdr">
+42·35
+</td>
+<td class="tdr">
+46·71
+</td>
+</tr>
+<tr>
+<td class="tdr">
+30
+</td>
+<td class="tdr">
+23·7
+</td>
+<td class="tdr">
+23·5
+</td>
+<td class="tdr">
+23·8
+</td>
+<td class="tdr">
+24·1
+</td>
+<td class="tdr">
+24·1
+</td>
+<td class="tdr">
+24·9
+</td>
+<td class="tdr">
+24·4
+</td>
+<td class="tdr">
+33·87
+</td>
+<td class="tdr">
+37·94
+</td>
+</tr>
+<tr>
+<td class="tdr">
+40
+</td>
+<td class="tdr">
+19·6
+</td>
+<td class="tdr">
+19·2
+</td>
+<td class="tdr">
+19·4
+</td>
+<td class="tdr">
+19·6
+</td>
+<td class="tdr">
+19·5
+</td>
+<td class="tdr">
+19·5
+</td>
+<td class="tdr">
+19·5
+</td>
+<td class="tdr">
+26·03
+</td>
+<td class="tdr">
+29·67
+</td>
+</tr>
+<tr>
+<td class="tdr">
+50
+</td>
+<td class="tdr">
+16·1
+</td>
+<td class="tdr">
+15·8
+</td>
+<td class="tdr">
+15·7
+</td>
+<td class="tdr">
+16·1
+</td>
+<td class="tdr">
+15·9
+</td>
+<td class="tdr">
+15·7
+</td>
+<td class="tdr">
+15·8
+</td>
+<td class="tdr">
+19·09
+</td>
+<td class="tdr">
+22·17
+</td>
+</tr>
+<tr>
+<td class="tdr">
+60
+</td>
+<td class="tdr">
+12·2
+</td>
+<td class="tdr">
+12·4
+</td>
+<td class="tdr">
+12·1
+</td>
+<td class="tdr">
+11·9
+</td>
+<td class="tdr">
+11·9
+</td>
+<td class="tdr">
+12·0
+</td>
+<td class="tdr">
+11·9
+</td>
+<td class="tdr">
+13·09
+</td>
+<td class="tdr">
+15·39
+</td>
+</tr>
+<tr>
+<td class="tdr">
+70
+</td>
+<td class="tdr">
+9·4
+</td>
+<td class="tdr">
+8·6
+</td>
+<td class="tdr">
+8·7
+</td>
+<td class="tdr">
+8·5
+</td>
+<td class="tdr">
+8·3
+</td>
+<td class="tdr">
+8·7
+</td>
+<td class="tdr">
+8·5
+</td>
+<td class="tdr">
+8·17
+</td>
+<td class="tdr">
+9·57
+</td>
+</tr>
+<tr>
+<td class="tdr">
+80
+</td>
+<td class="tdr">
+5·9
+</td>
+<td class="tdr">
+5·7
+</td>
+<td class="tdr">
+5·7
+</td>
+<td class="tdr">
+5·7
+</td>
+<td class="tdr">
+5·7
+</td>
+<td class="tdr">
+6·3
+</td>
+<td class="tdr">
+6·2
+</td>
+<td class="tdr">
+4·79
+</td>
+<td class="tdr">
+5·39
+</td>
+</tr>
+<tr><td colspan="10" class="tdc">
+Showing the expectations of life in
+London for each decade from 1730-1800,
+with recent data for comparison.
+</td></tr>
+</table>
+
+
+<table class="autotable3">
+<tr>
+<td class="tdc">
+<i>Age</i>
+</td>
+<td class="tdr">
+1730-9
+</td>
+<td class="tdr">
+1740-9
+</td>
+<td class="tdr">
+1750-9
+</td>
+<td class="tdr">
+1760-9
+</td>
+<td class="tdr">
+1770-9
+</td>
+<td class="tdr">
+1780-9
+</td>
+<td class="tdr">
+1790-9
+</td>
+<td class="tdr">
+1911-12
+</td>
+</tr>
+<tr>
+<td class="tdr">
+10-20
+</td>
+<td class="tdr">
+6·5
+</td>
+<td class="tdr">
+5·9
+</td>
+<td class="tdr">
+5·9
+</td>
+<td class="tdr">
+7·1
+</td>
+<td class="tdr">
+8·2
+</td>
+<td class="tdr">
+7·1
+</td>
+<td class="tdr">
+6·5
+</td>
+<td class="tdr">
+—
+</td>
+</tr>
+<tr>
+<td class="tdr">
+20-30
+</td>
+<td class="tdr">
+17·5
+</td>
+<td class="tdr">
+17·6
+</td>
+<td class="tdr">
+17·2
+</td>
+<td class="tdr">
+17·9
+</td>
+<td class="tdr">
+17·3
+</td>
+<td class="tdr">
+16·4
+</td>
+<td class="tdr">
+15·1
+</td>
+<td class="tdr">
+3·7
+</td>
+</tr>
+<tr>
+<td class="tdr">
+30-40
+</td>
+<td class="tdr">
+27·1
+</td>
+<td class="tdr">
+26·3
+</td>
+<td class="tdr">
+26·1
+</td>
+<td class="tdr">
+25·2
+</td>
+<td class="tdr">
+25·0
+</td>
+<td class="tdr">
+23·9
+</td>
+<td class="tdr">
+23·7
+</td>
+<td class="tdr">
+6·2
+</td>
+</tr>
+<tr>
+<td class="tdr">
+40-50
+</td>
+<td class="tdr">
+36·6
+</td>
+<td class="tdr">
+38·6
+</td>
+<td class="tdr">
+35·9
+</td>
+<td class="tdr">
+36·3
+</td>
+<td class="tdr">
+35·5
+</td>
+<td class="tdr">
+35·4
+</td>
+<td class="tdr">
+34·3
+</td>
+<td class="tdr">
+11·7
+</td>
+</tr>
+<tr>
+<td class="tdr">
+50-60
+</td>
+<td class="tdr">
+45·5
+</td>
+<td class="tdr">
+47·9
+</td>
+<td class="tdr">
+45·7
+</td>
+<td class="tdr">
+42·1
+</td>
+<td class="tdr">
+45·0
+</td>
+<td class="tdr">
+44·7
+</td>
+<td class="tdr">
+44·6
+</td>
+<td class="tdr">
+21·1
+</td>
+</tr>
+<tr>
+<td class="tdr">
+60-70
+</td>
+<td class="tdr">
+61·4
+</td>
+<td class="tdr">
+63·4
+</td>
+<td class="tdr">
+63·7
+</td>
+<td class="tdr">
+64·4
+</td>
+<td class="tdr">
+62·8
+</td>
+<td class="tdr">
+64·7
+</td>
+<td class="tdr">
+64·1
+</td>
+<td class="tdr">
+40·3
+</td>
+</tr>
+<tr>
+<td class="tdr">
+70-80
+</td>
+<td class="tdr">
+83·7
+</td>
+<td class="tdr">
+98·3
+</td>
+<td class="tdr">
+96·4
+</td>
+<td class="tdr">
+101·8
+</td>
+<td class="tdr">
+105·0
+</td>
+<td class="tdr">
+101·7
+</td>
+<td class="tdr">
+104·4
+</td>
+<td class="tdr">
+87·3
+</td>
+</tr>
+<tr>
+<td class="tdr">
+80-90
+</td>
+<td class="tdr">
+143·1
+</td>
+<td class="tdr">
+150·4
+</td>
+<td class="tdr">
+151·0
+</td>
+<td class="tdr">
+153·0
+</td>
+<td class="tdr">
+152·7
+</td>
+<td class="tdr">
+153·0
+</td>
+<td class="tdr">
+155·1
+</td>
+<td class="tdr">
+181·9
+</td>
+</tr>
+<tr><td colspan="9" class="tdc">
+Showing the death-rates at Age groups in London
+for each decade from 1730-1800,
+with recent data for comparison.
+</td></tr>
+</table>
+
+<figcaption>
+<p class="center"><span class="smcap">Fig. 91</span><span class="allsmcap">A.</span> TABLES showing that vital conditions in the eighteenth century did not deteriorate but
+improved with the Industrial Revolution.
+</p>
+</figcaption>
+</figure>
+
+<p>But if the streets had improved there was much
+<span class="pagenum"><a id="Page_177"></a><a id="Page_178"></a>178</span>under and around them which would horrify us now.
+Water-supply, as in London, was usually drawn mainly
+from surface wells and rivers. In most towns a continuous
+water-supply was unknown. Even when water
+mains existed, the supply to the houses was limited.
+Thus, even in the early nineteenth century London
+houses had a water-supply only three times a week, and
+then only for a few hours at a time. The water mains
+were often defective, and there was not always that clear
+distinction between a water main and a sewer that we
+now regard as desirable. Floods were a constant trouble
+in all riverside towns. Cesspools were in use even in
+London as late as the middle of the nineteenth century,
+and water-closets did not become general, even in the
+better houses, until about 1828. The methods of disposal
+of sewage hardly bear relation. In London the
+sewage simply polluted the rivers.</p>
+
+<p>The improvement of such conditions as these could
+only be made by State action. The eighteenth century
+did well where individual activity was concerned. It
+was reserved for Southwood Smith (p. 193) and Chadwick
+(p. 194) to introduce into the sphere of practical
+political action the truth, set forth by Bentham (<a href="#Page_190">pp. 190-2</a>),
+that all factors which influence the health of
+the country must be the concern of the Legislature.</p>
+
+<p>We gladly pass from this darker picture to the Hospital
+and Dispensary Movement which took its rise about
+the middle of the eighteenth century. Many of the
+great hospitals both in England and in Continental
+countries were either founded or rebuilt about this
+time. Thus, the London Hospital was rebuilt in 1752,
+St. Bartholomew’s in 1730-53. Between 1700 and</p>
+
+<p><span class="pagenum"><a id="Page_179"></a><a id="Page_180"></a>180</span></p>
+
+<p>1825 no less than 154 hospitals and dispensaries were
+founded in the British Isles. Though defective from
+the modern point of view, yet under the influence of
+the sanitary reformers, Hales (p. 146), Pringle (p. 169),
+Lind (p. 170), and Percival (<a href="#Page_170">pp. 170-1</a>), these were
+incomparably better equipped, better ventilated and
+better found than such institutions would have been
+at the beginning of the eighteenth century. The notes
+of the industrious Howard (p. 171) give us a very complete
+picture of them, and one that is more favorable
+than might, perhaps, have been expected.</p>
+
+<p>A defect of the hospitals of the time was certainly
+the nursing. This, however, was somewhat better in
+the Lying-in-Hospitals, where the services of a higher
+type of woman were available and where ladies served
+on the committee of management. The general state
+of the hospitals remained much the same until transformed
+by the changes in surgery and nursing in the
+second half of the nineteenth century, though a number
+of special fever hospitals and pest-houses were established.</p>
+
+<p>Something must be said of the more prevalent
+diseases of the Industrial Revolution. Stress is often
+laid on the effect of urban conditions on child life. Yet
+there can be little doubt that historically the movement
+has been beneficial to it. This comes out well
+in the death-rates. Thus, in England in the period
+around 1740, before the industrial revolution had begun,
+about 75 per cent. of children born died before
+the age of five. In the period around 1800, when the
+industrial revolution had set in, the percentage of
+deaths had fallen to about 41. In the period 1915-24
+<span class="pagenum" id="Page_181">181</span>it was about 14. Among the most characteristic
+diseases of children is Rickets. It is very difficult to
+trace the early history of this disease, but its incidence
+seems to have been very high about 1700, and to have
+fallen progressively throughout the eighteenth century.
+This fall, it has been suggested, was due to agricultural
+improvements which led to better supplies of
+better-fed meat. It was these improvements and better
+supplies that, in their turn, made the big towns possible.</p>
+
+<p>We have already spoken of Scurvy on ships. It was,
+however, well known on land, especially in winter when
+green vegetables were not to be had. Lind (p. 170)
+in 1753 found it common in the land population. The
+advances in agriculture removed it altogether from
+the land diseases during the eighteenth century.</p>
+
+<figure class="figcenter illowe40" id="i179">
+  <img class="w100" src="images/i179.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 92.</span> ST. BARTHOLOMEW’S HOSPITAL AT SMITHFIELD, LONDON, in 1720.
+  </figcaption>
+</figure>
+
+
+<p><span class="pagenum" id="Page_182">182</span></p>
+<figure class="figcenter illowe30" id="i181">
+  <img class="w100" src="images/i181.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 93.</span> A VIEW OF THE PEST HOUSE in Tothill Fields, London,
+    in 1796. From a print in the British Museum.
+  </figcaption>
+</figure>
+
+<h3 id="12_control_and_recognition">§ 12. <i>Control and Recognition of Epidemic Diseases.</i></h3>
+
+<p>Over one department of public health there was
+State supervision during the eighteenth century. The
+ports were guarded against the introduction of Epidemic
+Diseases, and especially against Plague. Throughout
+the eighteenth and early nineteenth century there
+was Plague in the Near East which extended at times
+to various parts of Europe. It was epidemic in Russia
+in 1709 and some 150,000 died of it. In 1719 it spread
+to Eastern Central Europe. One historic outbreak was
+at Marseilles and Toulon in 1720, when 90,000 died.
+The outbreak caused great alarm in England, but did
+not reach this country, nor has there since been any
+outbreak here. Quarantine is now regarded as antiquated,
+vexatious, inhumane, expensive, and ineffectual.
+It seems probable, however, that during the
+eighteenth century, when drastically enforced, as in
+France with the Marseilles epidemic, it had indeed the
+effect of keeping the disease within bounds. Incidentally,
+it led to the foundation of many plague hospitals
+or Lazarettos, of the conduct of some of which Howard
+(p. 171 and <a href="#i173">Fig. 88</a>) speaks well.</p>
+
+<p>During the eighteenth century Small-pox was never
+absent from this country. From time to time the disease
+became epidemic, and there were grave and fatal outbreaks.
+Thus, in 1774 there was an outbreak of small-pox
+at Chester. Next year an investigation was made
+of the degree to which the population had suffered. It
+was then found that before the outbreak there were in
+Chester only 15 per cent. who had not already had the
+disease. The incidence on those unprotected by a
+<span class="pagenum" id="Page_183">183</span>previous attack was 53 per cent., with a death-rate of
+about 17 per cent. of those actually infected and of
+about 9 per cent. of the entire unprotected population.</p>
+
+<p>With the certainty of contracting small-pox before
+their eyes, men sought a way of getting it in a mild
+form. Outbreaks of small-pox varied greatly in virulence,
+and infection with a mild form would lead to
+protection from a graver one. In the East a method of
+direct inoculation of the disease from a patient suffering
+from a slight attack was widely in vogue from an early
+date. The practice attracted little attention in Europe
+until Lady Mary Wortley Montagu (1689-1762)
+studied it at Constantinople. It was then soon taken
+up in England, and became recognized on the Continent.</p>
+
+<p>The efforts of Lady Mary in England were reflected
+on the other side of the Atlantic. The famous Puritan
+leaders, Increase Mather (1639-1723) and Cotton
+Mather (1663-1728), turning from their exploits
+against the witches, ardently urged the operation. In
+England the learned Dr. Richard Mead (1673-1754),
+an eminent and far-seeing physician who exercised very
+great influence on the medical world in his day, published
+in 1747 a work in which he supported the practice
+of inoculation with all the weight of his authority.
+During the subsequent half-century the practice
+spread widely. The operation was largely in the hands
+of specialists who were not always medical men.</p>
+
+<p>Such was the state of affairs when the country practitioner
+Edward Jenner (1749-1823) came upon the
+scene. In 1796 a dairymaid became infected with a
+<span class="pagenum" id="Page_184">184</span>disease of the udders of cows, distantly resembling
+small-pox. She developed pustules on her hand. Jenner
+inserted a little of the matter from one of these into the
+arm of a boy of eight, who developed typical cow-pox.
+Jenner next inoculated this boy with small-pox, which,
+however, failed to develop. The evidence, so far as it
+went, was complete. It is an entire justification of what
+might seem nowadays to be a reckless experiment, that
+at that time inoculation of small-pox was a normal and
+effective defensive procedure. The disease of cows has
+since become known as Vaccinia, and the process of
+inoculating it as <i>Vaccination</i>.</p>
+
+<figure class="figcenter illowe30" id="i184">
+  <img class="w100" src="images/i184.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 94.</span> HAND OF DAIRYMAID infected with cow-pox from a
+    cow’s udder. From Edward Jenner, <i>Inquiry into the Causes and Effects of
+    the Variolae vaccinae, a Disease discovered in some of the Western Counties
+    of England, particularly Gloucestershire, and known by the name of the Cow
+    Pox</i>, London, 1798.</p>
+  </figcaption>
+</figure>
+
+<p>The discovery of vaccination, important though it be,
+is a mere trifle compared to the train of new work and
+new thought that has been opened out by it. The whole
+study of Immunity, which has now become an independent
+science, arises from it. The work of Pasteur
+(p. 225), Lister (p. 239), and Koch (p. 234), and a large
+<span class="pagenum" id="Page_185">185</span>part of modern therapy, are among the achievements of
+this movement.</p>
+
+<p>Besides Plague and Small-pox, many other epidemic
+diseases became more clearly understood during the
+period we are considering. Among these was Scarlet
+Fever, the history of which is particularly interesting
+for the variations which it has shown in virulence. It
+first became clearly recognizable as a mild disease without
+prominent symptoms about 1650. Good observers
+in the half-century that followed considered it a new
+disease. In England it continued to be of little importance
+till about 1748, when it began to be associated
+with grave throat symptoms and to be confused with
+Diphtheria. This phase continued for about ten years.
+The virulence then dropped and the disease continued
+of slight consequence till 1785. It then grew virulent
+again and remained so till about 1808. The malignancy
+then fell again and remained low for about thirty years.
+It rose about 1837 and from then till 1884 it was one
+of the great killing diseases, especially of childhood.
+Since then, the mortality from it has steadily decreased.</p>
+
+<p>During most of its history Scarlet Fever has been
+liable to greater or less confusion with Diphtheria.
+The clinical distinction was first clearly made in 1826 by
+Pierre Bretonneau of Tours (1771-1862), who gave
+Diphtheria its present name. The same French physician
+performed the first successful tracheotomy in a
+case of Diphtheria. He is also known for pioneer work
+in the recognition of Typhoid Fever.</p>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_186">186</span></p>
+
+
+  <h2 class="nobreak" id="VI">
+    VI
+    <br>
+    PERIOD OF SCIENTIFIC SUBDIVISION
+    <br>
+    <span class="sm">(FROM ABOUT 1825 ONWARDS)</span>
+  </h2>
+</div>
+
+
+<h3 id="1_origins_and_implications">§ 1. <i>Origins and Implications of Scientific Specialization.</i>
+</h3>
+<p>We have seen how the philosophy of Newton, with its
+implication, the Reign of Law, which is the Uniformity
+of Nature, has come to pervade scientific thought
+(p. 137). Now, before Newton as after him, there were
+certain natural divisions of scientific activity corresponding,
+in some degree, to the types and faculties of
+men. Since Science first began there have been Mathematicians,
+Biologists, Physical Experimenters, because
+in fact the particular powers which enable a man to
+reach distinction in one of these departments are of less
+value in the others. Until the period of which we are
+now to treat, investigators were accustomed to explore
+at large within these great departments. Such specialist
+professions as Actuarial Calculators, Economic Entomologists,
+Physical Chemists, or, in the department of
+Medicine, Medical Statisticians, Aural Surgeons, or
+Vaccine Therapists—familiar to us now—were unknown
+and undreamt of then. This subdivision is a new
+thing, and is a characteristic product of the period of
+which we have now to treat. The subdivisions, unlike
+those of old, are largely artificial. Thus, the Aural Surgeon
+who deals with the organ of hearing cannot be
+separated clearly by his training, his powers and faculties,
+his operative skill, nor even perhaps by his field of
+work, from the Stomatologist who deals with the mouth,
+or the Rhinologist who deals with the nose. Nevertheless
+<span class="pagenum" id="Page_187">187</span>these minute subdivisions are convenient and beneficent
+in medical as in other departments. The question
+of scientific specialization is so important and characteristic
+that we must examine it a little farther.</p>
+
+<p>It is often thought that, since no man can compass
+all knowledge, this scientific subdivision is merely an
+attempt to compass a part of that growing mass of
+knowledge which is becoming progressively less compassable
+in its entirety. The movement, however, both
+in origin and development, is less simple than this, for
+there never was a time when a man could know all that
+was known about his world. In this respect our own
+age is even as other ages. Were the view philosophically
+tenable—which it is not—that Science becomes
+yearly less comprehensible, our outlook would be
+gloomy indeed. For since there is no evidence of any
+increase in the mental capacity of the human race—at
+least in historic time—such a view would imply a progressive
+diminution in the number of those competent
+to treat any wide scientific area, and a corresponding
+progressive separation from each other of minds with
+scientific insight. Fortunately such conditions do not
+prevail; the view that they do is simply due to a gross,
+yet widespread, misconception of the nature of Science.</p>
+
+<p>Equally fallacious is the idea, which has become
+diffused by the existence of scientific specialization
+itself, that the progress of any science is to be measured
+by the mass of observations that its votaries
+have succeeded in accumulating. This is far from
+being the case. The advance of a science is measured
+by the degree with which it succeeds in bringing
+a multiplicity of observations under general laws.
+<span class="pagenum" id="Page_188">188</span>Judged by this standard, we should probably rate
+very highly, for example, the present state of what is
+called <i>Demography</i>, the study of the life conditions of
+communities, while we should rank much less highly,
+for example, the present state of the study of Aural
+Surgery. Yet, for one publication on Demography
+there must be many on Aural Surgery. In the one
+case, however, the accumulation of knowledge follows
+a well-directed and rational scheme. In the other it is
+prompted and occasioned by the immediate needs of
+individual sufferers. This must not be considered as
+derogatory to those whose task it is to treat the sufferers.
+The point is that the one department, of its nature,
+exhibits the rational spirit better than does the other.</p>
+
+<p>Since Rational Medicine is the subject that we treat
+here, we shall select for discussion those departments
+which best illustrate its spirit. This does not imply,
+and is not meant to imply, any belittlement of the less
+fortunate departments. On the contrary, the less any
+scientific department has succeeded in eliciting general
+laws, the more necessary it is that those most capable
+for the prosecution of such advance should devote
+their attention to that department. It may, indeed,
+reasonably be urged that a leading defect in our scientific
+organization is that men of scientific insight crowd
+to just those studies where their special powers have
+already been best exhibited.</p>
+
+<p>In previous chapters, dealing with more remote
+times, we have been able to place our facts in historic
+perspective. Despite the enormous mass of scientific
+literature dating from the seventeenth, eighteenth, and
+early nineteenth centuries, there is no real obstacle to
+<span class="pagenum" id="Page_189">189</span>selecting what is most important in it. True, it is beyond
+the power of any one student to examine all this
+literature at first hand, but it has been arranged and indexed,
+posterity has passed its verdict, and the historian
+can find his way through the thicket. It is also true that
+important advances are sometimes forgotten, as happened
+to Mayow’s discovery of Oxygen in the seventeenth
+century (pp. <a href="#Page_126">126</a>, <a href="#Page_151">151</a>), which was repeated by
+Priestley a hundred years later (p. 154). But the fact
+that we know of such neglected discoveries shows that,
+however unjust the fates may have been to Mayow, yet
+his influence has not been underestimated by later historians.
+The History of Science, therefore, can up to
+a certain point be written along the same lines as
+political or economic history.</p>
+
+<p>The face of affairs changes, however, when we pass
+into a period which differs for different topics, but may
+be roughly defined as beginning somewhere between
+about 1820 and about 1870. We then begin to encounter
+the very questions with which men of Science
+are occupied in our own time. Since many of these
+questions still remain unsettled, it is impossible for the
+historian to say with certainty which are the most fruitful
+lines of work. The most he can hope to do is to distinguish
+the most influential and stimulating thinkers
+and observers from those who have been less so, and to
+say something about the ideas with which the more
+important schools of thought were instinct.</p>
+
+<p>When we look into the origin of the system of specialization,
+whether in Medicine or in any other
+department of Science, we shall find certain philosophical
+tendencies at work of which the modern man
+<span class="pagenum" id="Page_190">190</span>of Science is the heir, though often the unconscious and
+sometimes the ungrateful and even the misunderstanding
+heir. Neither men of Science nor medical men
+are always philosophers, or at least not always consciously
+so. Nevertheless, they are as surely influenced
+by the streams of thought of their time as they are by
+their heredity and their physical environment. The
+general tendencies of Medicine in this or in any other
+age cannot be interpreted without some reference to the
+intellectual atmosphere in which it has arisen and in
+which it has flourished.</p>
+
+<p>The intellectual atmosphere in which scientific
+specialism arose was that of the so-called ‘Utilitarian
+Philosophy’. Many of the dicta of that school, which
+came into prominence toward the end of the eighteenth
+century, are still used as part of the language of men
+of Science and others. ‘The greatest happiness of the
+greatest number’ is a formula launched upon our common
+speech by Joseph Priestley (1733-1804, <a href="#Page_154">p. 154</a>).
+The pursuit of such happiness as the main object of
+human activity is taught by the ‘Utilitarian’ philosophy,
+a word coined by the English political and social
+thinker, Jeremy Bentham (1748-1832). To Bentham,
+the founder of that philosophy, we owe such useful
+additions to our language as ‘codification’ and ‘international’,
+and these, together with ‘utilitarian’, give us
+some clue to the character and mode of his thought. It
+is probable that no thinker had a larger share than
+Bentham in ushering in the era of the subdivision of
+the sciences.</p>
+
+<p>Bentham made a sustained attempt to draw a parallel
+between the physical and the social sciences, and this
+<span class="pagenum" id="Page_191">191</span>gave him a special influence over medical thinkers and
+especially over those that dealt with the public health.
+His pupil, John Stuart Mill (1806-73), speaks of his
+master’s mode of working as ‘the chemical method’. It
+is thus not remarkable that Bentham should exert a
+profound influence on Medicine, both directly and indirectly.
+The peculiarly logical, uncompromising and
+perhaps un-English character of his mind, while it prevented
+him, fortunately for himself, from taking an
+active share in the task of government, did not prevent
+<span class="pagenum" id="Page_192">192</span>him from influencing those who did. Specifically, he
+is the direct begetter of our modern system of organization
+of the Science of Preventive Medicine.</p>
+
+<figure class="figcenter illowe30" id="i191">
+  <img class="w100" src="images/i191.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 95.</span> A CARTOON OF THE EARLY NINETEENTH CENTURY
+    illustrating the condition of children in the factories of the time. A
+    bale is directed to Sir Robert Peel. This is the first Baronet (1750-1830),
+    father of the statesman. Peel the elder was a cotton-spinner who imported
+    from the London workhouses deserted children whom he treated well, but
+    used to work his factories in Lancashire. He was a Member of Parliament
+    and in 1802 carried the Act which was the forerunner of all factory legislation,
+    <i>An Act for the Preservation of the Health and Morals of Apprentices and others,
+    employed in Cotton and other Mills</i>.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_2_The_Revolution_in_Preventive_Medicine">
+  § 2. <i>The Revolution in Preventive Medicine.</i>
+</h3>
+
+<p>Of all the many changes in Medicine and Medical
+thought that the Period of Scientific Subdivision has
+witnessed, none have been more revolutionary than
+those in the department which deals with Preventive
+Medicine. Great and important reforms were introduced
+during the course of the eighteenth century.
+These, however, even when the result of legislation,
+were the outcome of the effort of individuals, or were
+concerned with the Army and Navy (p. 169). In the
+period that follows, the Public Health becomes a
+general political, legislative, and administrative matter,
+and ‘Prevention’ becomes its watchword. The public
+consciousness—moralists will call it the public <i>conscience</i>—had
+been aroused, and has never again entirely
+slept. The chief agent in the awakening process,
+the intellectual force at its back, was and is Jeremy
+Bentham.</p>
+
+<p>Rational Medicine has, in general, no national frontiers.
+To it men of all the national units have made
+important contributions. But the care of the Public
+Health in the period on which we now enter, being
+an affair of legislation and administration, has developed
+along national lines and it is difficult to discuss it save
+on a national basis. It is a source of justifiable national
+pride that Britain has, from the first and throughout,
+been the leader of the Public Health movement. But
+while we lose little and gain much by telling the story
+<span class="pagenum" id="Page_193">193</span>from the British point of view, it has still to be remembered
+that, just as Rational Medicine has, fortunately,
+no spiritual frontiers, so, unfortunately, sickness and
+suffering have no physical frontiers. Epidemics pass
+the most scientifically constructed boundaries upon the
+surface of the map, and without a passport. In our time
+this evident proposition has obtained, at least, formal
+recognition. International health legislation has at last
+appeared. A future historian of Rational Medicine will
+be able to write his chapter on the Public Health from
+the point of view of Humanity at large. The historian
+who has the misfortune to be born too early must still
+content himself with treating the subject along national
+lines.</p>
+
+
+<h4 id="a_Preventive_Medicine_in_Britain">
+  (a) <i>Preventive Medicine in Britain.</i>
+</h4>
+
+<p>If Bentham be the spiritual father of Public Health
+legislation, the protagonists whose names must be associated
+with the development of the movement along
+practical lines in England are Thomas Southwood
+Smith (1788-1861) and Edwin Chadwick (1800-90).</p>
+
+<p>Thomas Southwood Smith was a Unitarian minister,
+and long combined this office with that of physician.
+Settling in London in 1820 he came under the influence
+of Bentham. By his essay on <i>The Use of the Dead
+to the Living</i> he did something to remove the odium
+attached to dissection. The scandals of the time and
+the common sense of the ‘utilitarians’ (p. 190) led to the
+passing of the Anatomy Act of 1832. Thus by a proper
+legal process bodies became available for dissection by
+medical students. Bentham died just before this Act
+became law and by his will left his body to Southwood
+<span class="pagenum" id="Page_194">194</span>Smith to be the subject of dissection and of an anatomical
+lecture.</p>
+
+<p>Southwood Smith’s services to the spread of interest
+in Public Health were very numerous. He circulated
+a simple and popular <i>Philosophy of Health</i> (1835). He
+served on a board of inquiry as to the condition of
+children in factories (1832, cp. Fig. 191), and he was
+especially useful to the Poor Law Commissioners by
+reason of his exceptional knowledge of fevers. He was
+the founder of a ‘Health of Towns Association’ (1840),
+and of another association for ‘improving the Dwellings
+of the Industrial Classes’ (1842). In 1848 he became a
+member of a new government department, the ‘General
+Board of Health’ (p. 195). His official reports on
+Quarantine (1845), Cholera (1850), Yellow Fever
+(1852), and on the results of sanitary improvement
+(1854), were of world-wide use.</p>
+
+<p>Edwin Chadwick (1800-90), who was not a medical
+man, introduced to public notice what he called the
+‘sanitary idea’, a conception that colored the whole
+of his extraordinarily active life. He sat on Government
+Commissions on Poor Law, on Police, and on the
+investigation of the condition of factory children. One
+of his Reports (1833), issued while he and the century
+were both in the early thirties, recommended a system
+of inspection with a view to limiting children’s hours
+of work. The current system of pensions and of trade
+instruction to soldiers and sailors is the descendant of
+a scheme of Chadwick’s devising. An item in the
+evidence attached to one of his Reports is the public
+provision of open spaces for recreation, a topic of
+current interest at the moment of writing.</p>
+
+<p><span class="pagenum" id="Page_195">195</span></p>
+
+<p>At the time of the accession of Queen Victoria in
+1837 Chadwick was agitating for the appointment of
+a Sanitary Commission. Two years later, as a result of
+a grave epidemical outbreak in London, the Commission
+was appointed. Its reports, which drew wide attention
+at the time, have had a large share in determining
+the general course of health legislation in the ninety
+years that have since elapsed. The scientific basis of
+health legislation can only be determined if proper vital
+statistics be available. The Registration Act of 1838,
+under a developed form of which we still live and die,
+was in essence his work. If we search into the history
+of any department of the scientific treatment of the
+Public Health, we shall always ultimately work back
+either to Southwood Smith or to Chadwick and through
+them to Bentham.</p>
+
+<p>Among the most important documents for which
+Chadwick was responsible was the <i>Parliamentary
+General Report on the Sanitary Condition of the Labouring
+Population of Great Britain</i> (1842). It came to fruit in
+1848 with the <i>Public Health Act</i>, which established a
+new governmental department, the ‘General Board of
+Health’ (p. 196). The same year saw the passage of the
+<i>Nuisances Removal and Diseases Prevention Act</i>, by
+which summary action in such matters was rendered
+possible on the complaint of specially authorized local
+authorities. Just as the Board came into action there
+was an outbreak of Cholera in England, of which 54,000
+persons died. The statistics available under the new
+system made possible the deduction that the infection is
+conveyed by drinking-water and led to suitable precautions.
+This is one of the many instances in which the
+<span class="pagenum" id="Page_196">196</span>practice of prevention of a germ-borne disease preceded
+any knowledge of its organic cause, or indeed any
+direct knowledge of disease germs at all.</p>
+
+<p>The first town in England to appoint a Medical
+Officer of Health was Liverpool. The City of London
+followed in 1848, when Simon took office. After
+Southwood Smith and Chadwick, Sir John Simon
+(1816-1904) was the foremost figure in the history of
+the Public Health of this country. He later became
+medical officer to the ‘General Board of Health’.
+The work of this Board—together with its medical
+officer—was taken over, for political and administrative
+reasons, by the Privy Council. The medical department
+of the Privy Council became in 1871 part of
+<span class="pagenum" id="Page_197">197</span>the Local Government Board, the medical functions of
+which were absorbed by the new Ministry of Health
+in 1917.</p>
+
+<p>To Simon are due the abolition of urban cesspits and
+improvement of the system of sewers, and the institution
+of sanitary inspectors and legislation concerning
+housing and overcrowding. One important result of
+these measures was that it became possible to abandon
+the cruel and wasteful system of quarantine that had
+been of value in the eighteenth century. Simon’s plan,
+which was gradually adopted, was to trust to the same
+preventive methods for foreign as for native infections.
+This was, of course, only possible with an efficient
+sanitary service such as he succeeded in instituting.
+Such measures were aided by laboratory investigations,
+begun by a small staff. At first largely occupied with
+examinations in connection with actual outbreaks, its
+scientific functions rapidly grew. Working on a wider
+basis, these functions have been performed for the
+nation since 1911 under the direction of the Medical
+Research Council.</p>
+
+<figure class="figcenter illowe30" id="i196">
+  <img class="w100" src="images/i196.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 96. Annual death-rate in London per thousand living over
+    a period of 85 years.</span></p>
+    <p>It will be seen that the curve begins definitely to take a downward trend
+    about 1870. It has been falling ever since. It is now less than half of what it
+    was sixty years ago. This fall is largely, though not entirely, due to decrease
+    in infant mortality. Some of the more important epidemics are indicated.
+    Typhus disappears as an important cause of death in the forties and Cholera
+    and Small-pox in the sixties. Since then the death-rate has been considerably
+    influenced by Influenza outbreaks.</p>
+  </figcaption>
+</figure>
+
+
+<h4 id="b_Preventive_Medicine_in_the_United_States">
+  (b) <i>Preventive Medicine in the United States.</i>
+</h4>
+
+<p>In the United States the history of the national
+Public Health Service has been very different from that
+of the English system. The same philosophical tendencies
+have been at the basis of the American as of the
+English system. In the United States, however, the
+National Service has been linked with the Army and
+Navy in a manner quite foreign to British traditions.
+The Federal health system had its origin in the old
+Marine Hospital Service, first authorized by Congress
+<span class="pagenum" id="Page_198">198</span>in 1798. This enabled the President to appoint medical
+officers at ports and elsewhere for the purpose of giving
+medical treatment to disabled merchant seamen. The
+funds were obtained by a tax on those employed on
+American vessels.</p>
+
+<p>The first marine hospital under the Act was at Norfolk,
+Va., in 1800. In 1802 a marine hospital was built
+for the port of Boston, and from time to time hospitals
+were built at other important seaports. To provide for
+the relief of seamen on inland waters Congress passed
+in 1837 an Act for the appointment of a board of advisory
+medical officers of the Army. A number of
+hospitals were established on its advice.</p>
+
+<p>The evolution of public health functions from this
+service was along natural lines. The medical officers,
+in providing care for the American merchant marine,
+were often the first physicians to diagnose such diseases
+as Cholera, Yellow Fever, Small-pox and the like, which
+were being imported into the United States. In the
+epidemics of Cholera which occurred in certain ports
+of the United States the marine hospitals and their
+medical officers were utilized for the relief of those
+suffering from the disease. During the Civil War the
+marine hospitals, together with the medical officers,
+<span class="pagenum"><a id="Page_199"></a><a id="Page_200"></a>200</span>were used by the military authorities, both North and
+South, for the care of the military forces.</p>
+
+<p>Not until 1878 did Congress authorize any extensive
+use of the Marine Hospital Service as a Federal Health
+Service. An Act of 1878 gave broad powers to the Service
+to co-operate with State and local health authorities
+in the control of disease, especially of Yellow Fever. In
+1890 Congress decided to utilize the Marine Hospital
+Service as the Federal Health agency for the prevention
+of inter-State spread of Cholera, Yellow Fever, Small-pox
+and Plague. In 1893 the powers of the Marine
+Hospital Service in this regard were extended to cover
+all infectious and contagious diseases, in co-operation
+with State and local health agencies.</p>
+
+<p>The efficiency of the Marine Hospital Corps in the
+control of epidemic diseases became widely recognized.
+In 1889 Congress passed an Act which made possible
+the further organization of the Marine Hospital Corps,
+and provided that the officers be commissioned in grades
+similar to those of the medical department of the United
+States Army. An Act of 1875 had already provided that
+the Surgeon-General (supervising surgeon) should be appointed
+by the President, with the consent of the Senate.</p>
+
+<p>In 1893 the Marine Hospital Service was organized
+into the Federal Health Service. Congress continued to
+impose additional health functions upon the Service,
+and in 1902 changed its name to the ‘Public Health and
+Marine Hospital Service’ and made it a health service
+in name as well as function. The larger part of its
+duties, up to this time, had been the combating of epidemics,
+especially those of Yellow Fever, which from
+time to time swept the country. With the threat of
+<span class="pagenum" id="Page_201">201</span>Bubonic Plague in 1900 at San Francisco, the Marine
+Hospital Service was placed in charge of control
+methods and succeeded in preventing any extensive
+spread of the disease.</p>
+
+<p>In addition to the quarantine and hospital functions,
+the activities of the Service soon came to include research
+and educational work. In 1902 Congress
+authorized the establishment of the Hygienic Laboratory
+for investigating Cholera, Yellow Fever, and other
+conditions. The Laboratory grew rapidly and is now
+a very important research institution, equipped for
+carrying on pathological, zoological, pharmacological,
+bacteriological, chemical, and physiological work.</p>
+
+<p>From the control of epidemics, the Public Health
+and Marine Hospital Service began to develop control
+measures for the more common contagious and infectious
+diseases, such as Typhoid Fever, Diphtheria,
+and Scarlet Fever. The history of the wonderful control
+of Typhoid Fever which has taken place in the
+United States within the past twenty years is a part of
+the history of the Public Health Service in co-operation
+with State and local health agencies. Typhoid fever,
+which formerly took a toll of more than 50,000 lives
+annually, is responsible for the death of a mere fraction
+of this number at the present day.</p>
+
+<p>The development of health functions of the Public
+Health and Marine Hospital Service continued until
+Congress in 1912 changed the name to its present one,
+the ‘United States Public Health Service’, and at the
+same time gave it broad powers to investigate the diseases
+of man and the pollution of navigable streams and lakes.</p>
+
+<p>During the courses of Federal development the
+<span class="pagenum" id="Page_202">202</span>separate States of the Union were not devoid of protagonists
+of State intervention in matters of public health.
+Among these was Lemuel Shattuck (1793-1859), who,
+like Chadwick, was no medical man, but a student
+of social problems. Under the influence of Chadwick
+he drafted in 1850 the <i>Report of the Massachusetts Sanitary
+Commission</i>. This publication set forth a complete
+scheme of Public Health organization. The formation
+of the first State Board of Health in Massachusetts was,
+however, delayed till 1869. In this matter Massachusetts
+was, in fact, anticipated by Louisiana, which
+obtained a State Board of Health in 1855, and by New
+York City, which obtained a Board of Health in 1866.
+Most of the States followed in the seventies. The
+seventies and eighties were the decades in which the
+general principles suggested by the work of Pasteur
+and Koch were put into effect. The working hypothesis
+of sanitarians of the time was that filth and ill-drainage
+were direct factors in the production of
+epidemic disease. The view is now untenable, but there
+was unquestionably an immense improvement in health
+conditions resulting both directly and indirectly from
+the improved drainage, water-supply, housing, and the
+like that the agitation had stimulated.</p>
+
+<p>As the bacteriological discoveries of the time became
+generally accepted, they were widely applied on
+American soil to the administrative control of disease,
+notably by the New York Department of Health under
+Hermann M. Biggs. That body, in 1892, instituted
+a bacteriological laboratory, the scope of which has
+steadily increased. Its work in connection with Diphtheria
+is elsewhere discussed (<a href="#Page_265">pp. 265-6</a>).</p>
+
+<p><span class="pagenum" id="Page_203">203</span></p>
+
+<p>To follow into our own time the development of
+factory legislation, vital statistics, school medical service,
+local health authorities, municipal laboratories and
+clinics, methods of food inspection, would be to write
+a text-book of Public Health Administration. In all
+these developments we see working the rational spirit
+in the peculiarly English field of Preventive Medicine.
+The spirit of Rational Medicine cannot function, however,
+without material upon which to work. The basis,
+the elementary matter, as it were, of that material, is
+the conception we form of the nature of the bodily processes.
+Such a conception it is the function of Physiology
+to provide and to Physiology we therefore now turn.</p>
+
+<figure class="figcenter illowe40" id="i199">
+  <img class="w100" src="images/i199.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 97.</span> THE OLD <i>DREADNOUGHT</i> HOSPITAL SHIP.</p>
+    <p>A ‘Seamen’s Hospital Society’ was founded in England in 1817. Its first
+    hospital was the <i>Grampus</i>, an old 50 gun ship moored off Greenwich. This
+    was succeeded in 1830 by the <i>Dreadnought</i>, 104 guns, and this in 1857 by the
+    <i>Caledonia</i>, 120 guns, renamed <i>Dreadnought</i>. In 1870 this last wooden <i>Dreadnought</i>
+    was broken up and the patients were transferred to a building on shore
+    close by. The darkness, damp, ill-ventilation, noisiness and septic character
+    of a wooden ship made it thoroughly unsuitable for hospital purposes.</p>
+    <p>In 1899 the ‘Seamen’s Hospital Society’ established a special Hospital and
+    School for Tropical Diseases such as are peculiarly common among seamen.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_3_The_Transition_to_a_Physiological_Synthesis">
+  § 3. <i>The Transition to a Physiological Synthesis.</i>
+</h3>
+
+<p>Modern developments in physiological knowledge
+introduce an important period in the History of Medicine,
+for the study of the functions of the body is a
+natural portal of entry to the study of the perversions
+and suspensions of those functions that we call disease.
+The general character of physiological thought during
+the modern period may perhaps be described as the
+‘synthetic study of the animal body’. The study has
+become synthetic because organs have not been studied
+so much in and for themselves as in relation to other
+organs. There has been, in fact, during the period, an
+increasing consciousness of the integration of the organs
+into one organic whole, the entire process being under
+the control of the nervous system, the various parts of
+which are themselves integrated (p. 308). This movement
+has, to some extent, mitigated the ever growing
+evils of scientific specialization.</p>
+
+<p><span class="pagenum" id="Page_204">204</span></p>
+
+
+<h4 id="a_Anatomy_and_Embryology">
+(a) <i>Anatomy and Embryology in the Earlier Nineteenth
+Century.</i>
+</h4>
+
+<p>Let us first glance at the state of anatomical knowledge
+in the early and middle nineteenth century. The
+general structure of the animal body was well known.
+Descriptive Anatomy was not far from where it now is.
+Comparative Anatomy, which had made good progress,
+was given a fresh impetus by the researches and by the
+authority of a brilliant group of French investigators,
+headed by Baron Georges Cuvier (1769-1832), whose
+influence spread to England, Germany, and America,
+where the leading exponents were Richard Owen
+(1804-92), Karl Gegenbaur (1826-1903), and E. D.
+Cope (1840-97). Cuvier was a biological dictator
+whose opinion did much to encourage investigation,
+and something to discourage some important investigators.
+His services to Comparative Anatomy can
+hardly be overrated. There was, however, still no effective
+knowledge of the anatomical differences between
+the races of man, while the species of man and of
+allied forms, whose skeletons palaeontologists have
+since described, were quite unknown.</p>
+
+<p>As regards knowledge of the process of Development
+of the animal body, the broad lines of Embryology
+were being put on a firm basis by Karl Ernst von
+Baer (1792-1876), whose work was finished in 1837,
+though he lived another forty years. The subject was
+to be given a new meaning by the evolutionary school,
+which applied to new details and to particular instances
+the work of Charles Darwin (1809-82). Foremost of
+this school was Francis Maitland Balfour (1851-82).</p>
+
+<p><span class="pagenum" id="Page_205">205</span></p>
+
+
+<h4 id="b_Chemical_Physiology_in_the_Earlier_Nineteenth_Century">
+  (b) <i>Chemical Physiology in the Earlier Nineteenth Century.</i>
+</h4>
+
+<p>The analysis of the functions and workings of the
+body had advanced far less than the knowledge of its
+structure. The study of Respiration was perhaps in the
+best position. The elementary conception of Respiration
+attained by Lavoisier at the end of the eighteenth
+century (p. 155) was hardly extended till E. F. W.
