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diff --git a/old/67326-0.txt b/old/67326-0.txt deleted file mode 100644 index f6f1c69..0000000 --- a/old/67326-0.txt +++ /dev/null @@ -1,12147 +0,0 @@ -The Project Gutenberg eBook of The A.B.-Z. of our own nutrition, by -Horace Fletcher - -This eBook is for the use of anyone anywhere in the United States and -most other parts of the world at no cost and with almost no restrictions -whatsoever. You may copy it, give it away or re-use it under the terms -of the Project Gutenberg License included with this eBook or online at -www.gutenberg.org. If you are not located in the United States, you -will have to check the laws of the country where you are located before -using this eBook. - -Title: The A.B.-Z. of our own nutrition - -Author: Horace Fletcher - -Release Date: February 5, 2022 [eBook #67326] - -Language: English - -Produced by: Mark C. Orton, Les Glloway and the Online Distributed - Proofreading Team at https://www.pgdp.net (This file was - produced from images generously made available by The - Internet Archive) - -*** START OF THE PROJECT GUTENBERG EBOOK THE A.B.-Z. OF OUR OWN -NUTRITION *** - - - Transcriber’s Notes - -Obvious typographical errors have been silently corrected. Variations -in hyphenation and accents have been standardised but all other -spelling and punctuation remains unchanged. - -Italics are represented thus _italic_ and bold thus =bold=. - - - - - THE A. B.-Z. - - OF - - OUR OWN NUTRITION - - - - - HORACE FLETCHER’S WORKS - - - THE A. B.-Z. OF OUR OWN NUTRITION. 462 pp. Just issued. - - THE NEW MENTICULTURE; OR, THE A-B-C OF TRUE LIVING. Fortieth thousand. - 310 pp. - - THE NEW GLUTTON OR EPICURE; OR, ECONOMIC NUTRITION. 324 pp. Just - issued. - - HAPPINESS AS FOUND IN FORETHOUGHT MINUS FEARTHOUGHT. Tenth thousand. - 251 pp. - - THAT LAST WAIF; OR, SOCIAL QUARANTINE. 270 pp. - - - - - _The_ A. B.-Z. - _of_ OUR OWN - NUTRITION - - - _By_ HORACE FLETCHER - _Author of “Menticulture,” “Happiness,” “That - Last Waif,” “Glutton or Epicure,” Etc., Etc._ - - EXPERIMENTALLY ASSISTED BY - DR. ERNEST VAN SOMEREN, - M. R. C. S., L. R. C. P., _of Venice, Italy_ - & DR. HUBERT HIGGINS, M.A., - M. R. C. S., L. R. C. P., _of Cambridge, England_ - - - _NEW YORK_ ‧ FREDERICK A. - STOKES COMPANY ‧ _PUBLISHERS_ - - - COPYRIGHT, 1903 - BY HORACE FLETCHER - - - Published November, 1903 - Reprinted February, 1904, August, 1904 - February, 1905, August, 1905 - - - THE UNIVERSITY PRESS - CAMBRIDGE U. S. A. - - - - - CONTENTS - - - Page - INTRODUCTION ix - - POSTINTRODUCTORY xxvii - - THE A.B.-Z. PRIMER - - Explanation 3 - - Some Pertinent Questions 4 - - A.—The Psychology of Nutrition 6 - - B.—The Mechanical and Chemical Physiology of - Nutrition 8 - - Method 9 - - Z.— The True Chemical End-Point of Digestion 10 - - A.B.-Z. Figure 12 - - Preface to 1906 Edition 13 - - - HISTORY OF DEVELOPMENT AND SUPPORTING - EVIDENCE - - Summary of the Foregoing Pages by an Experimenter - of One Month’s Experience 19 - - First Scientific Recognition of the Principles of - Economic Nutrition Outlined in “Glutton or Epicure.” H.F. 26 - - Was Luigi Cornaro Right? by Ernest Van Someren 27 - - The Cambridge Tests.H.F. 47 - - Experiments upon Human Nutrition, by Sir Michael - Foster, K.C.B., M.P., F.R.S. 48 - - Report of a Plan for the Institution of an International - Inquiry into the Subject of Human - Nutrition.H.F. 53 - - Proposal to Found an International Laboratory of - Research for the Study of Nutrition in all Its - Aspects. Recommended by the following 55 - Professors of Physiology, etc.: - - Sir Michael Foster, Cambridge, England. - Angelo Mosso, Turin, Italy. - Hugo Kronecker, Bern, Switzerland. - N. Zuntz, Berlin, Germany. - Paul Heger, Brussels, Belgium. - A. Dastre, Paris, France. - Henry P. Bowditch, Harvard Medical School. - Russell H. Chittenden, Yale University. - William H. Welch, Johns Hopkins University. - J.P. Pawlow, Saint Petersburg, Russia. - - Nationality and Scientific Titles of the above Board - of Scientific Assessors 68 - - Persistent Scientific Doubts.H.F. 69 - - Physiological Economy in Nutrition, by Professor - Russell H. Chittenden 72 - - Introduction to Dr. Harry Campbell’s Contribution - on the Importance of Mastication.H.F. 92 - - Observations on Mastication, by Harry Campbell, - M.D., F.R.C.P. 96 - - Introduction to Professor Pawlow’s Demonstrations - of Psychic Influence in Digestion.H.F. 180 - - Selected Lectures by Professor J.P. Pawlow (Dr. - W.H. Thompson’s translation) 182 - - Lecture IV.: General Scheme of an Innervation - Mechanism--The Work of the Nervous Apparatus - of the Salivary Glands--Appetite, the First - and Most Potent Exciter of the Gastric Secretion 182 - - Lecture V.: Period of Occurrence and Importance - of the Psychic or Appetite Juice in the Secretory - Work of the Stomach--The Inefficiency of - Mechanical Stimulation of the Nervous