+Pflüger of Bonn (1829-1910), in the sixties and
+seventies of the nineteenth century, showed that the
+essential chemical changes of respiration do not occur
+in the blood or in the lungs, but in the tissues.</p>
+
+<p>A very important figure in the scientific world of the
+thirties and forties of the nineteenth century was the
+German Justus von Liebig (1803-73), professor of
+Chemistry at Giessen. He was a convinced mechanist,
+and over the door of the University Laboratory which
+he founded he had inscribed the dictum <i>God has
+ordered all His Creation by Weight and Measure</i>. His
+great achievement was his application of chemical
+knowledge to physiology. He did much to introduce
+laboratory teaching, and certain apparatus which he
+invented is still in constant use.</p>
+
+<p>Liebig greatly improved the methods of organic
+analysis and notably he introduced a method for determining
+the amount of urea in a solution. This substance
+is found in human blood and urine, and was the first
+organic compound to be ‘synthetized’, that is to say,
+built up from inorganic materials. It is of very great
+physiological importance. This is due to the fact that
+it is regularly formed in the body in the process of
+breaking down the characteristic nitrogenous substances
+<span class="pagenum" id="Page_206">206</span>known as proteins. Along with his colleague,
+Friedrich Wöhler (1800-82), who had already synthetized
+urea, Liebig wrote a famous paper (1832) in
+which he showed, for the first time, that a complex organic
+group of atoms—or ‘radicle’ as it is called—is
+capable of forming an unchanging constituent through
+a long series of compounds, behaving throughout as
+though it were an element. This discovery is of primary
+importance for our conceptions of the chemical changes
+in the living body.</p>
+
+<p>From 1838 onwards, Liebig devoted himself to attempting
+a chemical elucidation of living processes. In
+the course of his investigations he did pioneer work
+along many lines that have since become well recognized.
+He taught the true doctrine, then little recognized,
+that animal heat is the result of combustion, and
+is not ‘innate’ (compare <a href="#Page_156">p. 156</a>). He classified articles
+of food with reference to the functions that he conceived
+they fulfilled in the animal economy. An outcome of
+this was his food for infants and his extract of meat.
+Very important was his teaching that plants derive the
+constituents of their food, their carbon and nitrogen,
+from the carbon dioxide and ammonia in the atmosphere,
+and that these compounds are returned by the
+plants to the atmosphere in the process of putrefaction.
+This discovery made possible a philosophical conception
+of a sort of ‘circulation’ in Nature. That which is
+broken down is constantly built up, to be later broken
+down again. Thus the wheel of Life goes on, the
+motor power being energy from without, derived
+ultimately from the heat of the sun.</p>
+
+<p>It was very unfortunate that Liebig conceived and
+<span class="pagenum" id="Page_207">207</span>adhered to a totally wrong view of the nature of putrefaction
+and fermentation, which it took Pasteur long
+years to displace.</p>
+
+
+<h4 id="c_Nervous_Physiology_in_the_Earlier_Nineteenth_Century">
+  (c) <i>Nervous Physiology in the Earlier Nineteenth Century.</i>
+</h4>
+
+<p>From Chemical Physiology we turn to glance at the
+knowledge of the Nervous System. Charles Bell and
+his contemporaries (p. 145) had attained to a clear distinction
+of the nature of motor and sensory nerves and
+their separate origin from the two spinal roots (<a href="#i208">Fig. 98</a>).
+The next fundamental contribution was made by Marshall
+Hall (1790-1857), who established the difference
+between volitional action and unconscious reflex (1833).</p>
+
+<p>The fundamental ideas in the conception of reflex
+action had already been adumbrated by Descartes. In
+the view of that philosopher, any stimulus is transmitted
+along nerve-fibers to the central nervous system. There,
+on account of existing nervous connections, it gives rise
+to a fresh impulse which passes along outgoing nerve-fibers
+to the active organ, muscle, or gland, which is
+thereby excited to activity (p. 128). Thus, every action
+of the organism, and its life as a whole, conforms to
+definite laws. These laws must be directed to its preservation,
+or organisms would cease to exist. It is thus
+possible to look on organisms simply as elaborate
+mechanisms. Except that we know that we ourselves
+think and feel, we might eliminate mind from our consideration
+of the action of beings other than ourselves.
+Such was the view taken by the mechanists and other
+members of the iatro-physical school (<a href="#Page_127">pp. 127-131</a>),
+which followed, to a greater or less extent, the teaching
+of Descartes. The course of physiological advance
+<span class="pagenum" id="Page_208">208</span>may be described, briefly, as the expulsion of the mental
+element from process after process associated with
+vital activity. This avenue leads on to a philosophical
+discussion whither we shall not now follow. It will suffice,
+at the moment, to remind the reader that only
+through the channel of <i>his own</i> thinking and feeling is
+he able to follow these physiological discussions at all.</p>
+
+<p>The conceptions of Descartes and of his successors
+were greatly extended by Marshall Hall. Interest was
+lent to Hall’s work by the contemporary discovery by
+French observers of what was regarded as a special
+center governing respiration—a very important reflex—in
+the lower part of the brain. Hall’s work gave
+‘reflex action’ a permanent place in Physiology.</p>
+
+<figure class="figcenter illowe30" id="i208">
+  <img class="w100" src="images/i208.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 98. Diagram of Transverse Section of the Spinal Cord and
+    the Main Nerves derived from it.</span>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i209">
+  <img class="w100" src="images/i209.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 99. Diagram to illustrate simplest form of reflex</span> (cf. <a href="#i208">Fig. 98</a>).</p>
+    <p>An afferent impression from a sense organ to the spinal cord may give rise
+    to an efferent impulse by a purely intra-spinal process. This impulse may
+    be of the nature of a complex and balanced muscular act involving a whole
+    system of muscles, some of which may be antagonistic to each other. All this
+    may take place not only unconsciously, without any intervention from the
+    higher nerve-centers in the brain, but even in an animal from which the brain
+    has been removed. On the other hand, channels exist (and are indicated in
+    the diagram) for passage of impressions to and impulses from higher centers.
+    These higher centers in many cases control or modify the resulting muscular
+    or other action to a greater or less degree.</p>
+  </figcaption>
+</figure>
+
+<p>Since Hall’s time there has been a great extension of
+the conception of reflexes. It has been shown that,
+besides the simple nervous arc (<a href="#i209">Fig. 99</a>), there are more
+complex nervous arcs which depend for their action on
+the integrity of an elaborate mechanism. The nervous
+<span class="pagenum" id="Page_209">209</span>system is ‘integrated’ under higher and higher centers,
+till at last the highest centers of the brain are reached
+(<a href="#Page_308">pp. 308-11</a>). Many of the ordinary acts of life, sneezing,
+coughing, standing, walking, even breathing, are
+expressible as reflexes. The attempt has also been made
+to press the ‘instincts’ into the same category. But it is
+difficult to separate the instinctive from the volitional
+elements or to define either. Vast, therefore, as is the
+development of this department of physiology, it is a
+very delicate task for the historian to pass any verdict
+upon it. The ultimate value of all this work must
+depend upon the conception that the next generation
+<span class="pagenum" id="Page_210">210</span>attaches to the mental element in vital phenomena.
+There is evidence of reaction at the present time from
+the extreme mechanist physiological position.</p>
+
+<p>Lastly, in the discussion of work on the nervous
+system comes the question of the localization of functions
+of the brain. The possibility of such localization
+is a very ancient speculation. The idea was developed
+along rational lines, in the first third of the nineteenth
+century, by certain Viennese workers who, having made
+important contributions to science, unfortunately afterwards
+degenerated into phrenological quacks. Later
+several German observers began the study of the electrical
+excitation of those parts of the cortex of the
+<span class="pagenum" id="Page_211">211</span>brain which specially control movement (<a href="#i210">Fig. 100</a>). The
+work was continued and developed by a number of distinguished
+French and English observers, among whom
+Paul Broca (1824-80), Hughlings Jackson (1834-1911),
+and Sir David Ferrier (1843-) should be commemorated.
+Under their influence many operations usually regarded
+as involving complex mental processes, such as vision,
+speech, reading, writing, drawing, have been represented
+as depending on simple nervous relationships. Centers
+for the initiation of these operations have been described.
+Of late years, there has been reaction from this
+mechanical conception of the brain as an organ of the
+mind. The older school has, however, achieved clinical
+success especially at the hands of the great French physician
+Jean Marie Charcot (1825-93) and his pupils.</p>
+
+<figure class="figcenter illowe30" id="i210">
+  <img class="w100" src="images/i210.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 100. Diagram to illustrate some of the main facts of
+    Cerebral localization.</span>
+  </figcaption>
+</figure>
+
+
+<h3 id="_4_The_Experimental_Foundations_of_Modern_Medicine">
+  § 4. <i>The Experimental Foundations of Modern Medicine.</i>
+</h3>
+
+<p>We may turn back to consider those who have been
+the immediate progenitors of modern Physiology.
+Among these, three men stand out beyond all others.
+In order of seniority, and perhaps of genius, they are
+Johannes Müller, Claude Bernard, and Karl Ludwig.</p>
+
+
+<h4 id="a_The_Work_of_Johannes_Muller">
+  (a) <i>The Work of Johannes Müller.</i>
+</h4>
+
+<p>Johannes Müller (1801-58) was the greatest physiologist
+Germany has produced, and perhaps the greatest
+physiologist of all time. His genius was of the universal
+type and, despite his early death, he attained equal distinction
+in every department which he touched. Among
+these were Comparative Anatomy, Embryology, Physiological
+Chemistry, Psychology and Pathology. He
+was a careful scholar, well versed in the history of the
+<span class="pagenum" id="Page_212">212</span>subjects which he taught, and as great a teacher as he
+was an investigator. A very large number of the best-known
+men who have advanced Medicine during the
+nineteenth century were his pupils while he was a professor
+at Berlin. His lovable character was pervaded
+by a mystical tendency.</p>
+
+<p>Müller’s text-book of Physiology began to appear
+in 1834. It introduced into the subject the comparative
+and psychological points of view, which were not fully
+appreciated until the generation that followed. The
+most remarkable generalization associated with his
+name—and one further developed by Ewald Hering
+(1834-1918)—is the ‘Law of Specific Energies’.
+According to this law each sensory nerve, however
+stimulated, gives rise to its own specific sensation and
+to no other. Conversely, the same stimulus applied to
+different organs of sense produces a different sensation
+in each organ—that sensation, in fact, that is its specific
+attribute. Thus electrical, mechanical, thermal
+stimulation produce only the sensation of light when
+applied to the optic nerve. On the other hand, any
+particular form of stimulation, for example electrical,
+produces sensations of light, smell, hearing or taste if
+applied to the appropriate nerves.</p>
+
+<p>A moment’s reflection will enable the reader to realize
+the very great philosophical importance of these conclusions.
+They provide experimental evidence that the
+things of the external world are not in themselves discernible
+by us. Such external things we know only by
+the events to which they give rise acting on our senses,
+and yet from one and the same event utterly different
+sensations arise within us. To beings with senses different
+<span class="pagenum" id="Page_213">213</span>from ours the world also would be different. The
+‘Law of Specific Energies’ is thus fundamental for our
+view as to the range of validity of Scientific Method.</p>
+
+<p>Among other important contributions of Johannes
+Müller to the physiology of the nervous system were
+his experimental confirmation of Bell’s researches
+on the spinal roots (p. 145) and his experiments on
+the production of the voice. He launched important
+theories in explanation of color vision, of the mechanism
+of hearing, and of the phenomena of fever. He
+was one of the first to use the microscope in pathology
+and he was one of the founders of Physiological Chemistry.</p>
+
+<p>Like every investigator Müller made mistakes. In
+1840 he stated that the velocity of a nervous impulse
+could never be measured. By 1852 his gifted pupil,
+Hermann von Helmholtz (1821-94), had measured it.
+Much of Helmholtz’s work hardly comes within our
+department. He was, however, inventor of the instrument
+known as the <i>Ophthalmoscope</i>, by means of which
+the interior of the eye can be examined. This is the
+main factor which has enabled Ophthalmology to
+develop along true scientific lines (p. 319).</p>
+
+
+<h4 id="b_The_Work_of_Claude_Bernard">
+  (b) <i>The Work of Claude Bernard.</i>
+</h4>
+
+<p>Claude Bernard (1813-78), the great French physiologist,
+was Müller’s junior by twelve years and was in
+almost every respect a contrast to him. His mind was
+of that peculiarly French type to which anything
+mystical is abhorrent. He had few eminent pupils who
+owed much to him directly, but the influence of his
+ideas, through his writings, can hardly be exaggerated.
+<span class="pagenum" id="Page_214">214</span>Especially Bernard was the founder of ‘Experimental
+Medicine’, that is of the artificial production of disease
+by chemical and physical means. This is one of the
+most important scientific movements within our field.</p>
+
+<p>Bernard’s great discovery, which occupied him for
+over ten years, was that the liver has the power of
+building up and storing certain highly complex substances,
+derived from the food and brought to it by the
+blood. The substances thus stored, and notably that
+known as <i>glycogen</i>, are distributed to the body according
+to its needs, in simplified and modified form. Now
+Wöhler in 1828 had synthetized urea (p. 206) and it
+was well recognized that this substance is a final degradation
+product which the body manufactures by breaking
+down the substances derived from food. It was also
+recognized that from this breaking-down process the
+bodily energy is obtained. Bernard showed that the
+body could build up complex chemical substances as
+well as break them down. This destroyed the conception,
+then still dominant, that the body could be regarded
+as a bundle of organs, each with its appropriate
+and separate functions. Bernard thus introduced what
+we may call a ‘Physiological Synthesis’, a conception of
+great import for the development of medical ideas.</p>
+
+<p>No less important, and bearing on the synthetic view
+of the working of the animal body, was Bernard’s work
+on the physiology of digestion. Up to the time of
+Bernard, an elementary knowledge of the facts of
+digestion in the stomach constituted the whole of digestive
+physiology. While Bernard was working on the
+glycogenic function of the liver, another worker had
+suggested that the secretion of the organ known as the
+<span class="pagenum" id="Page_215">215</span>‘pancreas’, or sweetbread, emulsifies fats. Soon after, a
+German researcher showed that pancreatic juice acts on
+starch. Bernard now stepped in and cleared up the
+whole subject. He showed that digestion in the stomach
+is, as he described it, ‘only a preparatory act’. He proceeded
+to demonstrate that the pancreatic juice, passing
+into the intestine, emulsifies the fatty food substances
+there and splits them up into fatty acids and glycerin.
+He further demonstrated the power of the pancreatic
+juice to convert starch into sugar, and he showed that it
+has a solvent action on such ‘proteids’ or organic nitrogenous
+substances as have not been dissolved in the
+stomach.</p>
+
+<p>The third great achievement of Bernard was his
+exposition of how the blood-supply to the different
+parts of the body is regulated. This we now call the
+‘Vaso-Motor Mechanism’. In 1840 the existence of
+muscle fibers in the coats of the smaller arteries was
+discovered. Bernard showed that the contraction and
+expansion of the ‘arterioles’ is associated with a complex
+nervous apparatus. The reactions of this apparatus
+depend upon a variety of circumstances in a variety of
+other organs; again an illustration of the close and complex
+interdependence of the various functions of the
+body upon each other.</p>
+
+
+<h4 id="c_The_Work_of_Karl_Ludwig">
+  (c) <i>The Work of Karl Ludwig.</i>
+</h4>
+
+<p>Karl Ludwig (1816-95) held a series of professorships
+at Marburg, Zürich, Vienna and Leipzig. He
+was, after Müller, the greatest of German physiological
+teachers, and he surpassed even Müller in the number
+of his pupils. As a physiologist he was chiefly remarkable
+<span class="pagenum" id="Page_216">216</span>for his ingenuity as an inventor, for his wide and
+deep knowledge of the physical sciences and for his
+extreme generosity in handing over his work to his
+pupils.</p>
+
+<p>Among the many lines of investigation of fundamental
+importance which Ludwig initiated, some of
+the most remarkable depended on the discovery of new
+methods. Just as the microscope had opened to the
+anatomist unexplored fields of research by bringing him
+into closer relation with objects which were hitherto
+beyond his scrutiny, so the rapid progress of physics and
+chemistry had placed more exact modes of observation
+and of measurement within reach of the physiologist.
+But the application of these methods was attended
+with great difficulty; there was no physiological
+laboratories, no instruments, no capable mechanicians
+to whom the physiologist could apply for assistance.
+Under such conditions, ingenuity and resource were
+indispensable to success, and in these qualities Ludwig
+was pre-eminent.</p>
+
+<p>Accordingly, we find that two of the most important
+of the early investigations of Ludwig were as much due
+to his ingenuity as an inventor as to his clear grasp of
+the physiological questions which his inventions were
+intended to elucidate. The most interesting of these
+inventions, or rather adaptations, is the mechanically
+rotating drum or <i>kymograph</i>, as it is called. The word
+itself is derived from two Greek words which mean
+‘wave writer’. This instrument is now widely used, not
+only in Physiology but in every department of Science
+in which permanent records of any continuous movement
+are desired. The most familiar instance is the
+<span class="pagenum" id="Page_217">217</span>self-recording barometer. The kymograph—the use of
+which had been suggested by Thomas Young (p. 319,
+and <a href="#i217">Fig. 101</a>) in 1807—led to much wider applications
+of the method of automatic record. Ludwig himself applied
+it to indicate the movements of respiration, as well
+as the variations in arterial pressure. Subsequently it
+<span class="pagenum" id="Page_218">218</span>became further adapted to the ‘graphic method’, and it
+serves not only for the investigation of animal movements
+of every conceivable kind, but even for the
+transient and delicate electrical changes which are
+associated with vital action.</p>
+
+<p>An instrument invented by Ludwig is the mercurial
+blood-pump, the purpose of which is to separate from
+a known quantity of blood, derived directly from the
+circulation, the mixture of gases which it yields to a
+vacuum. This is an indispensable apparatus for the
+investigation of the physiology of breathing.</p>
+
+<p>Ludwig devoted much attention to the physiology
+of secretion. Here his work has been of great importance
+in connection with the time-honored discussion
+between the ‘vitalists’ and the ‘mechanists’. He succeeded
+in showing that the process of secretion can
+be so transformed experimentally as to do external
+mechanical work. This was victory for the mechanist
+theory. The idea has since been applied to many
+structures.</p>
+
+<p>It is impossible to attempt here any general summary
+of the conclusions reached by physiological research
+since Ludwig. Some have affected the actual practice
+of Medicine. Others are too recent or too little certain
+to have reacted in this manner. It is, however, safe
+to say that the more important conclusions of the three
+modern founders of the science, Müller, Bernard, and
+Ludwig, form the main scientific background of the
+clinical practice of our time. The results of the movement
+that they represent, together with the knowledge
+of the cellular structure of the body (§ 5, <a href="#Page_219">p. 219</a>) and of
+the life-histories of the disease-causing organisms (§ 6,
+<span class="pagenum" id="Page_219">219</span>p. 224), are the three main groups of ideas which separate
+the physician of our day from Laënnec (p. 161).</p>
+
+<figure class="figcenter illowe30" id="i217">
+  <img class="w100" src="images/i217.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 101. Thomas Young’s Kymograph.</span></p>
+    <p>The cylinder <span class="allsmcap">H</span> turns with the axis <span class="allsmcap">AB</span> on which it is rigidly fixed. It is
+    rotated by a handle at <span class="allsmcap">A</span> which raises the weight <span class="allsmcap">C</span>. When the weight is
+    allowed to fall the cylinder rotates automatically. The rest of the apparatus
+    is devised to secure constancy in rate of rotation. This was done by utilizing
+    the effects of centrifugal force.</p>
+    <p>(As the rate of rotation increases the pendula <span class="allsmcap">D</span> and <span class="allsmcap">E</span> fly apart, they
+    separate the weights <span class="allsmcap">F</span> and <span class="allsmcap">G</span>. These move with friction which increases as
+    they separate, thus decreasing the rate of rotation.)</p>
+    <p>The movements of the pen at <span class="allsmcap">K</span> are transferred into permanent graphic
+    form by writing on the rotating cylinder <span class="allsmcap">H</span>.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_5_The_Cell_Theory_and_Cellular_Pathology">
+  § 5. <i>The Cell Theory and Cellular Pathology.</i>
+</h3>
+
+<p>During the process of the microscopic analysis of
+plants that took place in the seventeenth century a
+number of observers distinguished the walls of plant-cells
+and the word <i>cell</i> was introduced into the English
+language. Less clearly, a similar structure was discerned
+in animals. No real understanding of the nature
+of cells was, however, reached. Little farther progress
+was made in the eighteenth century, but just at its close
+a young French microscopist, Marie François Xavier
+Bichat (1771-1802), likened the microscopic structure
+of the animal body to the substance of a woven fabric.
+The word he used was the old French term <i>tissu</i>. He
+perceived that the different parts of the body, bones,
+muscles, nerves, blood-vessels, and the like, each presented
+a characteristic microscopic pattern. According
+to these appearances he analyzed the parts of the body
+into twenty-one ‘tissues’. Study of this kind came to
+be called ‘Histology’ (Greek <i>histos</i> = web).</p>
+
+<p>During the seventeenth, eighteenth, and early nineteenth
+centuries, some advances were made in the
+knowledge of those organisms whose bodies are made
+up of only one cell, but their essential nature was still
+unappreciated. In the early nineteenth century a number
+of botanists and others were observing cells and cell
+contents. But no important advance in the interpretation
+of the appearances was made until the matter was
+taken up by Schleiden.</p>
+
+<p>Matthias Jakob Schleiden (1804-81), professor at
+<span class="pagenum" id="Page_220">220</span>Jena in 1838, put the matter in a new light. He noted,
+as had certain of his predecessors, the constant presence
+in every cell of the structure we now call the ‘nucleus’,
+and came to the conclusion that it is essential to the
+life of every cell. He reached the conception, moreover,
+that in a multi-cellular organism, such as a tree,
+every cell has a double life, one an essential and independent
+one, pertaining to its own development alone,
+the other an incidental and dependent one, in so far as
+it is an integral part of the plant. His work was somewhat
+vitiated by a fanciful conception of the origin of
+new cells.</p>
+
+<p>The work of Schleiden was amplified and corrected
+in 1839 by Theodor Schwann (1810-82), a pupil of
+Müller. He showed that the tissues of animals, like
+those of plants, are susceptible of analysis into cells,
+and the difficulty of this process arises from the extreme
+modification of such cells as have developed for various
+special purposes. He showed too that the ovum or egg
+of animals is, in the first instance, a single cell, and
+that the cells of the body are derived and descended
+from it. He demonstrated that the entire animal or
+plant body is composed either of cells or of substances
+that are excreted or thrown off by cells. He gained
+some insight into the life of animal cells and in doing
+so he invented the very useful word <i>metabolic</i>. The
+word means ‘liable to change’. It was used by Schwann,
+and is still habitually used in modern Medicine to
+indicate chemical changes within the body which are
+specially associated with living activity.</p>
+
+<p>Contributions to the cell theory were made by other
+botanists. Hugo von Mohl of Tübingen (1805-72)
+<span class="pagenum" id="Page_221">221</span>distinguished the contents of the vegetable cell just
+under the cell-wall from the watery sap that fills the
+interior, introducing for it the term <i>protoplasm</i> (1846).
+The Swiss, Karl v. Nägeli (1817-91), by chemical
+<span class="pagenum" id="Page_222">222</span>examination proved that protoplasm is nitrogenous and
+differs from other cell constituents (1862).</p>
+
+<p>The cell theory was placed on a firm and clear footing
+by Max Schultze (1825-74), successor of Helmholtz
+(p. 213) as professor of Anatomy at Bonn. He defined
+the cell as ‘a lump of nucleated protoplasm’ (1861),
+introduced the idea of protoplasm as ‘the physical basis
+of life’, and showed that it presented essential similarities,
+physiological and structural, whether in plants or
+animals, and whether in higher or lower forms.</p>
+
+<p>The study of tissues, Histology, was raised to the
+status of an independent science by the Swiss, Albrecht
+von Kölliker (1817-1905), pupil of Müller and professor
+at Würzburg, who wrote the first text-book on
+the subject (1850-52). Apart from this achievement,
+Kölliker is remarkable for having reached some of the
+conclusions in connection with heredity that are associated
+with the name of Mendel, of whose work he
+knew nothing.</p>
+
+<p>Even more influential on medical thought than Kölliker
+was Rudolf Virchow (1821-1902) of Berlin, one
+of the leading names in modern Medicine. There is
+indeed hardly any department of medical thought that
+has not gained something from Virchow’s work. His
+great achievement is the way in which he carried the
+Cell Theory into the analysis of diseased tissues. In
+his <i>Cellular Pathology</i> (1858) he analyzes diseased
+tissues from the point of view of cell formation and cell
+structure. Important sections of the science of Cellular
+Pathology have been explored so well by Virchow that
+they have been little extended by his successors. He
+initiated the familiar idea that the body may be regarded
+<span class="pagenum" id="Page_223">223</span>as ‘a cell State in which every cell is a citizen’.
+Disease is often but a civil war. The white blood corpuscles,
+which have the power of engulfing and rendering
+innocuous bacteria and other foreign bodies,
+have been compared to police or scavengers. In some
+respects Virchow was strangely conservative, and
+notably he opposed the evolutionary view of the origin
+of living forms. Virchow’s conceptions of the functions
+of the white blood corpuscles were largely extended by
+the Russian biologist Élie Metschnikoff (1845-1916)
+and the English worker Almroth Wright (1861-).</p>
+
+<p>Since Virchow and Kölliker the study of the intimate
+structure and workings of the cells themselves, as distinct
+from the tissues, has become a separate and independent
+science under the name of <i>Cytology</i>. It may
+even be extended to the study of cells in disease as
+<i>Cyto-Pathology</i>.</p>
+
+<p>Among the major developments of Cellular Pathology
+and Cyto-Pathology is the study of abnormal ‘new
+growths’. The most malignant types of these belong to
+the group known as the ‘Cancers’. The occurrence
+of most of these becomes more frequent as life
+advances (<a href="#i337">Fig. 135</a>). Their cytological features are
+now well known. A cancer consists essentially of an
+increase of cellular tissue, following abnormally rapid
+multiplication of one type of cell. The new growth
+is equipped with a blood-supply which enables it to
+increase at the expense of other tissues and regardless
+of their needs.</p>
+
+<p>Cancers almost always arise at one point, and are
+very seldom multiple in origin. It is fairly established
+that they are not infectious or contagious, and there is
+<span class="pagenum" id="Page_224">224</span>no very satisfactory evidence that a tendency to them is
+inherited. Our scientific knowledge of Cancers is
+largely derived from animals. Cancers are ‘specific’ in
+the sense that those of one animal species will not grow
+when inoculated into another species. An immense
+amount of work has been done on inoculated Cancers,
+but it has become evident that some physiological factor
+is involved in Cancer incidence such that an inoculated
+Cancer is not entirely comparable with so-called ‘spontaneous’
+Cancer. As to what that physiological factor
+can be we are still in the dark.</p>
+
+<p>Although we know nothing effective as to this
+physiological factor, yet experiments in the artificial
+production of Cancer, apart from inoculation, have been
+attended with success. That various forms of chronic
+irritation are associated with the onset of Cancer has
+long been clinically recognized. It has been found
+possible to reproduce experimentally this relation between
+irritation and new growth, and so, for example,
+to induce Tar Cancer in mice. Nevertheless, it must be
+admitted that Cancer investigation is in an unsatisfactory
+state, and has yielded fewer positive results
+than any other department of Pathology of comparable
+importance. It is possible that we do not yet know
+enough of normal Cell Physiology to investigate with
+profit the forms of cellular perversion known as
+Cancer.</p>
+
+<figure class="figcenter illowe30" id="i221">
+  <img class="w100" src="images/i221.jpg" alt="figures 102 to 105">
+  <figcaption>
+    <p class="center">Drawings by Theodor Schwann to illustrate the nature and origin of
+    animal cells. All are highly magnified.</p>
+    <p><span class="smcap">Fig. 102.</span> The first step in the origin of cartilage from cellular tissues.
+    At the lower part the young cells are without cell-walls. In the upper part
+    they have formed walls and are beginning to secrete cartilaginous substance.
+    Nuclei and nucleoli are clearly visible.</p>
+    <p>Above is shown a piece of maturer cartilage, in which the cells are imbedded
+    in a mass of cartilaginous material.</p>
+    <p><span class="smcap">Fig. 103.</span> Pigment cells, such as are characteristic of the skin of the frog.
+    In the lowest cell, which is contracted, the nucleus is concealed by the pigment.
+    The upper two are more expanded and in them nuclei can be seen.</p>
+    <p><span class="smcap">Figs. 104 &amp; 105</span> show how structures of very diverse form can be differentiated
+    from cells of the same type.</p>
+    <p><span class="smcap">Fig. 104.</span> Young cells from a developing feather. These cells may enlarge,
+    secrete hard walls, and form the fine spongy tissue of the inner part of the
+    shaft of the feather. Or the cells may elongate, the protoplasm become
+    granular, and finally break up into fibers (<a href="#i221">Fig. 105</a>). These form the tough
+    fibrous matter of the outer part of the shaft of the feather. In either case, the
+    nucleus disappears and the cell dies.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="6_establishment">§ 6. <i>Establishment of the Doctrine of the Germ Origin of
+Disease.</i></h3>
+
+<p>The view that many diseases, especially those of a
+contagious or infectious nature, originate from the
+<span class="pagenum" id="Page_225">225</span>invasion of the body by special organisms and their
+multiplication within the body, came into prominence
+in the second half of the nineteenth century. There had
+been many previous adumbrations of this view and, in
+its final establishment, more than one hand may be
+discerned. Above all others who have worked in this
+field towers the mighty figure of Louis Pasteur (1822-95).
+We shall do no grave injustice to any man if we
+treat the scientific demonstration of the doctrine as
+the product of his superb genius.</p>
+
+<p>The opening of Pasteur’s interest in disease can be
+seen in his work on fermentation. At first he was faced
+with the opposition of Liebig. According to that
+eminent chemist, fermentation was not the result of
+vital activity but was a purely chemical change (p. 207).
+A ferment he regarded as an unstable organic product,
+the character of which determined the manner of
+decomposition of the medium in which it is placed.
+Pasteur demonstrated that, as there is a specific alcoholic
+ferment, so there is a specific milk-souring ferment.
+Any nitrogenous matter present in a fluid containing it
+will serve as food for the development of a ferment, but
+will not of itself induce fermentation. Ferments have,
+he demonstrated, the power of reproduction. Pasteur
+rapidly seized on the idea of the specificity of ferments.
+An albuminous sugar solution can be converted into
+various products by the addition of various ferments.
+According as one sows, so will one reap. The milk-souring
+ferment, Pasteur concluded, is organized and
+living, and its action is correlated to its development
+and organization. No life, no ferment; no ferment, no
+fermentation.</p>
+
+<p><span class="pagenum" id="Page_226">226</span></p>
+
+<figure class="figcenter illowe30" id="i226">
+  <img class="w100" src="images/i226.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 106. Organisms of Fermentation highly magnified</span> from
+    Louis Pasteur’s <i>Studies on Beer</i> of 1876.</p>
+    <p>1. Bacillus of Turned Wine. 2. Ferment of Soured Milk. 3. Butyric
+    Ferment. 4. Ferment of Ropy Wine. 5. Ferment of Vinegar. 6. Amorphous
+    deposit. 7. Sarcinae.</p>
+  </figcaption>
+</figure>
+
+<p>During the next years Pasteur applied himself to
+a study of ferments and notably of those which involve
+deterioration of wines and beers. This led him to perceive
+that there is a great multiplicity and variety of
+these organisms. Now it was an old and well-known
+<span class="pagenum" id="Page_227">227</span>view that fermentation, putrefaction, and the infection
+of disease had much in common. It was perfectly
+natural, therefore, for Pasteur to regard the latter in the
+light of a vital process. A great difficulty was, however,
+the demand that any such doctrine made on the germ-bearing
+capacity of the air. Cities were not slow to
+avail themselves of this weakness, and pointed out that,
+according to Pasteur, the air must be one solid mass
+of germs! For the opponents of Pasteur the living
+organisms found in the process of fermentation or
+decomposition were the result, not the cause, of the
+process. These organisms were regarded by them as
+spontaneously generated in the fermentation process.
+Thus arose a discussion of the old theme of spontaneous
+generation.</p>
+
+<p>By 1859—the year of publication of Darwin’s <i>Origin
+of Species</i>—Pasteur was engaged in controversy as to
+the ‘Origin of Life’. The discussion specially turned
+round what were then regarded as the lowest forms
+of life, the Bacteria. Were they ever spontaneously
+generated, or were they not? If a flask of broth,
+supposedly sterilized by boiling, went ‘bad’ and
+organisms appeared in it, was it certain that they had
+come from without, or could they have been spontaneously
+generated by the broth itself? Life must
+begin somewhere. Then why not here at this lowest
+stage? If this view be justifiable, Pasteur’s doctrine
+of the nature of ferments must fall to the ground.</p>
+
+<p>Pasteur had thus before him the task of proving a
+universal negative—a task impossible in Formal Logic.
+But Science is not Formal Logic. In the end he
+clinched the matter by an exquisitely simple experiment
+<span class="pagenum" id="Page_228">228</span>which must, at once, carry conviction. A flask
+with a long S-shaped neck is filled with a putrescible
+fluid. It is heated to boiling, to kill all organisms, and
+then left in the still air of a room. Air can enter, but
+any floating germs that enter naturally fall on the floor
+of the S-shaped neck of the flask. Months may go by
+without any change in the liquid, but once the neck is
+severed, so that organisms can enter freely from the air,
+fermentation sets in within a few hours, and organisms
+can be detected in the liquid. Only living organisms
+from the air can have caused the change.</p>
+
+<figure class="figcenter illowe30" id="i228">
+  <img class="w100" src="images/i228.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 107. Pasteur’s crucial experiment</span> to prove that fermentation
+    or putrefaction is the result of the action of air-borne organisms. The S-shaped
+    flask contains a putrescible fluid such as meat broth. The flask
+    containing the broth is subjected to prolonged heating to destroy all organisms.
+    It is then left in position with the mouth open. Days, weeks, months,
+    even years, may pass without sign of putrefaction. No organisms reach the
+    broth, since any that enter the open mouth fall on the floor of the neck and
+    remain there. Sever the neck of the flask so that organisms can fall from the
+    air directly on to the surface of the fluid and these multiply. In a few hours
+    putrefaction sets in. This is shown by the formation of a film or scum on the
+    surface just below the severed neck. Microscopically the broth is seen to be
+    teeming with organisms.</p>
+  </figcaption>
+</figure>
+
+<p>The first disease which Pasteur was able to demonstrate
+as causatively related to a living organism was
+a condition that was devastating the silk-worm industry
+of France. In 1866 he proved the contagiousness of the
+disease, showed that it was due to a living organism,
+<span class="pagenum" id="Page_229">229</span>and followed the organism through the life-history of
+moth, egg, worm, and chrysalis.</p>
+
+<p>In 1870 the Franco-Prussian war broke out. Pasteur
+now decided to make investigations into the diseases
+of beer, his object being to improve the French brews
+and to carry the war into the enemy’s camp by making
+them equal to the German! He succeeded in isolating
+special organisms, mostly yeasts, which produced defects
+in beer (<a href="#i226">Fig. 106</a>). This work naturally led to an
+enlargement of his views on the nature and action of
+micro-organisms.</p>
+
+<p>About this time Pasteur was elected a member of the
+French Academy of Medicine, a very unusual honor
+for one not a medical man. Lister had already begun
+his teaching, based partly on the work of Pasteur, and
+indeed his first important paper on antiseptic surgery
+had been published in the very year of the Franco-Prussian
+war. On entering the Academy Pasteur
+found himself faced by all kinds of ancient prejudices
+and misconceptions in connection with his new
+doctrine, and especially with his denial of spontaneous
+generation. Among his supporters was the physiologist,
+Claude Bernard (p. 213). His work proceeded to more
+and more triumphant issues.</p>
+
+<p>The first disease that affects man on which Pasteur
+was able to throw light was Anthrax, in relation to
+which his work interdigitates with that of Robert
+Koch and some other observers. Anthrax is a deadly
+and highly contagious condition which commonly
+affects cattle, but sometimes spreads to man. As early
+as 1855, a German observer had noted microscopic
+rod-like objects in the blood of beasts dead of the
+<span class="pagenum" id="Page_230">230</span>disease. In 1868 an older French contemporary of
+Pasteur had shown that a bacillus is not simply the
+inseparable companion of the disease, but also is its
+cause and its only constantly acting cause. At this time
+the losses of cattle from Anthrax in France were enormous.
+The character of the outbreaks had been studied
+and seemed wholly unexplained by what was known of
+the bacillus. Farmers found that they lost cattle in
+fields from which infected animals had been excluded
+for months or even years. How was it to be explained?</p>
+
+<p>The explanation was, in fact, advanced in 1876 by
+the German observer, Robert Koch of Berlin (1843-1910),
+whose work was now beginning. He showed
+that the anthrax bacilli under certain conditions formed
+‘spores’, that is to say small encysted bodies, exceedingly
+resistant to heat and to other changes of external
+conditions (<a href="#i231">Fig. 108</a>). This discovery opened up a new
+field which was cultivated by Koch and Pasteur and
+their followers.</p>
+
+<figure class="figcenter illowe30" id="i231">
+  <img class="w100" src="images/i231.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 108. Bacilli of Anthrax</span>, from a culture, highly magnified.</p>
+    <p>
+    The rod-like organisms are growing typically in chains. Some of the rods
+    have white clear spots in them. These are the highly resistant ‘spores’.
+    </p>
+  </figcaption>
+</figure>
+
+<p>While making his studies on ferments in 1863,
+Pasteur had witnessed the formation of spores in the
+organisms of butyric fermentation, but had failed to
+grasp their significance. In 1869 he had again found
+spores forming in the organisms of silk-worm disease,
+and had shown that they resisted prolonged drying.
+On the basis of their resistance he had explained the
+persistence and latency of the silk-worm disease. Other
+observers had had similar experiences. The investigations
+of none of them, however, approached in
+brilliance and completeness those of Koch.</p>
+
+<p>Koch found that spores always form in the blood
+and tissues of animals dead of Anthrax, provided that</p>
+
+<p><span class="pagenum" id="Page_231">231</span></p>
+
+<p>(1) the temperature is suitable, and (2) there is sufficient
+oxygen. These two conditions, temperature and oxygen,
+were found to be necessary. Below 18° Centigrade
+spores are not formed; at 30° Centigrade they occur
+at the end of thirty hours; at 35° Centigrade in twenty
+hours. The rapidity with which spores are formed
+is, therefore, proportional to the amount of heat.
+Oxygen was also found to be indispensable. Anthrax
+blood, if deprived of oxygen, ceases to be virulent in
+twenty-four hours without putrefaction. When the
+blood is allowed to putrefy the virulence also disappears
+if putrefaction exhausts the oxygen quickly
+enough to prevent the spores having time to form. If
+<span class="pagenum" id="Page_232">232</span>the spores have already formed, putrefaction does not
+kill them, nor does it prevent them from developing
+later if circumstances become favorable. The persistence
+of the disease and its return in an infected
+country was thus explained. It was the spore which
+was the agent of preservation, which persisted where
+the conditions of temperature and of aeration had permitted
+it to form, and which always held itself in
+readiness to make new victims.</p>
+
+<p>The matter was carried further by Pasteur in 1877.
+At that time he did not know of all the work of Koch.
+He succeeded in obtaining pure cultures of Anthrax.
+The question was then still being debated in France
+as to whether Anthrax was caused by a ‘virus’, that is
+to say a non-living poison, or by a microbe. Pasteur had
+long been a believer in the microbic theory, and it
+seemed to him probable that the blood of an animal
+infected with Anthrax, if sown in a suitable medium,
+would stock it solely with anthrax bacilli which he could
+then keep pure for an indefinite time in successive
+cultures, as he had done with yeast and other ferments.</p>
+
+<p>Experiment proved this to be the case, and showed
+that the anthrax organism multiplied abundantly in
+urine made neutral or slightly alkaline. From that time
+the problem was solved. Take a series of cultures of
+the organism, transferring each time one drop from the
+preceding culture into 50 c.c. of fresh urine. The first
+dilution is 1/1000, the second one in a million, the
+third one in a thousand million. After ten cultures it
+falls to such a figure that the original drop of blood
+has been drowned in an ocean. Everything that it
+carried with it, to which we might attribute the production
+<span class="pagenum" id="Page_233">233</span>of Anthrax—red corpuscles, white corpuscles,
+granules of all sorts—is either destroyed by the change
+of medium or is widely disseminated in this ocean
+and is lost. Only the organism can escape the dilution.
+Why? Because it has multiplied in each of the cultures.
+A drop from the last culture killed a rabbit or guinea-pig
+as surely as a drop of anthrax blood. It was, therefore,
+to the organism that the virulence belonged. A conclusion
+of the first rank was firmly established.</p>
+
+<p>With a ‘pure culture’ of Anthrax in his possession
+Pasteur was able to experiment in a way which none
+had previously attempted. The most interesting stage
+of his work was now entered upon. He perceived that
+there are some species of animals which are refractory
+to Anthrax. Such are the birds. Nevertheless, the blood
+of a bird, when drawn from the animal, is an excellent
+culture medium for the bacterium. Why does it
+resist infection in the animal? Pasteur showed that the
+anthrax organism will not live in the bird because the
+living-blood in full circulation is filled with an infinite
+number of corpuscles which, in order to live and perform
+their physiological function, need free oxygen.
+When, therefore, the anthrax organism enters normal
+blood of living birds, it meets competitors ready to seize
+the oxygen for their own use. But the blood of other
+animals besides birds contains corpuscles eager for oxygen.
+Why can anthrax grow in them and not in birds?
+This question Pasteur answered by a convincing series
+of experiments (1878). The normal temperature of
+birds is higher than that of mammals and is, moreover,
+higher than that at which the growth of the anthrax
+organism is most vigorous. Thus the blood corpuscles
+<span class="pagenum" id="Page_234">234</span>of the bird have the anthrax bacteria at a disadvantage.
+But if, by a cold bath, the temperature of a bird be
+lowered to that of a mammal, and if anthrax organisms
+be injected into the blood-stream, they will grow and
+flourish at the expense of the bird.</p>
+
+<p>The experiments with Anthrax on fowls led to experiments
+on the same creatures with another disease, the
+virulence of which was known to vary, Chicken Cholera.
+Thus arose naturally Pasteur’s ideas and observations
+in the department of Immunity (p. 261).</p>
+
+<p>If Pasteur can be said to have laid the foundations
+of the knowledge of the nature of infection, it is to
+Koch that we owe the main basis of the technique by
+which diseases are now studied. He it was who
+elevated Bacteriology into the position of a separate
+science. Soon after his work on Anthrax he published
+a remarkable research which placed our knowledge of
+wound infection on a firm footing. He is thus among
+those who helped to create modern surgical technique.
+Many other communications came from him. None
+was of more far-reaching importance than his demonstration
+of the organism of Tuberculosis in 1882. All
+subsequent work in connection with Consumption and
+allied conditions has been rendered possible only by
+this discovery of Koch. Other investigations associated
+with his name are on Cholera and on Sleeping Sickness.
+Koch was unquestionably the greatest bacteriologist
+that the world has seen. His genius was limited as
+compared to that of Pasteur, but his exquisite technical
+skill and acumen have never been excelled.</p>
+
+<p>Since the time of Pasteur and Koch, the study of
+infectious disease has developed along various special
+<span class="pagenum" id="Page_235">235</span>lines. The work of these two men, however, has determined
+the direction of those lines, and they themselves
+are the most typical, as well as the greatest, representatives
+of the most important of all movements in modern
+Medicine.</p>
+
+
+<h3 id="_7_Anaesthesia">
+  § 7. <i>Anaesthesia.</i>
+</h3>
+
+<p>The aspect of surgical practice was dramatically
+changed during the course of the nineteenth century
+by two discoveries, that of Anaesthesia and that of the
+Antiseptic method. It will be convenient to consider
+Anaesthesia first.</p>
+
+<p>There were from the earliest times many devices for
+producing more or less complete unconsciousness during
+surgical operations. An idea of the extremes to
+which surgeons at the beginning of the nineteenth
+century were put in this matter can be gathered from
+a glance at some of their devices (<a href="#i236">Fig. 108a</a>).</p>
+
+<p>The new era began in 1846 when the dentist,
+William Thomas Green Morton (1819-68), demonstrated
+at the Massachusetts General Hospital the
+simplicity and safety of Ether anaesthesia. The idea
+immediately caught on. Before the year was out
+Ether was being used for surgical purposes in England.