Apparatus - of the Gastric Glands 212 - - Lecture VIII.: Physiological Action and the Teaching - of Instinct: Experiences of the Physician 247 - - Introduction to Dr. Cannon’s Papers on Movements - in the Alimentary Canal studied by Means - of the Röntgen Rays.H.F. 284 - - Swallowing and Movements of the Stomach and - Intestines, by W.B. Cannon, M.D. 285 - - The Movements of the Food in the Œsophagus, - by W.B. Cannon and A. Moser 285 - - The Movements of the Stomach, by W.B. Cannon 301 - - The Movements of the Intestines, by W.B. Cannon 342 - - The Battle Creek Laboratories.H.F. 389 - - Experimental Investigation of the Influence of - Mastication and Cooking of Food, etc., in the - Laboratories of the Battle Creek, Michigan, Sanitarium, - under the direction of Dr.J.H. Kellogg 391 - - Dr. Edward Hooker Dewey and the “No Breakfast - Plan.” H.F. 396 - - Professor Jaffa and the Fruitarians.H.F. 397 - - Dr.H.P. Armsby.H.F. 397 - - Explanation of the A.B.C. Series.H.F. 399 - - INDEX 409 - - - - -INTRODUCTION - - - _DO WE EAT TOO MUCH?_ - CAN WE LEARN TO EAT RIGHT? - WITHOUT LOSS OF ENJOYMENT? - WITHOUT CARE BEING A NUISANCE? - WITHOUT SOCIAL INTERFERENCE? - WITH ASSURANCE OF HEALTH? - WITH INCREASE OF ENERGY? - WITH INCREASE OF ENDURANCE? - - * * * * * - - TO ALL THESE VITAL QUESTIONS, - THIS BOOK ANSWERS ONLY “YES.” - - * * * * * - - VERIFY THIS BY PERSONAL EXPERIMENT. - IRRESISTIBLE DESIRE FOR PHYSICAL EXERCISE - WILL FOLLOW, AS A MATTER OF COURSE, - PROBABLY FRUITING IN USEFUL ACCOMPLISHMENT - BY THE SAME INVITATION OF HEALTHY IMPULSE - WHICH CAUSES CHILDREN TO PLAY TIRELESSLY. - DO RIGHT YOUR FEEDING OF THE BODY. - NATURE WILL DO ALL THE REST FOR YOU ARIGHT. - - - - - Introduction - - DO WE EAT TOO MUCH? - -(_A propos of the Scientific-Military Experiments at Yale University_) - - -Do we eat too much? - -Nine out of every ten physicians tell us “Yes,” and tell us true! - -How much too much? - - * * * * * - -Luigi Cornaro suggested that all persons in his time ate more than was -necessary; most persons ate twice as much as was good for them; and -some, who were extravagantly gluttonous, ate ten times as much as was -their most economic need; and Cornaro, who was a dissipated wreck at -forty, reformed his manner of eating and lived to be a hundred to prove -his declaration. - -Experiments carried on in this country and in Europe during the -past five years confirm this estimate of habitual excess; but -fortunately they have also revealed a natural protection, heretofore -unappreciated, available to all, which can regulate the appetite to -suit the real needs of nutrition and thus avoid the dangerous excess -which predisposes to discomfort and disease. - - * * * * * - -Luigi Cornaro lived more than three hundred years ago. His charmingly -frank and interesting autobiography has been published in English -upwards of forty times in different new editions, and no one has -disproved the possibility or probability of his claim. We all know that -Cornaro was right. We know, in a general way, that the great Italian -dietitian and philosopher was wise and uttered wisdom, and we are told -that most, if not all, of the diseases which pain, worry, and afflict -us are caused by indigestion or mal-assimilation of food, the result -of some indiscretions of eating. The questions then are “What are our -indiscretions?” “How can we avoid them?” and “What is the new discovery -that will protect us and, at the same time, add to the pleasures of the -palate and of living?” - -The answers to all these queries will be found herein, as will also -an explanation of the very active interest which is being taken just -now in the problem of human nutrition by scientific and military -authorities, as evidenced by the Yale investigation. - -The author has, in collaboration with several others, found a way how -_not to eat too much_ while eating _all that the appetite desires_, and -in a way that leads to a _maximum of good taste_ and at a _minimum of -cost and waste_, but it is necessary to test many persons of different -physiques and varying temperaments, and also to test other methods of -attainment of economy, to learn what is best for general application, -and that is what is being done at Yale. - - * * * * * - -The cost to the pocket that is saved by economic nutrition is of little -matter as compared with the saving of the waste of energy and the -menace of disease. - - * * * * * - -Nature certainly never intended that we should weaken, depress, and -distress ourselves in the way that is common to present-day living, as -is made evident by the prevalence of discomfort and disease relative -to our daily food. Nature’s plan of evolution does not work that way -in general, does not retrograde in the progress of the improvement -of plants and dumb animals, and certainly does not intend that Man, -the First Assistant of Nature in the cultivation of things