+In January, 1847, Sir James Young Simpson (1811-70)
+was using it in Edinburgh for obstetric purposes. A
+few months later he adopted Chloroform, which had
+been prepared by Liebig in 1832.</p>
+
+<p>The use of the drugs spread very rapidly and almost
+as rapidly changed the character of surgical technique.
+Until the adoption of anaesthesia, speed was of primary
+importance in surgical procedure. Excessive speed
+<span class="pagenum" id="Page_236">236</span>now became a matter of less importance, and operative
+neatness and completeness took its place as the chief
+quality of good surgery. Moreover, operations of a
+more drastic character could be undertaken since the
+shock to the patient was minimized. Women in labor
+were found to bear Chloroform peculiarly well and
+safely, and its use in midwifery steadily spread despite
+some foolish and fanatical opposition.</p>
+
+<p>Soon after the introduction of anaesthetics efforts
+were made by various methods to secure a painless state
+of a part without involving unconsciousness. The first
+successes were obtained in 1884 at Vienna with applications
+of solutions of the alkaloid (p. 325) Cocaine,
+first to the eye, then to the nose and other parts. Cocaine,
+or some derivative of it, has ever since been much
+used in Medicine. It was soon being given by injection
+under the skin for small superficial operations. Next,
+good results from injecting solutions of it into the
+nerves were obtained by several American surgeons,
+earliest of whom was W. S. Halsted (1852-). His
+work of 1885 was extended in 1898 by Harvey Cushing
+(1869-). Yet another American surgeon, J. L.
+Corning (1855-), introduced the method of so-called
+‘spinal anaesthesia’. This is secured by injecting a
+<span class="pagenum" id="Page_237">237</span>solution of Cocaine or one of its derivatives into the
+spinal canal and thereby inducing insensibility to pain
+(‘analgesia’) below the site of injection. In 1908 the
+American G. W. Crile (1864-) introduced a valuable
+method of combining local and general anaesthesia,
+whereby he minimized the effects of ‘shock’ (<a href="#Page_310">pp. 310-11</a>)
+during the progress of the operation.</p>
+
+<p>From first to last almost all the pioneer work upon
+anaesthetics and analgesics has been of American origin.
+Even the word <i>anaesthesia</i> is an American invention.
+It was introduced or at least familiarized by Oliver
+Wendell Holmes (1809-94), the distinguished and
+brilliant author of the ‘Breakfast Table’ series. Laughing
+Gas was first applied to dental purposes a short
+time before Ether was given its surgical application,
+and its introduction for this purpose was the work of
+the American dentist Horace Wells (1815-45), of
+Hartford, Connecticut.</p>
+
+<figure class="figcenter illowe30" id="i236">
+  <img class="w100" src="images/i236.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 108</span>a. SCREW adapted to the lower limb, as used by surgeons in the
+    eighteenth century and the early nineteenth century, to compress the nerves
+    in order to secure analgesia during amputation. Its application, however,
+    was extremely painful in itself and injurious to the part operated on.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_8_The_Revolution_in_Surgery">
+  § 8. <i>The Revolution in Surgery.</i>
+</h3>
+
+<p>This history of antiseptic surgery is inseparably
+linked with the name of Lord Lister (1827-1912),
+whose work naturally dovetails into that of Pasteur.
+Lister’s attention was first called to the work of Pasteur
+in 1865. But Pasteur’s views on the life of micro-organisms
+came to a mind that had been prepared for
+them. Lister had had, moreover, a long and varied
+surgical experience and had been present at the first
+operation performed in England under Ether anaesthesia
+in 1846.</p>
+
+<p>At that time and for long after, Surgery was cursed
+by the constant fear of sepsis. A vast amount of death
+<span class="pagenum" id="Page_238">238</span>and suffering was due to this cause, and surgeons
+were reluctant to perform many operations that we
+should now regard as trivial. Lister’s first attempt to
+make any scientific analysis of the septic state is to be
+found in a paper by him on <i>The Early Stages of Inflammation</i>
+(1853). He showed that the effects of irritation
+on the tissues are twofold. Firstly, there is a dilatation
+of the arteries which is developed through the
+nervous system. Secondly, there is an alteration in the
+tissues on which the irritant acts directly. This alteration
+imparted, as Lister thought, an adhesiveness to
+both the red and the white corpuscles, making them
+prone to stick to one another and to the walls of the
+vessels, and so giving rise to stagnation of blood and
+ultimately to obstruction.</p>
+
+<p>Some years before (1847) A. V. Waller (1816-1870),
+a pupil of Magendie, had shown that during the process
+of inflammation there is an active migration of white
+blood corpuscles through the walls of the capillary
+blood-vessels. Waller’s observations attracted but little
+attention at the time. They were, however, amply confirmed
+in 1878 and the following years by the German
+pathologist Julius Cohnheim (1839-84), a pupil of
+Virchow. Cohnheim showed that this process of migration
+of white blood corpuscles is the essence of inflammation
+and that when inflammation goes on to suppuration
+the pus that is formed consists largely of white blood
+corpuscles in a dead and disintegrating state.</p>
+
+<p>Irritation, and the reaction of the body against it,
+‘inflammation’, are encountered in all injuries in which
+the healing is not direct and healthy. It was those cases
+of injury in which the healing was indirect and unhealthy
+<span class="pagenum" id="Page_239">239</span>which then formed the surgeon’s chief problem.
+Of these there are a variety, now rare, then very common
+and fatal, as Blood-Poisoning, Erysipelas, Pyaemia,
+Septicaemia, Hospital Gangrene, and that form, then
+so common as to be almost normal, simple suppuration
+of a wound.</p>
+
+<p>About 1861 Lister began to teach publicly that the
+occurrence of suppuration in a wound is determined
+‘simply by the influence of decomposition’. The nature
+of decomposition was revealed to him by the writings
+of Pasteur. From him he learned that putrefaction was,
+in fact, a fermentation, and that it was caused by the
+growth of minute microscopic organisms borne by the
+air. It was generally supposed that air was the cause of
+sepsis, and precautions were taken to exclude it from
+wounds. But Lister now saw that not air but that
+which it carried was the mischief-maker.</p>
+
+<p>The general course of action was now clear to him.
+As a laboratory proposition the destruction of the
+organisms of the air was simple. The problem was to
+exclude them from wounds during and after operation.
+The solution of that problem developed as ‘Antiseptic
+Surgery’, which later became ‘Aseptic Surgery’. At first
+he paid most attention to air, as the source of infection.
+He recognized, however, that he must also deal with the
+germs present in the wound and on his hands. Of the
+methods available for ridding the air of its germs, viz.
+heat, filtration, and chemical action, he chose the last.</p>
+
+<p>At that time carbolic acid was in use as a means of
+treating sewage. At first, therefore, Lister tried lint
+soaked in crude carbolic. This he found liable to cause
+superficial sloughing and death of the tissues. He next
+<span class="pagenum" id="Page_240">240</span>obtained a purer acid, using a solution in oil. A putty
+formed of common whitening and a solution of carbolic
+acid in linseed oil was used as a dressing. He adopted
+later a system of spraying the part during operation
+(<a href="#i241">Fig. 109</a>).</p>
+
+<figure class="figcenter illowe30" id="i241">
+  <img class="w100" src="images/i241.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 109.</span> THE ‘DONKEY ENGINE’, an apparatus designed and used
+    by Lord Lister to maintain a carbolic spray over a part during operation.
+    The engine is worked by the up and down movement of the handle to the
+    right and the spray is delivered through the tube to the left.</p>
+  </figcaption>
+</figure>
+
+<p>When Lister began his work, amputation of a limb
+was a very fatal operation. Yet it had to be performed
+in most cases of severe fracture in which the bone was
+exposed because, without it, death from sepsis was almost
+certain. The improvement in Lister’s own records
+of amputation, incident upon his adoption of the antiseptic
+method, is well brought out by his own figures:</p>
+
+
+<table class="autotable3">
+<tr>
+<td class="tdc">
+<i>Years.</i>
+</td>
+<td class="tdc">
+<i>Cases.</i>
+</td>
+<td class="tdc">
+<i>Recovered.</i>
+</td>
+<td class="tdc">
+<i>Died.</i>
+</td>
+<td class="tdc">
+<i>Mortality.</i>
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1864-66
+</td>
+<td class="tdc">
+35
+</td>
+<td class="tdc">
+19
+</td>
+<td class="tdc">
+16
+</td>
+<td class="tdc">
+43% without antiseptics
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1867-70
+</td>
+<td class="tdc">
+40
+</td>
+<td class="tdc">
+34
+</td>
+<td class="tdc">
+6
+</td>
+<td class="tdc">
+15% with antiseptics
+</td>
+</tr>
+</table>
+
+<p>These results were considered extraordinarily good in
+their day. It is an index of the further advance since
+Lister’s first attempts that results ten times as good
+would now be regarded as unsatisfactory. Moreover
+not only has the further development of Lister’s method
+rendered amputation safer, but also it has enabled the
+surgeon to treat many cases without amputation, when
+before he would have been compelled to resort to that
+measure.</p>
+
+<p>Lister first recorded his observations on the antiseptic
+system of surgery in 1867. Apart from the
+technical advances that he then set forth, he recorded
+also many new pathological facts that have since proved
+of great practical importance. Thus he showed that
+an uninfected clot, if undisturbed, can become organized
+into a living tissue, and that a piece of dead bone
+may be absorbed in an aseptic wound. These are now
+<span class="pagenum" id="Page_241">241</span>matters of common knowledge, but then they were
+instrumental in introducing a radically new outlook.</p>
+
+<p>Lister gradually perfected his technique, chiefly in
+the direction of using milder antiseptics and adopting
+heat for the sterilization of instruments and dressings.
+The antiseptic system was given its military application
+in France during the war of 1870. It was soon taken
+up also by German surgeons. The history of surgery
+since Lister’s day has been very often told. An important
+element in it is the gradual supersession of
+‘antiseptic’ by ‘aseptic’ methods (p. 248).</p>
+
+<p>The Listerian system, in rendering surgery safer,
+<span class="pagenum" id="Page_242">242</span>had also the effect of opening up many fields of operation
+that had previously been regarded as impracticable.
+Especially is this the case with abdominal surgery,
+which effectively dates from the introduction of the
+antiseptic system. Lister was often misunderstood and
+some of his contemporaries, and some even of those
+who opposed him, were really practising his system
+without knowing it.</p>
+
+<p>Among the most important reactions of antiseptic
+surgery was that upon the conduct of labor. Here
+Lister had a predecessor, as he gladly and generously
+<span class="pagenum" id="Page_243">243</span>acknowledged. This was the unfortunate and almost insane
+Viennese genius, Ignaz Semmelweis (1818-65). At
+the great lying-in hospital at Vienna in which he was an
+assistant the death-rate at one time rose to thirty per
+cent., the so-called ‘puerperal fever’ being the active
+cause. The women were attended by students or physicians
+who were visiting the post-mortem room. Semmelweis
+showed that the infective material that conveyed
+the fever was brought by the hands of the operator
+from the dead bodies and he showed that puerperal
+fever was caused by decomposed animal matter. By insisting
+on the hands of the operators being sterilized,
+Semmelweis succeeded in 1846 in enormously reducing
+the mortality. After the acceptance of Lister’s antiseptic
+system the methods of Semmelweis were universally
+introduced into the practice of Midwifery. Another
+predecessor of Lister was Oliver Wendell Holmes. As
+early as 1843 he pointed out that the mysterious ‘puerperal
+fever’ was contagious, and carried by the hands
+of the operator. He suggested precautions not dissimilar
+to those of Semmelweis.</p>
+
+<figure class="figcenter illowe30" id="i242">
+  <img class="w100" src="images/i242.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 109a.</span> OPERATING TABLE USED BY LORD LISTER
+    in the Glasgow Royal Infirmary.
+  </figcaption>
+</figure>
+
+
+<h3 id="_9_Some_Modern_Surgical_Advances">
+  § 9. <i>Some Modern Surgical Advances.</i>
+</h3>
+
+<p>Among the most capable surgeons of Lister’s own
+day was Thomas Spencer Wells (1818-97) of London.
+This great operator had been opening the abdomen
+successfully for certain conditions since 1858. By 1867
+his methods were approaching the Listerian. Under
+Lister’s inspiration he further improved his technique
+and did more than any other man to raise the possibilities
+of abdominal surgery. Spencer Wells stands
+out for the extreme simplicity, directness, and effectiveness
+<span class="pagenum" id="Page_244">244</span>of his methods (<a href="#i245">Fig. 111</a>), and for his exceptionally
+conscientious care as an operator. His name is commonly
+attached to an instrument of his invention of
+catching the bleeding ends of cut blood-vessels. The
+familiar ‘Spencer Wells forceps’ is at this day probably
+more frequently used than any other surgical instrument
+(<a href="#i244">Fig. 110</a>).</p>
+
+<figure class="figcenter illowe30" id="i244">
+  <img class="w100" src="images/i244.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 110.</span> ‘SPENCER WELLS FORCEPS.’
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i245">
+  <img class="w100" src="images/i245.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 111.</span> SPENCER WELLS performing an abdominal operation about
+    1870. The picture illustrates the extreme simplicity of the methods of this
+    great surgeon. It also shows a method of administering chloroform. Air is
+    pumped through a bottle into a mask held at a variable distance from the face
+    of the patient.</p>
+  </figcaption>
+</figure>
+
+<p>Since the time of Lister many branches of Science
+have contributed to the development of surgical technique.
+No addition to the surgical armory has, however,
+been more important than that made by the
+physicist Wilhelm Conrad Röntgen (1845-1923). In
+1895 he found that when an electric discharge passes
+through a high vacuum rays are emitted that are far
+more penetrating than ordinary light. These rays have
+since then been placed in series with light rays, ultra-violet
+rays and infra-red rays, and it has been shown
+that they differ from these only in their wave-length.
+The surgical application of the Röntgen or X-rays was
+at once made to the examination of bone. Since then
+the more accurate knowledge of the properties of these
+<span class="pagenum" id="Page_245">245</span>rays has made them of value in exploring almost every
+organ of the body. Radiography is now constantly
+applied in the diagnosis of medical and surgical conditions
+of the organs of the chest and abdomen.</p>
+
+<p>The more dramatic achievements of modern surgery,
+the drastic operations that surgeons are now able to
+perform on the great cavities of the body—head, chest,
+and abdomen—have attracted much public attention.
+Nevertheless few surgical advances have relieved so
+much suffering and disability as the unsensational
+development in the treatment of fractures.</p>
+
+<p><span class="pagenum" id="Page_246">246</span></p>
+
+<p>After the advent of Listerian methods the technique
+of the treatment of compound fractures was gradually
+perfected. Simple fractures—which are far commoner—continued,
+however, to be treated with splints in the
+traditional fashion. Plaster of Paris bandages, which
+came into wide use in the ’seventies, were some improvement;
+but prolonged immobilization of a limb, in
+either splints or plaster bandages, always involves much
+subsequent pain and stiffness, lasting, at best, for
+<span class="pagenum" id="Page_247">247</span>months. To obviate this, Massage—a practice of immemorial
+antiquity in Folk Medicine—had been introduced
+into Surgery in the sixteenth century by Ambroise
+Paré (<a href="#Page_92">pp. 92-94</a>). The subject was little heard of till the
+last thirty years of the nineteenth century. The pioneer
+was the Dutch surgeon Johann Mezger (1839-1900),
+through whom some scientific advance was made.</p>
+
+<figure class="figcenter illowe30" id="i246">
+  <img class="w100" src="images/i246.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 112.</span> AN OPERATION IN THE SIXTEENTH CENTURY.</p>
+    <p>The semi-conscious patient lies face downward on an elaborately carved bed.
+    The bearded surgeon, dressed in his ordinary clothes, is trephining his skull
+    and is rotating the trephine between his hands. Against the side of the bed
+    lounges a gallant to whom a servant brings refreshment. In the background
+    are two women assistants. A male assistant is spreading a plaster and another
+    warming a towel over a brazier. Note that all present, surgeon, nurses,
+    assistants, &amp;c., wear their ordinary dress. No arrangements are made for
+    washing. In the foreground is a cat playing with a mouse.</p>
+  </figcaption>
+</figure>
+
+<p>The introduction of X-rays into Surgery made for
+<span class="pagenum" id="Page_248">248</span>very accurate diagnosis of the state of fractures. It has
+thus gradually become possible to treat a large proportion
+of these injuries without immobilization either by
+splints or plaster. In many cases the injured limb is
+merely held in correct position between sandbags and
+massage used from the first. Much stiffness and disability
+is thereby avoided and the length of the period
+of treatment greatly shortened. The rise of a class of
+scientifically trained Masseurs has made possible a
+wider application of this valuable curative procedure.</p>
+
+<p>Improvements in methods of operation have been
+very numerous during the last generation. Many can
+be appreciated only by those with technical knowledge.
+In 1886 Ernst von Bergmann of Berlin (1836-1907)
+introduced steam sterilization of dressings and thus
+moved toward the replacement of antiseptic by aseptic
+methods. W. S. Halsted, then of New York, had been
+working to the same end. In 1890, finding it impossible
+to sterilize the hands completely, he introduced the
+rubber gloves now universally employed by surgeons
+during operations. Much important work in experimental
+surgery has been done by Alexis Carrel of New
+York (1873-) and some of his laboratory methods
+have become available in surgical practice. The technique
+of abdominal surgery has been greatly advanced
+by many workers, important among whom are J. B.
+Murphy (1857-1916) of Chicago and the brothers
+Charles and William Mayo (1865 and 1861) of Rochester,
+Minnesota. The surgery of the brain was prosecuted
+in England by Rickman Godlee (1849-1925),
+the nephew and biographer of Lister, by Victor Horsley
+(1857-1916), and above all by William Macewen
+<span class="pagenum" id="Page_249">249</span>(1848-1926), a successor to Lister’s chair at Glasgow
+and one of the finest exponents of Listerian methods.
+The surgery of the nervous system in general, and that
+of the brain in particular, has been carried to extraordinary
+refinements in America by Harvey Cushing.
+There can be no doubt that during the twentieth century
+advances in Surgery have been more important
+and more numerous in the United States than in any
+other country.</p>
+
+<figure class="figcenter illowe30" id="i247">
+  <img class="w100" src="images/i247.jpg" alt="">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 113.</span> AN ABDOMINAL OPERATION UNDER
+    MODERN CONDITIONS</p>
+    <p>Only those directly concerned with the operation are present in the room.
+    All wear aseptic clothes and aseptic rubber gloves. Every source of infection
+    is guarded against and all breathe through masks. The patient is
+    covered by aseptic cloths and only the part operated on is exposed.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_10_Bacteriology_becomes_a_special_Science">
+  § 10. <i>Bacteriology becomes a special Science.</i>
+</h3>
+
+<p>We have seen the microbic view of the origin of
+disease demonstrated as a reality by Pasteur (<a href="#Page_224">pp. 224-35</a>)
+and extended to special disease conditions by him
+and by Koch (<a href="#Page_229">pp. 229-32</a>). While the French observer
+stood above all men for the clearness and steadiness of
+his vision and for his persistence and resource in following
+what he had seen from afar, his German colleague
+had a genius for visualizing particulars and for adapting
+mechanical devices and scientific discoveries to particular
+ends. Koch thus vastly improved and elaborated
+the methods for detecting and examining minute organisms.
+The significance of his results was at once
+recognized, but the complexity of the technique involved
+and the time and training necessary demanded
+the elevation of the subject into the position of a special
+science.</p>
+
+<p>Though but fifty years old, the science of Bacteriology
+has itself undergone repeated subdivision. Noteworthy
+though the results of this process of constant
+subdivision have proved, it must be emphasized that
+the state of scientific subdivision cannot be final, and
+<span class="pagenum" id="Page_250">250</span>is indeed without meaning unless it lead to a subsequent
+synthesis—an event which we still await. It is
+the general Laws reached by these special sciences
+that are philosophically important, and the specialist
+himself is often ill-placed and ill-equipped for the
+estimation of the true significance of such Laws. The
+philosophic thinker who deals with generalities and
+centuries must often be content to pass the details in
+silence. Nor is this true only of the professed philosopher.
+It applies no less to the philosophical physician.
+It is his task to try to see life steadily and see it whole.
+He must think both in terms of the individual life and of
+the community life, and for him the results of the bacteriologist,
+the physiologist, and of all their colleagues
+are as means to an end. It is from this standpoint that
+we should seek to visualize the fruits that bacteriological
+science in this last age has laid at the feet of humanity.</p>
+
+<p>With Koch’s work on Anthrax in 1876, on the bacteria
+that commonly infect wounds in 1878, and with
+his great discovery of the bacillus of Tuberculosis in
+1882, the study of the infective diseases entered on a
+new stage. The enemy had been seen and was now
+known for what he was. The bacteriologist had succeeded
+in making prisoners. These had been isolated
+and made to live in test-tubes. Moreover, the organisms
+had been compelled to dwell alone without mixing
+with other species. They had been obtained, as bacteriologists
+say, in ‘pure cultures’, and delicate methods
+of detecting and differentiating them had been developed.
+With a pure culture in his hands, the bacteriologist
+can determine the influences favorable or
+unfavorable to the growth of the disease organism,
+<span class="pagenum" id="Page_251">251</span>and he can investigate conditions that can exalt, destroy,
+or modify its activity (p. 233).</p>
+
+<p>An important series of criteria established by Koch
+have remained the tests by which the disease-bearing
+character of these organisms can be established. To
+prove that an organism is the inseparable cause of any
+disease we need to demonstrate:</p>
+
+<p>1. The constant presence of the organism in every
+case of the disease.</p>
+
+<p>2. The preparation of a pure culture, which must be
+maintained for repeated generations.</p>
+
+<p>3. The reproduction of the disease in animals by
+means of a pure culture removed by several generations
+from the organisms first obtained.</p>
+
+<p>These conditions have been fulfilled for many
+diseases. Evidently the third test can be applied only
+in conditions to which animals other than man are susceptible.
+Now in this matter the organisms that produce
+disease vary greatly. Some, for instance those of
+Anthrax, are easily conveyed to a variety of species of
+animals; others, for instance those of Syphilis, are with
+difficulty conveyed to very few species of animal; yet
+others, for instance human Malaria, cannot be conveyed
+to any animal save man.</p>
+
+<p>Some light is thrown on the life-history of the second
+and third classes by recent discoveries. The science of
+Comparative Pathology, that is the knowledge of the
+relations of the diseases of different species of animals,
+is of very recent growth. It has already demonstrated,
+however, the existence of organisms bearing some resemblance,
+for instance, to those of human Syphilis and
+human Malaria as the cause of disease in animals. By
+<span class="pagenum" id="Page_252">252</span>studying the life-history of these organisms in animals
+and by studying their effect on animals, valuable side-lights
+have often been thrown on the allied diseases in
+man. Moreover, in exceptional cases and in some
+special diseases, it has been possible to convey a disease
+experimentally to man.</p>
+
+<p>A second important factor has gradually come into
+prominence with the extension of bacteriological knowledge.
+It is evident that not all men are subject to all
+human diseases. Even in the most destructive epidemic
+there are some that escape. These lucky ones may be
+naturally ‘immune’. Many diseases, such as Measles,
+seldom recur in individuals who have been infected,
+so our lucky ones may thus have an ‘Acquired Immunity’.</p>
+
+<p>The general nature of Immunity we shall presently
+discuss (p. 259), but we note here that Immunity
+may be relative or absolute, and may, moreover,
+vary according to the circumstances of the individual.
+Thus, for instance, a well-fed, well-housed person of
+temperate habits, living an open-air life, is unlikely to
+develop consumption. Restrict his diet, confine him in
+an office, deteriorate his mode of life, and he may well
+fall a victim to it. The investigation of facts such as
+these on a large scale has demonstrated that the <i>soil</i> in
+which disease grows is of no less import than the <i>seed</i>
+from which it grows. The problem of disease causation
+is thus immensely complex. We are only just
+beginning to draw up general laws on the subject, and
+in approaching it we are beyond the frontiers of our
+positive knowledge. Turned back from this difficult
+borderland, we must content ourselves with surveying
+<span class="pagenum" id="Page_253">253</span>a part of the better-known territory and considering a
+few specific bacteriological achievements. These we
+may now consider under the headings of the diseases
+associated with them.</p>
+
+
+<h3 id="_11_Some_Important_Bacteriological_Results">
+  § 11. <i>Some Important Bacteriological Results.</i>
+</h3>
+
+<p><i>Diphtheria</i> is a disease for which physicians now
+habitually demand a bacteriological diagnosis. Bretonneau
+of Tours (p. 185), working on clinical and post-mortem
+material, and without the use of a microscope,
+was able to distinguish Diphtheria as a specific disease
+(1826). Half a century later (1883) Edwin Klebs
+(1834-1913) of Zürich, a pupil of Virchow, described
+the specific organism of the disease. In the following
+year Friedrich Loeffler (1852-1915), a Prussian and
+an assistant of Koch, succeeded in cultivating it. The
+organism has since been known as the ‘Klebs-Loeffler
+Bacillus’. Its study has thrown much light on the
+nature of bacterial action in general and has, moreover,
+led to important therapeutic developments (p. 263).</p>
+
+<p>Of all diseases destructive of human life, none is so
+dramatic as <i>Plague</i>, the scourge of mankind throughout
+history. The bacillus of Plague was discovered
+independently by the Japanese Shibasaburo Kitasato
+(<i>c.</i> 1860-), a pupil of Koch, and by the Frenchman
+Alexandre Yersin (1863-), a pupil of Pasteur,
+during an epidemic at Hong Kong in 1894. These
+two observers cultivated the organism and reproduced
+the disease by inoculation of pure cultures in animals.
+It had long been observed that outbreaks of a deadly
+disease of rats and mice were liable to precede Human
+Plague. These ‘epizootics’ which precede ‘epidemics’
+<span class="pagenum" id="Page_254">254</span>are now known to be due to the bacillus of Plague. A
+mass of evidence has been collected to show that the
+normal carrier of the Plague infection is the rat flea.
+This knowledge has led to the formulation of effective
+measures for the control of Plague. These measures are
+based on the wholesale extermination of the rat population
+which harbors the infective fleas. The study of
+the Natural History of the Plague Bacillus has also led
+to prophylactic measures for the safety of individuals.</p>
+
+
+<div class="columnstack"><figure class="figcenter illowe30" id="i254">
+  <img class="w100" src="images/i254.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 114. Bacilli of Diphtheria from a Culture.</span> Highly magnified.
+    In cultures these bacilli are liable to degenerate into thick club-shaped forms
+    several of which are here seen.</p>
+  </figcaption>
+</figure></div>
+
+<div class="columnstack"><figure class="figcenter illowe30" id="i255">
+  <img class="w100" src="images/i255.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 115. Bacilli of Plague from a Culture.</span> Highly magnified.</p>
+  </figcaption>
+</figure></div>
+
+<p class="clear"><i>Malta Fever</i> is a disease of much wider distribution
+than its name implies. Not only is it found throughout
+the Mediterranean area, but it is also encountered in
+China, South Africa, and parts of both North and South
+<span class="pagenum" id="Page_255">255</span>America. It is a long, tedious and wearing disease,
+and though the mortality from it is low, yet it was at
+one time one of the main causes of disability in the
+British army at Malta. In 1887 an English military
+surgeon, David Bruce (1855-), succeeded in cultivating
+a characteristic bacillus from the spleen of a patient
+dead of the disease, and he established its causal
+relation to Malta Fever. In 1904 its mode of propagation
+was studied by a British Government Commission.
+The goat was shown to be the normal host of the bacillus,
+and in Malta 50 per cent. of these animals were found
+to be infected. The disease, it was discovered, is usually
+transmitted by goat’s milk. The knowledge has led to
+the application of very effective precautions (<a href="#i256">Fig. 116</a>).</p>
+
+<p><span class="pagenum" id="Page_256">256</span></p>
+
+<figure class="figcenter illowe30" id="i256">
+  <img class="w100" src="images/i256.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 116.</span> DIAGRAM SHOWING THE INCIDENCE OF MALTA
+    FEVER in the British garrison at Malta immediately before and immediately
+    after the institution of the preventive measure of cutting off the supply
+    of unboiled goats’ milk. The figures of 1905—before the new regulation
+    came into force—are represented in black. The figures in the margin refer
+    to the number of cases per ten thousand of strength. The figures for 1907
+    are represented in white on the same scale. There is a drop in the
+    maximum monthly incidence from 94 to 2. The size of the garrison itself
+    remained almost constant throughout the period.</p>
+  </figcaption>
+</figure>
+
+<p>Among the most anciently described diseases is the
+condition known as <i>Tetanus</i> or ‘Lockjaw’. There are
+unmistakable references to it in the <i>Hippocratic Collection</i>
+and notably in the <i>Aphorisms</i>. Two of these</p>
+
+<p><span class="pagenum" id="Page_257">257</span></p>
+
+<p>references we have already quoted (p. 23). A general
+association of Tetanus with wounds has long been
+recognized. In the eighties the disease was shown to
+be transmissible from animal to animal. It was, moreover,
+experimentally produced in animals by the inoculation
+into them of garden mold. In 1889 Koch’s pupil,
+Kitasato, obtained the Bacillus of Tetanus in pure
+culture and conveyed the disease to animals. He found
+the organism would grow only in the absence of Oxygen.
+It is, in fact, a type of a large and now well-known
+group, the ‘anaerobic’ bacteria. The natural habitat of
+the Tetanus Bacillus has been proved to be soil, and
+especially richly manured soil. The knowledge of the
+<span class="pagenum" id="Page_258">258</span>bacillus, of its habitat, and of its mode of growth
+has led to the development of a valuable protective
+process.</p>
+
+<p>Looking backward from the standpoint of present-day
+knowledge we can trace <i>Typhoid Fever</i> far back
+in history. Nevertheless, it was not till 1837 that the
+distinction between the two distinct conditions known
+now as ‘Typhoid’ and ‘Typhus’ was first clearly made.
+This was the work of an American physician, William
+Gerhard (1809-72), of Philadelphia. The English were
+backward in adopting the distinction. The organic
+cause of Typhoid Fever was first seen in 1880 by Karl
+Joseph Eberth (1835-1927), a pupil of Virchow, and
+<span class="pagenum" id="Page_259">259</span>after him it is known as ‘Eberth’s Bacillus’. It was not
+isolated, however, until some years later. It is an inhabitant
+of the intestine, and its natural history was obscured
+by confusion with certain other and very similar
+organisms, which also dwell in the intestine. These have
+now been fairly differentiated from each other, and in
+the course of this process the ‘flora’, both normal and
+pathological, of the intestinal canal has become well
+known. Moreover, it has been shown that typhoid organisms
+are not always of the same species, but that
+several closely allied forms produce several closely allied
+diseases. Lastly, certain of the effects wrought by the
+typhoid group of organisms on the body, which is their
+host, have been exactly investigated. These investigations
+have led to improved methods of recognition of
+the disease, that is to say, <i>diagnosis</i>, and also of prevention
+of its incidence, that is to say, <i>prophylaxis</i>. To
+these methods of diagnosis and of prophylaxis we now
+turn.</p>
+
+<div class="columnstack"><figure class="figcenter illowe30" id="i257">
+  <img class="w100" src="images/i257.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 117. Bacilli of Tetanus from a Culture.</span> Highly magnified.
+    The drum-stick forms are very typical.</p>
+  </figcaption>
+</figure></div>
+
+<div class="columnstack"><figure class="figcenter illowe30" id="i258">
+  <img class="w100" src="images/i258.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 118. Bacilli of Typhoid Fever from a Culture.</span> Highly
+    magnified. The long flagellae, which are constantly in motion and are very
+    characteristic of these organisms, are well seen.</p>
+  </figcaption>
+</figure></div>
+
+
+<h3 id="_12_The_Study_of_Immunity">
+  § 12. <i>The Study of Immunity.</i>
+</h3>
+
+<p>In the production of disease by living organisms two
+main factors are involved. There is, firstly, the multiplication
+of the organisms themselves, and there is,
+secondly, the production by the organisms of poisonous
+substances or <i>toxins</i>. The former phenomena are spoken
+of as <i>infection</i>, the results of the latter come under the
+title of <i>intoxication</i> or <i>toxic</i> effects. The first toxins to be
+investigated were those isolated from putrefying substance
+and named <i>ptomaines</i> (1876, by false formation
+from Greek <i>ptoma</i> ‘a corpse’). These are, in fact, definite
+chemical substances of the group known to chemists
+<span class="pagenum" id="Page_260">260</span>as ‘alkaloids’ (p. 325). Later, toxins were prepared
+from actual disease organisms such as those of Typhoid
+and Tetanus (1888). The method was introduced of
+filtering the bacteria away from their fluid cultures and
+thus obtaining a bacterium-free liquid containing the
+poisonous bacterial products. This was the starting point
+of the scientific study of toxins. These, it soon
+became clear, were either substances which were normally
+sent out by the bacteria, <i>exotoxins</i>, or they were
+normally retained within the bacteria and could only be
+obtained in solution by breaking up the bodies of the
+bacteria, <i>endotoxins</i>. The use of these toxins has been
+essential for the scientific study of Immunity.</p>
+
+<p>The word <i>Immunity</i> is derived from a Latin word
+which means ‘exemption from military service’. In
+Medicine it indicates an exemption, relative or absolute,
+from the incidence of a disease. Immunity in the
+medical sense is of various kinds. There is ‘species
+immunity’, some species not being liable to diseases to
+which others fall victims. There is relative and there is
+absolute immunity. There is innate and acquired immunity.
+Of acquired immunity there is a natural immunity
+resulting from the ordinary contraction of a
+disease, and there is an ‘artificial immunity’. It is
+only artificial immunity that is in the hands of the
+physician.</p>
+
+<p>Artificial immunity itself is of two kinds, and both
+kinds are of use and of importance in Medicine. There
+is an <i>Active Immunity</i>, which is produced directly by
+injection of disease organisms or their products. It
+is found, however, that if a high degree of active immunity
+be attained the blood serum of the immunized
+<span class="pagenum" id="Page_261">261</span>animal, when injected into a second animal, may itself
+produce a state of immunity. The state thus indirectly
+produced is described as <i>Passive Immunity</i>.</p>
+
+<p>The early observers found that when organisms are
+cultivated outside the body they lose their virulence
+to a greater or less degree. Pasteur found this for
+Chicken Cholera (p. 234). He found, moreover, that
+such ‘attenuated cultures’, when inoculated, protect
+against the disease. By the use of attenuated cultures he
+succeeded in establishing a state of ‘Active Immunity’
+against Chicken Cholera. But there are many other
+ways of attenuating the virulence of an organism. Thus,
+in 1882, Pasteur showed that to grow Anthrax bacilli at
+a high temperature would reduce their virulence. These
+bacilli of reduced virulence could be injected into a
+sheep. They would give the animal the disease in a
+mild form and protect it against further attacks of the
+disease. They acted, in fact, in the same way as did the
+old ‘Inoculation’ of Small-Pox (p. 183).</p>
+
+<p>It has been found, however, that the same kind of
+immunity which is produced by administering attenuated
+cultures is sometimes given even by dead cultures.
+Nearly all active immunization is therefore done by
+inoculating such killed cultures. These are usually
+called ‘Vaccines’ from the analogy which they bear to
+vaccination. The most familiar and effective ‘vaccine’
+is that against Typhoid. Moreover, it has been found
+that in certain cases the principle of the induction of
+Active Immunity may be applied directly in the treatment
+of disease. The conditions that respond best to
+this line of treatment are those which present some
+localized infection, such as a boil or carbuncle. In such
+<span class="pagenum" id="Page_262">262</span>cases we must suppose that, while the local capacity for
+resistance is lowered, yet reserves of resistance in other
+parts of the body can be brought into play. These
+reserves are called up by the signal that reaches them
+by the reaction of the body against the Vaccine.</p>
+
+<p>It has been shown that, for the production of Active
+Immunity, the actual bodies of the disease organisms are
+not always necessary. In some cases, toxins obtained
+from these disease organisms are themselves sufficient
+to induce Active Immunity. The matter may become
+of great medical importance in the future and is already
+applied for Diphtheria (p. 265).</p>
+
+<p>We turn to ‘Passive Immunity’. The fact that Immunity
+can be transferred from one animal to another
+via the serum proves that the immunizing serum contains
+substances antagonistic to the bacterium or toxin
+against which immunity is conveyed. These antagonistic
+substances are spoken of as <i>Antibodies</i>. A series
+of very important observations on Antibodies has been
+made, and may in time profoundly modify not only our
+views of Disease but also our whole conception of the
+workings of the living body. We find that it is not
+only toxins that stimulate the formation of antibodies.
+Antibodies can be elicited also by the introduction into
+the tissues of the living body of red blood corpuscles,
+of embryonic tissue, and of various soluble tissue-constituents
+of animal or vegetable origin. We are still
+only on the threshold of the investigation of this subject,
+which may be as important philosophically as it is
+therapeutically.</p>
+
+<p><span class="pagenum" id="Page_263">263</span></p>
+
+
+<h3 id="_13_Some_Practical_Applications_of_Immunity">
+  § 13. <i>Some Practical Applications of Immunity.</i>
+</h3>
+
+<p>We may now consider a few special applications of
+our knowledge of the defences against bacterial action.</p>
+
+<p><i>Diphtheria</i> is a disease in which the characteristic
+organisms are found only locally, and in artificially
+produced cases only at the site of inoculation. It therefore
+seemed probable from the first that the symptoms
+were due not to the organisms themselves but to poisons
+that they threw off, that is to their ‘exotoxins’. This
+was given demonstrational form in 1889 by two pupils
+of Pasteur, Pierre Roux (1853-) and Alexandre
+Yersin (1863-), who investigated many of the properties
+of these toxins. In the following year (1890)
+<span class="pagenum" id="Page_264">264</span>Emil von Behring (1854-1917), a Prussian Army Surgeon,
+and Kitasato showed that it was possible to produce
+a Passive Immunity against Tetanus by a serum
+from an infected animal, the immunity being efficient
+against 300 times the fatal dose of Tetanus. Their paper
+contains for the first time the word <i>antitoxic</i>. Immediately
+after, von Behring showed that against Diphtheria,
+too, immunity could be obtained by injecting
+serum from an animal that had been previously injected
+with living cultures of the Diphtheria bacillus. This
+epoch-making discovery of von Behring was soon given
+a practical application. It was found possible to induce
+a degree of immunity even after the onset of the disease.
+The first human case was a child in a clinic at Berlin in
+1891. Antidiphtheritic serum was placed on the market
+in 1892. In a few years’ time its administration had
+become a routine part of the treatment of the disease.
+Diphtheria antitoxin is one of the greatest additions to
+therapeutics. With competent administration the case
+mortality of Diphtheria is one-half or one-quarter of
+what it is without the use of Antidiphtheritic serum.
+(<a href="#i263">Fig. 119</a>.)</p>
+
+<figure class="figcenter illowe30" id="i263">
+  <img class="w100" src="images/i263.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 119. Death-rate of cases of Laryngeal Diphtheria in Public
+    Hospitals in London.</span> Antitoxic serum came into use in London in 1895
+    and into full use in 1896. As its application became more general and as
+    the method of administration improved the death-rate from this very grave
+    condition progressively fell.</p>
+  </figcaption>
+</figure>
+
+<p>An important aspect of the reaction of the body to
+the Diphtheria toxin was revealed by B. Schick of
+Vienna in 1908. The technique of inducing it was perfected
+by him in 1913, and the test is known by his
+name. He showed that susceptibility to the disease
+could be detected by the behavior of the skin after
+injection of minute doses into it. It has thus been found
+that new-born infants are seldom susceptible and that
+the proportion of susceptibles increases up to two years
+of age, but that then it diminishes. The actual proportions
+<span class="pagenum" id="Page_265">265</span>of susceptibles, as estimated in a large number of
+cases in New York City in 1919, are as follows:</p>
+
+
+<table class="autotable3">
+<tr>
+<td class="tdl">
+Of those under
+</td>
+<td class="tdr">
+3
+</td>
+<td class="tdl">
+months
+</td>
+<td class="tdc">
+</td>
+<td class="tdr">
+</td>
+<td class="tdl">
+</td>
+<td class="tdl">
+15% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those between
+</td>
+<td class="tdr">
+3
+</td>
+<td class="tdl">
+months
+</td>
+<td class="tdc">
+and
+</td>
+<td class="tdr">
+6
+</td>
+<td class="tdl">
+months
+</td>
+<td class="tdl">
+30% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those between
+</td>
+<td class="tdr">
+6
+</td>
+<td class="tdl">
+months
+</td>
+<td class="tdc">
+and
+</td>
+<td class="tdr">
+1
+</td>
+<td class="tdl">
+year
+</td>
+<td class="tdl">
+60% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those between
+</td>
+<td class="tdr">
+1
+</td>
+<td class="tdl">
+year
+</td>
+<td class="tdc">
+and
+</td>
+<td class="tdr">
+2
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdl">
+70% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those between
+</td>
+<td class="tdr">
+2
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdc">
+and
+</td>
+<td class="tdr">
+3
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdl">
+60% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those between
+</td>
+<td class="tdr">
+3
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdc">
+and
+</td>
+<td class="tdr">
+5
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdl">
+40% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those between
+</td>
+<td class="tdr">
+5
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdc">
+and
+</td>
+<td class="tdr">
+10
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdl">
+30% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those between
+</td>
+<td class="tdr">
+10
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdc">
+and
+</td>
+<td class="tdr">
+20
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdl">
+20% are susceptible
+</td>
+</tr>
+<tr>
+<td class="tdl">
+Of those over
+</td>
+<td class="tdr">
+20
+</td>
+<td class="tdl">
+years
+</td>
+<td class="tdc">
+</td>
+<td class="tdr">
+</td>
+<td class="tdl">
+</td>
+<td class="tdl">
+15% are susceptible
+</td>
+</tr>
+</table>
+
+
+<p>These figures show why Diphtheria is mainly a disease
+of childhood and is relatively seldom encountered in
+adults. They also make it evident that steps for protecting
+individuals against contracting the disease—‘prophylactic
+measures’ as they are called—need only
+be taken with a fraction of the population. The useful
+term <i>Prophylaxis</i> is derived from a Greek word meaning
+a watchman or guard. It is used to describe preventive
+measures against disease in general, but is more specially
+applied to that form of protection which is achieved
+through the artificial production of Immunity.</p>
+
+<p>Such prophylactic measures are now available against
+Diphtheria. They differ from those in use against any
+other disease, since the substance injected is neither the
+living infective material as in vaccination against Small-pox
+(p. 184), nor is it a killed culture of the organisms
+as in immunization against Typhoid (p. 268), nor is it
+the serum of an immunized animal as in the protective
+measures against Tetanus (p. 267). The Toxin itself
+(mixed with an experimentally determined proportion
+of its antitoxin) is now in wide and effective use as a
+<span class="pagenum" id="Page_266">266</span>prophylactic against Diphtheria. The method was proposed
+by von Behring (cp. <a href="#Page_264">p. 264</a>) in 1913. The details,
+however, have since been worked out in the laboratories
+of the New York City Department of Public Health and
+have been mainly the work of W. H. Park (1863-).
+The susceptibles are first determined by the Schick
+test and are then immunized against the disease. The
+immunization reduces the likelihood of contracting the
+disease to about one quarter.</p>
+
+<p>Plague differs from Diphtheria in that the organisms,
+instead of being local, pullulate throughout the body of
+the victim. As in the case of most diseases of this type,
+the toxins of Plague are chiefly <i>endotoxins</i>, unlike those
+of Diphtheria, which are <i>exotoxins</i> (p. 263). Thus, the
+filtrate of a culture of Plague Bacilli is but little toxic and
+confers little or no immunity. Protective vaccines of a
+killed culture of Plague Bacilli are, however, prepared,
+and these confer considerable immunity. It is claimed
+that they reduce the liability to the disease by about
+three-quarters, and the case mortality by about one-half.
+Prophylactic inoculation against Plague is associated
+especially with the name of the Russian investigator
+Waldemar Haffkine (1860-), a pupil of Pasteur, who
+was for many years in the service of the British Government
+in India, the Plague center of the world.</p>
+
+<p>After Diphtheria one of the earliest diseases of which
+the toxins were investigated was <i>Tetanus</i>. Kitasato
+found in 1891 that the filtrates of pure cultures injected
+into animals are very toxic. A peculiar feature is the
+incubation period of some days that occurs between the
+inoculation and the advent of the symptoms. This fact
+had been referred to, more than two thousand years
+<span class="pagenum" id="Page_267">267</span>earlier, in the <i>Aphorisms</i> of Hippocrates (p. 23). Moreover,
+it has been found that, soon after inoculation, the
+Tetanus toxin disappears from the blood-stream. This,
+it has been shown, is due to its affinity for nervous
+tissue, with which it rapidly enters into some sort of
+combination. The fact is of clinical significance and of
+therapeutic application.</p>
+
+<p>By injection of small and progressively increasing
+doses of Tetanus toxin into animals, a high and long-lasting
+degree of immunity to the disease is produced.
+The serum of such immunized animals has the capacity
+to protect animals susceptible to the disease against an
+injection of a fatal dose. It is now a routine treatment
+to inject serum derived from an immunized horse into
+those who have wounds likely to result in Tetanus.
+Owing to the rapid disappearance of the Tetanus toxin
+from the blood-stream, and owing to its tendency to
+unite with nervous tissue, it is important to inject the
+serum as soon as possible after the infliction of the
+wound. In some cases it is advisable to inject the serum
+into the sheath that surrounds the spinal cord in order
+to give it as rapid access to the nervous centers as possible.
+During the Great War prophylactic doses of Antitetanic
+Serum were given to every wounded man after
+1914. Before the practice was adopted, the incidence of
+Tetanus among the wounded was 16 per 1,000. After
+the introduction of this line of treatment as a routine,
+the incidence fell to 2 per 1,000. Countless lives were
+thus saved. Antitetanic serum should be injected as
+early as possible in every case of a large ragged wound,
+especially if contaminated with soil.</p>
+
+<p><i>Typhoid Fever</i> differs from Diphtheria, Plague, and
+<span class="pagenum" id="Page_268">268</span>Tetanus in that it can hardly be conveyed to animals.
+It has thus proved impracticable to produce anything
+in the way of passive immunity in man. On the other
+hand, there is no disease in which the production of
+active immunity by means of Vaccines of dead cultures
+has been attended with more favorable results. The
+researches which led up to the introduction of active
+immunization against Typhoid Fever are bound up
+with investigations concerning the diagnosis of the
+disease which are of wide importance in connection with
+several other diseases.</p>
+
+<p>The discovery of Antibodies (p. 262) gave rise to
+great activity in their investigation. Among the most
+interesting and important of the antibodies is a group
+which will cause ‘agglutination’ or clumping of the
+disease organisms with which they are specially associated.
+This reaction is specific for the corresponding
+organisms, within certain limitations. Given, therefore,
+(1) a pure culture of an organism, and (2) the knowledge
+of the highest degree of dilution of the serum containing
+such an antibody that will cause agglutination of that
+particular organism, the physician has in his hands
+a means of detecting or excluding infection with that
+organism. The method was especially studied by the
+Parisian investigator Fernand Widal (1862-), who in
+1896 succeeded in making it practicable for Typhoid
+Fever, and his name is attached to the test. It is now
+universally applied in that disease. Similar tests have
+been devised for Malta Fever and for other conditions.</p>
+
+<p>There are other groups of antibodies that have been
+investigated. Some of these possess the power of dissolving
+the corresponding organism. They are, therefore,
+<span class="pagenum" id="Page_269">269</span>known as <i>Bacteriolysins</i>. Their existence gives a
+certain insight into the defensive mechanism of the
+animal body against bacterial invasion. They are sometimes
+of practical use in distinguishing types of disease-producing
+bacteria. The method is applicable, for
+example, in detecting certain types of dysentery organisms.</p>
+
+<p>Another group of antibodies act not against bacteria
+but against certain specific substances. Antibodies of
+this type were first detected by the Belgian workers
+Jules Bordet (1870-) and Octave Gengou (1875-)
+in the year 1900. The physician avails himself of
+the existence of such an antibody in the test that is
+applied for Syphilis, which was introduced in 1904 by
+Ehrlich’s pupil, August von Wassermann (1866-), and
+is known by his name.</p>
+
+<p>Of late years a special aspect of Immunity has come
+into view in connection with the so-called ‘Carrier Problem.’
+With many diseases, acquisition of Immunity
+on the part of the patient implies the death within his
+body of the organism that has been causing the disease.
+There are conditions, however, in which the organisms
+may lurk in some individuals long after the symptoms
+have subsided. These persons may even contract the
+disease so lightly that they are unconscious of it, but
+nevertheless they become capable of conveying it. Such
+individuals are known as <i>carriers</i>. Evidently the existence
+of carriers introduces special difficulty into attempts
+to delimit an infective disease in any population.</p>
+
+<p>Among the diseases of known bacterial origin that
+are sometimes conveyed by carriers are Typhoid Fever,
+Diphtheria, and Spotted Fever or Cerebrospinal Meningitis.
+<span class="pagenum" id="Page_270">270</span>A special case of the Carrier Problem is afforded
+by Infantile Paralysis, a disease due to ‘ultra-microscopic’
+organism—since the virus is ‘filtrable’ (p. 274).
+This disease, like that of Cerebrospinal Meningitis, is
+probably transmitted by carriers who do not themselves
+suffer.</p>
+
+<p>Typhoid Fever, Diphtheria, Influenza, Scarlet Fever,
+and many other conditions are often conveyed by
+‘ambulant’ cases. This term is applied to those cases
+which, while definitely suffering from a disease, do not
+regard themselves as ill enough to take to their beds
+but continue their ordinary avocations. Such ambulant
+cases are not less but more dangerous to their neighbors
+than those more severely stricken.</p>
+
+<p>The whole study of the Carrier Problem is in its
+infancy. It is beset with extraordinary difficulties. In
+the case of Diphtheria and Typhoid Fever, however,
+the demonstration that a suspected individual is or is
+not a ‘carrier’ is easy. The difficulty is to trace him in
+the first instance!</p>
+
+
+<h3 id="_14_The_Conquest_of_the_Tropics">
+  § 14. <i>The Conquest of the Tropics.</i>
+</h3>
+
+<p>Nowhere in Medicine has the rational spirit been
+more triumphantly vindicated than in connection with
+the diseases peculiar to hot countries. The increase in
+the habitability of the Tropics may be traced to two
+main causes. First is the application of the ordinary
+laws of Hygiene. Second is the increasingly exact
+knowledge of the microbic origin of tropical diseases,
+leading to a more complete apprehension and a stricter
+application of the laws of Hygiene.</p>
+
+<p>We have glanced at the great changes wrought in
+<span class="pagenum" id="Page_271">271</span>the social organization of temperate countries by the rise
+of modern Hygiene (<a href="#Page_172">pp. 172-78</a>), which commenced
+to be felt about the middle of the eighteenth century.
+The death-rate then began to fall, and has fallen steadily
+ever since. The mid-eighteenth century marks, for
+temperate countries, the end of the ‘Middle Ages’ of
+Hygiene. But with the advent of the modern period
+the fall in the death-rate in temperate countries has not
+been the only change in the public health. Even more
+significant is a change in the <i>causes</i> of death.</p>
+
+<p>Certain diseases have gradually receded from the
+more civilized and settled temperate countries, and are
+now almost unknown there. Thus, Malaria, Plague,
+Typhus, Leprosy and Dysentery, once of world-wide
+distribution, have come to be regarded as more or less
+distinctively ‘tropical’ diseases. A time is approaching
+when we shall be able to place other diseases with
+which temperate countries are still afflicted, such as
+Typhoid Fever, in the same category. The ultimate
+exclusion of Typhoid as a disease of civilized communities
+is suggested by the death-rates of England and
+Wales.</p>
+
+
+<p class="center"><i>Average Annual Death-rate in England and Wales from Typhoid
+per million living.</i></p>
+
+
+<table class="autotable3">
+<tr>
+<td class="tdc">
+1871-80
+</td>
+<td class="tdc">
+1881-90
+</td>
+<td class="tdc">
+1891-1900
+</td>
+<td class="tdc">
+1901-10
+</td>
+<td class="tdc">
+1911-20
+</td>
+<td class="tdc">
+1921-26
+</td>
+</tr>
+<tr>
+<td class="tdc">
+332
+</td>
+<td class="tdc">
+198
+</td>
+<td class="tdc">
+174
+</td>
+<td class="tdc">
+91
+</td>
+<td class="tdc">
+35
+</td>
+<td class="tdc">
+24
+</td>
+</tr>
+</table>
+
+
+<p>In the category of such removable diseases which,
+being excluded from temperate countries, are regarded
+as tropical are Malaria, Plague, Typhus, Leprosy, and
+certain forms of Dysentery. These diseases are ‘tropical’
+only in the sense that it is in the Tropics that the
+general hygienic conditions most favorable to their
+<span class="pagenum" id="Page_272">272</span>development are still found. If the hygienic conditions
+of the Tropics could be raised to those of the civilized
+temperate countries—a task, it is true, of very great
+difficulty—these particular diseases might become as
+rare there as they are with us. Indeed, it is possible
+to foresee a world in which a number of these so-called
+tropical diseases will have disappeared altogether.</p>
+
+<p>There are, however, other diseases that are tropical
+in another sense. Such diseases have seldom or never
+visited the shores of temperate countries, or at least
+have obtained no lasting foothold there, even when
+the conditions have been favorable to them. Among
+such diseases are Yellow Fever, Sleeping Sickness
+(which must not be confused with the so-called ‘Sleepy
+Sickness’), Beri-Beri, Dengue, Sprue, Kalar-azar, and
+a host of other less known conditions.</p>
+
+<p>It must be said, to avoid misunderstanding, that ‘the
+<span class="pagenum" id="Page_273">273</span>Tropics’ in the medical sense is a region considerably
+wider and far less well-defined than the geographical
+Tropics. Moreover, despite the existence of diseases
+peculiar to the Tropics, ‘tropical diseases’ form no
+natural group based on any common organic causation.
+The organisms that give rise to the various ‘tropical
+diseases’ differ from one another just as much as the
+organisms that give rise to the diseases of temperate
+countries.</p>
+
+<p>Since we cannot speak of tropical diseases on the
+basis of their common causation, we are forced to deal
+with them as separate entities and especially from the
+point of view of their prevention. We will therefore
+select two diseases, the history of which illustrates the
+process by which the Tropics have been rendered safer
+both for European and for native races. These will
+serve as types, and we will choose one from the truly
+tropical group which does not invade temperate climes,
+and the other from the group which is being gradually
+excluded from temperate climes. No better instances
+of these two groups can be adduced than Yellow Fever
+and Malaria.</p>
+
+<figure class="figcenter illowe30" id="i272">
+  <img class="w100" src="images/i272.jpg" alt="figures 120 and 121">
+  <figcaption>
+    <p class="center"><span class="smcap">Fig. 120.</span> A common Malaria-carrying mosquito × 3.</p>
+    <p class="center"><span class="smcap">Fig. 121.</span> The Yellow Fever-carrying mosquito × 3.</p>
+  </figcaption>
+</figure>
+
+
+<h4 id="a_Yellow_Fever">
+  (a) <i>Yellow Fever.</i>
+</h4>
+
+<p>In discussing the history of Yellow Fever, as of many
+other conditions, it is perhaps best to begin at the end,
+for modern knowledge of the organic cause of a disease
+often illumines and gives a meaning to historical records.</p>
+
+<p>In 1918 the Japanese investigator Noguchi observed
+a very delicate and minute spiral organism in the blood
+of a case of Yellow Fever at Guayaquil, the principal
+port of Ecuador, on the West Coast of South America,
+<span class="pagenum" id="Page_274">274</span>one of the most important endemic centers of the
+disease. Noguchi showed that guinea-pigs inoculated
+with the blood of this infected case developed symptoms
+similar to those of Yellow Fever, and he was able to
+demonstrate the same organism in the sick guinea-pigs.
+He passed the disease by means of inoculation from
+one guinea-pig to another. He succeeded in obtaining
+pure cultures of the organism on artificial media. He
+passed such cultures through a series of guinea-pigs
+and finally recovered it in pure culture again. He
+showed that different strains vary greatly in virulence,
+a fact in accord with the great variability in the gravity
+of attacks of Yellow Fever.</p>
+
+<p>One of the reasons why the discovery of this organism
+has been so long delayed is doubtless the very small
+numbers in the blood of patients suffering from Yellow
+Fever. Thus, the toxins must be extremely powerful.
+Indeed, it has been shown that 1/10,000 of a cubic
+centimeter of a virulent culture rapidly induces fatal
+symptoms in a guinea-pig.</p>
+
+<p>There are other important points about the Yellow
+Fever organism. It passes through a stage in which it
+is so small as to be beyond the reach even of microscopic
+vision. This fact is known because the blood
+of a Yellow Fever patient is infective when passed
+through any but the finest filters. The organism in fact
+exists in what is called a ‘Filter-Passing’ stage. Of late
+years a number of infective diseases have been shown
+to be due to filter-passing organisms of this type.
+Among them is the organism of the disease known as
+Infantile Paralysis (p. 270). The study of ‘filter-passers’
+bids fair to be in itself a special science.</p>
+
+<p><span class="pagenum" id="Page_275">275</span></p>
+
+<p>Finally, Noguchi threw light on the nature of Yellow
+Fever epidemics. He was able to pass the parasite from
+one guinea-pig to another, not only by inoculation in
+the ordinary way, but also by means of the bite of a
+species of mosquito which has long been known to be
+the carrier of the disease for man. He showed that
+a period of some twelve days’ duration within the body
+of the insect is necessary for the parasite again to
+develop its dangerous phase. The period of incubation
+in man, that is, the time that passes between the infective
+insect bite and the appearance of the disease, is
+3-5 days, but 12-14 days is the period that usually
+elapses after the introduction of a case of the disease
+before other cases occur. The discrepancy is now explained.
+The disease is not infectious except through
+the mosquito, so the developmental period of the parasite
+within the mosquito corresponds to the incubation
+period of the epidemic.</p>
+
+<p>Outbreaks of Yellow Fever have struck the public
+imagination, have given rise to folk tales and have inspired
+poets. The story of the <i>Flying Dutchman</i> is that
+of a ship stricken with Yellow Fever. The specter ship
+is supposed by sailors to haunt the seas around the
+Cape of Good Hope, and to bode ill for those who see
+it. A murder was committed on the ship, and following
+it ‘Yellow Jack’ broke out. All ports were closed to the
+wretched crew, who finally all died of the disease. The
+<i>Flying Dutchman</i> was the subject of an opera by Wagner
+and a novel by Marryat. A picture of a ship smitten
+by Yellow Jack is to be found in Coleridge’s <i>Ancient
+Mariner</i>.</p>
+
+<p>An historic case may be quoted. In 1837 a barque
+<span class="pagenum" id="Page_276">276</span>named <i>Huskisson</i> was at Sierra Leone. She was lading
+when Yellow Fever appeared among the crew. All but
+two or three died. Yellow Fever broke out in the
+colony, but gradually died down. The <i>Huskisson</i>, in the
+meantime, remained in harbor without hands for three
+months. At last, hands were obtained, tempted by very
+high pay. Again the Yellow Fever broke out among
+them and again nearly all died. They were bitten by
+infected mosquitoes which remained in the ship during
+the three months. Many cases, no less dramatic, are on
+record. The disease is among those which are peculiarly
+common and fatal among medical men. Thus, Senegal
+has twice been denuded of medical men by Yellow
+Fever. In 1830 six died out of twelve, and in 1878
+twenty-two out of twenty-seven.</p>
+
+<p>An attack of Yellow Fever confers Immunity. In
+children it assumes a mild form, and therefore, in
+countries where the disease is endemic, the population
+consists largely of the survivors of attacks. On this
+account terrible outbreaks of the <i>Flying Dutchman</i> or
+<i>Ancient Mariner</i> type are always either on immigrant
+ships or in places which have remained long unvisited
+by the disease, in other words such outbreaks occur
+under conditions in which immune persons are few or
+absent.</p>
+
+<p>The distribution of the Yellow Fever mosquito is
+wider than the distribution of Yellow Fever at the
+present day, but Yellow Fever is never found, save in
+sporadic outbreaks, where the mosquito cannot live
+permanently. The distribution of the mosquito corresponds,
+however, to the areas where the disease has
+in the past, from time to time, established itself, but is
+<span class="pagenum" id="Page_277">277</span>smaller than the area wherein sporadic outbreaks have
+been reported.</p>
+
+<p>During the seventeenth and eighteenth and even the
+nineteenth century there were repeated outbreaks of
+Yellow Fever far beyond the region to which it is now
+confined. Along the eastern shores of North America
+it has at times extended as far north as New York, and
+there have been destructive outbreaks in Baltimore,
+Philadelphia, and even Boston. The disease has been
+found along most of the littoral of South America. In
+the Old World it has visited chiefly West Africa, where
+it was imported very early by the slave trade. It has
+visited at times Spain, Portugal, and Italy with devastating
+epidemics, and has even occasionally made a call
+in France and once in England. The last considerable
+outbreak in Europe was at Madrid in 1878.</p>
+
+<p>England has always had important interests in the
+West Indies. During the eighteenth and first half of the
+nineteenth century she had, moreover, large military
+establishments there, which were regarded as very bad
+stations. In Thackeray’s <i>Vanity Fair</i>, which refers to the
+period just after the Napoleonic wars, the disreputable
+and unfortunate Rawdon Crawley is sent as governor to
+‘Coventry Island’ in the West Indies, and is not expected
+to last long! There are many historic occasions
+on which the British forces in the West Indies lost
+almost incredible numbers from Yellow Jack, garrisons
+being practically wiped out. In Jamaica the mean
+annual mortality in the garrison was for many years
+185 per 1,000! In the Bermudas the mortality was
+about 80 per 1,000. One should remember that soldiers
+are picked men in the prime of life, and that these
+<span class="pagenum" id="Page_278">278</span>mortality rates were in places now regarded as health
+resorts! A hundred years ago, Jamaica had the highest
+death-rate in the Empire, with the exception of West
+Africa, where the mean annual mortality of whites
+at Sierra Leone was 362 per 1,000!</p>
+
+<p>Conditions in the West Indies began to improve
+definitely from about 1850 onwards. At that time
+there was no effective knowledge of the organic cause
+of Yellow Fever, nor, for that matter, of any other
+tropical disease. Only lately has the basic reason for
+this early improvement become obvious. From about
+1850 onwards the water-supply in the more settled parts
+of the West Indies, and notably in the larger towns,
+came to be arranged by pipes. Now these towns were
+the special resorts of the Yellow Fever mosquito. The
+removal of open standing water, the enclosure of water-supplies,
+and the introduction of ordinary modern sanitation
+in the clearing away of rubbish, did good work
+without any knowledge of the organic cause of the
+disease.</p>
+
+<p>We now know the life-course of the Yellow Fever
+mosquito. We know her breeding habits and how the
+water-living larvae congregate specially in the small
+collections of water in the neighborhood of houses.
+Precautions have been taken against them and under
+favorable circumstances the disease has completely
+disappeared in well-managed districts under British
+and American control. The romantic story of the
+destruction of Yellow Fever in the Panama zone, in
+Cuba, Puerto Rico, Jamaica, Barbadoes, Trinidad, New
+Orleans, has been too often recited to be detailed again.
+Every one has heard of the tragic event in connection
+<span class="pagenum" id="Page_279">279</span>with the American Mosquito Commission of 1900 and
+of the death of Lazear. He and his colleagues, led by
+Walter Reed (1851-1902), finally proved that the
+disease is never conveyed by bedding, or by clothes,
+or by other objects, but always and only, in nature, by
+the bite of an infected mosquito.</p>
+
+<p>During the experiments of the American Commission,
+cases of Yellow Fever were produced in volunteers
+by bites of infected mosquitoes, by injection of
+blood of infected patients, and by injection of <i>filtered</i>
+blood serum of infected patients (p. 74). With this
+knowledge in his hands, the American chief sanitary
+officer of Havana, William C. Gorgas (1854-1920),
+began to destroy mosquitoes systematically and to treat
+all Yellow Fever patients under mosquito nets. Within
+three months Havana was free from Yellow Fever for
+the first time for one hundred and fifty years. These
+wonderful results are brought out by a table:</p>
+
+
+<p class="center">
+  <i>Deaths in Havana from Yellow Fever.</i>
+</p>
+
+<table class="autotable3">
+<tr>
+<td class="tdc">
+<i>Year.</i>
+</td>
+<td class="tdr">
+<i>Deaths.</i>
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+<i>Year.</i>
+</td>
+<td class="tdr">
+<i>Deaths.</i>
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1885
+</td>
+<td class="tdr">
+165
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1895
+</td>
+<td class="tdr">
+553
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1886
+</td>
+<td class="tdr">
+161
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1896
+</td>
+<td class="tdr">
+1,282
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1887
+</td>
+<td class="tdr">
+532
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1897
+</td>
+<td class="tdr">
+858
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1888
+</td>
+<td class="tdr">
+468
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1898
+</td>
+<td class="tdr">
+136
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1889
+</td>
+<td class="tdr">
+303
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1899
+</td>
+<td class="tdr">
+103
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1890
+</td>
+<td class="tdr">
+308
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1900
+</td>
+<td class="tdr">
+310
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1891
+</td>
+<td class="tdr">
+356
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1901
+</td>
+<td class="tdr">
+18
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1892
+</td>
+<td class="tdr">
+357
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1902
+</td>
+<td class="tdr">
+0
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1893
+</td>
+<td class="tdr">
+496
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1903
+</td>
+<td class="tdr">
+0
+</td>
+</tr>
+<tr>
+<td class="tdc">
+1894
+</td>
+<td class="tdr">
+382
+</td>
+<td class="tdc">
+&nbsp;&nbsp;&nbsp;&nbsp;
+</td>
+<td class="tdc">
+1904
+</td>
+<td class="tdr">
+0
+</td>
+</tr>
+</table>
+
+
+<p>Except for the semi-civilized states of Central and
+South America, Yellow Fever is now generally under
+control. It is perhaps not always realized, however,
+that, while the local extinction of this disease may be
+<span class="pagenum" id="Page_280">280</span>among the future triumphs of modern science, its substantial
+control over large areas is part of the history of
+world hygiene (p. 278), and that it is part of the very
+same movement that has made our own cities healthier
+and more habitable than they were in the Middle Ages.</p>
+
+
+<h4 id="b_Malaria">
+  (b) <i>Malaria.</i>
+</h4>
+
+<p>The history of Malaria, which is also carried by a
+mosquito, is very different from that of Yellow Fever.
+Malaria was, till recent times, a disease of temperate
+as well as of tropical countries. The old name for the
+disease is <i>Ague</i>. The word <i>Malaria</i> is of no great antiquity
+in the English language. It came into use only
+in the eighteenth century. Like the word <i>Influenza</i>, it
+is of Italian origin, and, like <i>Influenza</i>, it carries with it
+a forgotten pathological theory. <i>Malaria</i> is simply <i>mal
+aria</i>, that is, ‘bad air’. So <i>Influenza</i> is <i>the influence</i>,
+that is to say, the influence of unpropitious planets or
+comets that were held to rain down poison into the air.
+It was believed that these diseases were the result of
+local atmospheric conditions. In Rome and the Campagna
+the natives still believe that just as the sun goes
+down the air becomes specially poisonous.</p>
+
+<p>While the <i>term</i> Malaria is comparatively modern,
+nevertheless, recognizable accounts of the <i>condition</i> are
+perhaps more ancient than those of any other disease.
+Of all diseases produced by micro-organisms, Malaria
+has perhaps changed its type least during the course of
+historic time. The disease is distinctly described in
+several places in the <i>Hippocratic Collection</i>.</p>
+
+<p>The conception of diseases as separate entities is,
+of course, modern. In the case of most infectious
+<span class="pagenum" id="Page_281">281</span>diseases, therefore, we cannot hope to follow the history
+very far back. But the symptoms associated with a
+malarial attack are so definite that there is no difficulty
+in tracing the disease with certainty as far back as
+1000 <span class="allsmcap">B.C.</span> The real division into ancient and modern
+times comes, for this disease, with the use of Cinchona,
+which is the plant from which Quinine (p. 326) is now
+derived. Very soon after the introduction of Cinchona
+in the seventeenth century, fevers came to be habitually
+divided into those which respond to Cinchona and those
+which do not. Cinchona—and therefore its derivative,
+<span class="pagenum" id="Page_282">282</span>Quinine—is one of the drugs that we owe to the discovery
+of the New World (p. 95). The rind of the
+Cinchona tree was taken as a remedy by the aborigines.
+In Europe, where it was introduced by Jesuit missionaries,
+it became known as ‘Jesuits’ bark’. It was
+popularized by Sydenham (p. 100) and has ever since
+been widely used in medicine.</p>
+
+<figure class="figcenter illowe30" id="i281">
+  <img class="w100" src="images/i281.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 122. Geographical Distribution of Indigenous Malaria
+    in England and Wales about 1860.</span>
+  </figcaption>
+</figure>
+
+<p>Sydenham gave a good description of Malaria.
+During the seventeenth and eighteenth centuries
+epidemic after epidemic of ‘Ague’ swept over England
+as over other European countries. These epidemics
+spread from their endemic centers, the low-lying ill-drained,
+swampy districts, where the Malaria mosquito
+could breed freely in the slowly flowing water. Of such
+places the principal in England were the Fens of
+Cambridgeshire, Lincolnshire, and the surrounding
+counties, the marshes on either side of the estuary of
+the Thames in Kent and Essex, the marshes of Romney
+and Pevensey on the South coast, and those around
+Bridgewater near the Bristol Channel (<a href="#i281">Fig. 122</a>). There
+Malaria was never absent, though it differed greatly in
+prevalence and severity in different years. Ague remained
+prevalent in London as late as 1859. The
+proportion of ague cases to the total number of in-patients and
+out-patients at St. Thomas’s Hospital in London from
+1850-60 varied from between 12 per 1,000 at lowest to
+over 60 per 1,000 at highest. Thus, over one-twentieth
+of the patients in a large London hospital suffered from
+what we now regard as a tropical disease, within the
+lifetime of men who are still with us!</p>
+
+<p>In London the rise in the value of land led to the
+erection of the Thames Embankment, which effectually
+<span class="pagenum" id="Page_283">283</span>reclaimed the land around the river. Extensive works of
+drainage were at the same time being undertaken in
+other infested districts. These soon had their now well-known
+effect. In 1864 Malaria was found to be rapidly
+diminishing everywhere, and to have left many of its
+old haunts. The disease retreated rapidly. At the beginning
+of the twentieth century a systematic search was
+made for a native case in England. After much labor
+one single case was at last found. It may safely be
+prophesied that native Malaria will never again be anything
+but a rare disease in any temperate country with
+an efficient sanitary service.</p>
+
+<p>The story of the discovery of the malarial parasite
+is worth recounting. These organisms inhabit the red
+blood corpuscles and were first seen by Alphonse
+Laveran (1845-) in 1880 in Algiers. His observations
+were extended by French and Italian observers,
+who showed that the sudden rise in temperature in
+Malaria coincides with a process of division of the parasite.
+Later the suggestion that the parasite might be
+conveyed to man by the mosquito was made by Patrick
+Manson (1844-1922). The matter was clinched in
+1898 by Ronald Ross (1857-), who showed that the
+malarial parasite necessarily passes through a stage in
+the stomach of the mosquito. The process was first
+traced by Ross in a malarial parasite that is peculiar to
+certain birds, and was subsequently demonstrated for the
+allied species of parasite that produces human Malaria.</p>
+
+<p>We have here an illustration of the value of comparative
+pathological studies. Since the demonstration
+of the life-cycles of the malarial parasites of man (<a href="#i285">Fig. 123</a>),
+the chief attention of hygienists interested in</p>
+
+
+<p><span class="pagenum"><a id="Page_284"></a><a id="Page_285"></a><a id="Page_286"></a>286</span></p>
+<p>Malaria has been directed to the mosquito (<a href="#i287a">Fig. 124</a>).
+Controlling the breeding of the mosquito has proved
+the best method of reducing the incidence of the disease.
+Engineering and sanitary works in some places previously
+infested with Malaria have had the effect of
+almost entirely eliminating disease. The classical instance
+is the Panama zone, where, as is well known, the
+two mosquito-born diseases, Yellow Fever and Malaria,
+have disappeared. There are now many areas in the
+Tropics, previously infested, in which the disease is
+almost unknown. There are many devices for dealing
+with the mosquito larvae.</p>
+
+<p>By advances such as have been made in the knowledge
+of Yellow Fever and Malaria, those areas of the
+Tropics which are under proper sanitary control have
+become far safer habitats. There is good hope of an
+early and rapid extension of the process, ultimately
+rendering new areas of the Tropics suitable for permanent
+habitation by the white races and healthier and
+happier places for the colored.</p>
+
+<figure class="figcenter illowe30" id="i285">
+  <img class="w100" src="images/i285.jpg" alt="">
+  <figcaption>
+    <p class="center big"><span class="smcap">Fig. 123.</span> THE LIFE-HISTORY OF THE PARASITE OF MALARIA</p>
+    <p>The life-histories of the parasites of the malarial diseases of man have been
+    completely traced. The parasites run through a double cycle, one in man and
+    the other in the mosquito. In our diagram the cycles of only one species are
+    represented; there are however two other special malarial parasites in man.</p>
+    <p>On either side the head of the mosquito involved is diagrammatically
+    shown, just below the ‘cycle in man’.</p>
+    <p>In man the parasites conveyed by the bite of the mosquito (32) or formed
+    by a division of a parasite already in the blood (7) make their way into the
+    red blood corpuscles (1 and 2), develop there (3 and 4). Some of them
+    ultimately divide to go through the same cycle (5, 6, 7 and back to 1, 2).
+    The process of division corresponds to the period of fever. Others develop
+    into crescent-shaped bodies (8, 9 and 10), which can be differentiated into
+    two slightly different forms corresponding to two sexes (9 male, 10 female).
+    These, if sucked up by a biting mosquito of the right species, pass into the
+    animal’s stomach where they develop further (11, 12, 13 male; 14, 15, 16
+    female) and end by dividing into forms which conjugate (17). The resultant
+    of this conjugation or union of the two sexes (17) develops into a lanceolate
+    form (18, 19, 20) which passes into the cells of the mosquito’s stomach (21,
+    22) and finally penetrates these cells (23). The parasite then secretes a cell-wall
+    and forms a ‘cyst’ (24), which enlarges (25). The enlargement continues
+    while the nucleus breaks up (26, 27, 28). In the cyst, which is still growing,
+    a large number of needle-like forms develop, each of which contains a fragment
+    of the nucleus (29). Finally the cyst bursts (30), the needle-like forms
+    are cast forth into the body of the mosquito, and ultimately lodge in her
+    salivary glands (31). When the mosquito bites another man, she injects some
+    of her saliva into him through her proboscis. Thus she infects his blood with
+    some of the needle-shaped parasites that lurk in her salivary gland (32). So
+    the cycle is re-enacted again and again. We may note that to prevent this
+    process of repeated reinfection it is only necessary to break either cycle at
+    one point. Thus destruction of mosquitoes or of their breeding-places will
+    suffice, or, again, protection of human hosts from bites of mosquitoes will be
+    sufficient. Either process, if persisted in, will lead to the extinction of the
+    parasite in the region under supervision. In England both methods have
+    been in operation and the disease is almost extinct there so long as any of
+    the malarial mosquitoes remain in one district. However, the disease can always
+    be reintroduced by the introduction of subjects of malaria from without.</p>
+    <p>(From C. M. Wenyon’s <i>Protozoology</i>, Vol. II, by kind permission of
+    Messrs. Baillière, Tindall and Cox. Slightly reduced in size.)</p>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i287a">
+  <img class="w100" src="images/i287a.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Figs.</span> 124 and 125. A common Malaria-carrying mosquito and a
+    common gnat sometimes confused with the Malaria-carrying mosquitoes.
+    They are both in sitting posture and may be easily distinguished by the
+    attitude that they then assume.</p>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i287b">
+  <img class="w100" src="images/i287b.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 126. Chart of cases of Malaria</span> reported in Italy in recent years,
+    showing the seasonal variation of the disease. The date of the year is written,
+    in each case, below a vertical line corresponding to midsummer. It will be
+    seen that the maximum incidence is always in the months July to September,
+    and the minimum incidence is always in the months January to March. This
+    incidence corresponds to the known facts of the life-history of the mosquito
+    and of the evolution of the malarial parasite within the body of the mosquito.</p>
+  </figcaption>
+</figure>
+
+
+<h3 id="_15_The_Changed_View_of_Insanity">
+  § 15. <i>The Changed View of Insanity.</i>
+</h3>
+
+<p>Insanity is as old as History. The Bible, Homer,
+and the <i>Hippocratic Collection</i>, for instance, recount
+numerous examples of the disease. Until the nineteenth
+century there was practically no scientific knowledge of
+the conditions classed as insanity. Nevertheless, hospitals
+for the insane were instituted at an early date. A
+well-known instance is Bethlem Hospital or <i>Bedlam</i> in
+London, which was developed as an insane asylum in
+the fourteenth century.</p>
+
+<p>The new era in the treatment of insanity begins with
+<span class="pagenum"><a id="Page_287"></a><a id="Page_288"></a>288</span>the abolition of the old system of restraint. This was
+primarily due to two noble-minded men, one a Frenchman
+and the other an Englishman. Philippe Pinel
+(1745-1826), physician at the Bicêtre and afterwards
+at the Salpêtrière at Paris, at great personal risk both
+to his life and liberty, insisted on freeing from their
+chains the unfortunate lunatics under his charge. His
+<i>Medico-philosophical Treatise on Mental Alienation</i>
+(1791) was devoted to championing the humaner treatment
+of the insane. His contemporary, the Quaker
+philanthropist William Tuke (1732-1822), succeeded in
+1792 in establishing at York a small retreat for the
+insane, where the antiquated, unnecessary and cruel
+restraints were abolished (<a href="#i289">Fig. 127</a>).</p>
+
+<p>While Pinel was beginning the humaner treatment
+of insanity in France, considerable interest was aroused
+in the subject in Germany. There, however, the medical
+profession was still under the influence of the mystical
+Stahl (<a href="#Page_132">pp. 132-3</a>), who regarded all forms of insanity as
+perversions of the moral tendencies of the soul, produced
+by sin!</p>
+
+<p>In France Pinel was succeeded in 1810 by Jean
+Étienne Dominique Esquirol (1772-1840). The influence
+of Esquirol was as radical for the scientific study of
+the subject as had been that of Pinel for the humane
+treatment of the sufferers. Esquirol threw himself into
+the task of founding properly conducted asylums, and
+he produced in 1838 his monumental work <i>On Mental
+Diseases considered in their Medical, Hygienic, and Legal
+relations</i>. It is the first important, rational, scientific
+treatise on the subject. Esquirol abandoned the barren
+type of speculation that had characterized previous
+<span class="pagenum"><a id="Page_289"></a><a id="Page_290"></a>290</span>works on the subject and devoted himself to the systematic
+collection of data. He was able to sketch out some
+of the main forms of insanity, including that now known
+as ‘General Paralysis of the Insane’. This disease was
+finally differentiated by one of his pupils. Another pupil
+of Esquirol was the first to succeed in the training of
+idiots. The main school of French alienists is descended
+from Esquirol. In the early forties his work resulted
+in the foundation of journals and societies devoted to
+the study of Insanity in France, England, the United
+States, and Germany.</p>
+
+<p>England was behind France in her treatment of the
+Insane. Not until 1828 were there proper laws governing
+their certification. In 1844 the great and good
+Lord Shaftesbury (1801-85), the seventh Earl, brought
+in his Bill establishing the Board of Lunacy Commissioners
+with the duty of inspecting all lunatic asylums.
+It was a subject to which that great philanthropist gave
+much thought. The same period saw also an awakening
+in the United States, where Miss Dorothea Lynde Dix
+(1802-87) carried on a very successful campaign for
+the better treatment of the insane and the establishment
+of proper houses for their reception. Her labors
+resulted in the foundation of many asylums on a reformed
+model in the United States and Canada. In
+1845 the provision of asylums out of the local rates
+was made compulsory on the local Justices in England.</p>
+
+<p>The late sixties and early seventies saw in every
+country a further change for the better in the treatment
+of the Insane. The causes of this improvement were
+two. On the one hand, Insanity came generally to be
+recognized as a group of diseases which, like other
+<span class="pagenum" id="Page_291">291</span>diseases, have usually a traceable physical basis. On the
+other hand, the great improvement of the system of
+nursing under the inspiration of Florence Nightingale
+(<a href="#Page_289">pp. 298-300</a>) began to reach the asylums. In 1877
+there was a Parliamentary investigation into the care
+of the Insane in England and Wales, and in 1890 the
+duties of asylum administration were transferred from
+the Justices to the County Councils. This has resulted
+in an immense improvement in the accommodation and
+treatment of the insane poor in England. At the same
+time the order of a magistrate became necessary for the
+consignment of a private patient to an asylum. In 1913
+provision was made for the mentally defective, who do
+not come within the Lunacy Act. Lastly, with the
+establishment of a Ministry of Health in 1917, the
+general control of the Insane has passed to that body.</p>
+
+<p>Many types of insanity have been traced to an
+organic cause in the Nervous System itself. The Morbid
+Anatomy, both coarse and microscopic, of some of
+these diseases has become recognized. Chief among
+them is the well-known condition known as ‘General
+Paralysis of the Insane’. During the intensive study of
+the factors in the causation of Insanity it has become
+clear that in some groups, as in General Paralysis, which
+is always preceded by Syphilis, a ‘toxic cause’ is at
+work. Other types of toxic insanity are due to the
+actual intake of a poisonous substance. This is sufficiently
+evident in cases which are associated with Alcoholism.
+There is also evidence that in a considerable
+number of cases toxic conditions result from perversion
+of metabolic processes, or, again, are associated with
+‘deficiency’ states (<a href="#Page_302">pp. 302-8</a>). This is a very hopeful
+<span class="pagenum" id="Page_292">292</span>finding, since by removing the toxic cause, or by remedying
+the deficiency, relief may be possible.</p>
+
+<p>Much less hopeful is the outlook with those forms
+of insanity, especially common in the adolescent, which
+are of the nature of a perversion of development. Such
+is the large group known as ‘Dementia praecox’. These
+cases almost invariably originate from a mentally unsatisfactory
+stock. This is less so with the Epileptic
+insane, though a considerable proportion of epileptics
+may be classed with those who are born mentally
+defective and are liable to give rise to a bad stock.
+Whatever view may be taken of the question of the
+artificial limitation of human fertility, it is almost impossible
+to imagine that the free breeding of these
+classes of defectives, epileptics and their congeners, will
+continue unchecked in any civilized community.</p>
+
+<p>The general care and treatment of the insane has improved
+out of all knowledge during the last quarter of a
+century. It is probable that there is now no class of sick
+person who is more skilfully and considerately cared for.</p>
+
+<p>From time to time an alarm is raised at the rapid
+increase in Insanity, and it is a fact that the proportion
+of certified insane has been, for some time,
+steadily rising. A considerable part of this rise is certainly
+due to the greater willingness of the insane themselves
+to enter an asylum, and of their friends to allow
+them to do so. Part of the rise in numbers of the insane
+is due to their increased length of life under improved
+treatment. It must be remembered that more than
+90 per cent. of the insane in England and a similar
+percentage in other countries are paupers, who are not
+readily discharged as they have no means of support.
+<span class="pagenum" id="Page_293">293</span>Mild mental cases and the senile insane go now to the
+improved asylums. Before they would have been kept at
+home or sent to a rate-supported or a State infirmary.
+The general conclusion of those best qualified to judge is
+that Insanity, if increasing at all, is doing so only very
+slowly.</p>
+
+<figure class="figcenter illowe40" id="i289">
+  <img class="w100" src="images/i289.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 127.</span> ‘THE RETREAT’ NEAR YORK FOUNDED IN 1792<br>
+
+    being the first institution in England where the insane were accorded humane and scientific treatment.
+  </figcaption>
+</figure>
+
+
+<h3 id="_16_The_New_Movement_in_Psychology">
+  § 16. <i>The New Movement in Psychology.</i>
+</h3>
+
+<p>During the last half-century various new points of
+view have entered into our conception of Mind and
+its disorders. The evolutionary view of the origin of
+man, which was brought to wide notice by Charles
+Darwin, not only in his <i>Origin of Species</i> of 1859 but
+also in his <i>Descent of Man</i> of 1871 and his <i>Expression
+of the Emotions</i> of 1872, has given rise to new ideas as to
+the nature of many instincts and emotions. These views
+have been co-ordinated with our knowledge of lower
+types of man, both in his existing state and in his extinct
+and fossil forms. Much that we call Insanity has been
+found to be related to what is normal in other and less
+developed environments. The Mind, breaking free
+from its habitual restraints, ‘reverts to a lower type’.
+There is a constant though unconscious ‘conflict’ in the
+mind, which is variously resolved.</p>
+
+<p>Whole schools of Psychology have arisen in the discussion
+of the nature and resolution of these conflicts.
+Sigmund Freud of Vienna (1856-) takes the leading
+place among those who have dealt with this subject.
+He holds these conflicts to be rooted in sex and has
+introduced the method of <i>Psycho-analysis</i>, which lays
+great stress on the subconscious or unconscious element
+in mental life. Largely under the direction of C. G.
+<span class="pagenum" id="Page_294">294</span>Jung of Zürich (1875-), preventive and curative measures,
+based on this view, have been introduced into
+medicine. It has been established that painful experiences,
+lurking in the unconscious mind, disturb the
+equilibrium of health. Such disturbance is often of the
+nature of a struggle to repress into the unconscious
+unpleasant memories which are tending to surge up
+into the conscious. The psycho-analyst seeks to release
+the repressed experience into the conscious. The
+recognition and consideration that follow a success in
+this attempt is often far less painful than the repression.
+Persistent unreasonable fears on the part of adults, but
+especially of children, are frequently thus dispersed.</p>
+
+<p>The importance of suitable environment to children
+has always been recognized. But a new significance has
+been given to the mental impressions received in infancy
+by cumulative evidence of harmful results in the adult
+life of events in the early years of life that are seemingly
+forgotten. This recognition of the enduring character
+of mental impressions has led to a movement for the
+better instruction of mothers, and has thus been a factor
+in the remarkable development, in recent years, of work
+for infant welfare.</p>
+
+<p>It is recognized, moreover, that certain instincts—such,
+for example, as the self-regarding instinct and the
+sex instinct—must have expression. Mere repression
+of such instincts is always harmful, but they are susceptible
+of a process of transformation, technically
+known as <i>sublimation</i>, to an almost indefinite extent.
+Thus the self-regarding impulse need by no means lead
+to the inconvenience and discomfort of others, but,
+rightly guided, may develop into a sense of personal responsibility
+<span class="pagenum" id="Page_295">295</span>for the welfare of others. So, too, sex instinct
+is but one aspect of that creative vital activity on
+which depends the continuance not merely of the human
+race but also of the culture that the race has built up.
+The sex instinct is thus habitually sublimed into other
+creative channels, and there are many altars, beside
+those of Venus, at which young men and women may
+kindle their essential fires.</p>
+
+
+<h3 id="_17_The_Revolution_in_Nursing">
+  § 17. <i>The Revolution in Nursing.</i>
+</h3>
+
+<p>During the Middle Ages, and in Catholic countries
+after the Reformation, attendance on the sick in Hospitals
+and elsewhere was the task of religious sisterhoods.
+In Protestant countries the absence of these
+sisterhoods necessitated the employment of women
+specially for the purpose. The task was not an attractive
+one, nor did any social distinction attach to it. The
+profession of nurse became despised and was followed,
+for the most part, by a low and illiterate type of woman,
+though midwives were sometimes better educated and
+of a higher class (p. 180). The great philanthropists
+of the eighteenth century (<a href="#Page_171">pp. 171-72</a>) could do little
+to improve the nursing profession. The conditions of
+employment formed the root of the evil. The vast improvement
+that has resulted in health and happiness to
+our whole population from the improvement in the
+character and training of nurses is probably seldom
+realized, even by medical men. Yet it may reasonably
+be doubted whether all modern medical and surgical
+advances put together—apart from Preventive Medicine
+and Infant Hygiene—have saved as many lives
+as the Reform of Nursing.</p>
+
+<p><span class="pagenum" id="Page_296">296</span></p>
+
+<p>The reader may gain some insight into the life of
+a nurse from the conditions that prevailed until beyond
+the middle of the nineteenth century at a very good
+and well-managed English provincial hospital, the Radcliffe
+Infirmary at Oxford. The salary of a nurse was
+£5 a year. There was no distinction between a nurse
+and a domestic servant. One nurse only was the allowance
+for a ward of seventeen patients. A nurse’s day
+began at 6 a.m. The wards were cleaned till 7, when
+a bell was rung and each nurse had to bring down her
+ashes and sift them under the direction of the porter,
+who then gave her coals for the day. She took breakfast
+with the patients, who helped her, so far as they were
+able, with the ward work. At 2 p.m. she went to the
+servants’ hall, where she had her dinner in company
+with the servants on daily hire. During the dinner the
+ward was left in charge of a patient. After dinner she
+took away a plate of meat and vegetables for her supper.
+For the night there was normally only one nurse for
+the whole hospital of about 100 beds. There were no
+regular holidays, and the nurse was never allowed to
+leave the hospital before 6 p.m. The practice of nurses
+receiving gratuities from patients continued till 1870
+and even beyond. Those patients who wished to secure
+a nurse’s early attention for their dressings gave tips,
+those who did not frequently had to wait.</p>
+
+<p>What sort of woman could such a system produce?
+That some nurses at least were kind and skilful, even
+under such conditions, is a fact, and is pleasing evidence
+of the natural goodness and wisdom that reside in the
+human heart. Many, however, can have been no better
+than Sairey Gamp and Betsy Prig.</p>
+
+<p><span class="pagenum" id="Page_297">297</span></p>
+
+<p>The first important reform in Protestant countries
+began in Germany, through the influence of Elizabeth
+Fry (p. 171). In 1822 Theodor Fliedner (1800-64),
+the young pastor of the church at Kaiserswerth, a little
+town on the Rhine near Düsseldorf, visited England
+and was much impressed by Elizabeth’s teaching and
+example. Returning to his charge, he devoted himself
+to the spiritual and physical care of jail-birds. In 1833
+he and his devoted wife Frederica (1800-42) opened
+a refuge for discharged female convicts. From them
+the couple turned their attention to the sick poor. The
+conception of an organized body of specially trained
+women crossed their minds. In 1836 they opened a
+small hospital.</p>
+
+<p>At this hospital six young women of the most spotless
+character were induced to serve as ‘deaconesses’.