and in the -domestication of the powerful natural forces, should suffer and become -degenerate contrary to her general law. - -If we are agreed upon the foregoing, let us ask ourselves a few -questions. - -Without any undue egotism, may it not be possible for a generation of -human beings, who have progressed so far in intelligence as to be able -to move things by steam, to communicate across the ocean even without -wires to guide our messages, and to see clearly through objects that -are as dark as night to the unassisted human eye with the aid of an -artificial light, to learn the secret of right self-nutrition and -practise it in a manner that will not deprive us of the maximum of -pleasure which Nature invariably gives as a reward for conformity with -her beneficent requirements? May we not assume that beings who have -learned to breed and train horses to race with human intelligence, and -to run, trot, or pace a mile in less than two minutes, may also train -themselves to have the proportional relative speed, endurance, and -longevity that has been attained by race horses through man’s care, -and to enjoy the pleasure of living that is evident in these favoured -animals, mere servitors of man though they be? - -If this disparity of man is due to ignorance arising in self-neglect, -which is the usual accompaniment of genius, may we not now, at the -beginning of the pregnant twentieth century, rest for a moment from -discovering, developing, and improving the world outside our personal -selves and concentrate our attention for a while on learning to know -and care for ourselves? May we not, at least, give “horse sense” -attention to such a vital interest? - - * * * * * - -In the midst of the present confusion which exists among opinions as to -the right conduct of life and activity, and the best manner and system -of diet to be used to secure health and efficiency, it seems almost a -vain appeal to call for concert of action in a matter of common and -persistent neglect. Each person, as his own keeper, is careless, and -in matters of bodily management no one feels called upon to be his -brother’s keeper; but this is merely the lethargy of oversight and -consequent ignorance, and this book is published to call attention to -the oversight and to attempt to dispel the ignorance. - - * * * * * - -At the present moment of writing (October, 1903) there are quartered -at New Haven, Connecticut, twenty privates of the Hospital Corps of -the United States Army and three non-commissioned officers, under the -command of Assistant Surgeon, Lieutenant Wallace DeWitt. These men -and officers, while they are under regular army discipline and are -performing duty in conformity with their oath of enlistment, are yet -volunteers. They are from the same corps, if they are not the same -men, which furnished volunteers to investigate the causes of yellow -fever in Cuba, whose heroism resulted in stamping the fever out of the -islands and in that more effectually protecting our coast states from -its yearly incursions. These are the same men who generously refused to -accept the offered bounty. This latter expression of exalted manhood is -evidence of what humanity is whenever there is real need for heroes to -serve the general good. They refused to _sell_ themselves as risks for -money, but they freely _offered_ themselves as subjects of scientific -investigation for the benefit of their fellows and of mankind at large. - - * * * * * - -The duty that the soldiers are engaged in at Yale has no element of -risk, and need not have any feature of monotony or tediousness in -it, much less has it the romance of sacrifice, for it deals with an -attempt to restore normality and does not consort with disease. But the -service being rendered by these guardians of our health, these soldiers -of hygiene, is even more important than was the service rendered in -stamping out yellow fever, for it deals with an enemy much more -subtle, treacherous, common, and deadly than Yellow Jack. Yellow fever -calls for a halt and an immediate attempt at cure, and further, for -stringent defence to extermination; but indigestion and the American -plague, _dyspepsia_, work their evils slowly but surely to cut off our -best men and loveliest women in their prime and to rob us of their -richest product and of their maturest wisdom. - - * * * * * - -The investigation at Yale is a link in a chain of effort that has -developed in logical sequence and has been planned to effect a cure of -the common ignorance and practice relative to right human nutrition in -its relation to profitable thinking and doing; and to discourage the -personal neglect which has been responsible for the existing ignorance, -this book is issued to show what may easily be done and what has been -done, so far, in this direction. It is a compilation of important -knowledge which has been born of recent scientific