+It was their duty to perform all the tasks of the hospital
+in rotation. The physicians who attended the hospital
+gave them instruction. The Kaiserswerth idea rapidly
+spread and the ‘Kaiserswerth Deaconesses’ became and
+remain an important order, which is still occupied in
+good works in many parts of the world. The conception
+of the order is different from that of most religious
+orders in that the members make no attempt to withdraw
+from the world, and marriage is not forbidden
+to them. Moreover, the duties of the Kaiserswerth
+deaconesses are rather different from and more varied
+than those of a sick-nurse. They include teaching,
+both secular and religious, nursing, household duties,
+management of children and convalescents. In 1865 a
+preparatory school for probationers was opened.</p>
+
+<p>In England Anglican orders of a somewhat similar
+<span class="pagenum" id="Page_298">298</span>character were formed in the forties and fifties. In
+1850 and 1851 Florence Nightingale (1820-1910),
+who was a lady of good social rank, visited Kaiserswerth,
+and went through a regular training there. She
+was profoundly impressed by the extremely high character
+of the deaconesses, most of whom were only peasant
+women. The next three years she spent in writing and
+in examining hospitals in her own country.</p>
+
+<p>Florence Nightingale’s opportunity came with the
+outbreak of the Crimean War in 1854, and the rapid
+breakdown of the medical services, which contained no
+women nurses. The French had a number of ‘religieuses’
+to nurse their sick, and a feeling of shame arose
+in England at the neglect and mismanagement of the
+British sick and wounded. The Secretary of State for
+War asked Florence Nightingale to go to the Crimea
+to organize a nursing service. She left at once with
+thirty-eight nurses whom she selected personally. Ten
+of these were Roman Catholic sisters and all the others
+had had nursing experience. From that event dates
+the Revolution in Nursing. Florence Nightingale performed
+marvels under conditions of great difficulty
+(<a href="#i299">Fig. 128</a>) and in the face of determined opposition.
+She returned home in 1856 a national heroine. She had
+no difficulty in establishing a school and home for nurses
+at St. Thomas’s Hospital in London in 1860. The
+example was followed by the other London hospitals.</p>
+
+<p>Florence Nightingale was a woman of the most
+powerful will and an admirable organizer and administrator.
+Her system of nursing contained many
+new features, not quite all of which have stood the test
+of time. That nursing rapidly and steadily improved
+<span class="pagenum"><a id="Page_299"></a><a id="Page_300"></a>300</span>from the moment she was in authority cannot at all be
+doubted. Looking back, it is apparent that the immediate
+success of her methods was due to two main factors.
+First was her capacity to secure women of high character
+and good social position to accept positions of
+responsibility. Second was her removal of the control
+of the nursing staff entirely from the hands of men into
+those of women. Her influence soon passed across the
+Atlantic, and she was associated with the United States
+Sanitary Commission and the women who took charge
+of army nursing during the American Civil War.</p>
+
+<p>While Florence Nightingale was reforming Nursing,
+her contemporary, Mary Carpenter (1807-77), was
+applying herself to the kindred task of looking after
+neglected children, establishing Reformatory and Industrial
+Schools and improving the position of Indian
+women. She obtained a large measure of public support
+and exercised considerable influence in America, which
+she visited in 1873. Many other distinguished and
+devoted women worked on similar lines.</p>
+
+<p>Among the indirect results of the activity of Florence
+Nightingale was the establishment at Geneva in 1864
+of the International Red Cross Committee, the branches
+of which have done good service in many wars and
+have been no less useful in peace.</p>
+
+<p>Florence Nightingale opposed anything in the way
+of State registration of nurses. Concentrating on a high
+ideal of competence and character for the nurse, she
+failed to grasp some of the secondary effects of her own
+scheme. A large nursing service is now a necessity in
+every civilized country, as a result of her efforts and
+example. Having regard to human imperfections, we
+<span class="pagenum" id="Page_301">301</span>can as little hope that every woman who nurses will be
+a born nurse, devoted to her task, as that every doctor
+or teacher will have a natural vocation for his work. In
+an imperfect world mankind must protect itself against
+the incompetent and the unfit. Registration is a way—doubtless
+an imperfect way—of doing this. A Nurses’
+Registration Act became law in England in 1919.</p>
+
+<p>There have been many improvements in the details
+of the training of nurses, incident on the changes in
+Medicine and Surgery during the last half-century.
+Apart from these, the main improvements in Nursing
+have been due firstly to an increased interest in the
+welfare and health of the nurse herself, and secondly
+to the recognition that Nursing is a profession for
+which, as for Medicine, some preliminary scientific
+knowledge should precede professional training. Thus,
+the very long hours of the nurse have of late been
+reduced, and in the best schools instruction is now
+given to nurses in Anatomy, Physiology, Hygiene,
+Bandaging, and Cookery, before the commencement of
+actual hospital work.</p>
+
+<p>Further developments will probably be along the
+lines of State and Municipal Nursing Services. Since
+Health is a public as well as a private concern, the same
+must be true of the training and work of nurses.</p>
+
+<figure class="figcenter illowe40" id="i299">
+  <img class="w100" src="images/i299.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 128.</span> FLORENCE NIGHTINGALE RECEIVING WOUNDED AT SCUTARI<br>
+
+    <i>From a painting by Jerry Barrett</i>
+  </figcaption>
+</figure>
+
+
+<h3 id="18_some_modern">§ 18. <i>Some Modern Physiological Concepts of Clinical
+Import.</i></h3>
+
+<p>The vast activity in the sciences of Physiology and
+Pathology during the last fifty years, and their repeated
+divisions into independent sciences, each prosecuted
+by its own specialists, have yielded many ideas which
+<span class="pagenum" id="Page_302">302</span>have been imported into the clinical practice of Medicine.
+It is impossible to say which of these are of permanent
+value. All previous ages have had to discard
+part of the practice and a large proportion of the
+medical ideas that have been handed down to them, and
+there is no reason to suppose that the age that follows
+us will differ from those which have gone before us.
+Some ideas that have entered Medicine from the physiological
+laboratory, pushed by interested parties or
+seized on in despair by physicians at a loss for a line of
+treatment, are already seen by men of experience and
+judgment to be no permanent addition to our store.
+Other lines of physiological thought are still under discussion
+by them.</p>
+
+<p>There are, however, certain physiological conceptions
+which, apart from their general implications in
+the economy of the body, have received such wide
+application that their future, as an organic part of
+medical practice, seems assured. Certain of these conceptions
+demand discussion in even the most cursory
+survey of medical development.</p>
+
+
+<h4 id="a_Ductless_Glands_and_Internal_Secretions">
+  (a) <i>Ductless Glands and Internal Secretions.</i>
+</h4>
+
+<p>The nature and action of the various glands of the
+body has been a classical physiological field. Malpighi
+(<a href="#Page_116">pp. 116-20</a>) was the first to investigate the structure of
+these organs, and he was followed by many others. It
+became evident that many glands, such as the liver, the
+salivary glands, and the tear glands, are provided with
+ducts or tubes, which carry off the characteristic secretion
+of the glands. These secretions can be examined
+with comparative ease—as happened early with the
+<span class="pagenum" id="Page_303">303</span>secretion from the stomach, or ‘gastric juice’ (<a href="#Page_146">pp. 146-48</a>),
+and later with the secretion of other glands. There
+remain, however, certain glands unprovided with ducts.
+The action of such ‘ductless glands’ long remained a
+mystery. Of these the type is the ‘Thyroid gland’.
+Much of our physiological knowledge of this organ,
+together with the conception of its function as indispensable
+to normal life, has come through Surgery.</p>
+
+<p>It had long been known that certain symptoms were
+associated with enlarged Thyroid gland or ‘Goitre’.
+Attempts to remove the organ surgically were made
+after the introduction of antiseptic methods. Goitre is
+particularly common in Switzerland, and it is not remarkable
+that the technique of the very dangerous
+operation for the surgical removal of goitres was first
+perfected by Swiss surgeons, among whom Theodor
+Kocher (1841-1917) has taken the first place. The
+study of cases that had had their Thyroid glands removed
+gave a clue to the nature and action of the gland.</p>
+
+<p>It was found that those surgically deprived of the
+Thyroid gland develop abnormal slowness in movement
+and response. The temperature is low, the pulse
+small, the muscles are torpid and sometimes rigid,
+and there is a failure in ordinary fine muscular movements.
+The patient shows a thickening and swelling
+of the skin and presents a dull and very characteristic
+appearance. When the operation was performed on
+one whose growth was not yet complete, development
+was checked. Such a patient remains infantile or
+childish both in body and mind.</p>
+
+<p>The conditions were recognized by Swiss surgeons
+in the seventies as resembling those of a spontaneous
+<span class="pagenum" id="Page_304">304</span>disease to which the name <i>Myxoedema</i> was attached.
+Further the close relationship both of the surgical and of
+the spontaneous condition to the state of idiocy known
+as <i>Cretinism</i> came gradually into view. In Switzerland,
+as in other parts of Europe, stunted beings known as
+<i>Cretins</i> had long been known. These defectives are
+sometimes goitrous, sometimes without a Thyroid
+gland, but their general appearance and condition is an
+exaggerated version of what has been described for
+those with Thyroid glands removed (<a href="#i305">Fig. 129</a>).</p>
+
+<figure class="figcenter illowe30" id="i305">
+  <img class="w100" src="images/i305.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Figs.</span> 129 and 130. <span class="smcap">Cretinous infant before and after Thyroid
+    Treatment.</span><br>
+
+    <i>From the Collection of the Royal College of Surgeons.</i>
+  </figcaption>
+</figure>
+
+<p>The result of these observations was to direct the
+attention of physiologists to the Thyroid gland. It was
+soon found that the symptoms of Thyroid deprivation
+could be experimentally produced in animals. Moreover,
+it was shown by Moritz Schiff of Berne (1823-1890),
+in 1884, that the results of the removal of the
+Thyroid might be avoided if the animal were fed regularly
+on an extract of the glands. The results were soon
+applied to man and have led to one of the greatest of
+medical triumphs. By its means sufferers from myxoedema
+and cretinism can be either cured or improved. A
+drivelling and idiotic cretinous child, adequately treated
+with Thyroid, enters on a normal process of development.
+The improvement is almost incredible, and the
+child rapidly passes into a healthy and happy state, so
+that it is literally true to say that his own parents would
+not recognize him (<a href="#i305">Fig. 130</a>). Further, the gland may
+be given in excessive doses, and a condition produced
+that closely resembles a well-known pathological condition
+known as ‘Exophthalmic Goitre’, which is
+similarly susceptible of experimental investigation.</p>
+
+<p>The facts here enumerated justify the deduction that
+<span class="pagenum" id="Page_305">305</span>the Thyroid gland secretes something which is essential
+to normal well-being. The organ has no duct, and the
+secretion is, therefore, never normally thrown out of
+the body. The Thyroid is, in fact, an organ of what is
+called ‘internal secretion’. Investigations on this secretion
+led to the isolation of the active principle as a pure
+compound known as <i>Thyroxin</i> in 1916. The story of the
+Thyroid has recently (1926) been rounded off by the
+preparation of Thyroxin synthetically. The synthetic
+product has been given with effect in cases of Myxoedema.</p>
+
+<p>The observations made on the Thyroid directed
+further attention to other ductless organs of which a
+number have been shown to have their own ‘internal
+<span class="pagenum" id="Page_306">306</span>secretions’. Furthermore, it has been demonstrated
+that, among organs which throw out their products
+through a duct, there are those which also send an
+internal secretion into the blood-stream. Among these
+are the essential organs of sex, the testicle and ovary.
+The effect of castration on the general physique is well
+known. It may be compared with the effect of ‘spaying’
+or the removal of the ovary. This operation leads to an
+assumption by the female, in more or less modified
+degree, of the secondary sexual characters of the male.</p>
+
+<p>Peculiarly interesting for their practical results have
+been certain investigations made of late years upon the
+organ known as the ‘Pancreas’. The Pancreas has a
+duct which opens into the Intestine just below the
+Stomach. It has long been known that the secretion of
+the Pancreas is related to the amount and fate of sugar
+in the blood. The association of disease of the Pancreas
+with the symptom known as ‘Diabetes’, in which sugar
+appears in the urine, was also familiar. Later it became
+apparent that it was not the Pancreas as a whole that
+was related to the process but only certain isolated and
+peculiarly formed nests of cells. It is now possible to
+administer extracts of these cell-nests with very favorable
+results on the course of certain types of Diabetes.
+The extract is now in wide use under the name of <i>Insulin</i>.</p>
+
+<p>Among the ductless glands that have been best investigated
+are the so-called ‘suprarenal bodies’, which
+lie above the kidneys. As with the thyroid gland, the
+attention of physiologists was directed to these bodies
+as a result of clinical observations. These observations
+date back to the middle of the nineteenth century. In
+the last years of that century it was observed that an
+<span class="pagenum" id="Page_307">307</span>extract of the suprarenal bodies, injected into the circulation,
+caused a rise in blood-pressure, an effect
+opposite to that following the extirpation of the glands.
+The administration of extract from suprarenal bodies
+has found wide clinical application. Unlike the extract
+of thyroid, the effect of this extract is very temporary.
+It is easily oxidized and rapidly disappears from the
+blood. It belongs to the group of substances which are
+known as <i>hormones</i>. The active element in a suprarenal
+extract, the ‘suprarenal hormone’, has been recently
+prepared by a synthetic process.</p>
+
+<p>The nature of hormones has only come clearly into
+view of late years. The word ‘hormone’ is formed from
+a Greek word meaning ‘to excite’. The internal secretions
+have, in general, functions of considerable physiological
+complexity, and act, for the most part, slowly
+and continuously. The hormones are, however, exceptions
+to this rule. They act rapidly and in an
+excitatory manner. These substances appear to be of
+relatively simple chemical structure. They are easily
+oxidizable, so that they rapidly disappear from the body.
+They act, in fact, as ‘chemical messengers’, producing
+a state of ‘chemical correlation’ of the different parts
+of the body which is comparable to the better-known
+and more widely recognized ‘nervous correlation’.</p>
+
+<p>The hormones represent a very ancient and primitive
+physiological mechanism. In organisms consisting of
+but one cell, in which there are very few differentiated
+organs, the messages from one part of the body to
+another are necessarily of a chemical or hormonic
+character. In higher multi-cellular animals the intercommunication
+between different parts of the body is
+<span class="pagenum" id="Page_308">308</span>maintained, for the most part, by a specially developed
+nervous system. Certain necessary messages are, however,
+still conveyed by chemical messengers. The
+development of the conception of hormones has been
+especially the work of the London physiologist E. H.
+Starling (1866-1927).</p>
+
+<p>Internal secretions and especially hormones form
+part of the increasingly complex picture of the working
+of the animal body. They are not only of great physiological
+value, but have also entered the department of
+practical therapeutics. They are, moreover, of philosophical
+importance, since they yield us a conception of
+the body in which every part is dependent on every other
+part, and the whole is subject to a process of ‘integration’
+or linkage into a unitary system. We have glanced
+at the mechanism of chemical integration. We have
+now to turn to the mechanism of nervous integration.</p>
+
+
+<h4 id="b_Nervous_Integration">
+  (b) <i>Nervous Integration.</i>
+</h4>
+
+<p>If the simple reactions of animal bodies are tested,
+it will be found that they clearly serve certain ends.
+Lightly touch the foot of a sleeping child and it will
+withdraw it. Tickle the ear of a cat and it will shake it.
+Exhibit savory food to a hungry man and at once his
+digestive process will get to work—his mouth will
+‘water’. These instances might be multiplied a hundredfold.
+Such reflexes are admirably adapted to their
+ends. Many of them will continue in an animal in
+which the spinal cord is severed from the brain. Nevertheless,
+in the higher animals, and especially in man,
+they are controllable to a greater or less extent by the
+will. But to leave the question at that would give a
+<span class="pagenum" id="Page_309">309</span>false idea of the extremely complex integrative functions
+performed by the nervous system. Thus, the
+spinal cord, which, to the naked eye, is a longitudinal
+and little differentiated nervous mass, is, in fact, a
+collection of nerve-centers which have historically, both
+in the individual and in the race, been formed by the
+union of a series of separate segments. Each one of
+these segments is dependent on the action of the next
+segment in a fashion somewhat similar to that in which
+the actions of the cord itself are dependent on the brain.
+Each of the sections governs certain functions or movements
+of the body. There is thus a very complex process
+of integration which runs right through the
+nervous system.</p>
+
+<p>The investigation of the bodily functions of a chemical
+and physical nature reveals that these activities are
+far more largely under nervous control and discipline
+than was at one time conceived to be possible. Thus,
+the main factor in the activity of any part is its blood-supply,
+but the blood-supply is largely determined by
+the state of contraction of the vessels of supply, which
+are in their turn under nervous control. So it is with
+the state of nutrition of the muscles, with the action
+of the sweat glands of the skin, with the mechanism
+of childbirth, and with a thousand bodily states with
+which both physician and biologist are concerned.</p>
+
+<p>The investigation of nervous integration is especially
+associated with the name of Sir Charles Sherrington
+of Oxford. As the outcome of his work the picture
+formed of the nervous apparatus is that of a machine in
+which some parts work spontaneously, automatically,
+and with complete uniformity; others, though mainly
+<span class="pagenum" id="Page_310">310</span>automatic, are susceptible of various degrees of alteration
+and adjustment; others need intermittent or constant
+attention, and demand for their functioning fresh
+supplies of energy at longer or shorter intervals; while,
+finally, others have hardly yet taken a fixed form and
+are improvised as occasion demands. Thus the nervous
+system is a system of systems of every degree of independence.</p>
+
+<p>These systems, each with a certain individuality of
+its own, date from every stage of Evolution, the more
+ancient being, as a rule, the more automatic and the
+less dependent on other systems. The most ancient, the
+chemical messenger or ‘hormonic’ system (<a href="#Page_306">pp. 306-8</a>),
+we share with the lowest living things which consist of
+only one cell. Very recent are the factors in the nervous
+system that are specially developed in man as contrasted
+with the higher apes. Such are those associated with the
+delicate co-ordination of sensory impressions and motor
+impulses involved in such acts as speaking, reading,
+writing and the like. Each of these systems, high or low,
+ancient or recent, has its own place in the body. For
+many the exact position of the controlling center is
+demonstrable and some of the lower systems can
+function without the aid of any other systems save those
+which control their nutrition.</p>
+
+<p>Among these nervous relations there is one which
+calls for special mention on account of its great clinical
+importance. The state of ‘shock’, the general nature
+of which is vaguely understood by everybody, has
+been given a more exact physiological meaning of late
+years, especially by the American surgeon G. W. Crile
+(1864-). It has been found possible to localize ‘shock’
+<span class="pagenum" id="Page_311">311</span>experimentally. If a section of the spinal cord of an
+animal be cooled to a point just above freezing, the
+part of the body below the cooled level passes into a state
+of ‘shock’, that is to say, its reflexes no longer respond
+to irritation in the normal fashion. This shock effect is
+due to the removal of some influence exercised by the
+higher parts of the nervous system. In the experiment
+the shock effect is induced by an external agent, but
+there is an internal mechanism within the nervous system
+itself, which can cause it under appropriate conditions.</p>
+
+
+<h4 id="c_Vitamins">
+  (c) <i>Vitamins.</i>
+</h4>
+
+<p>There are no current medical problems that are more
+discussed than those of nutrition. It has long been
+recognized that articles of diet may be classified
+according to their constitution into ‘proteins’, ‘carbohydrates’,
+and ‘fats’. If an animal is fed on a diet
+containing these in correct proportion, but in a perfectly
+pure state, it will become ill and ultimately die.
+The onset of illness and death will be the more rapid
+if it be a young animal. This fact, observed as long ago
+as 1880, was reinvestigated by F. Gowland Hopkins
+of Cambridge in 1906, from whence dates our real
+knowledge of a very important subject. He found that,
+in the case of rats, the addition of a very small quantity
+of milk to this chemically pure diet would induce
+normal growth. The milk must therefore contain some
+growth-promoting substance or substances other than
+protein, fat, or carbohydrate. The result of many similar
+experiments by a large number of observers has shown
+that almost all fresh food contains such growth-promoting
+substances. They have been named ‘vitamins’.</p>
+
+<p><span class="pagenum" id="Page_312">312</span></p>
+
+<p>Several of these vitamins have been distinguished.
+None, however, has been isolated, and we depend for
+our knowledge of them on our investigation of their
+mode of action. One, known as <i>Vitamin A</i>, is produced
+in the growing green parts of plants, and is especially
+necessary for the promotion of growth. Vitamin A is
+abundant in cod-liver oil. It has been shown that the
+necessity for Vitamin A can to some extent be evaded if
+the animal is exposed to sunlight or ultra-violet rays.
+Moreover, it has been shown that the absence of Vitamin
+A or of some allied substance is associated with the
+disease of the bones known as ‘Rickets’ or ‘Rachitis’.
+The history of this disease (p. 181) is made intelligible
+by our knowledge of these facts. Rickets can be shown
+to be most prevalent under precisely those social conditions
+in which articles of diet containing Vitamin A
+are scarce and the amount of sunlight is inadequate.</p>
+
+<p>Our knowledge of this topic is in the process of active
+extension. The question of the actual influence of sunlight
+and of the rays of various wave-length which go to
+make it up is still too uncertain for discussion here.
+There is a special aspect of this topic, however, to
+which we may refer. It has been demonstrated that
+stable-fed cows, fed not on fresh food but on oil-cake,
+yield milk of little antirachitic power. It has, however,
+been shown that this milk becomes antirachitic after
+exposure to ultra-violet light. Therefore, some antirachitic
+substance is produced in the milk, as in the body,
+by the action of ultra-violet light. Now recent research
+has shown that the antirachitic elements are associated
+with a chemical substance known as <i>Cholestrol</i> which
+is of the nature of a complex alcohol. Nevertheless
+<span class="pagenum" id="Page_313">313</span>chemically pure Cholestrol has no antirachitic power,
+though it, too, acquires it by exposure to ultra-violet
+light. By chemical means 99·9 per cent. of rayed and
+antirachitic Cholestrol has been recovered as pure
+Cholestrol without antirachitic power. Therefore the
+antirachitic power, that is the vitamin factor, resides in
+the remaining one-tenth per cent. of rayed Cholestrol.
+The further investigation of this fraction may be
+expected to yield results of great importance both
+theoretically and practically.</p>
+
+<p>Another substance of the same order exists in the
+husks of rice. If animals such as fowls be fed on a diet
+of rice deprived of its husks, they develop a nervous
+affection. Now a somewhat similar nervous affection
+known as ‘Beri-beri’ is known in the East among natives
+who live on milled rice. The disease, whether in human
+beings or chickens, may be cured or avoided by giving
+the husks of the rice separately. The substance thus conveyed
+has been named <i>Vitamin B</i>. There is yet another
+disease, Scurvy (p. 170), which occurs in those who have
+been deprived of fresh food. <i>Vitamin C</i>, which cures this,
+is specially found in the juices of oranges and lemons.
+Our knowledge of ‘deficiency diseases’, of which Scurvy
+is one, is only just beginning. It may well be that they are
+of wider occurrence than has been supposed, and vitamins
+may be important curative and preventive agents.</p>
+
+
+<h3 id="_19_Knowledge_of_the_Eye_and_its_Disorders">
+  § 19. <i>Knowledge of the Eye and its Disorders.</i>
+</h3>
+
+<p>From an early date the treatment of ailments of
+the eye has stood somewhat apart from the rest of
+medical practice. Moreover, the knowledge of the
+structure and functions of the parts of the eye has not
+<span class="pagenum" id="Page_314">314</span>kept closely parallel with that of other departments of
+anatomy and physiology.</p>
+
+<figure class="figcenter illowe30" id="i314">
+  <img class="w100" src="images/i314.jpg" alt="">
+  <figcaption class="center">
+    <span class="smcap">Fig. 131. Diagram to show the Structure of the Eye, represented
+    in section.</span><br>For description see <a href="#Page_314">pp. 314-15</a>.
+  </figcaption>
+</figure>
+
+<p>The eye is a roughly spherical organ, enclosed in a
+tough capsule, the <i>Sclerotic coat</i> (<a href="#i314">Fig. 131</a>). The transparent
+front of this capsule, the <i>Cornea</i>, is the curved
+window through which we look upon our world. There
+is a watery space, the <i>Anterior Chamber</i>, behind the
+Cornea, at the back of which is situated the <i>Lens</i>, a
+horny transparent structure. In front of the Lens is
+a ring-shaped pigmented muscle which shuts out light
+from the Lens, except at the center, and gives the characteristic
+color to the eye. This circular colored muscle
+is the <i>Iris</i>, and the hole in its center is the <i>Pupil</i>. The
+<span class="pagenum" id="Page_315">315</span>pupil becomes smaller or larger with contraction or
+expansion of the Iris. This change is a reflex and unconscious
+act, depending on the amount of light and
+also on the degree to which the eye is adjusted to
+examine near objects.</p>
+
+<p>The edge of the Lens of the eye is attached by the
+circular <i>Suspensory Ligament</i> to the circular <i>Ciliary
+Muscle</i>. The Ciliary Muscle, by contracting or relaxing,
+alters the form of the Lens (<a href="#i317">Fig. 132</a>). This
+change in form of the Lens is part of the process of
+adjustment to near or distant vision. Behind the Lens
+is the large <i>Posterior Chamber</i>, containing a transparent
+gelatinous substance. At the back of the posterior
+chamber is the sensitive area or <i>Retina</i>, which is the
+essential organ of vision, and is backed by a pigmented
+coat, the <i>Choroid</i>. The Retina is continuous with the
+<i>Optic Nerve</i>, along which an artery enters the globe of
+the eye. At the point where this artery pierces the
+Retina there is the so-called <i>Blind Spot</i>.</p>
+
+<p>A ray of light penetrating the eye from the center
+of the Cornea through the center of the Lens falls on
+or near a specially sensitive area, the <i>Yellow Spot</i>, and
+images formed there are more distinctly perceived than
+those formed elsewhere. When an object is examined
+closely, the observer makes the attempt to bring the
+image of it on to his Yellow Spot. Any injury to the
+Yellow Spot causes a great diminution in clearness of
+vision. Man and his allies, the zoological group known
+as the ‘Primates’, are the only mammals, except the
+cat tribe, that possess a Yellow Spot. There can be
+little doubt that the possession of this Yellow Spot has
+done much to raise the importance of vision among the
+<span class="pagenum" id="Page_316">316</span>senses in the Primates. It has thus been a very potent
+factor in the evolution and elevation of Man himself.</p>
+
+<p>The eye is an optical instrument which, like other
+instruments, performs its functions with something less
+than perfection. Most purely optical errors of the eye
+can be remedied by spectacles. These aids to vision are
+of very great importance, since, by the time middle life
+is reached, few are fortunate enough to read in comfort
+without them. The introduction of spectacles, therefore,
+enormously extended the active intellectual life.
+Their social effects are incalculable.</p>
+
+<p>The commoner optical errors may be classified under
+four heads.</p>
+
+<p>First and commonest there is ‘old sight’. When a
+healthy eye adjusts to near vision, the Ciliary Muscle
+contracts towards its attachment at the junction of Conjunctiva
+and Sclerotic. This draws forward and relaxes
+the Suspensory Ligament. The elasticity of the Lens,
+no longer constrained by the Ligament, causes it to
+assume a more convex form. This more convex form
+is appropriate to the correct focussing of a near object
+on the Retina. At or about the age of forty-five the
+Lens usually begins to lose its elastic power, and thus
+has difficulty in adapting to near vision. The trouble is
+remedied by the use of convex glasses for reading or
+other near work.</p>
+
+<p>A second common error is the so-called ‘far sight’.
+In this form—save in extreme cases—the eye is competent
+for distant objects, but those that are near are not
+clearly seen. The incapacity for near vision is due to
+a deformity—usually innate—of the eye. The eye is
+too short along the axis <i>xy</i> (<a href="#i314">Fig. 131</a>). The resulting
+<span class="pagenum" id="Page_317">317</span>optical error can be remedied by the use of convex
+spectacle lenses.</p>
+
+<figure class="figcenter illowe30" id="i317">
+  <img class="w100" src="images/i317.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 132. Diagram to show the nature of Accommodation of the
+    Eye to near vision.</span> The Ciliary muscle, by contracting, pulls forward
+    the lateral attachment of the Suspensory Ligament to the Sclerotic. Thus the
+    ligament is relaxed and in turn relaxes its pull on the Lens. The Lens thereon
+    becomes more convex. As age advances the Lens loses this power and so the
+    sight fails for near vision.</p>
+  </figcaption>
+</figure>
+
+<p>Thirdly, there is the so-called ‘near sight’. In this
+state near objects can be clearly seen, but vision fails
+with those that are more distant. Near sight is usually
+an acquired condition. The eye is too long along the
+axis <i>xy</i> (Fig 131). The resulting optical error can be
+remedied by the use of concave spectacle lenses.</p>
+
+<p>Fourthly, there is ‘irregular sight,’ known as ‘astigmatism’.
+In extreme cases of this condition no perfectly
+clear image can be formed of any object, whatever
+its distance. It is in some measure both congenital
+and acquired, and is due to an irregular deformation
+of the optical apparatus of the eye. The remedy for
+astigmatism is a compensatory deformation of the
+spectacle lens, which may need, in other respects, to
+accord to the convex or concave form, according as the
+<span class="pagenum" id="Page_318">318</span>deformation of the eye is of the far-sighted or near-sighted
+type.</p>
+
+<p>Historically optical errors of the eye were relieved
+by spectacles before the nature of the defects was understood.
+The first suggestion of the use of convex lenses
+as an aid to old sight was made by Roger Bacon (1214-94)
+in the thirteenth century. Spectacles with convex
+lenses for old or for far sight first came into use about
+1300. By the fifteenth century they were widely known.
+It may well be that their adoption, by prolonging reading
+life, had an important effect upon that process of
+extension of knowledge that we dub the ‘Revival of
+Learning’. Concave lenses for the relief of near sight
+came in towards the end of the fifteenth century, but
+were not widely used till the eighteenth century. Astigmatic
+lenses were not contrived till well into the nineteenth
+century.</p>
+
+<p>In 1874 S. Weir Mitchell (1830-1914), a very able
+American physician, showed that the eye strain resulting
+from astigmatism was associated with many nervous
+conditions. Weir Mitchell’s name is familiarly associated
+with a line of treatment of these conditions. Since his discovery
+it has been the practice to examine for optical error
+all sufferers with headache and other neurotic symptoms.</p>
+
+<p>For long there was no means of estimating the degree
+of error, whether of old sight, far sight, or near sight,
+save by trial on the part of the patient himself. Spectacles
+were a common object of the hawker’s trays, and
+from them the sufferer selected the specimen that
+suited him best. The first essential improvement in
+this state of affairs was an elucidation of the mode of
+action of lenses. The paths of light rays in their passage
+<span class="pagenum" id="Page_319">319</span>through a lens were first correctly determined at the
+beginning of the seventeenth century by the astronomer
+Johannes Kepler (1571-1630). Knowledge of optics
+advanced during the seventeenth and eighteenth centuries,
+but the optical errors of the living eye were not
+accurately estimated until the time of the great Dutch
+ophthalmologist Frans Cornelis Donders (1818-89).
+The system of prescribing and fitting spectacles that is
+now in vogue dates from the publication of his work,
+<i>The Anomalies of Refraction and Accommodation</i>, in 1864.
+Hardly less important was the invention of the ophthalmoscope
+by Hermann von Helmholtz (p. 213). Very
+important also was the introduction of ‘test types’ for
+examining errors of vision by the Dutch ophthalmologist
+Hermann Snellen (1834-1904).</p>
+
+<p>One of the most remarkable minds that has ever
+applied itself to medical problems was that of the
+Quaker physician Thomas Young (1773-1829). He
+was a man of immense learning, and is remembered
+for having been the first to decipher Egyptian hieroglyphics.
+Young explained the power of the eye
+to ‘accommodate’ for near vision. This faculty of
+‘accommodation’ was, he showed, due to changes in
+the curvature of the crystalline lens (<a href="#i317">Fig. 132</a>). In
+his memoir <i>On the Mechanism of the Eye</i> (1801),
+Young gave the first scientific account of Astigmatism.
+His theory of color vision and his doctrine that light
+is due to waves in the ether are still important. His
+‘wave theory’ of light completely replaced the old view,
+the so-called ‘emission theory,’ that light is due to
+something material which goes forth from the luminous
+object. While we are referring to Young we may remind
+<span class="pagenum" id="Page_320">320</span>the reader that his work on ‘Energy’ lies at the
+back of all modern Physics, in the history of which he
+takes an extremely important place.</p>
+
+<p>The operative treatment of the eye is of great antiquity.
+The most important operative procedure is that
+for ‘cataract,’ a condition caused by an opacity of the
+lens. ‘Couching’ for cataract, that is depressing the
+opaque lens, was practised by Alexandrian surgeons in
+the third century <span class="allsmcap">B.C.</span> It is described by Celsus (p. 43)
+in the first and mentioned by Galen (p. 50) in the
+second Christian century. Contemporary with these
+authors are descriptions of the actual extraction of the
+lens affected with cataract.</p>
+
+<p>In Imperial Roman times there were surgeons who
+devoted themselves exclusively to cataract operations.
+These were practised during the Middle Ages by the
+Arabs and to a less extent by the Westerns. For the
+most part the operations were performed by wandering
+quacks, who were, however, often very skilful. In the
+sixteenth century operations on the eye began to pass
+into the hands of recognized medical practitioners. The
+advances in the knowledge of the anatomy and physiology
+of the eye in the eighteenth century enabled the
+French surgeon Jacques Daviel (1696-1762) to explain
+the real nature of cataract, which is usually nothing but
+a senile change in the lens of the eye. His knowledge
+made it possible for him greatly to improve the operation
+for extraction, so that, over a large range of cases,
+he had only 11 per cent. of failures.</p>
+
+<p>The modern era of ophthalmic surgery was ushered
+in by Donders (p. 319), von Helmholtz (pp. <a href="#Page_213">213</a> and
+<a href="#Page_319">319</a>), and Albrecht von Graefe (1828-70). The last was
+<span class="pagenum" id="Page_321">321</span>a professor at Berlin who greatly improved the operation
+for cataract and introduced or improved many other
+important operations on the eye. He was one of the first
+to make important clinical observations with the ophthalmoscope,
+and he showed how the instrument may be
+made to yield information not only of the condition of
+the eye itself, but also of the brain and of its membranes,
+an application which has become of the greatest value
+in later medical developments. Though he died before
+the most important work of Pasteur and Lister had
+become generally accepted, von Graefe was yet practising
+a system of surgery which was not far from
+aseptic.</p>
+
+<p>As with most departments of Medicine, so also with
+Ophthalmology, the most significant advances during
+the last generation have been in the direction of prevention
+rather than cure. Prominent among these measures
+are, firstly, school inspection with the consequent early
+detection and isolation of infectious cases of conjunctivitis;
+secondly, maternity welfare accompanied by
+prompt notification and treatment of the very dangerous
+and sight-destroying ‘Ophthalmia of the New-born’;
+thirdly, improved light regulation in factories
+and schools; and, fourthly, adequate provision of spectacles
+for school children with errors of vision.</p>
+
+<p>The recognition of the infectious character of the
+very chronic and sight-destroying disease known as
+<i>Trachoma</i>, or ‘Granular Conjunctivitis,’ has been of
+great importance for the Public Health. The disease
+is common in the near East and in Eastern Europe
+and by no means rare in slum quarters in the West.
+A rigid system of inspection of immigrants, together
+<span class="pagenum" id="Page_322">322</span>with quarantine combined with treatment, has done
+much to diminish its ravages in the United States.</p>
+
+
+<h3 id="_20_Investigation_of_the_Nature_and_Action_of_Drugs">
+  § 20. <i>Investigation of the Nature and Action of Drugs.</i>
+</h3>
+
+
+<h4 id="a_Entry_of_Vegetable_Drugs_into_the_Pharmacopoeia">
+  (a) <i>Entry of Vegetable Drugs into the Pharmacopoeia.</i>
+</h4>
+
+<p>An examination of the list of drugs that are in use at
+the present day—apart from those which have been introduced
+by the scientific movement of the last generation—yields
+some surprising results. Some thirty per
+cent. of the crude vegetable drugs in the modern official
+Pharmacopoeia were known in remote antiquity. The
+Egyptian medical papyri mention, among others, Aloes,
+Caraway, Castor Oil, Coriander, Dill, Fennel, Juniper,
+Mint, Myrrh, and Turpentine. Among Egyptian
+mineral remedies still in use are salts of copper and of
+lead. Assyrian medical tablets refer to most of the
+Egyptian drugs as well as to a number of others, among
+which are Almond Oil, Aniseed, Galbanum, and Liquorice.
+Among Assyrian mineral remedies that are used by
+us to this day are Alum and Bitumen. Early Indian
+medicine had a very copious pharmacopoeia. <i>Cannabis
+indica</i>, known as ‘Hashish’ or ‘Indian hemp’, Cardamoms,
+<i>Cassia fistula</i>, <i>Datura stramonium</i>, and <i>Nux vomica</i>
+are among the valuable Indian herbs now in use
+in scientific medicine, while Mercury preparations were
+perhaps ultimately of Indian origin.</p>
+
+<p>The medical herb lore of the Greeks comes to us
+chiefly from Dioscorides (p. 43), who mentions about
+five hundred plants. A large number of these are still
+in our own Pharmacopoeia. Among these, besides
+those of Egyptian, Assyrian, and Indian origin, are
+Ammoniacum, Belladonna, Camomile, Catechu, Cinnamon,
+<span class="pagenum" id="Page_323">323</span>Colchicum, Colocynth, Crocus, Galls, Gentian,
+Ginger, Hyoscyamus, Lavender, Linseed, Male Fern,
+Mallow, Marjoram, Mustard, Poppy, Rhubarb, Sesame,
+Stavesacre, Storax, Terebinth, Tragacanth, and Wormwood.
+About thirty-seven per cent. of our Pharmacopoeia
+was known to the later Greeks. From them the
+Arabs derived, adding, however, enormously to their
+drug-lists, so that we may say that about fifty per cent.
+of our drugs were in use by the Arabic-speaking physicians
+of the Middle Ages. With the discovery of
+America further important additions were made. Of
+these we have already discussed the introduction of
+Cinchona, Ipecacuanha, and Tobacco (p. 95). Few
+important additions were made in the eighteenth
+century, though among them was Digitalis (p. 328).</p>
+
+
+<h4 id="b_Active_Principles">
+  (b) <i>Active Principles.</i>
+</h4>
+
+<p>One of the things that separate the practice of Medicine
+of our time from that of previous ages is our power
+to give drugs in ‘pure’ form. This means not only that
+we can secure drugs without adulteration, but also that
+the active substances in drugs can be chemically isolated
+and given without admixture. Most drugs used in
+Medicine are, in fact, of vegetable origin. The possibility
+of giving them in chemically pure form depends upon
+the discovery, early in the nineteenth century, that plants
+owe their poisonous and remedial properties to small
+quantities of <i>Active Principles</i>, which are susceptible of
+chemical extraction and isolation. Thus the science that
+deals with the action and nature of drugs, <i>Pharmacology</i>,
+really took its rise about a hundred years ago, though
+many had experimented with drugs at an earlier date.</p>
+
+<p><span class="pagenum" id="Page_324">324</span></p>
+
+<p>Further progress in the same direction has been
+made by the so-called ‘synthetic’ preparation of drugs.
+Certain substances of vegetable origin do not readily
+yield their active principles and to extract them very
+complex chemical processes may be involved. There
+are special obstacles to the complete purification of
+other drugs, even when they have been obtained in a
+relatively pure state. These difficulties can sometimes
+be surmounted by the preparation of the drug from inorganic
+materials. This synthetic process of preparation
+is now possible for many substances that are of
+medical application. Furthermore, when a drug can be
+thus synthetically prepared, it is often possible to try
+chemical variants upon it, and thus to obtain a more
+effective preparation.</p>
+
+<p>In former times a vast number of drugs were habitually
+employed by physicians, and they were often given
+in very complicated prescriptions. ‘Polypharmacy’, the
+giving of many drugs, is a vice from which Medicine
+has now in large part freed itself. The number of drugs
+given by scientific physicians is far fewer that it was.
+For this there are several reasons. Firstly, many drugs
+were found useless for the purpose for which they were
+administered, and were at times even dangerous.
+Secondly, since attention has been drawn to the active
+principles of drugs rather than to the crude natural
+drugs, it has been seen that, in fact, many of the drugs
+that were being given were merely duplicates one of
+another, and that often the administration of the active
+principle itself was more effective and more reliable
+than that of the source from which it was obtained.</p>
+
+<p>What then is the nature of the drugs now being
+<span class="pagenum" id="Page_325">325</span>administered by scientific physicians? They fall into
+a number of classes. The nature and action of some of
+these is so simple that no prolonged discussion of them
+is necessary. There are, for instance, the inorganic
+acids and alkalis, the primary action of which, when
+taken internally, can be determined by a series of experiments
+on gastric juice in a test-tube kept at body
+temperature. Again, there are soluble inorganic salts,
+which are absorbed unchanged from the alimentary
+canal. These have the effect of increasing secretions.
+Their purgative effect is well known, though the physiological
+details of their action are not yet clear. There
+are yet other substances, such as metallic Mercury in
+‘grey powder’ or Bismuth, which act mechanically, even
+when administered internally. Over and above these
+simpler substances, and in addition to the traditional
+vegetable substances which have been in use as medicines
+for centuries, there are others which have only
+been accessible during the last few generations. We
+have already discussed under separate headings the
+derivatives from animal glands, such as of the Thyroid
+(p. 305), of the Adrenals (p. 307), or of the Pancreas
+(p. 306), as well as the bacterial Vaccines (p. 261)
+and Antitoxins (p. 267). We now turn to pure chemical
+substances of vegetable origin. Of these mention may
+be made especially of the groups known as the <i>Alkaloids</i>
+and the <i>Glucosides</i>.</p>
+
+
+<h4 id="c_The_Alkaloids">
+  (c) <i>The Alkaloids.</i>
+</h4>
+
+<p>By ‘Alkaloid’ is understood a nitrogenous substance,
+usually of vegetable origin, which forms salts with
+acids. The alkaloids are mainly obtained from the
+<span class="pagenum" id="Page_326">326</span>dicotyledonous plants. Generally they occur in nature
+in combination with plant acids such as citric or tartaric
+acid. The alkaloid group contains some of the most
+important drugs that we possess. Among them are
+Morphine, Strychnine, Cocaine, Atropine, and Quinine.</p>
+
+<p>The investigation of the alkaloids began with the
+nineteenth century. Morphine was isolated from Opium
+by the Parisian apothecary Charles Derosne (1780-1846)
+in 1803. He failed, however, to recognize
+its chemical affinities, which were first grasped by
+the German apothecary Adolf Sertürner (1783-1841).
+Their work, however, attracted but little notice until
+attention was drawn to it by the great French chemist
+Joseph Gay-Lussac (1778-1850), in 1817. The
+result was the concentration of much scientific ability
+on the alkaloids. Prominent among the early investigators
+were the French pharmacologists Pierre Joseph
+Pelletier (1788-1842) and Joseph Caventou (1795-1878).
+Between 1818 and 1820 they isolated from
+Cinchona (p. 95) certain alkaloids allied to Quinine,
+from Nux vomica the alkaloid Strychnine and certain
+of its allies, and from Coffee the alkaloid Caffeine.
+Pelletier in conjunction with the distinguished chemist
+Jean-Baptiste Dumas (1800-84) followed this by a
+quantitative examination of a number of alkaloids in
+1823. The first alkaloid to be used as such in medicine
+was Strychnine. It was introduced in 1821 by
+the French physiologist François Magendie (1783-1855),
+the teacher of Claude Bernard.</p>
+
+<p>In the thirties and forties of the nineteenth century
+Liebig, who had developed his doctrine of radicles
+(p. 206), attempted to determine the formula of alkaloids.