research but which -is hidden away from common comprehension in scientific publications; -and it relates the story of the development of which this book is an -exponent. Herein are given the reasons why the government and the -most eminent scientists in the line of researches in nutrition are -coöperating so earnestly and so unusually in a commonweal inquiry. - - * * * * * - -About ten years ago, at the critical age of forty-four, the author was -fast becoming a physical wreck in the midst of a business, club, and -social tempest. Although he was trained as an athlete in his youth -and had lived an active and most agreeable life, he had contracted a -degree of physical disorder that made him ineligible as an insurance -risk. This unexpected disability, with such unmistakable warning, was -so much a shock to his hopes of a long life that it led to his making -a strong personal effort to save himself. The study was taken up in -systematic manner, account of which is too long to relate here; but the -eager auto-reformer soon learned that his troubles came from _too much_ -of many things, among them too much food and too much needless worry; -and realising the danger ahead, he sought a way to cure himself of -his disabilities by the help of an economic food supply, as did Luigi -Cornaro; but what is even more important, he found a way to enjoy the -smaller quantity of food much more than any plethoric luxury can give, -and arrived at the method by a route that showed a means of conserving -a healthy economy and an increased pleasure of eating, at the same -time, in quite a simple and scientific manner, that any one may learn -and practise without any ascetic deprivation whatever. Cornaro buried -the real clew to his economic and pleasurable success with his body, -owing to his vague generality of description of his method. The author -is determined not to make the same mistake, and thereby bury _his_ key -to a happy and easy life. - - * * * * * - -The secret of the method is all told in this book and is confirmed -herein by both theoretically scientific and scientifically practical -authority; but the experiments which are being conducted at Yale by -Professor Chittenden, in coöperation with Surgeon-General O’Reilly of -the army, of which the _Daily Press_ has given notice, together with -experiments which are in progress in many university laboratories in -this country and in Europe, are for the purpose of explaining the -“reasons for things” by complete scientific reasoning, so that none may -doubt the disadvantage and sin of dietic ignorance and carelessness. - -The acceptance of the theory and method of the author at the great -Battle Creek Sanitarium, after more than a year’s trial, and elsewhere -among curative agencies, and their adoption and use as the first -requisite of treatment, of which the public have not so generally -heard, are indorsements coming from practical, intelligent, and expert -sources of experience and judgment, and hence they are of the utmost -value and significance. - - * * * * * - -This introductory chapter is being written after the “clippings” of -newspaper comment relative to the presence of the soldiers at Yale have -begun to come in. The majority of comments are generous in spirit, but -indicate a lack of complete understanding which this “Introduction” is -intended to correct. - - * * * * * - -Some of the comments are couched in ridicule, and express pity for the -poor soldiers who are being “misused” as subjects of starvation in an -investigation which promises to make starvation a rule in the army. To -the writers of such trifling and unfair paragraphs let me, one of the -fraternity in an amateurish way, beg consideration of the following. - -The campaign that has been started is against a common enemy of -mankind, and of the American and English nations in particular. In our -successes in agriculture, manufacture, and commerce we have cultivated -insidious, luxurious temptations which bring all of us some ill and -many of us, or our loved ones, fatal disease and premature death. The -advance agent of these enemies of ours is Eating-and-drinking-too-much. - - * * * * * - -The officers and men of the army and the eminent scientists of our -country and those of all nationalities who have entered into the -campaign with us, and the great power of the sanitaria joining as -practical nurses, demonstrators, and exponents of the reform, are all -working for you and for everybody. It is voluntary service and has -already cost some of the volunteers much time and patience and also a -considerable sum in money. - - * * * * * - -You, gentlemen of the Press, wielders of the helpful or careless pen, -have a conspicuous pulpit and a far-reaching influence. No one can -escape you. In the search for the news of the day you are encountered -at every turn in your editorials or your paragraphs. In this campaign -we need your assistance to make the coöperation between the army and -science easy and effective. They are too busy working for you and your -best interest to stop to argue to correct your misunderstanding, but -the cause will feel the benefit of your assistance. - -Encouragement has powerful influence in stimulating effort and also in -creating and conserving conditions in which men may “do their best.” -What we are trying to learn is, what man _may_ do, under favourable -conditions of knowledge and confidence, to relieve his body of the -_strain of energy-taxing labour_ in disposing of the waste _which any -excess of food imposes_. It is a constructive experiment and not a mere -statistical measurement. Appreciation and applause assist; doubt and -ridicule obstruct. - -The soldiers and physiologists are too busy studying indigestion and -possible proteid poisoning and what-not-other causes of intemperance, -disease, and suffering to ask you to assist in spreading only serious -report and right suggestion relative to the importance and purport of -the investigation, but it is my privilege to ask it for the general -good. - - * * * * * - -Just another word of introduction and then will follow some -_postintroductory_ coincidences relative to the work in hand, and then -an attempt to lay out a ten-page chart of the personal responsibility -in the care of the body and the nourishment of the mind by aid of an -economic and most satisfactory nutrition, so as to make conservation -of energy as easy as possible and life well worth the living. The -scientific support from the pens of professional observers is, however, -the real meat of the book, for which compiler and reader alike are and -should be grateful. - - * * * * * - -In serving in the humanitarian ranks in a commonweal campaign one -should not need to use the concealment of modesty, nor should he fail -to speak with all frankness. What are the motives behind all this -energy to reform the eating habits of the people? The question has been -so often asked that it is better thus publicly answered. - -No one concerned in the campaign has any personal monetary interest -in any kind of food, prepared or otherwise. The movement began in a -suggestion carried by an accidental word given to the author by a -friend, an old-time friend in Japan, and a friendship never to be -forgotten, as related in the author’s book “Menticulture.” Pursuit of -menticulture led further to the discovery that the best mental results -could not be accomplished in a body weakened by any indigestion, any -mal-assimilation of nutriment, any excess of the waste of indigestion. -Then came the quest for the causes of mal-nutrition, which were soon -found, by study of the natural sequences and by going behind the -hypotheses of text-book authority, to arise in the careless ingestion -of food, its neglect in the mouth, and the consequent glut of -unassimilable excess within the body, necessitating enormous expense -of brain and body energy to get rid of the excess. - -When the secret of the potency for good of a rationally economic -alimentation was revealed to the author, was confirmed by several -colleagues of different ages and both sexes, and was tested by work -and endurance measurement, and also by the test time, it became -necessary to have given to it the indorsement of highest authority -in order to have the information credited. The new rediscovery was -a simple matter, something everybody thought they knew all about -because it had been under their nose all their life and was one of the -commonplaces of every-day living, but for that very reason it failed -to receive credence, and the backbone of the doubt was habit--lifelong -habit--and this was hard to break even in those who accepted the theory -of economic nutrition as a logical conviction. It was also necessary -to prove that it was not personal idiosyncrasy that favoured us, its -advocates. - -It is in pursuit of the latter desideratum that the officers of the -army, the scientists, and the great humanitarian health-restoring -institutions have entered upon conclusive investigations, each in -their own way, to chart out a law of economy that will be generally -applicable and which, it is hoped, can be understood by kindergartners -and mothers for the benefit of the present and of coming generations. - - * * * * * - -It was just stated that no one concerned in the inquiry was interested -in any food product or in any personally profitable business concern, -and mention of the Battle Creek Sanitarium, so widely known as the -pioneer in fostering the pure food and prepared-cereal manufacture, -may cast a doubt upon the matter in the minds of those who do not -know that the Sanitarium organisation, in its every department, is a -philanthropic, humanitarian institution. It is the parent and feeder of -the American Medical Missionary Cause, which