+<span class="pagenum" id="Page_327">327</span>He was followed by Wöhler (p. 206). Since then
+an immense amount of work has been done in investigating
+the chemical nature and physiological action of
+alkaloids. The general result has been to reveal the
+fact that each alkaloid-yielding plant contains not one
+but a number of alkaloids. Those from the same plant
+often have similar but not identical action upon the
+animal body. The differences in physiological action
+of allied alkaloids have occupied much of the attention
+of pharmacologists. The accurate knowledge of these
+differences has made possible a far greater finesse in the
+administration of alkaloid drugs than was previously
+possible. Some alkaloids can be prepared synthetically,
+but the process is mostly of theoretical rather than
+practical importance.</p>
+
+
+<h4 id="d_The_Glucosides">
+  (d) <i>The Glucosides.</i>
+</h4>
+
+<p>The Glucosides are an ill-defined group which have
+in common the property of yielding a sugar-like substance—usually
+glucose itself—as a result of certain
+chemical processes. They are mostly of vegetable origin
+and the history of their investigation has been parallel
+with that of the alkaloids. The first glucoside to be isolated
+was Salicin, which was obtained from willows in
+1819. It is the active principle of the very ancient
+remedy for rheumatism, ‘Oil of Wintergreen’. Salicylic
+acid was introduced into Internal Medicine in 1873
+and its derivative, Aspirin, in 1899. Both drugs are of
+great importance, and many other derivatives of Salicin
+are in use. Salicin and its derivatives can be prepared
+synthetically, and the synthetic products are in use in
+Medicine.</p>
+
+<p><span class="pagenum" id="Page_328">328</span></p>
+
+<p>Of all the glucoside-yielding plants, perhaps medically
+the most important is the Foxglove, <i>Digitalis
+purpurea</i>. The use of the plant was known to some of
+the medieval herbalists, and is, moreover, recommended
+in the German and English printed herbals of the sixteenth
+and seventeenth centuries. Foxglove is mentioned
+as a folk remedy in George Eliot’s <i>Silas Marner</i>,
+the story of which refers to a period round about 1750
+before the Industrial Revolution, ‘when the spinning-wheels
+still hummed busily in the farm-houses’
+(<a href="#i175">Fig. 89</a>). It was introduced into scientific Medicine
+in 1785 by William Withering (1741-99) of Birmingham
+in his <i>Account of the Foxglove</i>, which gives
+details of numerous cases treated with it.</p>
+
+<p>Digitalis long resisted the attempts to extract an
+active principle, but since the seventies it has yielded to
+investigators a whole series of glucosides. Digitalis and
+its derivatives have become of much importance, especially
+in the treatment of cardiac conditions. Despite
+the success in obtaining glucosides from the Foxglove,
+the extract of the plant itself continues in wide use.</p>
+
+
+<h4 id="e_The_Study_of_Pharmacology">
+  (e) <i>The Study of Pharmacology.</i>
+</h4>
+
+<p>Since the middle of the nineteenth century the investigation
+of the physiological action of drugs has been
+mainly in German hands. The most prominent exponents
+of the method have been Karl Binz (1832-1912)
+and Oswald Schmiedeberg (1834-1921), both
+professors at Dorpat, where there has been a pharmacological
+laboratory since 1849. The first pharmacological
+laboratory in America, that at Ann Arbor
+established in 1893, and the first in England, that at
+<span class="pagenum" id="Page_329">329</span>University College, London, established in 1905, were
+successively occupied by A. R. Cushny (1866-1926).
+The work of these and of other pharmacologists has
+not tended to increase but to reduce the number of
+drugs. Nevertheless, some new drugs of great importance
+have been introduced by them. Of these, among
+the more valuable is Amyl nitrite, the inhalation of
+which was first recommended by T. Lauder Brunton
+(1844-1916) as early as 1867 as a remedy in certain
+cases of sudden heart seizure.</p>
+
+<p>Improvements have been made not only in the drugs
+themselves but also in modes of administration. The
+ancient methods of inunction and inhalation, as well as
+other older methods, have been greatly elaborated in
+modern times, and are now of wider application than
+they were. No advance of this order compares in
+importance with the introduction of the Hypodermic
+Syringe by the ingenious French surgeon Charles
+Gabriel Pravaz (1791-1853). By means of this instrument
+various drugs can be injected directly into the
+subcutaneous tissues or into the veins. This mode of
+administration is more accurate and under better control
+than any other, and the action of the drug so
+injected is swifter and more sure.</p>
+
+
+<h4 id="f_Chemotherapy">
+  (f) <i>Chemotherapy.</i>
+</h4>
+
+<p>During the twentieth century the outlook on drug
+treatment has been modified by the success obtained
+in the <i>specific</i> treatment of certain diseases, that is to
+say, treatment by remedies which strike at a particular
+disease and no other. Until quite recently scientific
+Medicine recognized very few specific remedies. It
+<span class="pagenum" id="Page_330">330</span>had been ascertained that Cinchona owes its value
+in Malaria to the alkaloid Quinine (p. 326), which acts
+as a specific exterminator of the malaria parasites, and
+not simply as a remedy for fever in general. It had also
+been ascertained that Ipecacuanha owes its value in
+tropical Dysentery to the alkaloid Emetine, which acts
+similarly as a specific exterminator of the protozoal
+organisms which are the infective agents. Quinine and
+its allied alkaloids and Emetine and its allied alkaloids
+were practically the only specifics the value of which had
+been scientifically proved, except Mercury for Syphilis.</p>
+
+<p>About the beginning of the twentieth century arose
+the new ‘Chemotherapeutic’ movement as it came to be
+called. This movement was initiated by the studies of
+natural Antibodies (p. 262) by Paul Ehrlich of Frankfurt
+(1854-1915). Antibodies are strongly antagonistic
+to the parasitic organism the toxin of which has elicited
+them, but, on the other hand, they are quite harmless
+to the animal body in which they reside. Here are ideal
+remedies provided by Nature herself. Ehrlich compared
+them to magic bullets, constrained by a charm to fly
+straight at their objective and to injure no other. No
+such perfect artificial drugs have yet been produced.
+The problem of Chemotherapy is rather how to poison
+the parasite as much as possible while poisoning the
+host as little as possible.</p>
+
+<p>When Ehrlich began the study of Chemotherapy
+observers had long known that certain aniline dyes have
+a special affinity for certain cells or organisms. Indeed
+the affinity of certain of the dyes for certain bacteria had
+made possible the work of Koch on Tuberculosis and
+on other diseases. As far back as the seventies and
+<span class="pagenum" id="Page_331">331</span>eighties much work had been done on the subject, and
+the action of these dyes had interested a large variety of
+investigators. Ehrlich’s first results were on a protozoal
+parasite, which infests dogs. By injecting small doses
+of a certain aniline dye into the veins of the infected
+animal it was found possible to destroy the parasites
+while doing very little injury to the dog.</p>
+
+<figure class="figcenter illowe30" id="i331">
+  <img class="w100" src="images/i331.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 133. The Organisms of Syphilis in a smear from the Local
+    Infection.</span> Highly magnified. They are best seen by means of a special
+    optical arrangement in which the outlines of the objects appear glistening
+    white and the background black. The round objects are pus corpuscles, the
+    two spiral objects the organisms of syphilis.</p>
+  </figcaption>
+</figure>
+
+<p>At this point Ehrlich turned aside from the aniline
+dyes to study the effects of much more toxic substances.
+He selected the compounds of arsenic for the purpose.
+After prolonged research, he obtained an arsenical derivative
+which proved very toxic to parasitic protozoa and
+little toxic to their animal hosts. When a vast number
+of experiments had been made, this substance was tried
+in 1910 in cases of human Syphilis. This disease had
+been shown by Fritz Schaudinn (1871-1906) in 1905
+to be due to a protozoal parasite, the <i>Spirochaeta pallida</i>
+<span class="pagenum" id="Page_332">332</span>(<a href="#i331">Fig. 133</a>). The results obtained by the new remedy
+were very satisfactory and a valuable specific was thus
+added to the medical armory. The drug became
+widely known as 606, since this is its number in the
+series of the arsenic derivatives with which Ehrlich had
+experimented. In the meantime others had been at
+work along lines suggested by the aniline experiments.
+Their investigations led in 1920 to the discovery of a
+specific against the deadly <i>Sleeping Sickness</i> or <i>Negro
+Lethargy</i>. This drug is known as <i>Bayer 205</i> from the
+firm that prepared it and the number in the series of
+substances that were tested.</p>
+
+<p>Since the first preparation of 606 and 205 some
+interesting facts have emerged concerning their action
+as well as the action of Quinine, Emetine, and other
+specific remedies. It has been found that the toxicity
+of these substances to the parasites against which they
+are aimed is much greater when the parasites are within
+the body than when the drugs are applied to the organisms
+outside the body. In other words, the drugs
+do something to the body, or the body does something
+to the drugs, that is inimical to the parasite. The nature
+of that something is still under discussion. In the case
+of Quinine it seems that the Quinine so affects the red
+blood corpuscles that the malarial parasites cannot
+enter them and so cannot go through their sexual cycle
+(<a href="#i285">Fig. 123</a>). Thus the Quinine does not act as a direct
+poison but attacks the parasite in a much more subtle
+manner. In the case of other parasites the action of
+the specifics is more difficult to understand. It should
+be pointed out, however, that the chief victories of
+Chemotherapy have been in dealing with the protozoal
+<span class="pagenum" id="Page_333">333</span>rather than the bacterial diseases. A main task of future
+Medicine will be the discovery of means of eliciting
+antibodies against the various bacterial infections. For
+this there is more immediate hope from the use of
+remedies of vital origin than from those synthetically
+produced.</p>
+
+
+<h3 id="_21_Interpretation_of_Collective_Medical_Data">
+  § 21. <i>Interpretation of Collective Medical Data.</i>
+</h3>
+
+<p>The drawing of a deduction of scientific value from
+experience is by no means a simple process. In many
+sciences the investigator has the power to control experience;
+in other words he can <i>experiment</i>. But even
+the interpretation of experiment needs special precautions.
+The physical experimenter must, for instance,
+make sure that he has but one ‘variable’. Thus, if
+examining the effects of pressure on a gas, he must see
+that in raising or lowering pressure he is not altering
+temperature, or if recording the effects of temperature
+he must satisfy himself that he is eliminating those of
+pressure. In experiments upon living things the limitation
+of the field of action to one simple factor is often—perhaps
+always—impossible. The biological investigator
+is therefore accustomed to accompany his experiment
+with ‘controls.’ Thus, if he wishes to ascertain
+the effect on the growth of animals of feeding with
+milk that has been boiled, he must feed one series of
+animals on unboiled milk while he is experimenting
+with a series fed with the boiled milk. He must take
+steps to ensure that the two series are similar as regards
+age, strength, size, &amp;c., and that the conditions under
+which they live are identical, except as regards the one
+factor the results of which he seeks to ascertain.</p>
+
+<p><span class="pagenum" id="Page_334">334</span></p>
+
+<p>When the observer is dealing with human material,
+it is very seldom that he can either restrict the number
+of variables to one or secure an adequate series of controls.
+Physicians are habitually in a position in which
+action of some kind is demanded. They cannot await
+the conclusion of laboratory researches, which may
+extend over years, for the patient must be relieved at
+once or die. Being often unable to use those most
+reliable instruments of science, experiment or observation
+under control conditions, physicians have come
+to rely on what is called ‘a general experience of
+disease’.</p>
+
+<p>One of the commonest fallacies of such general experience
+is assignment of causative relationship between
+two conditions, simply on the ground that they frequently
+occur in association. Thus it is a fact—and
+one to which attention has been drawn by medical
+observers—that rheumatic affections and red-headedness
+are often found together. But both conditions are
+common and it has not been satisfactorily demonstrated
+that the association of the two is any commoner than
+their frequency in the population at large would render
+probable. Such general experience is therefore very
+fallible and is incapable of scientific expression, though
+it is often very valuable and sometimes indeed entirely
+indispensable. To give such experience scientific expression,
+to place it in terms of the ‘primary qualities’ of
+the founders of modern Science (<a href="#Page_106">pp. 106-7</a>), it is necessary
+to put it into statistical form. Statistical statement
+thus becomes of the highest importance for medical
+progress. Medical statistics, when prepared from
+proper material and drawn up with the requisite skill,
+<span class="pagenum" id="Page_335">335</span>are at once the most exact and the most generalized
+expression of medical experience.</p>
+
+<figure class="figcenter illowe30" id="i335">
+  <img class="w100" src="images/i335.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 134. Diagram illustrating the alteration in the Percentage
+    of Age-Distribution of the population of England and Wales
+    from 1891 to 1926.</span> It will be observed that the people of England and
+    Wales have been getting steadily older.</p>
+  </figcaption>
+</figure>
+
+<p>Statistical statements, however, vary greatly in their
+value and ease of interpretation. The simplest statistical
+statements with which the medical man has to deal
+are perhaps those which relate to surgical operations.
+The categories in which the patient may be placed are
+here limited; he may die, recover, improve, or get
+worse. If the operation is a quite simple one, and if the
+surgeon is perfectly honest, and also—which is rarer—quite
+unbiased, a small body of statistics may carry
+immediate conviction as to the value of an operation.
+<span class="pagenum" id="Page_336">336</span>Thus, Lister’s first results with amputation, as obtained
+under his antiseptic conditions, at once satisfy
+the mind, although the conclusions are based on only
+forty cases (p. 240). No surgeon at once both able and
+willing to appreciate these results would hesitate to
+adopt the new method.</p>
+
+<p>The operation of amputation is, however, in a statistical
+sense, a particularly simple matter. The patient
+must either undergo the operation or not, and the
+proportion of cases in which the necessity is doubtful
+is very small. Further, he either recovers or dies—for
+the operation could hardly be in itself unsuccessful,
+nor the surgeon in doubt as to whether the patient had
+recovered or not. Many operations, however, are not
+of this order. They may be performed for conditions
+as to the exact nature of which the surgeon is uncertain,
+and for symptoms which may be only partially relieved.
+Thus, the removal of the appendix for Appendicitis may
+be most urgently necessary for the saving of life in one
+case and may be a matter of convenience for the relief
+of more or less indefinite symptoms in another. Further,
+what one surgeon calls appendicitis another may not.
+One surgeon may have every appendix that he removes
+submitted to skilled pathological examination before he
+accepts the case as one of appendicitis and places it
+among his statistics. Another may be quite content
+with naked-eye appearances of the nature of which he
+alone is witness, judge, and reporter. It is, therefore,
+clear that any collective statement as to the results of
+such an operation must be cautiously scrutinized before
+conclusions of the slightest scientific value can be
+drawn from them.</p>
+
+<p><span class="pagenum" id="Page_337">337</span></p>
+
+<figure class="figcenter illowe30" id="i337">
+  <img class="w100" src="images/i337.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 135. Death-rate from Cancer of the Tongue.</span> It will be
+    observed that it is not a common cause of death till about 45 years of age, but
+    that it then increases rapidly to fall again in both sexes in old age. These
+    features are clearly related to various factors in the causation of the condition.
+    One of these is certainly Syphilis, which is most frequently contracted between
+    20 and 30 and more often by men than women. The so-called ‘tertiary’
+    effects of this condition, some of which lead to Cancer of the Tongue,
+    do not usually make themselves felt, however, for many years after infection.
+    Contrast <a href="#i338">Fig. 136</a> and <a href="#i340">Fig. 137</a>.</p>
+  </figcaption>
+</figure>
+
+<p>There is a common and rather foolish saying that
+‘Statistics may be made to prove anything’. This is
+true, but it is true only in the sense that <i>evidence</i>
+may be made to prove anything. The matter turns on
+the questions, firstly whether the evidence is of a good
+or a bad order, and secondly whether the investigator
+is in a good or bad position to interpret the evidence.
+<span class="pagenum" id="Page_338">338</span>A statistical statement may be well or ill founded and
+well or ill interpreted, but statistical statement is, in
+fact, the only scientific method open to us for presenting
+long series of data. The conclusions to be drawn
+from those data, though sometimes evident and easily
+<span class="pagenum" id="Page_339">339</span>elicited, at other times demand specially skilled and
+specially trained interpreters. Moreover, to be of value
+to others, such interpreters must also be skilled in
+expression, so that the main body of those who have no
+statistical training may be in a position to understand
+the essential elements in their conclusions. In no
+medical department is literary power of greater importance
+than in that which deals with statistics. Thus
+has arisen the small but highly important class of
+medical statisticians. The rise of medical statistics into
+a vocation places the crown on Medicine <i>as a science</i>.
+It is not given to many medical men to be proficient in
+this department. But the duty lies on all medical men,
+and indeed on all citizens, to appreciate the value of
+this study and to seek to appraise its simpler and more
+established conclusions.</p>
+
+<p>It is remarkable how frequently a straightforward
+statistical statement may remove a false impression,
+even when the impression is based on evidence not of
+a wholly unscientific character.</p>
+
+<figure class="figcenter illowe30" id="i338">
+  <img class="w100" src="images/i338.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 136. Death-rate from Cancer of the Lip.</span> It will be observed
+    that this curve resembles in form that of the death-rate from Cerebral Haemorrhage
+    as shown in <a href="#i340">Fig. 137</a>, but differs from that of the death-rate from
+    Cancer of the Tongue as shown in <a href="#i337">Fig. 135</a>. The chances of dying from Cancer
+    of the Lip are negligible till middle age is past and then increase progressively
+    throughout life. In the causation of Cancer of the Lip Syphilis is
+    not an important factor. On the other hand the continuous irritation of
+    pipe-smoking, which acts not at one age but throughout life, has to be considered
+    as a causative element. Hence the resemblance to Fig. 137 rather
+    than to Fig. 135.</p>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i340">
+  <img class="w100" src="images/i340.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 137. Chart of death-rate from Cerebral Haemorrhage and
+    Allied States.</span> These conditions are extremely rare in the young, but
+    among the commonest causes of death in later life. The liability to them increases
+    progressively to extreme old age. This is explained by the fact that
+    Cerebral Haemorrhage, etc. follows on the rupture of a blood-vessel in the
+    brain and the rupture of the vessel is conditioned by the hardness and brittleness
+    of its coat. The hardness of the arteries increases progressively in later
+    life, whence the saying ‘a man is as old as his arteries’.</p>
+  </figcaption>
+</figure>
+
+<p>For example the increase in the incidence of deaths
+from Cancer has often been emphasized. But Cancer
+is a disease of advancing life. The age distribution of
+the death-rate from many forms of Cancer is closely
+parallel to that of certain other forms of senile disease
+(Figs. <a href="#i338">136</a> and <a href="#i340">137</a>). Now the age constitution of the
+population of most civilized countries is altering in the
+sense that the proportion of the elderly and aged is
+constantly increasing (<a href="#i335">Fig. 134</a>), so that some increase
+in the Cancer incidence must be expected. Moreover
+the appearance of some increase in the incidence of
+Cancer is due to improved diagnosis. How far there is a
+<span class="pagenum" id="Page_340">340</span>real increase, when these factors have been taken into
+account, is still somewhat doubtful. It must always be
+borne in mind that a relative decrease in the proportion
+of deaths from <i>any</i> cause must automatically increase
+the proportion of deaths from other causes.</p>
+
+
+<p><span class="pagenum" id="Page_341">341</span></p>
+<p>Again, there is no doubt of the fall in the death-rate
+in England and Wales from ‘Phthisis,’ or pulmonary
+tuberculosis, during the last fifty or sixty years. There
+is also no doubt of the effect both of bad housing and
+of urban conditions in inducing a susceptibility to chest
+disease in general and to pulmonary tuberculosis in
+particular. Further, there is no doubt that the rural
+population suffers less from pulmonary tuberculosis
+than the town population. These matters of common
+medical knowledge have naturally led to the conclusion
+that the rise of the great towns has led to a great increase
+of pulmonary tuberculosis, and that this increase
+has been remedied by the improved housing and sanitary
+conditions of the last generation. A study of the
+statistical evidence, however, negatives this view. The
+rise in the proportion of deaths from pulmonary
+tuberculosis took place before the Industrial Revolution.
+Moreover, the proportion began to fall long
+before the campaign against tuberculosis could affect
+the issue. The history of pulmonary tuberculosis may,
+in fact, be regarded as that of an ‘epidemic’ outbreak,
+extending over about 100 years, of a disease which has
+always been endemic and remains so now that the
+epidemic is past.</p>
+
+<figure class="figcenter illowe30" id="i343">
+  <img class="w100" src="images/i343.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 138. Curve showing percentage of deaths from Phthisis</span>
+    to total deaths from all causes in London over a period of 200 years. It will
+    be seen that the percentage begins to rise definitely about 1730 and to fall
+    definitely about 1830. This state of affairs may be pictured as an epidemic
+    lasting about 100 years.</p>
+  </figcaption>
+</figure>
+
+<p>These points are well brought out in the accompanying
+diagram (<a href="#i343">Fig. 138</a>). The fall in the proportion of
+deaths from Phthisis expressed there gives rise to
+further considerations. It might seem that the statement
+that the proportion of those who died from
+phthisis was diminishing left in itself no doubt that the
+disease was less prevalent than formerly. This, however,
+is not the case. Phthisis is more liable to affect
+<span class="pagenum" id="Page_342">342</span>those under forty-five years of age than those who are
+older. Now the proportion of the population that is under
+forty-five is steadily diminishing (<a href="#i335">Fig. 134</a>). This is
+one of the results of the steadily diminishing general
+death-rate (<a href="#i196">Fig. 96</a>, p. 196). Therefore the proportion of
+the more susceptible to the less susceptible is diminishing.
+It might have been the case (though it is not) that
+the ratio (more susceptibles)/(less susceptibles) was not only decreasing but
+was actually decreasing more rapidly than the ratio
+(total deaths)/(deaths from phthisis). Had this been so, the conclusion
+would have been justifiable that the fall in the proportion
+of deaths from the disease did not correspond to
+any decrease in its infectivity. In fact, however, the
+prolonged high mortality from phthisis and its later
+rate of fall do suggest the former prevalence of a more
+virulent type of the disease over a long period, in other
+words something of the nature of a prolonged epidemic.</p>
+
+<p>This conclusion leads us to the conception of the
+nature of an epidemic. To gain some conception of the
+ideas involved in that word, we must glance back in
+history.</p>
+
+<p>From the time of Hippocrates onward the subject of
+Epidemic outbursts of disease has drawn the attention
+of physicians. A writer in the <i>Hippocratic Collection</i>
+thought he could perceive an association of symptom-complexes
+with each other and with the weather. In
+the great work <i>Epidemics</i>, to which the name of the
+Father of Medicine is attached, such a view, known as
+that of ‘Epidemic Constitutions,’ is set forth. The view
+was revived by Sydenham in the seventeenth century
+<span class="pagenum" id="Page_343">343</span>and has given rise to a vast literature extending to our
+own time. In the eighteenth and nineteenth centuries
+the attempts of the investigators of vital statistics to
+place the leading events of life in a form capable of
+exact analysis (<a href="#Page_166">pp. 166-68</a>) focused attention on the
+search for a mathematical expression for the rise and
+fall of epidemic diseases.</p>
+
+<p>The first successful attempt to describe epidemics
+along these lines was made by William Farr (1807-1883),
+an official in the office of the Registrar-General in
+London, and one of the greatest of all epidemiological
+thinkers. His first publication on the subject was in
+1840, and had reference to the recent outbreak of
+small-pox, in which more than 30,000 had died in
+England and Wales. It was his merit to observe that
+the successive decreases in the number of cases in
+successive equal periods during the decline of the
+epidemic correspond to the successive increases in
+the number of cases during successive equal periods
+of the rise of the epidemic. In other words, he observed
+<span class="pagenum" id="Page_344">344</span>that the rise and decline of an epidemic tend to be
+mathematically symmetrical.</p>
+
+<p>Farr’s suggestion that epidemics are liable to follow
+the lines of regular mathematical rules drew little
+attention at the time, but in a later year it led to a most
+remarkable and striking prophecy. At the end of 1865
+Cattle-plague broke out in England. Week by week
+the number of cases increased. In the fourth week of
+February 1866 the responsible Minister, in a speech
+in Parliament, gave a very gloomy account of the state
+of affairs, expressing the belief that the devastation
+would be far beyond what had yet been encountered.
+Farr, however, had been watching the returns, and had
+been applying his rule to them. He thereupon made
+a public pronouncement of his belief that at an early
+date the outbreak would reach its maximum and would
+then decline. The outbreak did, in fact, very closely
+follow the course which he had predicted by reasoned
+calculation. Farr even prophesied the number of cases
+that would occur week by week. His prophecy was
+near the truth.</p>
+
+<p>During the years that followed Farr’s prediction his
+views were applied with success to a variety of epidemic
+conditions. The regular form of the development of
+the epidemic was found to apply in certain outbreaks
+of typhus, measles, and other conditions.</p>
+
+<p>Farr’s law was more exactly expressed by him in
+1868. It remained, however, simply a mathematical
+law, a rule of which the underlying cause was not apparent.
+It was soon observed that his law applied to
+many but by no means to all epidemics. Moreover, it
+was perceived that the actual figures which he gave for
+<span class="pagenum" id="Page_345">345</span>his epidemic of 1840 resembled those of certain other
+epidemics in that they could be fitted with greater or
+less exactness to a well-known mathematically described
+curve, known as the ‘normal curve of error’.
+We need not discuss the mathematical foundation of
+this curve, which is shown in two variants in <a href="#i345">Fig. 139</a>.
+For our immediate purpose it is enough to observe that
+it rises gradually at first, but then more steeply, that
+the steepness decreases after a while, and then the
+curve begins to decline again, as it rose. We note that
+it is symmetrical.</p>
+
+<figure class="figcenter illowe30" id="i345">
+  <img class="w100" src="images/i345.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 139. The Normal Curve of Error</span>, shown in two types made with
+    the same formula but with different constants. This curve has been shown
+    to be similar to that representing the incidence of cases in some Epidemics.</p>
+    <p>Vertical lines are drawn from two pairs of symmetrical points. The continuous
+    lines refer to the higher curve, the broken lines (from the points of
+    intersection of the two curves) refer to the lower curve. The lines will be
+    seen to divide the curves into three parts. This division is of such a character
+    that the sum of the two lateral areas is equal to the central area for each
+    case.</p>
+  </figcaption>
+</figure>
+
+<figure class="figcenter illowe30" id="i346">
+  <img class="w100" src="images/i346.jpg" alt="figures 140 and 141">
+  <figcaption>
+    <p><span class="smcap">Fig. 140.</span> Curve of monthly number of deaths from Small-pox during
+    an epidemic at Warrington, Lancashire, in 1743.</p>
+    <p><span class="smcap">Fig. 141.</span> Curve of weekly number of cases of Scarlet Fever registered
+    during an epidemic at Glasgow in 1892.</p>
+    <p>Both curves are fitted to the theoretical epidemic curve, and are modified
+    from Brownlee. The curves are in both cases explained on the assumption
+    that the infectivity, having reached a high point at the beginning of the
+    outbreak, decreases thenceforward in geometrical progression.</p>
+  </figcaption>
+</figure>
+
+<p>When we are dealing with living beings or are dealing
+with things that may indefinitely approximate to a
+mathematical rule, but never entirely fit it. Especially
+<span class="pagenum" id="Page_346">346</span>when the living beings are also human beings, with
+their infinitely complex relationships, various factors
+are present which interfere with the exact application
+of mathematical findings. Nevertheless, the theoretical
+form of the epidemic is an extremely useful framework
+into which actual epidemics may often be fitted, with
+greater or less exactness. In the accompanying figures
+(<a href="#i346">Figs. 140-141</a>) are adduced cases of greater exactness.
+There are, however, many cases in which an ‘outbreak’
+does not seem to fit the simple theoretical curve at all.
+Examination of such curves has in some cases suggested
+that we have not one epidemic or disease but
+<span class="pagenum" id="Page_347">347</span>two or more to deal with. In some cases it has been
+possible to analyze the outbreak on the basis of two
+or more theoretical curves, suggesting in fact two or
+more outbreaks of similar but not identical causation
+(<a href="#i347">Fig. 142</a>).</p>
+
+<figure class="figcenter illowe30" id="i347">
+  <img class="w100" src="images/i347.jpg" alt="">
+  <figcaption>
+    <p><span class="smcap">Fig. 142.</span> THE CURVES OF SOME EPIDEMICS, which do not
+    follow the theoretical curve, may be analyzed as compounded of two or more
+    epidemics, each of which accords individually to the mathematical rule.
+    Thus ‘Summer Diarrhoea’ is a seasonal disease very fatal to infants in England
+    during the hot months, July and August. The angular curve shows
+    the average daily incidence of deaths from this disease in London during the
+    fifty-three years 1850-1903. It can be analyzed into two of the theoretical
+    epidemic curves.</p>
+    <p>Each reading of the curve, calculated from the actual cases of ‘Summer
+    Diarrhoea of Infants’, can be divided into two, as indicated in the step-like
+    readings, one dotted and the other continuous. These accord beautifully
+    with two theoretical curves, thus indicating not one but two recurrent
+    epidemics. It thus seems probable that two separate sources of infection
+    are confused as ‘Summer Diarrhoea of Infants’.</p>
+  </figcaption>
+</figure>
+
+<p><span class="pagenum" id="Page_348">348</span></p>
+
+<p>What can be the causative element which constrains
+the incidence of a disease in a population to follow
+mathematical rules? An answer was provided by
+John Brownlee (1868-1927), the late statistician to the
+Medical Research Council of England. The leading
+fact about an Epidemic is that it rises to a maximum,
+falls, and then dies out, and that the curve representing
+the number of new cases in a series of equal and consecutive
+periods of time throughout the Epidemic is
+symmetrical. In practice the decline is usually a little
+slower than the rise. This is sometimes, at least, due to
+better observation and record of the later cases. Now
+why does an Epidemic die out? The possible reasons
+may be reduced to three. Firstly, the end of an
+Epidemic may be due to the exhaustion of susceptible
+persons in the population. That is to say, all the survivors
+are immune, either being so by nature or having
+become so by having contracted the disease and recovered.
+Secondly, it is conceivable that the liability
+to the disease should be decreased, not by rise in the
+proportion of immunes, but by externally acting causes,
+as, for instance, by rise of seasonal temperature, which
+would provide conditions under which the organism
+loses its infectivity. Expressed in older language,
+this is to say that the ‘Epidemic Constitution’ (p. 342)
+has changed. Thirdly, the infecting organisms may,
+of their own inner nature, lose their infectivity. The
+second factor may act in special cases, but may be disregarded
+except in those cases. We are, therefore,
+left with the first and third.</p>
+
+<p>Now it is possible to construct curves that would
+correspond to the exhaustion of the supply of susceptible
+<span class="pagenum" id="Page_349">349</span>persons by continuous increase of the proportion
+of those who become immune either by taking the
+disease or by dying. These curves, however, have the
+character that their descent is more rapid (and neither as
+rapid nor less rapid) than their ascent. It is the merit
+of Brownlee to have suggested that the actual curve of
+the Epidemic corresponds to a known though very
+little understood biological phenomenon, namely change
+in the infectivity of the invading organisms. The
+simplest expression of his discovery is that the loss of
+infectivity of these organisms is approximately in the
+ratio given by a geometrical progression. That is, if
+the infectivity of the Epidemic be <i>m</i>, and at the end of
+a unit of time <i>mg</i> (when <i>g</i> is less than unity), at the end
+of a second unit of time it will be <i>mg</i><sup>2</sup>, and at the end of
+the third <i>mg</i><sup>3</sup>, and so on. Assuming this to be a fact,
+the course of Epidemics would follow the curve of
+normal error (<a href="#i345">Fig. 139</a>).</p>
+
+<p>Of late years it has been possible to institute artificial
+epidemics in a series of animals under control
+conditions. Such experiments must, in the nature of
+the case, cover a large number of years, but they bid
+fair to throw much light on the nature and progress of
+human epidemics.</p>
+
+<p>These results seem to show, what was believed on
+other grounds, that in the case of highly infective
+disease, to which, in any population, there are many
+highly susceptible, isolation of declared cases has little
+or no effect on the course of the Epidemic. Such
+diseases are Scarlet Fever, Measles, Influenza, &amp;c.
+Moreover, the experimental epidemics seem to confirm
+the conclusions of Brownlee that in some cases at least
+<span class="pagenum" id="Page_350">350</span>the course of the epidemic is determined by biological
+changes within the parasitic beings that cause it.</p>
+
+<p>Thus in the end our health, our lives, and indeed the
+continuance of our civilization may well depend upon
+a factor which is outside ourselves. For reasons which
+we know not, the pullulating billions of living things
+which are around us, upon us, within us, take up
+a virulence which before they had not, and after a time
+they lose that virulence to become as they were before.
+The world is devastated by an outbreak of Plague, of
+Cholera, of Influenza. But how and why the organisms
+that carry these diseases should acquire a new and more
+deadly infectivity lies among the secrets yet locked
+within the living cell. Life—the life of the Cell, of
+the Bacterium, of Man himself—remains among the
+<i>Arcana Naturae</i>. These are the secret things that in their
+essence—which is Life—remain and will remain behind
+the veil. From such cells we came, through such cells
+we shall return. As to what is the force which starts
+these processes on their way, we are as ignorant as
+children, and must remain so, in essence, till we understand
+the nature of the processes of coming into being
+and passing away. So Medicine must end where she
+began, quaking before the Mystery of Life, a Mystery
+which could only be resolved if we could express
+Mind in terms simpler than itself. If this could be done
+the veil that is cast over all flesh would indeed be rent.
+But the author of this work believes that the hope of
+this is vain and that we are here in the presence of one
+of the ultimate things.</p>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum"><a id="Page_351"></a><a id="Page_352"></a>352</span></p>
+
+
+  <h2 class="nobreak" id="EPILOGUE">
+    EPILOGUE
+  </h2>
+</div>
+
+
+<p>We have now traced various movements in Medicine
+throughout the ages and have seen how all the sciences
+in turn have been made to bring their tribute to the
+alleviation of suffering. We have seen especially how
+the consideration of disease as a whole, and of the health
+of peoples as a whole, has introduced a new view in the
+handling of disease. Health is a public asset, and its
+promotion has now been recognized as a public duty.
+There are undeniable disadvantages in placing officers
+of the State in control of the personal liberties of its
+citizens, but, on the whole, the advantages, in matters
+of health, have outweighed the disadvantages. Only a
+professed pessimist or a crotchety reactionary could
+deny the gains to humanity from the passage of preventive
+measures from private into public hands.</p>
+
+<p>There is another side of the picture which we have
+need also to consider. The advances in Medicine and
+the advantages that have accrued therefrom have been
+entirely the result of the application of the rational
+method of observation and experiment. To control
+Nature we must above all things understand Nature.
+Neither the conception of Nature as the kind old nurse
+nor the conception of Nature ravening red in tooth and
+claw will stand. Least of all can we tolerate the picture
+of Nature as a bountiful mother. If we go to her asking
+something for nothing, she (far from bountiful) will
+give us little but what we have given her, and to him
+<span class="pagenum" id="Page_353">353</span>who but begs she gives no more than a beggar’s portion.
+It is thus that she has served the magician and the
+wizard, who think they can compel her to give them all
+things by their paltry charms!</p>
+
+<p>The amount of human labor and ingenuity that is
+now being thrown into the investigation of Nature is
+almost incredible even to men of science. Some conception
+of the enormous and unreadable bulk of scientific
+literature may be gained by a glance at the <i>International
+Catalogue of Scientific Literature</i>. This gives the <i>titles
+alone</i> of original articles in the various departments of
+physical science. These titles for the year 1914 alone
+occupied seventeen closely printed volumes! The rate
+of publication has accelerated considerably since then.
+There are now about 25,000 periodicals devoted to
+scientific publications! There are very few departments
+of science which do not have some bearing on Medicine.
+It is evident that no human mind can possibly compass
+even a year’s output of this material.</p>
+
+<p>And yet it is not the bulk of writing on Science that
+forms the only or even the chief deterrent to the general
+comprehension of its principles. The mass of scientific
+detail has always been beyond the power of one mind to
+grasp. But as we have traced Rational Medicine through
+its long course in Antiquity and the Middle Ages to
+its debouchment on to our own time, we have found not
+only a more difficult but also a new situation. In approaching
+our own age we have found ever more difficulty
+in discussing Rational Medicine as a single channel
+of thought. It spreads into a Delta, of which, though
+the many mouths may inosculate, yet the tendency
+seems to be for an ever wider divergence. This diffusion,
+<span class="pagenum" id="Page_354">354</span>induced by increased specialization, cannot go on for
+ever without defeating the very objects for which specialism
+was invented.</p>
+
+<p>On the other hand, when we glance at the tasks now
+being performed by the medical man, we cannot fail to
+be struck by the great increase in the number of things
+that have come to be regarded as within his sphere. It
+is a commonplace that he has in large part taken the
+place of the parson. But he has also made encroachments
+on the functions of the lawyer, the legislator and
+the judge, of the schoolmaster, the architect and the
+statistician. He has assumed some of the duties of
+the parent and guardian, while even the soldier and the
+policeman are to some degree under his control. In the
+ordering of their lives, and even in the regulation of
+their vices and the reform of their shortcomings, men
+and women are far more willing to seek the advice and
+help of the medical man than once they were. The
+reason is, without doubt, that his advice is much more
+worth having than it once was.</p>
+
+<p>The organization of research, the systematized record
+of experience, the improved intercommunications of our
+time, have combined to increase vastly the medical
+man’s sources of information and to make his application
+of them more accurate and more scientific. Moreover,
+there are factors in our social life itself that have tended
+not only to deepen the physician’s knowledge but to
+widen his experience. His effective working-day has
+greatly lengthened. No doubt, the motor car and railway
+train are important elements in this extension of
+the doctor’s day, but a far more fundamental element
+is the advent of the skilled nurse. Many tasks which
+<span class="pagenum" id="Page_355">355</span>occupied the time of the doctor in the old days are
+now relegated to her. The result is that the doctor
+sees a far greater number of patients and has a much
+greater experience of actual sickness than was formerly
+possible.</p>
+
+<p>But after we have discussed all those factors which
+have gone to the increase of the power of Physic we have
+still to consider the philosophical basis which has conditioned
+this increase. Men do not willingly accept that
+in which they do not believe. The shifting of men’s
+trust implies a shifting in their faith. In truth the
+triumph of Physic has underlying it a subtler triumph,
+that of Scientific Determinism. The great increase in
+the detailed knowledge of Nature has led to a great
+increase in the belief in the Reign of Law. Disease and
+death were once thought to be the special acts of Providence.
+They are now widely held to be illustrations of
+determined natural laws. Men of science in general, and
+medical men in particular, are not wont to profess themselves
+philosophers, but, in fact, much of their work is
+done in a spirit which would have us believe that these
+determined laws are universal and are wholly outside
+ourselves. Has there not arisen a school that would claim
+that our thinking is but a seeming, and that we do but
+behave as though we thought? Three centuries ago
+Descartes conceived that the animal might be treated
+as a machine. If man be but an animal, consequences
+are entailed from which Descartes shrank, for the watchword
+of his philosophy was ‘Cogito, ergo sum’, <i>I think,
+therefore I am</i>. There is a newer school whose work is
+intimately bound up with the progress of Medicine
+that would abandon this basic doctrine of the father of
+<span class="pagenum" id="Page_356">356</span>modern Philosophy, who is also the founder of Physiology,
+as a separate discipline.</p>
+
+<p>The position as it stands appears as a dilemma. The
+triumphs of Science have been secured by disregarding
+Mind, and yet they cannot be appreciated or advanced
+without invoking Mind. Unless we accept the full
+conclusions of the Determinist Philosophy, we are
+forced to the conclusion that Mind must do something
+to the animal body. If Mind holds the reins, there
+must be a point at which Mind pulls the reins. The
+matter ever in dispute is where that point may be. If
+life and growth are bound up with an Entelechy, as
+seems to the author of this work to be the case, there
+must somewhere and somehow be a level in the organism
+at which the laws of physics and chemistry are
+transcended by some other mode of action.</p>
+
+<p>It is no part of our task to provide a Philosophy
+which will resolve all the problems that our subject
+raises. Nevertheless, in the presence of this dilemma,
+such a work should not close on too optimistic a note,
+in the department either of medical thought or of
+its application. Even if looked at merely as an interpreter
+of its own terms, determinist thought, which lies
+at the basis of modern medical developments, has not
+been quite so universally successful as is often supposed,
+and as the preceding pages of this book may lead the
+reader to think. While enormously increasing the sum
+of our knowledge of Nature, it has also tended more
+and more to separate the parts of that knowledge from
+each other. It is clear that no such way of thinking can
+ever give us a survey of Nature as a whole. It can
+never enable us to ‘think things together’, and without
+<span class="pagenum" id="Page_357">357</span>such thinking together our life is and must remain a
+contradiction and a muddle.</p>
+
+<p>For a real survey of Nature we must look to another
+Philosophy and another Method. We are in this matter
+but just entering on a new era, and may it not be that
+some sort of solution will be provided by a better study
+of the Mind itself? Only by our minds can we know
+that Nature presents us with any order at all. It therefore
+behoves us to search out most diligently all that
+we can learn about our minds, to see whether, on the one
+hand, this determined order, which has so impressed
+our age, is in any degree within us and part of our
+observing instrument, or whether, on the other hand,
+it is wholly without us. There is much evidence that it
+is not wholly without us, and that Determinism is a
+habit in our method of thinking on certain topics, and
+that the emphasis on the ‘primary qualities’ (see pages
+106-8) which we inherit from Galileo is by no means
+justified. It may be that what we think and feel and see
+is not only as real as what we weigh and count and
+measure, but that weighing, counting, and measuring
+are but forms of thinking, feeling, and seeing. In this
+connection the reader should turn over again in his mind
+the implications of the ‘Law of Specific Nerve Energies’
+enunciated by Johannes Müller (see <a href="#Page_212">pp. 212-13</a>).</p>
+
+<p>Nor must we end on too optimistic a note as to the
+actual achievements of Science. Advances in our knowledge
+have certainly been very great, but they may
+be and often are exaggerated. We must always
+guard ourselves against considering mere accumulation
+of detail as an advance. The collection of data is
+but a means to an end, and if that end is not reached
+<span class="pagenum" id="Page_358">358</span>they are a very weariness and vexation of the philosophic
+spirit. Real advance in knowledge can only be
+tested by effective advances in theory, and thus judged
+the cost of progress—the cost in the brute accumulation
+of facts—has increased far more rapidly than progress
+itself. What is wanted is not so much new
+data as correlation in their accumulation. The increase
+in medical specialism is not so much evidence of
+advance as it is of the heaping up of uncoordinated
+observations.</p>
+
+<p>Works on Medicine intended for popular consumption
+are often couched in the jubilant terms of victory.
+Yet there are whole departments in which no progress
+whatever has been made. We pride ourselves on the
+advance in knowledge of infectious disease which the
+germ theory has brought us, and yet we are utterly and
+completely ignorant of the two things about infectious
+disease which are the two things most worth knowing on
+that topic. Firstly, no man has conceived the way in
+which the parasites of disease first fastened themselves
+on the animal body, a specific parasite to a specific animal.
+In other words, we have not the least idea how
+diseases first begin. Secondly, no man has conceived a
+reason why diseases, distributed over a wide area and
+in many bodies, should vary in virulence from time to
+time, why, for instance a relatively mild condition, such
+as influenza, should suddenly devastate the world. It is
+easy to say that human resistance varies, but that is
+only to restate the problem in terms of which we know
+nothing. On these high topics of Medicine we know as
+much and as little as Hippocrates.</p>
+
+<p>Moreover, if we turn to definite diseases, there are
+<span class="pagenum" id="Page_359">359</span>many conditions, and those among the most important,
+of which our ignorance is almost complete. Thus of
+the very common and painful diseases, muscular rheumatism
+and rheumatoid arthritis, we know hardly more
+than Hippocrates and our remedies are but little more
+effective than his. The common cold—economically
+the most important of all diseases, not excluding Cancer
+and Tuberculosis—has a vast literature, but the physician
+is almost helpless in its presence and can but let it
+run its course. Measles, Whooping-cough, and Influenza
+have become more deadly of late years. We have
+still no clear line of treatment for them. Nor have we
+any real insight into the nature of Cancer. Those who
+reach advanced age have no better chance of life than
+they had two hundred years ago (p. 177). Above all, it
+must be remembered that the great majority of deaths
+are caused by diseases theoretically preventable. There
+is a natural term to life which it is desirable that all
+should attain. Yet most of us will surely die a violent
+death as truly as though struck down by a felon’s hand.
+Death from disease is an unnatural and a violent death.</p>
+
+<p>Faced by facts of this order there are those who
+constantly urge increased activity in medical ‘research’.
+But research can only be prosecuted by those whose
+talents specially fit them for the work. With reason it
+may be and is doubted whether there are many in
+Western Europe or America who could profitably be
+employed on medical research who are not already so
+employed. It is easy to make investigations on a certain
+level, but those best qualified to judge are of opinion
+that the general level of medical research has fallen, not
+risen, of late years. The number of publications has
+<span class="pagenum" id="Page_360">360</span>multiplied manyfold, but there are those who doubt if
+there is much increase in investigation of the first order.
+The increase in specialism and the extremely narrow
+outlook of some workers has stultified much investigation,
+since with his decreased range the researcher is
+often less able to perceive the bearings of his own work.
+Thus he may labor for years elaborating a technique
+by means of which he may collect facts without that
+guiding wisdom or judgment that is the mark of
+genius. It must ever be borne in mind that the object
+of fact-collecting is the deduction of law. Not all facts
+can be collected, for facts are infinite in number, and
+it is therefore necessary to select. Selection involves
+<i>judgment</i>, the final and indefinable property of Mind;
+for, if from the facts no laws emerge, the facts themselves
+become an obstacle, not an aid, to scientific
+advance.</p>
+
+<p>All who have to read systematically large masses of
+modern scientific literature have been unfavorably
+impressed by its absence of form. It is evident that a
+large proportion of scientific workers lack adequate
+literary training and never acquire a proper sense of
+literary form. The growing interest in Science has had
+an unfavorable effect on Education in the direction of
+early and intensive specialization. The result is that
+many scientific publications are but semi-literate, they
+are often incoherent in presentation and even more frequently
+unnecessarily diffuse. Nor is it merely a matter
+of form. Language is but the outward and visible sign
+of which Thought is the inward and spiritual reality.
+Confused writing usually indicates and always leads to
+confused thinking. Thus the unliterary character of
+<span class="pagenum" id="Page_361">361</span>scientific writing bids fair to pass from being a mere
+nuisance to become a great scientific evil. Good and
+effective writing implies a broad and solid literary background,
+just as good and effective scientific research
+implies a broad and solid scientific background. The
+fact is that the Humanities and the Sciences are far from
+being as independent of each other as many suppose.
+If literary studies lead to clear and effective expression
+and clear and effective thinking in the domain of
+Science, scientific studies ventilate and inform and
+vitalize Literature. The separation of the two disciplines,
+especially in the adolescent stage of mental
+development, does an injury to both. The concentration
+of the endowments of Learning on the scientific
+departments and especially on the departments of
+applied science has given rise to a very widespread evil
+which is none the less evil because it is subtle.</p>
+
+<p>Within the sphere of the specifically medical sciences
+themselves there are tendencies which are open to
+somewhat similar criticism.</p>
+
+<p>The great fallacy from which scientific Medicine
+has suffered in the past, and still to some extent suffers,
+is the ‘direct attack’. We have come to look upon
+the animal organism as an immeasurably complex machine.
+For its elucidation knowledge from the most
+diverse quarters is therefore demanded. The physical
+chemist, the organic chemist, the physicist, the mathematician,
+the protozoologist, the systematic biologist,
+the botanist, the spectroscopist, the geologist, and a host
+of others are following callings which have no obvious
+bearing on the study of disease. Yet the results obtained
+by them, and by men of science in many other
+<span class="pagenum" id="Page_362">362</span>departments, must be utilized in the study of disease.
+Our knowledge of health and of disease thus depends
+on the sciences as a whole—nay, on Knowledge as a
+whole. Those who would promote the health of mankind
+would do well if they sought to encourage not so
+much the medical sciences as Science as a whole, or
+rather Learning as a whole, for Science is a way of life
+which may penetrate into all departments of Learning,
+and is something far greater than those discrete accumulations
+of knowledge that we call ‘the sciences’. The
+Sciences, working out their destiny, must in the end
+come together again.</p>
+
+<p>If that consummation be reached we may expect
+improvement in health and prolongation of life to a
+degree greater than any previous ages have seen. We
+may indeed expect something yet better, for we may
+hope for a philosophy of the mind that shall make life
+better worth the living.</p>
+
+<p>Medicine cannot give immortality, but it should
+enable us all to live out our full lives. Death, coming
+in due and not undue time, is shorn of all his terrors,
+when every man and every woman</p>
+
+<div class="poetry-container">
+  <div class="poetry">
+    <div class="stanza">
+      <div class="verse indent0">Shall come to his grave in a full age,</div>
+      <div class="verse indent0">Like as a shock of corn cometh in, in his season.</div>
+          </div>
+<div class="attrib"><i>Job</i> v. 26.</div>
+  </div>
+</div>
+
+<p><span class="pagenum" id="Page_363">363</span></p>
+
+<figure class="figcenter illowe30">
+  <img class="w100" src="images/i363.jpg" alt="">
+  <figcaption class="center">
+    FRIENDLY DEATH
+  </figcaption>
+</figure>
+
+
+<hr class="chap x-ebookmaker-drop" aria-hidden="true">
+<div class="chapter">
+
+<p><span class="pagenum" id="Page_364">364</span></p>
+
+
+  <h2 class="nobreak" id="INDEX">
+    INDEX
+  </h2>
+</div>
+
+
+<nav>
+<ul class="index">
+  <li class="ifrst">Abdominal Surgery, <a href="#Page_243">243-8</a></li>
+
+  <li class="indx">Achondroplasia, <a href="#Page_17">17</a></li>
+
+  <li class="indx">Adrenals, <a href="#Page_325">325</a></li>
+
+  <li class="indx">Aesculapius (Asklepios), <a href="#Page_4">4</a>, <a href="#Page_7">7</a>, <a href="#Page_8">8</a>, <a href="#Page_11">11</a>, <a href="#Page_49">49</a>,
+    <a href="#Page_51">51</a></li>
+
+  <li class="indx">Ague, <i>see</i> Malaria.</li>
+
+  <li class="indx">Air, Nature of, <a href="#Page_151">151-6</a></li>
+
+  <li class="indx">Air-Pump, Boyle’s, <a href="#Page_125">125-6</a></li>
+
+  <li class="indx">Albinus, Bernard Siegfried (1697-1770), <a href="#Page_140">140-1</a></li>
+
+  <li class="indx">Albucasis the Moor (11th cent.), <a href="#Page_67">67</a>, <a href="#Page_70">70</a></li>
+
+  <li class="indx">Alchemy, <a href="#Page_122">122-6</a></li>
+
+  <li class="indx">Alcoholism, <a href="#Page_291">291</a></li>
+
+  <li class="indx">Alexander the Great, <a href="#Page_27">27</a>, <a href="#Page_36">36</a></li>
+
+  <li class="indx">Alexandria, <a href="#Page_52">52</a></li>
+
+  <li class="indx">Alexandrian School, <a href="#Page_36">36-41</a></li>
+
+  <li class="indx">Alkaloids, <a href="#Page_325">325-7</a></li>
+
+  <li class="indx">Almond Oil, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Aloes, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Alum, <a href="#Page_322">322</a></li>
+
+  <li class="indx">American Civil War, <a href="#Page_300">300</a></li>
+
+  <li class="indx">Ammoniacum, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Amputation, <a href="#Page_240">240</a>, <a href="#Page_336">336</a></li>
+
+  <li class="indx">Amyl nitrite, <a href="#Page_329">329</a></li>
+
+  <li class="indx">Anaerobic bacteria, <a href="#Page_257">257</a></li>
+
+  <li class="indx">Anaesthesia, <a href="#Page_162">162</a>, <a href="#Page_235">235-7</a></li>
+
+  <li class="indx">Analgesia, <a href="#Page_237">237</a></li>
+
+  <li class="indx">Anatomy, <a href="#Page_122">122</a>, <a href="#Page_138">138</a>;</li>
+  <li class="isub1">of Galen, <a href="#Page_55">55-6</a>;</li>
+  <li class="isub1">Medieval, <a href="#Page_72">72-6</a>;</li>
+  <li class="isub1">Renaissance, <a href="#Page_82">82-92</a>;</li>
+  <li class="isub1">earlier 19th cent., <a href="#Page_204">204</a>;</li>
+  <li class="isub1">Morbid, <a href="#Page_156">156-9</a></li>
+
+  <li class="indx">Anatomy Act (1832), <a href="#Page_193">193</a></li>
+
+  <li class="indx">Aneurysm, <a href="#Page_166">166</a></li>
+
+  <li class="indx">Animal Spirit, <a href="#Page_58">58</a></li>
+
+  <li class="indx">Animism, <i>see</i> Nature-Worship</li>
+
+  <li class="indx">Aniseed, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Ann Arbor, <a href="#Page_328">328</a></li>
+
+  <li class="indx">Anthrax, <a href="#Page_229">229-34</a>, <a href="#Page_250">250-1</a>, <a href="#Page_261">261</a></li>
+
+  <li class="indx">Antibodies, <a href="#Page_262">262</a>, <a href="#Page_268">268-9</a>, <a href="#Page_330">330</a>, <a href="#Page_333">333</a></li>
+
+  <li class="indx">Antidiphtheritic serum, <a href="#Page_264">264</a></li>
+
+  <li class="indx">Antirachitics, <a href="#Page_312">312-13</a></li>
+
+  <li class="indx">Antiseptic Surgery, <a href="#Page_235">235</a>, <a href="#Page_237">237-43</a>.</li>
+
+  <li class="indx">Antiseptics, <a href="#Page_162">162</a></li>
+
+  <li class="indx">Antitoxins, <a href="#Page_264">264-5</a>, <a href="#Page_325">325</a></li>
+
+  <li class="indx">Antoninus, Emperor, Statute of (160), <a href="#Page_46">46</a></li>
+
+  <li class="indx">Apertorium, the, <a href="#Page_164">164</a></li>
+
+  <li class="indx">Aphorisms, the, <a href="#Page_256">256</a></li>
+
+  <li class="indx">Appendicitis, <a href="#Page_336">336</a></li>
+
+  <li class="indx">Aqueducts, Roman, <a href="#Page_46">46</a></li>
+
+  <li class="indx">Arabic Drugs, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Arabic Medicine, <a href="#Page_66">66-8</a></li>
+
+  <li class="indx">Aricia, <a href="#Page_12">12</a></li>
+
+  <li class="indx">Aristophanes, <a href="#Page_29">29</a></li>
+
+  <li class="indx">Aristotle (384-322 <span class="allsmcap">B.C.</span>), <a href="#Page_1">1</a>, <a href="#Page_14">14</a>, <a href="#Page_27">27-35</a>, <a href="#Page_37">37</a>,
+    <a href="#Page_69">69</a>, <a href="#Page_86">86</a></li>
+
+  <li class="indx">Arles, <a href="#Page_42">42</a></li>
+
+  <li class="indx">Arsenic, <a href="#Page_331">331</a></li>
+
+  <li class="indx">Asclepiades of Bithynia (d. <i>c.</i> 40 <span class="allsmcap">B.C.</span>), <a href="#Page_41">41-2</a></li>
+
+  <li class="indx">Aseptic Surgery, <a href="#Page_235">235</a>, <a href="#Page_237">237-43</a></li>
+
+  <li class="indx">Asklepios, <i>see</i> Aesculapius</li>
+
+  <li class="indx">Aspirin, <a href="#Page_327">327</a></li>
+
+  <li class="indx">Assyria, <a href="#Page_6">6</a>;</li>
+  <li class="isub1">Medical Tablets in, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Astigmatism (Irregular Sight), <a href="#Page_317">317-19</a></li>
+
+  <li class="indx">Astrology, <a href="#Page_54">54</a></li>
+
+  <li class="indx">Astronomy, <a href="#Page_103">103-5</a>, <a href="#Page_122">122</a>, <a href="#Page_135">135-6</a></li>
+
+  <li class="indx">Atomic Structure, <a href="#Page_37">37</a>, <a href="#Page_126">126</a></li>
+
+  <li class="indx">Atropine, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Auenbrugger, Leopold (1722-1809), <a href="#Page_160">160</a></li>
+
+  <li class="indx">Augustus, Emperor (reigned 27 <span class="allsmcap">B.C.</span>-<span class="allsmcap">A.D.</span> 14), <a href="#Page_42">42</a></li>
+
+  <li class="indx">Aural Surgery, <a href="#Page_188">188</a></li>
+
+  <li class="indx">Avicenna, the Persian (980-1036), <a href="#Page_67">67</a>, <a href="#Page_70">70</a>, <a href="#Page_72">72</a>, <a href="#Page_74">74</a>, <a href="#Page_82">82</a>,
+    <a href="#Page_180">180</a></li>
+
+  <li class="indx">Avignon, <a href="#Page_76">76</a></li>
+
+
+  <li class="ifrst">Babylonians, the, <a href="#Page_6">6-7</a></li>
+
+  <li class="indx">Bacon, Roger (1214-84), <a href="#Page_318">318</a></li>
+
+  <li class="indx">Bacteria, <a href="#Page_120">120</a>, <a href="#Page_121">121</a>, <a href="#Page_227">227</a></li>
+
+  <li class="indx">Bacteriology, <a href="#Page_249">249-53</a></li>
+
+  <li class="indx">Bacteriolysins, <a href="#Page_269">269</a></li>
+
+  <li class="indx">Baer, Karl Ernst von (1792-1876), <a href="#Page_204">204</a></li>
+
+  <li class="indx">Bagdad, <a href="#Page_66">66</a></li>
+
+  <li class="indx">Baillie, Matthew (1761-1823), <a href="#Page_158">158</a></li>
+
+  <li class="indx">Balfour, Francis Maitland (1851-82), <a href="#Page_204">204</a></li>
+
+  <li class="indx">Bayer, <a href="#Page_205">205</a>, <a href="#Page_332">332</a></li>
+
+  <li class="indx">Beaumont, William (1785-1853), <a href="#Page_148">148</a></li>
+
+  <li class="indx">Bedlam, <a href="#Page_286">286</a></li>
+
+  <li class="indx">Behring, Emil von (1854-1917), <a href="#Page_264">264</a>, <a href="#Page_266">266</a></li>
+
+  <li class="indx">Bell, Sir Charles (1774-1842), <a href="#Page_145">145</a>, <a href="#Page_207">207</a>, <a href="#Page_213">213</a></li>
+
+  <li class="indx">Belladonna, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Bentham, Jeremy (1748-1832), <a href="#Page_178">178</a>, <a href="#Page_190">190-2</a>, <a href="#Page_192">192-3</a></li>
+
+  <li class="indx">Bergmann, Ernst von (1836-1907), <a href="#Page_248">248</a></li>
+
+  <li class="indx">Beri-Beri, <a href="#Page_272">272</a>, <a href="#Page_313">313</a></li>
+
+  <li class="indx">Berlin, <a href="#Page_222">222</a>, <a href="#Page_230">230</a>, <a href="#Page_248">248</a>, <a href="#Page_321">321</a></li>
+
+  <li class="indx">Bernard, Claude (1813-78), <a href="#Page_213">213-15</a>, <a href="#Page_229">229</a>, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Bethlem Hospital, <a href="#Page_286">286</a></li>
+
+  <li class="indx">Biggs, Hermann M., <a href="#Page_202">202</a></li>
+
+  <li class="indx">Binz, Karl (1832-1912), <a href="#Page_328">328</a></li>
+
+  <li class="indx">Biology, <a href="#Page_132">132</a>, <a href="#Page_139">139</a></li>
+
+  <li class="indx">Bismuth, <a href="#Page_325">325</a></li>
+
+  <li class="indx">Bitumen, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Black, Joseph (1728-99), <a href="#Page_151">151-3</a></li>
+
+  <li class="indx">Black Death, the, <a href="#Page_80">80-1</a></li>
+
+  <li class="indx">Blood, Circulation of, <a href="#Page_111">111-20</a>, <a href="#Page_146">146</a></li>
+
+  <li class="indx">Blood-letting, <a href="#Page_39">39</a></li>
+
+  <li class="indx">Blood-poisoning, <a href="#Page_239">239</a></li>
+
+  <li class="indx">Blood-pump, mercurial, <a href="#Page_218">218</a></li>
+
+  <li class="indx">Board of Health, <a href="#Page_194">194-6</a></li>
+
+  <li class="indx">Boerhaave, Hermann (1668-1738), <a href="#Page_122">122</a>, <a href="#Page_139">139-42</a>, <a href="#Page_151">151</a>, <a href="#Page_156">156-7</a>,
+    <a href="#Page_169">169-70</a></li>
+
+  <li class="indx">Bologna, <a href="#Page_71">71-4</a>, <a href="#Page_76">76</a>, <a href="#Page_116">116</a>, <a href="#Page_149">149</a></li>
+
+  <li class="indx">Bonn, <a href="#Page_205">205</a>, <a href="#Page_222">222</a></li>
+
+  <li class="indx">Bordeaux, <a href="#Page_42">42</a></li>
+
+  <li class="indx">Bordet, Jules (1870-), <a href="#Page_269">269</a></li>
+
+  <li class="indx">Borelli, Giovanni Alfonso (1608-79), <a href="#Page_39">39</a>, <a href="#Page_129">129-31</a></li>
+
+  <li class="indx">Boston, Mass., <a href="#Page_198">198</a></li>
+
+  <li class="indx">Botany, <a href="#Page_95">95-6</a>, <a href="#Page_138">138</a></li>
+
+  <li class="indx">Boyle, Robert (1627-91), <a href="#Page_35">35</a>, <a href="#Page_101">101</a>, <a href="#Page_124">124-6</a>, <a href="#Page_151">151</a></li>
+
+  <li class="indx">Brahe, Tycho (1546-1601), <a href="#Page_103">103</a>, <a href="#Page_135">135</a></li>
+
+  <li class="indx">Brain, Aristotle on, <a href="#Page_29">29-30</a></li>
+
+  <li class="indx">Bretonneau, Pierre (1771-1862), <a href="#Page_185">185</a>, <a href="#Page_253">253</a></li>
+
+  <li class="indx">Broca, Paul (1824-80), <a href="#Page_211">211</a></li>
+
+  <li class="indx">Brownlee, John (1868-1927), <a href="#Page_348">348-9</a></li>
+
+  <li class="indx">Bruce, David (1885-), <a href="#Page_255">255</a></li>
+
+  <li class="indx">Bruno, Giordano (1548-1600), <a href="#Page_102">102-3</a></li>
+
+  <li class="indx">Brunton, T. Lauder (1844-1916), <a href="#Page_329">329</a></li>
+
+  <li class="indx">Brussels, <a href="#Page_85">85</a></li>
+
+  <li class="indx">Bubonic Plague, <a href="#Page_201">201</a></li>
+
+
+  <li class="ifrst">Caesar, Julius (102-44 <span class="allsmcap">B.C.</span>), <a href="#Page_45">45</a>, <a href="#Page_46">46</a></li>
+
+  <li class="indx">Caesarean Section, <a href="#Page_45">45</a></li>
+
+  <li class="indx">Caffeine, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Cambridge, <a href="#Page_111">111</a>, <a href="#Page_311">311</a></li>
+
+  <li class="indx">Camomile, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Canada, <a href="#Page_290">290</a></li>
+
+  <li class="indx">Cancers, <a href="#Page_223">223-4</a>, <a href="#Page_337">337-9</a>, <a href="#Page_359">359</a></li>
+
+  <li class="indx"><i>Cannabis indica</i>, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Caraway, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Carbohydrates, <a href="#Page_311">311</a></li>
+
+  <li class="indx">Carbolic Acid, <a href="#Page_239">239-40</a></li>
+
+  <li class="indx">Carbon dioxide, <a href="#Page_153">153</a>, <a href="#Page_155">155-6</a></li>
+
+  <li class="indx">Cardamoms, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Carpenter, Mary (1807-77), <a href="#Page_300">300</a></li>
+
+  <li class="indx">Carrel, Alexis (1873-), <a href="#Page_248">248</a></li>
+
+  <li class="indx">Carrier Problem, <a href="#Page_269">269-70</a></li>
+
+  <li class="indx"><i>Cassia fistula</i>, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Castor Oil, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Cataract of the Eye, <a href="#Page_320">320-1</a></li>
+
+  <li class="indx">Catechu, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Cattle-plague, <a href="#Page_344">344</a></li>
+
+  <li class="indx">Cavendish, Henry (1731-1810), <a href="#Page_153">153</a>, <a href="#Page_156">156</a></li>
+
+  <li class="indx">Caventou, Joseph (1795-1878), <a href="#Page_326">326</a></li>
+
+  <li class="indx">Cell Theory, <a href="#Page_219">219-24</a></li>
+
+  <li class="indx">Cellular Pathology, <a href="#Page_219">219-24</a></li>
+
+  <li class="indx">Celsus, <a href="#Page_43">43-4</a>, <a href="#Page_320">320</a></li>
+
+  <li class="indx">Census system, <a href="#Page_168">168</a></li>
+
+  <li class="indx">Cerebral Haemorrhage, <a href="#Page_338">338</a>, <a href="#Page_340">340</a></li>
+
+  <li class="indx">Cerebrospinal Meningitis, <a href="#Page_269">269-70</a></li>
+
+  <li class="indx">Chadwick, Edwin (1800-90), <a href="#Page_171">171</a>, <a href="#Page_178">178</a>, <a href="#Page_193">193-6</a>, <a href="#Page_202">202</a></li>
+
+  <li class="indx">Charcot, Jean Marie (1825-93), <a href="#Page_211">211</a></li>
+
+  <li class="indx">Charles V, Emperor, <a href="#Page_88">88</a></li>
+
+  <li class="indx">Chemotherapy, <a href="#Page_329">329-33</a></li>
+
+  <li class="indx">Chester, <a href="#Page_182">182</a></li>
+
+  <li class="indx">Cheyne-Stokes Respiration, <a href="#Page_25">25-6</a></li>
+
+  <li class="indx"><span class="pagenum" id="Page_365">365</span>Chicago, <a href="#Page_248">248</a></li>
+
+  <li class="indx">Child Life, 18th c., <a href="#Page_180">180-1</a></li>
+
+  <li class="indx">Children in Factories, <a href="#Page_191">191</a>, <a href="#Page_194">194</a></li>
+
+  <li class="indx">Chloroform, <a href="#Page_235">235</a>, <a href="#Page_236">236</a></li>
+
+  <li class="indx">Cholera, <a href="#Page_194">194-5</a>, <a href="#Page_198">198</a>, <a href="#Page_201">201</a>, <a href="#Page_234">234</a>;</li>
+  <li class="isub1">chicken, <a href="#Page_234">234</a>, <a href="#Page_261">261</a></li>
+
+  <li class="indx">Cholestrol, <a href="#Page_312">312-13</a></li>
+
+  <li class="indx">Christianity, <a href="#Page_61">61-2</a></li>
+
+  <li class="indx">Chyle, <a href="#Page_56">56</a></li>
+
+  <li class="indx">Cinchona, <a href="#Page_95">95</a>, <a href="#Page_281">281-2</a>, <a href="#Page_323">323</a>, <a href="#Page_326">326</a>, <a href="#Page_330">330</a></li>
+
+  <li class="indx">Cinnamon, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Claudius, Emperor (reigned 41-54), <a href="#Page_49">49</a></li>
+
+  <li class="indx">Cleopatra, <a href="#Page_36">36</a>, <a href="#Page_41">41</a></li>
+
+  <li class="indx">Clinical Medicine, <a href="#Page_100">100</a>;</li>
+  <li class="isub1">Methods and Instruments, <a href="#Page_159">159-61</a>;</li>
+  <li class="isub1">Teaching, Rise of, <a href="#Page_138">138-42</a></li>
+
+  <li class="indx">Clinical Thermometer, <a href="#Page_159">159</a></li>
+
+  <li class="indx">Cloaca Maxima, <a href="#Page_45">45</a></li>
+
+  <li class="indx">Cnidus, <a href="#Page_8">8</a></li>
+
+  <li class="indx">Cocaine, <a href="#Page_236">236-7</a>, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Coffee, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Cohnheim, Julius (1839-84), <a href="#Page_238">238</a></li>
+
+  <li class="indx">Colchicum, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Colocynth, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Constantine (d. 1087), <a href="#Page_64">64-5</a></li>
+
+  <li class="indx">Constantinople, <a href="#Page_183">183</a></li>
+
+  <li class="indx">Consumption, <a href="#Page_234">234</a></li>
+
+  <li class="indx">Contagious Diseases in 19th cent., <a href="#Page_201">201</a></li>
+
+  <li class="indx">Cook, James (1728-79), <a href="#Page_170">170</a></li>
+
+  <li class="indx">Cope, E. D. (1840-97), <a href="#Page_204">204</a></li>
+
+  <li class="indx">Copernicus, Nicholas (1473-1543), <a href="#Page_88">88</a>, <a href="#Page_102">102</a></li>
+
+  <li class="indx">Coriander, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Corning, J. L. (1855-), <a href="#Page_236">236</a></li>
+
+  <li class="indx">Cos, <a href="#Page_8">8</a>, <a href="#Page_14">14</a></li>
+
+  <li class="indx">Cretinism, <a href="#Page_304">304</a></li>
+
+  <li class="indx">Crile, G. W. (1864-), <a href="#Page_237">237</a>, <a href="#Page_310">310-11</a></li>
+
+  <li class="indx">Crimean War (1854), <a href="#Page_298">298</a></li>
+
+  <li class="indx">Crocus, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Curve of Error, <a href="#Page_345">345-9</a></li>
+
+  <li class="indx">Cushing, Harvey (1869-), <a href="#Page_236">236</a>, <a href="#Page_249">249</a></li>
+
+  <li class="indx">Cushny, A. R. (1866-1926), <a href="#Page_329">329</a></li>
+
+  <li class="indx">Cuvier, Georges (1769-1832), <a href="#Page_204">204</a></li>
+
+  <li class="indx">Cytology, <a href="#Page_223">223</a></li>
+
+  <li class="indx">Cyto-Pathology, <a href="#Page_223">223</a></li>
+
+
+  <li class="ifrst">Darwin, Charles (1809-82), <a href="#Page_204">204</a>, <a href="#Page_227">227</a>, <a href="#Page_293">293</a></li>
+
+  <li class="indx"><i>Datura stramonium</i>, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Daviel, J. (1696-1762), <a href="#Page_320">320</a></li>
+
+  <li class="indx">de Baillou, Guillaume (1538-1616), <a href="#Page_96">96</a>, <a href="#Page_98">98-9</a></li>
+
+  <li class="indx">de Chauliac, Guy (1300-68), <a href="#Page_76">76-7</a></li>
+
+  <li class="indx">Delirium, early case of, <a href="#Page_25">25</a></li>
+
+  <li class="indx">Dementia praecox, <a href="#Page_292">292</a></li>
+
+  <li class="indx">Democritus (<i>c.</i> 400 <span class="allsmcap">B.C.</span>), <a href="#Page_37">37</a></li>
+
+  <li class="indx">Demography, <a href="#Page_188">188</a></li>
+
+  <li class="indx">de Mondeville, Henri (<i>c.</i> 1270-1320), <a href="#Page_72">72</a>, <a href="#Page_74">74</a></li>
+
+  <li class="indx">Dengue, <a href="#Page_272">272</a></li>
+
+  <li class="indx">Derosne, Charles (1780-1846), <a href="#Page_326">326</a></li>
+
+  <li class="indx">Descartes, René (1596-1650), <a href="#Page_39">39</a>, <a href="#Page_103">103-4</a>, <a href="#Page_127">127-9</a>, <a href="#Page_207">207-8</a>,
+    <a href="#Page_355">355</a></li>
+
+  <li class="indx">Diabetes, <a href="#Page_306">306</a></li>
+
+  <li class="indx">Diarrhoea, <a href="#Page_347">347</a></li>
+
+  <li class="indx">Diderot, D. (1713-84), <a href="#Page_131">131</a></li>
+
+  <li class="indx">Digestion, <a href="#Page_146">146-8</a>, <a href="#Page_214">214-15</a></li>
+
+  <li class="indx">Digitalis (Foxglove), <a href="#Page_323">323</a>, <a href="#Page_328">328</a></li>
+
+  <li class="indx">Dill, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Dioscorides, <a href="#Page_43">43</a>, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Diphtheria, <a href="#Page_24">24</a>, <a href="#Page_185">185</a>, <a href="#Page_201">201</a>, <a href="#Page_253">253</a>;</li>
+  <li class="isub1">immunization, <a href="#Page_262">262-7</a></li>
+
+  <li class="indx">Dispensary Movement, <a href="#Page_178">178</a>, <a href="#Page_180">180</a></li>
+
+  <li class="indx">Dix, Dorothea Lynde (1802-87), <a href="#Page_290">290</a></li>
+
+  <li class="indx">Donders, Frans Cornelis (1818-89), <a href="#Page_319">319</a>, <a href="#Page_320">320</a></li>
+
+  <li class="indx">Dorians, the, <a href="#Page_4">4</a></li>
+
+  <li class="indx">Dorpat, <a href="#Page_328">328</a></li>
+
+  <li class="indx">Drugs, <a href="#Page_95">95</a>, <a href="#Page_322">322-33</a></li>
+
+  <li class="indx">Ductless Glands, <a href="#Page_302">302-8</a></li>
+
+  <li class="indx">Dürer, A., <a href="#Page_83">83</a></li>
+
+  <li class="indx">Düsseldorf, <a href="#Page_50">50</a></li>
+
+  <li class="indx">Dumas, Jean-Baptiste (1800-84), <a href="#Page_326">326</a></li>
+
+  <li class="indx">Dysentery, <a href="#Page_271">271</a>, <a href="#Page_330">330</a></li>
+
+
+  <li class="ifrst">Eberth, Karl Joseph (1835-1927), <a href="#Page_258">258</a></li>
+
+  <li class="indx">Edinburgh, <a href="#Page_235">235</a></li>
+
+  <li class="indx">Egyptian Civilization, <a href="#Page_7">7</a></li>
+
+  <li class="indx">Egyptian Medical Papyri, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Ehrlich, Paul (1854-1915), <a href="#Page_269">269</a>, <a href="#Page_330">330-1</a></li>
+
+  <li class="indx">Electricity, <a href="#Page_149">149-51</a></li>
+
+  <li class="indx">Elements, the Four, <a href="#Page_34">34</a>, <a href="#Page_124">124</a></li>
+
+  <li class="indx">Embryology, <a href="#Page_30">30-2</a>, <a href="#Page_110">110</a>, <a href="#Page_117">117-18</a>, <a href="#Page_120">120-1</a>, <a href="#Page_204">204</a></li>
+
+  <li class="indx">Emetine, <a href="#Page_330">330</a>, <a href="#Page_332">332</a></li>
+
+  <li class="indx">Emphysema, <a href="#Page_158">158</a></li>
+
+  <li class="indx"><i>Encyclopédie</i> (1751-72), <a href="#Page_130">130</a></li>
+
+  <li class="indx">Endotoxins, <a href="#Page_260">260</a>, <a href="#Page_266">266</a></li>
+
+  <li class="indx">Entelechy, <a href="#Page_ix">ix</a>, <a href="#Page_x">x</a>, <a href="#Page_33">33</a>, <a href="#Page_356">356</a></li>
+
+  <li class="indx">Epicurus (342-270 <span class="allsmcap">B.C.</span>), <a href="#Page_37">37</a></li>
+
+  <li class="indx">Epidaurus, <a href="#Page_11">11</a></li>
+
+  <li class="indx">Epidemics, <a href="#Page_182">182-5</a>, <a href="#Page_198">198</a>, <a href="#Page_200">200-1</a>, <a href="#Page_342">342-50</a></li>
+
+  <li class="indx">Epidemiology, <a href="#Page_138">138</a></li>
+
+  <li class="indx">Epileptics, <a href="#Page_292">292</a></li>
+
+  <li class="indx">Erasistratus of Chios (<i>c.</i> 300 <span class="allsmcap">B.C.</span>), <a href="#Page_36">36</a>, <a href="#Page_37">37-40</a></li>
+
+  <li class="indx">Erysipelas, <a href="#Page_239">239</a></li>
+
+  <li class="indx">Esquirol, Jean Étienne D. (1772-1840), <a href="#Page_288">288-9</a></li>
+
+  <li class="indx">Ether, <a href="#Page_235">235</a>, <a href="#Page_237">237</a></li>
+
+  <li class="indx">Evolution, Organic, <a href="#Page_27">27</a>, <a href="#Page_31">31</a></li>
+
+  <li class="indx">—, theory of, <a href="#Page_204">204</a></li>
+
+  <li class="indx">Exotoxins, <a href="#Page_260">260</a>, <a href="#Page_266">266</a></li>
+
+  <li class="indx">Experimental Medicine, <a href="#Page_211">211-19</a></li>
+
+  <li class="indx">Eye, the, and its Disorders, <a href="#Page_313">313-22</a></li>
+
+
+  <li class="ifrst">Fabricius, Jerome, of Aquapendente (1537-1619), <a href="#Page_109">109-11</a></li>
+
+  <li class="indx">‘Far Sight’, <a href="#Page_316">316-18</a></li>
+
+  <li class="indx">Farr, W. (1807-83), <a href="#Page_343">343-5</a></li>
+
+  <li class="indx">Fat, <a href="#Page_311">311</a></li>
+
+  <li class="indx">Federal Health Service, <a href="#Page_200">200</a></li>
+
+  <li class="indx">Fennel, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Fermentation, <a href="#Page_225">225-8</a>, <a href="#Page_230">230</a>, <a href="#Page_239">239</a></li>
+
+  <li class="indx">Ferrier, D. (1843-), <a href="#Page_211">211</a></li>
+
+  <li class="indx">Fevers, <a href="#Page_67">67</a>, <a href="#Page_101">101</a>, <a href="#Page_169">169</a>, <a href="#Page_171">171-2</a>, <a href="#Page_174">174</a>, <a href="#Page_185">185</a>,
+    <a href="#Page_194">194</a>, <a href="#Page_200">200-1</a>, <a href="#Page_243">243</a>, <a href="#Page_254">254-5</a>, <a href="#Page_258">258-9</a>;</li>
+  <li class="isub1"><i>see also specific fevers</i> (Malaria, Typhoid, Yellow, &amp;c.)</li>
+
+  <li class="indx">Fliedner, Frederica (1800-42), <a href="#Page_297">297</a></li>
+
+  <li class="indx">Fliedner, Theodor (1800-64), <a href="#Page_297">297</a></li>
+
+  <li class="indx">Floyer, Sir J. (1649-1734), <a href="#Page_159">159</a></li>
+
+  <li class="indx">Foxglove, <i>see</i> Digitalis</li>
+
+  <li class="indx">Fracastoro, Girolamo (1483-1553), <a href="#Page_96">96</a>, <a href="#Page_98">98</a></li>
+
+  <li class="indx">Fractures, <a href="#Page_246">246-8</a></li>
+
+  <li class="indx">Frankfurt, <a href="#Page_330">330</a></li>
+
+  <li class="indx">Franklin, Benjamin (1706-90), <a href="#Page_171">171</a></li>
+
+  <li class="indx">Freud, S. (1856-), <a href="#Page_293">293</a></li>
+
+  <li class="indx">Fry, Elizabeth (1780-1845), <a href="#Page_171">171</a>, <a href="#Page_297">297</a></li>
+
+
+  <li class="ifrst">Galbanum, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Galen of Pergamum (130-200), <a href="#Page_1">1</a>, <a href="#Page_39">39</a>, <a href="#Page_50">50-3</a>, <a href="#Page_320">320</a>;</li>
+  <li class="isub1">his Medical System, <a href="#Page_53">53-60</a>;</li>
+  <li class="isub1">in the Renaissance, <a href="#Page_82">82-90</a></li>
+
+  <li class="indx">Galilei, Galileo (1564-1642), <a href="#Page_103">103</a>, <a href="#Page_104">104-8</a>, <a href="#Page_108">108-9</a>, <a href="#Page_115">115</a>, <a href="#Page_135">135-6</a>,
+    <a href="#Page_138">138</a>, <a href="#Page_159">159</a>, <a href="#Page_356">356</a></li>
+
+  <li class="indx">Galls, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Galvani, Luigi (1737-98), <a href="#Page_149">149-51</a></li>
+
+  <li class="indx">Galvanism, <a href="#Page_149">149-51</a></li>
+
+  <li class="indx">Gastric Juice, <a href="#Page_148">148</a>, <a href="#Page_303">303</a></li>
+
+  <li class="indx">Gay-Lussac, Joseph (1778-1850), <a href="#Page_326">326</a></li>
+
+  <li class="indx">Gegenbaur, Karl (1826-1903), <a href="#Page_204">204</a></li>
+
+  <li class="indx">Geneva, <a href="#Page_300">300</a></li>
+
+  <li class="indx">Gengou, O. (1875-), <a href="#Page_269">269</a></li>
+
+  <li class="indx">Gentian, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Gerhard, William (1809-72), <a href="#Page_258">258</a></li>
+
+  <li class="indx">Germ Origin of Disease, <a href="#Page_224">224-37</a></li>
+
+  <li class="indx">Giessen, <a href="#Page_205">205</a></li>
+
+  <li class="indx">Gilbert, W. (1544-1603), <a href="#Page_103">103</a></li>
+
+  <li class="indx">Ginger, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Glands, Ductless, <a href="#Page_302">302-8</a></li>
+
+  <li class="indx">Glasgow, <a href="#Page_249">249</a></li>
+
+  <li class="indx">Glucosides, <a href="#Page_327">327-8</a></li>
+
+  <li class="indx">Glycogen, <a href="#Page_214">214</a></li>
+
+  <li class="indx">Godlee, Rickman (1849-1925), <a href="#Page_248">248</a></li>
+
+  <li class="indx">Goitre, <a href="#Page_303">303-4</a></li>
+
+  <li class="indx"><i>Golden Bough, The</i>, <a href="#Page_12">12-13</a></li>
+
+  <li class="indx">Gorgas, William C. (1854-1920), <a href="#Page_279">279</a></li>
+
+  <li class="indx">Gout, <a href="#Page_99">99</a></li>
+
+  <li class="indx">Graefe, Albrecht von (1828-70), <a href="#Page_320">320-1</a></li>
+
+  <li class="indx"><span class="pagenum" id="Page_366">366</span>Gravity, <a href="#Page_136">136</a></li>
+
+  <li class="indx">Greek Medical Lore, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Greek Medicine, <a href="#Page_1">1-13</a></li>
+
+  <li class="indx">Guayaquil, <a href="#Page_273">273</a></li>
+
+
+  <li class="ifrst">Haffkine, Waldemar (1860-), <a href="#Page_266">266</a></li>
+
+  <li class="indx">Hales, Stephen (1677-1761), <a href="#Page_145">145-6</a>, <a href="#Page_147">147</a>, <a href="#Page_171">171</a>, <a href="#Page_180">180</a></li>
+
+  <li class="indx">Hall, Marshall (1790-1857), <a href="#Page_207">207</a>, <a href="#Page_208">208</a></li>
+
+  <li class="indx">Haller, Albrecht von (1708-77), <a href="#Page_139">139</a>, <a href="#Page_142">142-5</a>, <a href="#Page_151">151</a></li>
+
+  <li class="indx">Halley, Edmund (1656-1742), <a href="#Page_167">167</a></li>
+
+  <li class="indx">Halsted, W. S. (1852-), <a href="#Page_236">236</a>, <a href="#Page_248">248</a></li>
+
+  <li class="indx">Hartford, Conn., <a href="#Page_237">237</a></li>
+
+  <li class="indx">Harvey, W. (1578-1657), <a href="#Page_32">32</a>, <a href="#Page_103">103</a>, <a href="#Page_111">111-15</a>, <a href="#Page_135">135</a></li>
+
+  <li class="indx">Hashish, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Health of Towns Association (1840), <a href="#Page_194">194</a></li>
+
+  <li class="indx">Heart, Aristotle on, <a href="#Page_29">29</a>, <a href="#Page_31">31</a></li>
+
+  <li class="indx">Heberden, W., the elder (1710-1801), his <i>Commentaries</i>, <a href="#Page_22">22</a></li>
+
+  <li class="indx">Helmholtz, Hermann von (1821-94), <a href="#Page_213">213</a>, <a href="#Page_319">319-20</a></li>
+
+  <li class="indx">Herbs, <a href="#Page_322">322-3</a></li>
+
+  <li class="indx">Hering, E. (1834-1918), <a href="#Page_212">212</a></li>
+
+  <li class="indx">Herophilus of Chalcedon (<i>c.</i> 300 <span class="allsmcap">B.C.</span>), <a href="#Page_36">36-7</a></li>
+
+  <li class="indx">Hippocrates, <a href="#Page_1">1</a>, <a href="#Page_8">8</a>, <a href="#Page_14">14-18</a>, <a href="#Page_102">102</a>, <a href="#Page_267">267</a>, <a href="#Page_342">342</a>,
+    <a href="#Page_358">358-9</a></li>
+
+  <li class="indx">Hippocratic Collection, <a href="#Page_9">9-10</a>, <a href="#Page_13">13-18</a>, <a href="#Page_22">22-3</a>, <a href="#Page_26">26</a>, <a href="#Page_95">95</a>,
+    <a href="#Page_256">256</a>, <a href="#Page_342">342</a></li>
+
+  <li class="indx"><i>Hippocratic facies</i>, <a href="#Page_26">26</a></li>
+
+  <li class="indx">Hippocratic Oath, <a href="#Page_17">17-18</a></li>
+
+  <li class="indx">Hippocratic Practice, <a href="#Page_18">18-26</a></li>
+
+  <li class="indx">Hippolytus, <a href="#Page_11">11</a></li>
+
+  <li class="indx">Histology, <a href="#Page_219">219</a>, <a href="#Page_222">222</a></li>
+
+  <li class="indx">Holmes, Oliver Wendell (1809-94), <a href="#Page_237">237</a>, <a href="#Page_243">243</a></li>
+
+  <li class="indx">Hong Kong, <a href="#Page_253">253</a></li>
+
+  <li class="indx">Hopkins, Sir Frederick Gowland, <a href="#Page_311">311</a></li>
+
+  <li class="indx">Hormones, <a href="#Page_307">307-8</a></li>
+
+  <li class="indx">Horsley, V. (1857-1916), <a href="#Page_248">248</a></li>
+
+  <li class="indx">Hospital Gangrene, <a href="#Page_239">239</a></li>
+
+  <li class="indx">Hospitals, <a href="#Page_48">48-50</a>, <a href="#Page_77">77-81</a>, <a href="#Page_178">178-80</a>, <a href="#Page_198">198</a>, <a href="#Page_200">200</a></li>
+
+  <li class="indx">Howard, John (1726-90), <a href="#Page_171">171</a>, <a href="#Page_180">180</a>, <a href="#Page_182">182</a></li>
+
+  <li class="indx">Humors, the Four, <a href="#Page_34">34</a></li>
+
+  <li class="indx">Hunter, John (1728-93), <a href="#Page_162">162</a>, <a href="#Page_165">165-6</a></li>
+
+  <li class="indx">Hunter, William (1718-83), <a href="#Page_158">158</a>, <a href="#Page_165">165</a></li>
+
+  <li class="indx">Hunterian Museum, <a href="#Page_166">166</a></li>
+
+  <li class="indx">Hygiene, <a href="#Page_40">40</a>, <a href="#Page_169">169-72</a>;</li>
+  <li class="isub1">Roman, <a href="#Page_45">45</a>;</li>
+  <li class="isub1">Medieval, <a href="#Page_77">77-81</a>;</li>
+  <li class="isub1">18th cent., <a href="#Page_174">174</a> sqq.;</li>
+  <li class="isub1">19th cent., <a href="#Page_192">192-203</a>;</li>
+  <li class="isub1">Tropical, <a href="#Page_270">270</a> sqq.</li>
+
+  <li class="indx">Hyoscyamus, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Hypodermic Syringe, <a href="#Page_329">329</a></li>
+
+
+  <li class="ifrst">Iatrochemistry, <a href="#Page_127">127</a>, <a href="#Page_131">131-2</a></li>
+
+  <li class="indx">Iatrophysics, <a href="#Page_127">127-31</a></li>
+
+  <li class="indx">Imhotep, <a href="#Page_7">7</a>, <a href="#Page_8">8</a></li>
+
+  <li class="indx">Immunity, <a href="#Page_184">184</a>, <a href="#Page_234">234</a>, <a href="#Page_252">252</a>, <a href="#Page_259">259-70</a>, <a href="#Page_276">276</a></li>
+
+  <li class="indx">Indian Hemp, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Indian Medicine, Early, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Industrial Revolution, <a href="#Page_172">172-81</a></li>
+
+  <li class="indx">Infantile Paralysis, <a href="#Page_270">270</a>, <a href="#Page_274">274</a></li>
+
+  <li class="indx">Infectious Diseases, <a href="#Page_96">96</a>, <a href="#Page_98">98</a>, <a href="#Page_102">102</a>, <a href="#Page_201">201</a>, <a href="#Page_234">234-5</a>,
+    <a href="#Page_358">358</a></li>
+
+  <li class="indx">Infirmaries, Roman, <a href="#Page_49">49</a></li>
+
+  <li class="indx">Inflammation, <a href="#Page_238">238-9</a></li>
+
+  <li class="indx">Influenza, <a href="#Page_270">270</a>, <a href="#Page_280">280</a>, <a href="#Page_349">349</a>, <a href="#Page_359">359</a></li>
+
+  <li class="indx">Inoculation, <a href="#Page_183">183-4</a>, <a href="#Page_261">261</a></li>
+
+  <li class="indx">Insanity, <a href="#Page_286">286-93</a></li>
+
+  <li class="indx">Insulin, <a href="#Page_306">306</a></li>
+
+  <li class="indx">Internal Medicine, <a href="#Page_77">77</a>, <a href="#Page_95">95-102</a></li>
+
+  <li class="indx">Internal Secretions, <a href="#Page_302">302-8</a></li>
+
+  <li class="indx">International Health Legislation, <a href="#Page_193">193</a></li>
+
+  <li class="indx">International Red Cross Committee, <a href="#Page_300">300</a></li>
+
+  <li class="indx">Invisible College, the, <a href="#Page_124">124</a></li>
+
+  <li class="indx">Ionians, the, <a href="#Page_4">4</a></li>
+
+  <li class="indx">Ipecacuanha, <a href="#Page_95">95</a>, <a href="#Page_323">323</a>, <a href="#Page_330">330</a></li>
+
+  <li class="indx">‘Irregular Sight’, <i>see</i> Astigmatism</li>
+
+  <li class="indx">Isaac of Kairouan (852-952), <a href="#Page_67">67</a>, <a href="#Page_70">70</a></li>
+
+
+  <li class="ifrst">Jackson, Hughlings (1834-1911), <a href="#Page_211">211</a></li>
+
+  <li class="indx">Jamaica, <a href="#Page_278">278</a></li>
+
+  <li class="indx">Jena, <a href="#Page_220">220</a></li>
+
+  <li class="indx">Jenner, E. (1749-1823), <a href="#Page_183">183</a></li>
+
+  <li class="indx">Johnson, Dr. (1709-84), <a href="#Page_158">158</a></li>
+
+  <li class="indx">Jung, C. G. (1875-), <a href="#Page_293">293-4</a></li>
+
+  <li class="indx">Juniper, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Justinian, Emperor, <a href="#Page_46">46</a></li>
+
+
+  <li class="ifrst">Kaiserswerth, <a href="#Page_297">297-8</a></li>
+
+  <li class="indx">Kalar-azar, <a href="#Page_272">272</a></li>
+
+  <li class="indx">Kepler, Johannes (1571-1630), <a href="#Page_103">103</a>, <a href="#Page_104">104</a>, <a href="#Page_136">136</a>, <a href="#Page_319">319</a></li>
+
+  <li class="indx">Kitasato, Shibasaburo (<i>c.</i> 1860-), <a href="#Page_253">253</a>, <a href="#Page_257">257</a>, <a href="#Page_264">264</a>, <a href="#Page_266">266</a></li>
+
+  <li class="indx">Klebs, E. (1834-1913), <a href="#Page_253">253</a></li>
+
+  <li class="indx">Klebs-Loeffler Bacillus, <a href="#Page_253">253</a></li>
+
+  <li class="indx">Koch, Robert (1843-1910), <a href="#Page_184">184</a>, <a href="#Page_202">202</a>, <a href="#Page_229">229-30</a>, <a href="#Page_232">232</a>, <a href="#Page_234">234</a>,
+    <a href="#Page_249">249-51</a>, <a href="#Page_253">253</a>, <a href="#Page_321">321</a>, <a href="#Page_330">330</a></li>
+
+  <li class="indx">Kocher, T. (1841-1917), <a href="#Page_303">303</a></li>
+
+  <li class="indx">Kölliker, Albrecht von (1817-1905), <a href="#Page_222">222</a></li>
+
+  <li class="indx">Koronis, <a href="#Page_11">11</a></li>
+
+  <li class="indx">Kymograph, the, <a href="#Page_216">216-17</a></li>
+
+
+  <li class="ifrst">Laënnec, René Théophile Hyacinthe (1781-1826), <a href="#Page_160">160-1</a>, <a href="#Page_219">219</a></li>
+
+  <li class="indx">Laughing Gas, <a href="#Page_237">237</a></li>
+
+  <li class="indx">Lavender, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Laveran, A. (1845-), <a href="#Page_283">283</a></li>
+
+  <li class="indx">Lavoisier, Antoine Laurent (1743-94), <a href="#Page_155">155-6</a>, <a href="#Page_205">205</a></li>
+
+  <li class="indx">Law, Reign of, <a href="#Page_135">135-8</a></li>
+
+  <li class="indx">Lazarettos, <a href="#Page_182">182</a></li>
+
+  <li class="indx">Lazear, <a href="#Page_279">279</a></li>
+
+  <li class="indx">Leeuwenhoek, A. von (1632-1723), <a href="#Page_39">39</a>, <a href="#Page_118">118</a>, <a href="#Page_120">120-1</a></li>
+
+  <li class="indx">Leipzig, <a href="#Page_215">215</a></li>
+
+  <li class="indx">Leonardo da Vinci (1452-1518), <a href="#Page_83">83-5</a></li>
+
+  <li class="indx">Leprosy, <a href="#Page_78">78-80</a>, <a href="#Page_98">98</a>, <a href="#Page_162">162</a>, <a href="#Page_271">271</a></li>
+
+  <li class="indx">Lesions, <a href="#Page_157">157</a>, <a href="#Page_160">160</a></li>
+
+  <li class="indx">Licorice, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Liebig, Justus von (1803-73), <a href="#Page_205">205-7</a>, <a href="#Page_225">225</a>, <a href="#Page_235">235</a>, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Lind, James (1716-94), <a href="#Page_170">170-1</a>, <a href="#Page_180">180-1</a></li>
+
+  <li class="indx">Linseed, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Leyden, <a href="#Page_131">131</a>, <a href="#Page_139">139-42</a></li>
+
+  <li class="indx">Lister, Lord (1827-1912), <a href="#Page_184">184</a>, <a href="#Page_229">229</a>, <a href="#Page_237">237-43</a>, <a href="#Page_248">248</a>, <a href="#Page_321">321</a>,
+    <a href="#Page_336">336</a></li>
+
+  <li class="indx">Liverpool, <a href="#Page_196">196</a></li>
+
+  <li class="indx">Lockjaw, <i>see</i> Tetanus, <a href="#Page_256">256-8</a></li>
+
+  <li class="indx">Loeffler, Friedrich (1852-1915), <a href="#Page_253">253</a></li>
+
+  <li class="indx">London Hospital, <a href="#Page_178">178</a></li>
+
+  <li class="indx">Louisiana, <a href="#Page_202">202</a></li>
+
+  <li class="indx">Louvain, <a href="#Page_85">85</a></li>
+
+  <li class="indx">Ludwig, Karl (1816-95), <a href="#Page_215">215-19</a></li>
+
+  <li class="indx">Lyons, <a href="#Page_42">42</a></li>
+
+
+  <li class="ifrst">Macewen, William (1848-1926), <a href="#Page_248">248-9</a></li>
+
+  <li class="indx">Magendie, François (1783-1855), <a href="#Page_238">238</a>, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Magic, <a href="#Page_3">3</a>, <a href="#Page_16">16</a></li>
+
+  <li class="indx">Malaria, <a href="#Page_174">174</a>, <a href="#Page_251">251</a>, <a href="#Page_271">271</a>, <a href="#Page_330">330</a>;</li>
+  <li class="isub1">history, <a href="#Page_280">280-6</a></li>
+
+  <li class="indx">Male Fern, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Mallow, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Malpighi, Marcello (1628-94), <a href="#Page_114">114</a>, <a href="#Page_116">116-20</a>, <a href="#Page_302">302</a></li>
+
+  <li class="indx">Malta Fever, <a href="#Page_254">254-6</a>, <a href="#Page_268">268</a></li>
+
+  <li class="indx">Manson, Patrick (1844-1922), <a href="#Page_283">283</a></li>
+
+  <li class="indx">Marburg, <a href="#Page_215">215</a></li>
+
+  <li class="indx">Marine Hospital Service, <a href="#Page_200">200</a>, <a href="#Page_201">201</a></li>
+
+  <li class="indx">Marjoram, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Marseilles, <a href="#Page_42">42</a>, <a href="#Page_182">182</a></li>
+
+  <li class="indx">Massachusetts, <a href="#Page_202">202</a>, <a href="#Page_235">235</a></li>
+
+  <li class="indx">Massage, <a href="#Page_247">247</a>, <a href="#Page_248">248</a></li>
+
+  <li class="indx">Mather, Cotton (1663-1728);</li>
+  <li class="isub1">Increase (1639-1723), <a href="#Page_183">183</a></li>
+
+  <li class="indx">Mayo, Charles &amp; William, <a href="#Page_248">248</a></li>
+
+  <li class="indx">Mayow John (1645-79), <a href="#Page_126">126</a>, <a href="#Page_151">151-2</a>, <a href="#Page_189">189</a></li>
+
+  <li class="indx">Mead, Dr. Richard (1673-1754), <a href="#Page_183">183</a></li>
+
+  <li class="indx">Measles, <a href="#Page_67">67</a>, <a href="#Page_252">252</a>, <a href="#Page_349">349</a>, <a href="#Page_359">359</a></li>
+
+  <li class="indx">Mechanics, <a href="#Page_106">106</a>, <a href="#Page_122">122</a>, <a href="#Page_138">138</a></li>
+
+  <li class="indx">Medical Theorists in the Renaissance, <a href="#Page_126">126-34</a></li>
+
+  <li class="indx">Medical Research Council, <a href="#Page_197">197</a>, <a href="#Page_348">348</a></li>
+
+  <li class="indx">Medieval Medical Revival, <a href="#Page_68">68-72</a></li>
+
+  <li class="indx">— Anatomy, &amp;c., <a href="#Page_72">72-7</a></li>
+
+  <li class="indx">— Hospitals and Hygiene, <a href="#Page_77">77-81</a></li>
+
+  <li class="indx">Mendel, <a href="#Page_222">222</a></li>
+
+  <li class="indx">Mercury, <a href="#Page_162">162</a>, <a href="#Page_322">322</a>, <a href="#Page_325">325</a>, <a href="#Page_330">330</a></li>
+
+  <li class="indx"><span class="pagenum" id="Page_367">367</span>Mesopotamian peoples, <a href="#Page_7">7</a></li>
+
+  <li class="indx">Metabolism, <a href="#Page_107">107</a>, <a href="#Page_108">108</a>, <a href="#Page_220">220</a></li>
+
+  <li class="indx">Metschnikoff, Élie (1845-1916), <a href="#Page_223">223</a></li>
+
+  <li class="indx">Mezger, Johann (1839-19-), <a href="#Page_247">247</a></li>
+
+  <li class="indx">Michael Scot (d. 1235), <a href="#Page_68">68</a></li>
+
+  <li class="indx">Michelangelo, <a href="#Page_83">83</a></li>
+
+  <li class="indx">Microscope, <a href="#Page_105">105</a>, <a href="#Page_115">115-22</a>, <a href="#Page_159">159</a></li>
+
+  <li class="indx">Microscopic Analysis, <a href="#Page_115">115-22</a>, <a href="#Page_138">138</a></li>
+
+  <li class="indx">Midwives, <a href="#Page_295">295</a></li>
+
+  <li class="indx">Milan, <a href="#Page_81">81</a></li>
+
+  <li class="indx">Military Medicine, <a href="#Page_169">169-70</a></li>
+
+  <li class="indx">Mill, J. S. (1806-73), <a href="#Page_191">191</a></li>
+
+  <li class="indx">Ministry of Health, <a href="#Page_197">197</a>, <a href="#Page_291">291</a></li>
+
+  <li class="indx">Minoans, the, <a href="#Page_3">3-5</a></li>
+
+  <li class="indx">Mint, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Mitchell, S. Weir (1830-1914), <a href="#Page_318">318</a></li>
+
+  <li class="indx">Mohl, Hugo von (1805-72), <a href="#Page_220">220-1</a></li>
+
+  <li class="indx">Moivre, Abraham de (1667-1754), <a href="#Page_167">167</a></li>
+
+  <li class="indx">Mondino di Luzzi (c. 1270-1326), <a href="#Page_74">74</a>, <a href="#Page_76">76</a></li>
+
+  <li class="indx">Montagu, Lady Mary Wortley (1689-1762), <a href="#Page_183">183</a></li>
+
+  <li class="indx">Montpellier, <a href="#Page_74">74</a>, <a href="#Page_76">76</a></li>
+
+  <li class="indx">Morgagni, Giovanni Battista (1682-1771), <a href="#Page_157">157-8</a></li>
+
+  <li class="indx">Morphine, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Morton, William Thomas Green (1819-68), <a href="#Page_235">235</a></li>
+
+  <li class="indx">Mosquito Net, <a href="#Page_45">45</a></li>
+
+  <li class="indx">Mosquitoes, <a href="#Page_273">273-80</a></li>
+
+  <li class="indx">Müller, Johannes (1807-58), <a href="#Page_28">28</a>, <a href="#Page_211">211-13</a>, <a href="#Page_356">356</a></li>
+
+  <li class="indx">Murphy, J. B. (1857-1916), <a href="#Page_248">248</a></li>
+
+  <li class="indx">Mustard, <a href="#Page_323">323</a></li>
+
+  <li class="indx"><i>Mustelus laevis</i>, <a href="#Page_28">28-9</a></li>
+
+  <li class="indx">Myrrh, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Myxoedema, <a href="#Page_304">304-5</a></li>
+
+
+  <li class="ifrst">Nägeli, Karl v. (1817-91), <a href="#Page_221">221-2</a></li>
+
+  <li class="indx">Nature-Worship (Animism), <a href="#Page_3">3</a>, <a href="#Page_12">12</a>, <a href="#Page_16">16</a></li>
+
+  <li class="indx">Natural Spirit, <a href="#Page_56">56</a></li>
+
+  <li class="indx">Naval Medicine, <a href="#Page_170">170-1</a></li>
+
+  <li class="indx">Near Sight, <a href="#Page_317">317</a>, <a href="#Page_318">318</a></li>
+
+  <li class="indx">Nervous Integration, <a href="#Page_308">308-11</a></li>
+
+  <li class="indx">Nestorians, the, <a href="#Page_66">66</a></li>
+
+  <li class="indx">New York, <a href="#Page_202">202</a>, <a href="#Page_248">248</a></li>
+
+  <li class="indx">Newton, Sir Isaac (1642-1727), <a href="#Page_104">104</a>, <a href="#Page_136">136-8</a>, <a href="#Page_186">186</a></li>
+
+  <li class="indx">Nightingale, Florence (1820-1910), <a href="#Page_291">291</a>, <a href="#Page_298">298-301</a></li>
+
+  <li class="indx">Nîmes, <a href="#Page_42">42</a></li>
+
+  <li class="indx">Noguchi, <a href="#Page_273">273-5</a></li>
+
+  <li class="indx">Norfolk, Va., <a href="#Page_198">198</a></li>
+
+  <li class="indx">Nursing, <a href="#Page_180">180</a>, <a href="#Page_295">295-301</a></li>
+
+  <li class="indx">Nutrition, <a href="#Page_311">311-13</a></li>
+
+  <li class="indx">Nux vomica, <a href="#Page_322">322</a>, <a href="#Page_326">326</a></li>
+
+
+  <li class="ifrst">Obstetrics, <a href="#Page_161">161-6</a>, <a href="#Page_236">236</a>, <a href="#Page_243">243</a></li>
+
+  <li class="indx">Oil of Wintergreen, <a href="#Page_327">327</a></li>
+
+  <li class="indx">‘Old Sight’, <a href="#Page_316">316</a>, <a href="#Page_319">319</a></li>
+
+  <li class="indx">Ophthalmic Surgery, <a href="#Page_320">320-2</a></li>
+
+  <li class="indx">Ophthalmoscope, <a href="#Page_213">213</a>, <a href="#Page_319">319</a>, <a href="#Page_321">321</a></li>
+
+  <li class="indx">Opium, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Owen, R. (1804-92), <a href="#Page_204">204</a></li>
+
+  <li class="indx">Oxygen, <a href="#Page_126">126</a>, <a href="#Page_154">154</a>, <a href="#Page_156">156</a>, <a href="#Page_189">189</a></li>
+
+
+  <li class="ifrst">Padua, <a href="#Page_75">75</a>, <a href="#Page_86">86</a>, <a href="#Page_108">108</a>, <a href="#Page_110">110</a>, <a href="#Page_139">139</a>,
+    <a href="#Page_157">157</a></li>
+
+  <li class="indx">Panama, <a href="#Page_286">286</a></li>
+
+  <li class="indx">Pancreas, the, <a href="#Page_215">215</a>, <a href="#Page_306">306</a>, <a href="#Page_325">325</a></li>
+
+  <li class="indx">Paré, Ambroise (1517-90), <a href="#Page_92">92-4</a>, <a href="#Page_162">162</a>, <a href="#Page_247">247</a></li>
+
+  <li class="indx">Paris, <a href="#Page_76">76</a>, <a href="#Page_85">85</a>, <a href="#Page_160">160</a>, <a href="#Page_288">288</a></li>
+
+  <li class="indx">Park, W. H. (1863), <a href="#Page_266">266</a></li>
+
+  <li class="indx">Pasteur, Louis (1822-95), <a href="#Page_148">148</a>, <a href="#Page_184">184</a>, <a href="#Page_202">202</a>, <a href="#Page_225">225-35</a>, <a href="#Page_239">239</a>,
+    <a href="#Page_249">249</a>, <a href="#Page_253">253</a>, <a href="#Page_261">261</a>, <a href="#Page_321">321</a></li>
+
+  <li class="indx">Pathology, Medieval, <a href="#Page_77">77</a>;</li>
+  <li class="isub1">Modern, <a href="#Page_301">301-13</a>;</li>
+  <li class="isub1">Cellular, <a href="#Page_219">219-24</a>;</li>
+  <li class="isub1">Comparative, <a href="#Page_251">251-2</a></li>
+
+  <li class="indx">Pavia, <a href="#Page_149">149</a></li>
+
+  <li class="indx">Peel, Sir Robert (1750-1830), <a href="#Page_191">191</a></li>
+
+  <li class="indx">Pelletier, Pierre Joseph (1788-1842), <a href="#Page_326">326</a></li>
+
+  <li class="indx">Percival, Thomas (1740-1804), <a href="#Page_170">170-1</a>, <a href="#Page_180">180</a></li>
+
+  <li class="indx">Percussion, <a href="#Page_160">160</a></li>
+
+  <li class="indx">Pergamum, <a href="#Page_52">52</a></li>
+
+  <li class="indx">Pest Houses, <a href="#Page_180">180</a>, <a href="#Page_181">181</a></li>
+
+  <li class="indx">Petty, Sir William (1623-87), <a href="#Page_166">166-7</a>, <a href="#Page_169">169</a></li>
+
+  <li class="indx">Pflüger, E. F. W. (1829-1910), <a href="#Page_205">205</a></li>
+
+  <li class="indx">Pharmacology, <a href="#Page_323">323</a>, <a href="#Page_328">328-9</a></li>
+
+  <li class="indx">Philadelphia, <a href="#Page_171">171-2</a>, <a href="#Page_258">258</a></li>
+
+  <li class="indx">Philip of Macedon, <a href="#Page_27">27</a></li>
+
+  <li class="indx">Philosopher’s Stone, the, <a href="#Page_124">124</a></li>
+
+  <li class="indx">Phlogiston, <a href="#Page_132">132</a>, <a href="#Page_151">151-4</a></li>
+
+  <li class="indx">Phthisis, <a href="#Page_341">341-3</a></li>
+
+  <li class="indx">Physical Synthesis, <a href="#Page_102">102-8</a></li>
+
+  <li class="indx">Physiological Synthesis, <a href="#Page_203">203-11</a></li>
+
+  <li class="indx">Physiology: of Galen, <a href="#Page_56">56-60</a>;</li>
+  <li class="isub1">Medieval, <a href="#Page_77">77</a>, <a href="#Page_129">129</a>;</li>
+  <li class="isub1">Renaissance, <a href="#Page_95">95</a>, <a href="#Page_99">99</a>, <a href="#Page_100">100</a>, <a href="#Page_108">108-15</a>;</li>
+  <li class="isub1">Earlier 19th cent., &amp;c., <a href="#Page_207">207-19</a>;</li>
+  <li class="isub1">Modern, <a href="#Page_122">122</a>, <a href="#Page_127">127</a>, <a href="#Page_138">138</a>, <a href="#Page_142">142-51</a>, <a href="#Page_301">301-13</a></li>
+
+  <li class="indx">Pinel, Philippe (1745-1826), <a href="#Page_288">288</a></li>
+
+  <li class="indx">Pisa, <a href="#Page_104">104</a>, <a href="#Page_105">105</a></li>
+
+  <li class="indx">Plague, <a href="#Page_80">80-1</a>, <a href="#Page_182">182</a>, <a href="#Page_185">185</a>, <a href="#Page_200">200-1</a>;</li>
+  <li class="isub1">Bacilli of, <a href="#Page_253">253-5</a>;</li>
+  <li class="isub1">Immunization, <a href="#Page_266">266</a></li>
+
+  <li class="indx">Plaster of Paris, <a href="#Page_246">246</a></li>
+
+  <li class="indx">Plato, <a href="#Page_14">14</a>, <a href="#Page_27">27</a>, <a href="#Page_29">29</a></li>
+
+  <li class="indx">Plethora, <a href="#Page_39">39</a></li>
+
+  <li class="indx">Pneumatism, <a href="#Page_38">38</a>, <a href="#Page_56">56</a>, <a href="#Page_58">58</a></li>
+
+  <li class="indx">Political Economy, <a href="#Page_166">166-7</a></li>
+
+  <li class="indx">Polypharmacy, <a href="#Page_324">324</a></li>
+
+  <li class="indx">Poppy, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Population, <a href="#Page_176">176</a></li>
+
+  <li class="indx">Post-mortems, <a href="#Page_156">156-9</a></li>
+
+  <li class="indx">Pravaz, C. (1791-1853), <a href="#Page_329">329</a></li>
+
+  <li class="indx">Preventive Medicine, <a href="#Page_192">192-203</a></li>
+
+  <li class="indx">Priestley, Joseph (1733-1804), <a href="#Page_154">154-5</a>, <a href="#Page_189">189-90</a></li>
+
+  <li class="indx">Pringle, Sir John (1707-82), <a href="#Page_169">169-70</a>, <a href="#Page_171">171</a>, <a href="#Page_180">180</a></li>
+
+  <li class="indx">Prison Medicine, <a href="#Page_171">171-2</a></li>
+
+  <li class="indx">Prophylaxis, <a href="#Page_265">265</a></li>
+
+  <li class="indx">Proteids, <a href="#Page_215">215</a></li>
+
+  <li class="indx">Proteins, <a href="#Page_206">206</a>, <a href="#Page_311">311</a></li>
+
+  <li class="indx">Protoplasm, <a href="#Page_221">221-2</a></li>
+
+  <li class="indx">Prout, W. (1785-1850), <a href="#Page_148">148</a></li>
+
+  <li class="indx">Psyche, the, <a href="#Page_31">31-3</a>, <a href="#Page_133">133</a></li>
+
+  <li class="indx">Psycho-analysis, <a href="#Page_293">293-5</a></li>
+
+  <li class="indx">Psychology, <a href="#Page_293">293-5</a></li>
+
+  <li class="indx">Ptomaine, <a href="#Page_259">259</a></li>
+
+  <li class="indx">Ptolemy, <a href="#Page_36">36</a>, <a href="#Page_40">40</a></li>
+
+  <li class="indx">Public Health, <a href="#Page_192">192-203</a></li>
+
+  <li class="indx">Puerperal Fever, <a href="#Page_243">243</a></li>
+
+  <li class="indx">Pulmonary Tuberculosis, <a href="#Page_341">341-3</a></li>
+
+  <li class="indx">Pulse Watch, <a href="#Page_159">159</a></li>
+
+  <li class="indx">Pulsimeter, <a href="#Page_109">109</a></li>
+
+  <li class="indx">Putrefaction, <a href="#Page_225">225-8</a>, <a href="#Page_231">231-2</a>, <a href="#Page_239">239</a></li>
+
+  <li class="indx">Pyaemia, <a href="#Page_239">239</a></li>
+
+
+  <li class="ifrst">Qualities, the Four Primary, <a href="#Page_33">33-4</a></li>
+
+  <li class="indx">Quarantine, <a href="#Page_173">173</a>, <a href="#Page_182">182</a>, <a href="#Page_194">194</a>, <a href="#Page_197">197</a></li>
+
+  <li class="indx">Quetelet, Lambert (1796-1874), <a href="#Page_168">168</a></li>
+
+  <li class="indx">Quinine, <a href="#Page_281">281-2</a>, <a href="#Page_326">326</a>, <a href="#Page_330">330</a>, <a href="#Page_332">332</a></li>
+
+
+  <li class="ifrst">Radcliffe Infirmary, <a href="#Page_296">296</a></li>
+
+  <li class="indx">Radiography, <a href="#Page_245">245</a></li>
+
+  <li class="indx">Ragusa, <a href="#Page_81">81</a></li>
+
+  <li class="indx">Raphael, <a href="#Page_83">83</a></li>
+
+  <li class="indx">Réaumur, René Antoine de (1683-1757), <a href="#Page_146">146-7</a>, <a href="#Page_148">148</a></li>
+
+  <li class="indx">Reed, W. (1851-1902), <a href="#Page_279">279</a></li>
+
+  <li class="indx">Registration Act (1838), <a href="#Page_195">195</a></li>
+
+  <li class="indx">Research, Method and Meaning of, <a href="#Page_135">135</a></li>
+
+  <li class="indx">Respiration, <a href="#Page_151">151-6</a>, <a href="#Page_205">205</a></li>
+
+  <li class="indx">Reymond, E. Du Bois-, (1818-96), <a href="#Page_151">151</a></li>
+
+  <li class="indx">Rhazes of Basra (860-932), <a href="#Page_67">67</a>, <a href="#Page_70">70</a></li>
+
+  <li class="indx">Rheumatism, <a href="#Page_98">98</a>, <a href="#Page_358">358-9</a></li>
+
+  <li class="indx">Rhubarb, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Rickets, <a href="#Page_181">181</a>, <a href="#Page_312">312</a>, <a href="#Page_313">313</a></li>
+
+  <li class="indx">Rochester, Minn., <a href="#Page_248">248</a></li>
+
+  <li class="indx">Röntgen, Wilhelm Conrad (1845-1923), <a href="#Page_244">244-5</a></li>
+
+  <li class="indx">Röntgen Rays, <a href="#Page_244">244-5</a></li>
+
+  <li class="indx">Rokitansky, Karl (1804-78), <a href="#Page_158">158-9</a></li>
+
+  <li class="indx">Roman Empire: Medical Teaching, <a href="#Page_41">41-4</a>;</li>
+  <li class="isub1">Medical Services, <a href="#Page_45">45-8</a>;</li>
+  <li class="isub1">Hospitals, <a href="#Page_48">48-50</a></li>
+
+  <li class="indx">Ross, Ronald (1857-), <a href="#Page_283">283</a></li>
+
+  <li class="indx">Roux, Pierre (1853-), <a href="#Page_263">263</a></li>
+
+  <li class="indx">Royal Society, <a href="#Page_104">104</a>, <a href="#Page_118">118</a>, <a href="#Page_124">124</a>, <a href="#Page_167">167</a></li>
+
+  <li class="indx">Rush, Benjamin (1745-1813), <a href="#Page_171">171-2</a></li>
+
+
+  <li class="ifrst">St. Luke, <a href="#Page_63">63</a></li>
+
+  <li class="indx">St. Bartholomew I., <a href="#Page_49">49</a>, <a href="#Page_51">51</a></li>
+
+  <li class="indx"><span class="pagenum" id="Page_368">368</span>St. Bartholomew’s Hospital, <a href="#Page_178">178-9</a></li>
+
+  <li class="indx">St. Gall, <a href="#Page_50">50</a></li>
+
+  <li class="indx">St. Thomas’s Hospital, <a href="#Page_298">298</a></li>
+
+  <li class="indx">Salerno, <a href="#Page_64">64-5</a></li>
+
+  <li class="indx">Salicin, <a href="#Page_327">327</a></li>
+
+  <li class="indx">Salts of Copper, <a href="#Page_322">322</a></li>
+
+  <li class="indx">Salts of Lead, <a href="#Page_322">322</a></li>
+
+  <li class="indx">San Francisco, <a href="#Page_201">201</a></li>
+
+  <li class="indx">Sanctorius (1561-1636), <a href="#Page_107">107-9</a>, <a href="#Page_159">159</a></li>
+
+  <li class="indx">Sanitary Commission, <a href="#Page_195">195</a></li>
+
+  <li class="indx">Sanitation, <a href="#Page_45">45</a>, <a href="#Page_194">194</a></li>
+
+  <li class="indx">Saragossa, <a href="#Page_42">42</a></li>
+
+  <li class="indx">Scarlet Fever, <a href="#Page_185">185</a>, <a href="#Page_201">201</a>, <a href="#Page_270">270</a>, <a href="#Page_349">349</a></li>
+
+  <li class="indx">Schaudinn, Fritz (1871-1906), <a href="#Page_331">331-2</a></li>
+
+  <li class="indx">Schick, B., <a href="#Page_264">264</a></li>
+
+  <li class="indx">Schiff, Moritz (1823-90), <a href="#Page_304">304</a></li>
+
+  <li class="indx">Schleiden, Matthias Jakob (1804-81), <a href="#Page_219">219-20</a></li>
+
+  <li class="indx">Schmiedeberg, Oswald (1834-1921), <a href="#Page_328">328</a></li>
+
+  <li class="indx">Schultze, M. (1825-74), <a href="#Page_222">222</a></li>
+
+  <li class="indx">Schwann, T. (1810-82), <a href="#Page_220">220-1</a></li>
+
+  <li class="indx">Scurvy, <a href="#Page_170">170</a>, <a href="#Page_181">181</a>, <a href="#Page_313">313</a></li>
+
+  <li class="indx">Seamen’s Hospital Society, <a href="#Page_198">198</a></li>
+
+  <li class="indx">Secretions, Internal, <a href="#Page_302">302-8</a></li>
+
+  <li class="indx">Semmelweis, Ignaz (1818-65), <a href="#Page_243">243</a></li>
+
+  <li class="indx">Septicaemia, <a href="#Page_239">239</a></li>
+
+  <li class="indx">Serpent, Cult, <a href="#Page_4">4-5</a>, <a href="#Page_8">8</a>, <a href="#Page_11">11</a></li>
+
+  <li class="indx">Sertürner, Adolf (1783-1841), <a href="#Page_326">326</a></li>
+
+  <li class="indx">Sesame, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Sex organs, <a href="#Page_306">306</a></li>
+
+  <li class="indx">Shaftesbury, 7th Earl (1801-85), <a href="#Page_290">290</a></li>
+
+  <li class="indx">Shakespeare, William, <a href="#Page_26">26</a></li>
+
+  <li class="indx">Shattuck, Lemuel (1793-1859), <a href="#Page_202">202</a></li>
+
+  <li class="indx">Sherrington, Sir Charles, <a href="#Page_309">309</a></li>
+
+  <li class="indx">‘Shock’, Nervous, <a href="#Page_310">310-11</a></li>
+
+  <li class="indx">Sierra Leone, <a href="#Page_276">276</a>, <a href="#Page_278">278</a></li>
+
+  <li class="indx">Sight, Deficient, <a href="#Page_316">316-20</a></li>
+
+  <li class="indx">Simon, Sir John (1816-1904), <a href="#Page_196">196-7</a></li>
+
+  <li class="indx">Simpson, Sir James Young (1811-70), <a href="#Page_235">235</a></li>
+
+  <li class="indx"><strong>606</strong>, <a href="#Page_332">332</a></li>
+
+  <li class="indx">Sleeping Sickness, <a href="#Page_234">234</a>, <a href="#Page_272">272</a>, <a href="#Page_332">332</a></li>
+
+  <li class="indx">Sleepy Sickness, <a href="#Page_272">272</a></li>
+
+  <li class="indx">Small-pox, <a href="#Page_182">182-5</a>, <a href="#Page_198">198</a>, <a href="#Page_200">200</a>, <a href="#Page_261">261</a>, <a href="#Page_265">265</a>,
+    <a href="#Page_343">343</a></li>
+
+  <li class="indx">Smith, Thomas S. (1788-1861), <a href="#Page_171">171</a>, <a href="#Page_178">178</a>, <a href="#Page_193">193-6</a></li>
+
+  <li class="indx">Smyrna, <a href="#Page_52">52</a></li>
+
+  <li class="indx">Spallanzani, Lazaro (1729-99), <a href="#Page_147">147-8</a></li>
+
+  <li class="indx">Specialization, Scientific, <a href="#Page_186">186-92</a>, <a href="#Page_359">359</a></li>
+
+  <li class="indx">Specific Energies, Law of, <a href="#Page_212">212-13</a></li>
+
+  <li class="indx"><i>Speculum matricis</i>, <a href="#Page_164">164</a></li>
+
+  <li class="indx">Spencer Wells, <i>see</i> Wells</li>
+
+  <li class="indx">Spencer Wells Forceps, <a href="#Page_244">244</a></li>
+
+  <li class="indx">Spinal anaesthesia, <a href="#Page_236">236-7</a></li>
+
+  <li class="indx"><i>Spirochaeta pallida</i>, <a href="#Page_331">331-2</a></li>
+
+  <li class="indx">Spotted Fever, <a href="#Page_269">269-70</a></li>
+
+  <li class="indx">Sprue, <a href="#Page_272">272</a></li>
+
+  <li class="indx">Stahl, George Ernest (1660-1734), <a href="#Page_132">132-3</a>, <a href="#Page_151">151</a>, <a href="#Page_288">288</a></li>
+
+  <li class="indx">Starling, E. H. (1866-1927), <a href="#Page_308">308</a></li>
+
+  <li class="indx">Statistics, Medical, <a href="#Page_334">334-50</a>;</li>
+  <li class="isub1">Vital, <a href="#Page_166">166-8</a></li>
+
+  <li class="indx">Stavesacre, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Stethoscope, the, <a href="#Page_160">160-1</a></li>
+
+  <li class="indx">Stoic Philosophy, <a href="#Page_54">54</a></li>
+
+  <li class="indx">Stomach, Ruminant, <a href="#Page_28">28</a></li>
+
+  <li class="indx">Storax, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Strychnine, <a href="#Page_326">326</a></li>
+
+  <li class="indx">Sublimation, <a href="#Page_294">294-5</a></li>
+
+  <li class="indx">Superstition, <a href="#Page_3">3</a>, <a href="#Page_6">6</a></li>
+
+  <li class="indx">Suprarenal bodies, <a href="#Page_306">306-7</a></li>
+
+  <li class="indx">Surgery: Greek, <a href="#Page_49">49</a>;</li>
+  <li class="isub1">Medieval, <a href="#Page_76">76-7</a>;</li>
+  <li class="isub1">Renaissance, <a href="#Page_92">92-4</a>;</li>
+  <li class="isub1">18th cent., <a href="#Page_161">161-6</a>;</li>
+  <li class="isub1">Modern, <a href="#Page_243">243-9</a></li>
+
+  <li class="indx">Süssmilch, J. P. (1707-82), <a href="#Page_167">167-8</a></li>
+
+  <li class="indx">Swammerdam, J. J. (1637-80), <a href="#Page_39">39</a>, <a href="#Page_121">121-3</a>, <a href="#Page_140">140</a>, <a href="#Page_143">143</a></li>
+
+  <li class="indx">Switzerland, <a href="#Page_303">303</a></li>
+
+  <li class="indx">Sydenham, Thomas (1624-89), <a href="#Page_96">96</a>, <a href="#Page_100">100-2</a>, <a href="#Page_282">282</a>, <a href="#Page_342">342</a></li>
+
+  <li class="indx">Sylvius, Franciscus (1614-72), <a href="#Page_131">131-2</a>, <a href="#Page_139">139</a>, <a href="#Page_148">148</a></li>
+
+  <li class="indx">Syphilis, <a href="#Page_98">98-9</a>, <a href="#Page_162">162</a>, <a href="#Page_251">251</a>, <a href="#Page_269">269</a>, <a href="#Page_291">291</a>, <a href="#Page_330">330-2</a>,
+    <a href="#Page_337">337</a></li>
+
+
+  <li class="ifrst">Telescope, the, <a href="#Page_105">105</a></li>
+
+  <li class="indx">Temperaments, Four, <a href="#Page_97">97</a></li>
+
+  <li class="indx">Terebinth, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Tetanus (Lockjaw), <a href="#Page_23">23</a>, <a href="#Page_256">256-8</a>, <a href="#Page_260">260</a>, <a href="#Page_264">264</a>, <a href="#Page_265">265</a>;</li>
+  <li class="isub1">immunization, <a href="#Page_266">266-7</a></li>
+
+  <li class="indx">Thaddeus of Florence (1223-1303), <a href="#Page_72">72</a></li>
+
+  <li class="indx">Theophrastus (372-287 <span class="allsmcap">B.C.</span>), <a href="#Page_35">35</a></li>
+
+  <li class="indx">Thermometer, the, <a href="#Page_108">108-9</a>;</li>
+  <li class="isub1">clinical, <a href="#Page_159">159</a></li>
+
+  <li class="indx">Theseus, <a href="#Page_12">12</a></li>
+
+  <li class="indx">Thessaly, <a href="#Page_14">14</a></li>
+
+  <li class="indx">Thyroid Gland, <a href="#Page_303">303-6</a>, <a href="#Page_325">325</a></li>
+
+  <li class="indx">Thyroxin, <a href="#Page_305">305</a></li>
+
+  <li class="indx">Tiberius, Emperor (1st c.), <a href="#Page_42">42</a></li>
+
+  <li class="indx">Tobacco, <a href="#Page_95">95</a>, <a href="#Page_99">99</a>, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Toulon, <a href="#Page_182">182</a></li>
+
+  <li class="indx">Tours, <a href="#Page_185">185</a>, <a href="#Page_253">253</a></li>
+
+  <li class="indx">Toxins, <a href="#Page_259">259-60</a>, <a href="#Page_262">262-7</a>, <a href="#Page_330">330-3</a></li>
+
+  <li class="indx">Trachoma, <a href="#Page_321">321-2</a></li>
+
+  <li class="indx">Tragacanth, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Trephining, <a href="#Page_18">18-19</a>, <a href="#Page_20">20</a>, <a href="#Page_63">63</a>, <a href="#Page_64">64</a>, <a href="#Page_72">72</a></li>
+
+  <li class="indx">Tropical Diseases, <a href="#Page_198">198</a></li>
+
+  <li class="indx">Tropical Hygiene and Medicine, <a href="#Page_170">170</a>, <a href="#Page_270">270-86</a></li>
+
+  <li class="indx">Tuberculosis, <a href="#Page_234">234</a>, <a href="#Page_250">250</a>, <a href="#Page_330">330</a>, <a href="#Page_359">359</a></li>
+
+  <li class="indx">Tübingen, <a href="#Page_220">220</a></li>
+
+  <li class="indx">Tuke, W. (1732-1822), <a href="#Page_288">288</a></li>
+
+  <li class="indx">Turpentine, <a href="#Page_322">322</a></li>
+
+  <li class="indx"><strong>205</strong>, <a href="#Page_332">332</a></li>
+
+  <li class="indx">Typhoid Fever, <a href="#Page_185">185</a>, <a href="#Page_201">201</a>, <a href="#Page_258">258-61</a>, <a href="#Page_265">265</a>;</li>
+  <li class="isub1">immunization, <a href="#Page_267">267-70</a>;</li>
+  <li class="isub1">death-rate, <a href="#Page_271">271</a>;</li>
+  <li class="isub1">state, the, <a href="#Page_25">25</a></li>
+
+  <li class="indx">Typhus, <a href="#Page_98">98</a>, <a href="#Page_258">258-9</a>, <a href="#Page_271">271</a></li>
+
+
+  <li class="ifrst">United States, <a href="#Page_171">171</a>, <a href="#Page_290">290</a>;</li>
+  <li class="isub1">Preventive Medicine in, <a href="#Page_197">197-203</a>;</li>
+  <li class="isub1">Public Health Service (1912), <a href="#Page_201">201</a>;</li>
+  <li class="isub1">Sanitary Commission, <a href="#Page_300">300</a></li>
+
+  <li class="indx">Universities, Medieval, <a href="#Page_70">70-2</a></li>
+
+  <li class="indx">Urea, <a href="#Page_205">205</a>, <a href="#Page_214">214</a></li>
+
+  <li class="indx">Uterus, Aristotle’s nomenclature of, <a href="#Page_28">28</a>, <a href="#Page_29">29</a></li>
+
+  <li class="indx">Utilitarian Philosophy, <a href="#Page_190">190</a></li>
+
+
+  <li class="ifrst">Vaccination, <a href="#Page_184">184</a></li>
+
+  <li class="indx">Vaccines, <a href="#Page_261">261-2</a>, <a href="#Page_265">265</a>, <a href="#Page_266">266</a>, <a href="#Page_268">268</a>, <a href="#Page_325">325</a></li>
+
+  <li class="indx">Vaso-Motor Mechanism, <a href="#Page_215">215</a></li>
+
+  <li class="indx">Venereal Disease, <i>see</i> Syphilis</li>
+
+  <li class="indx">Venice, <a href="#Page_81">81</a></li>
+
+  <li class="indx">Ventilation, <a href="#Page_146">146</a>, <a href="#Page_147">147</a></li>
+
+  <li class="indx">Vesalius, Andreas (1514-64), <a href="#Page_85">85-92</a>, <a href="#Page_108">108</a>, <a href="#Page_135">135</a>, <a href="#Page_140">140</a></li>
+
+  <li class="indx">Vespasian, Emperor (1st cent.), <a href="#Page_42">42</a></li>
+
+  <li class="indx">Victoria, Queen, <a href="#Page_195">195</a></li>
+
+  <li class="indx">Vienna, <a href="#Page_158">158</a>, <a href="#Page_160">160</a>, <a href="#Page_215">215</a>, <a href="#Page_236">236</a>, <a href="#Page_243">243</a></li>
+
+  <li class="indx">Virchow, R. (1821-1902), <a href="#Page_222">222</a>, <a href="#Page_238">238</a>, <a href="#Page_253">253</a>, <a href="#Page_258">258</a>, <a href="#Page_264">264</a></li>
+
+  <li class="indx">Vital Spirit, <a href="#Page_58">58</a></li>
+
+  <li class="indx">Vital Statistics, <a href="#Page_166">166-8</a></li>
+
+  <li class="indx">Vitalism, <a href="#Page_127">127</a>, <a href="#Page_132">132-3</a></li>
+
+  <li class="indx">Vitamins, <a href="#Page_311">311-13</a></li>
+
+  <li class="indx">Volta, Alessandro (1745-1827), <a href="#Page_149">149-50</a></li>
+
+  <li class="indx">Voltaic pile, <a href="#Page_149">149</a></li>
+
+
+  <li class="ifrst">Waller, A. V. (1816-70), <a href="#Page_238">238</a></li>
+
+  <li class="indx">Wassermann, August von (1866-), <a href="#Page_269">269</a></li>
+
+  <li class="indx">Water, <a href="#Page_156">156</a></li>
+
+  <li class="indx">Water Supply, <a href="#Page_178">178</a></li>
+
+  <li class="indx">Wells, Horace (1815-45), <a href="#Page_237">237</a></li>
+
+  <li class="indx">Wells, Thomas Spencer (1818-97), <a href="#Page_243">243-5</a></li>
+
+  <li class="indx">Whooping Cough, <a href="#Page_98">98</a></li>
+
+  <li class="indx">Widal, F. (1862-), <a href="#Page_268">268</a></li>
+
+  <li class="indx">William of Saliceto (1215?-1280?), <a href="#Page_72">72</a></li>
+
+  <li class="indx">Withering, W. (1741-99), <a href="#Page_328">328</a></li>
+
+  <li class="indx">Wöhler, Friedrich (1800-82), <a href="#Page_206">206</a>, <a href="#Page_214">214</a>, <a href="#Page_327">327</a></li>
+
+  <li class="indx">Wormwood, <a href="#Page_323">323</a></li>
+
+  <li class="indx">Wright, A. (1861-), <a href="#Page_223">223</a></li>
+
+  <li class="indx">Würzburg, <a href="#Page_222">222</a></li>
+
+
+  <li class="ifrst">X-rays, <a href="#Page_244">244-5</a>, <a href="#Page_247">247</a></li>
+
+  <li class="indx">Xavier, Marie François (1771-1802), <a href="#Page_219">219</a></li>
+
+
+  <li class="ifrst">Yellow Fever, <a href="#Page_172">172</a>, <a href="#Page_194">194</a>, <a href="#Page_198">198</a>, <a href="#Page_200">200</a>, <a href="#Page_201">201</a>,
+    <a href="#Page_272">272</a>;</li>
+  <li class="isub1">history of, <a href="#Page_273">273-80</a></li>
+
+  <li class="indx">Yersin, Alexandre (1863-), <a href="#Page_253">253</a>, <a href="#Page_263">263</a></li>
+
+  <li class="indx">York, <a href="#Page_288">288-9</a></li>
+
+  <li class="indx">Young, Thomas (1773-1829), <a href="#Page_217">217</a>, <a href="#Page_319">319-20</a></li>
+
+
+  <li class="ifrst">Zürich, <a href="#Page_215">215</a>, <a href="#Page_253">253</a>, <a href="#Page_294">294</a></li>
+</ul>
+</nav>
+
+
+<hr class="chap x-ebookmaker-drop">
+<div class="chapter transnote">
+<p class="center"> Transcriber’s Notes.</p>
+
+<p>
+Evident typographical and punctuation errors have been corrected silently.  Inconsistent spelling/hyphenation has been normalised.
+</p>
+
+<p> The usage of "cholestrol" is the author’s.
+</p>
+
+<p> A half-title and chapter title reiteration have been discarded.
+</p>
+
+<p>
+To improve text flow, illustrations have been relocated between paragraphs. Page number links in the List of Illustrations may no longer be relevant, but will link to the image location.
+</p>
+
+<p> Cover art created for this eBook is granted to the public domain.
+</p>
+
+</div>
+
+
+</main>
+<div style='text-align:center'>*** END OF THE PROJECT GUTENBERG EBOOK 78966 ***</div>
+</body>
+</html>
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diff --git a/LICENSE.txt b/LICENSE.txt
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+This book, including all associated images, markup, improvements,
+metadata, and any other content or labor, has been confirmed to be
+in the PUBLIC DOMAIN IN THE UNITED STATES.
+
+Procedures for determining public domain status are described in
+the "Copyright How-To" at https://www.gutenberg.org.
+
+No investigation has been made concerning possible copyrights in
+jurisdictions other than the United States. Anyone seeking to utilize
+this eBook outside of the United States should confirm copyright
+status under the laws that apply to them.
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+[Project Gutenberg](https://www.gutenberg.org) public repository for eBook [#78966](https://www.gutenberg.org/ebooks/78966)