already has established -branches in something over sixty localities situated in or near large -cities in different parts of the world, chiefly America. By perpetual -charter all the profits revert to the spread of the work and the -employees serve for a mere pittance, deriving their major compensation -from enjoyment of the altruistic work. - - * * * * * - -The old prejudice against the human race which declared that “everybody -had an axe to grind,” that there was “a nigger in every woodpile,” and -such like slanders, must be modified in the light of recent altruistic -development. Altruism has always been existent and had a great new -birth with the beginning of our era, but it was never before so frankly -put upon a business basis as it is now, and this is fast being applied -to every department of business activity. It is now done, not in the -name of any particular creed or cult, or for future reward, but because -_it pays_--first, last, and all the time. - - * * * * * - -In the study and pursuit of menticulture the author has found that -working for the common good is as necessary to happiness as working for -self, and that the retroactivity and reciprocity of the idea multiplies -the profits indefinitely. - -The sequence of profitable, altruistic interrelation is stated in the -“Explanation” of the chain of the A. B. C. Life Series, of which this -book is one of the links. - - * * * * * - -Aside from those actively engaged in the several investigations to whom -reference is often made, the author wishes to express special gratitude -to Sir Michael Foster and to Professor Henry Pickering Bowditch of -the Board of Scientific Assessors. Unselfish and unremitting in their -assistance and encouragement, the author’s work has been made easy -since their interest was enlisted. - -Sir Michael, as Member of Parliament in England, and as a physiological -savant, knows that economic nutrition is the key to England’s welfare, -as well as the basic necessity of temperance, morality, health, and -efficiency, as is expressed in the two documents from him reproduced -in the “Report of a Plan for an International Investigation into -the Subject of Human Nutrition” and in his “Note” on the Cambridge -examination of the author and Dr. Van Someren at Cambridge University -laboratories, given herein. - -Professor Bowditch, as a distinguished physiologist, publicist, and -especially as the President of the Children’s Aid Society, of Boston, -Massachusetts, often mentioned as the model institution of its kind -in the world, realises that the effort of the author to secure basic -knowledge relative to right nutrition, adaptable to kindergarten -teaching and home training during the impressionable period of youth, -is of the greatest importance in social reform. - -A trial suggestion relative to ways and means of _beginning right_ with -_all the children_ and thus insuring a regeneration of the classes most -in need of reform, in not longer than two decades, is outlined in the -author’s appeal for the waifs of society, entitled “That Last Waif; or -Social Quarantine.” - -Whenever there is any disposition to slack up in patience or enthusiasm -to accomplish the ultimate end aimed at, the picture of the waif -in that story is flashed back by memory, and there can be neither -forgetfulness, indifference, nor repose until “that last waif” has been -given _at least a chance of choosing_ between the right and the wrong, -the good and the bad. - - - - - POSTINTRODUCTORY - - -[Just before “going to press” the author has received a letter from -his esteemed colleague, Dr. Hubert Higgins, giving the gist of -interviews with an eminent European physiologist and with a famous -American chemist and dietitian, which so well describes the attitude -of the scientific mind towards the problem of human nutrition that the -scientific mentor of the writer advises its addition to the book. - -By the same post there arrived a letter from Dr. J. H. Kellogg, the -life and director of the Battle Creek Sanitarium, expressing practical -appreciation, the result of demonstration, of what is being done to -solve the problem. - -Eliminating the personal element and keeping the ultimate object in -view, these communications are coincidentally _a propos_ and intimate -to our “Introduction”; hence their reproduction here. - -Numerous other letters and extracts from communications received by the -writer, bearing upon this subject, from the above and other sympathetic -friends are reproduced in “The New Glutton or Epicure,” a free and -easy companion of this book, intended to appeal to a variety of readers. - -When it is known that the proceeds of all the publications of the -author are dedicated to the promotion of the objects they advocate, -reference to them or advertisement of them cannot be considered -inappropriate.—HORACE FLETCHER.] - - - EXTRACTS FROM DR. HIGGINS' LETTER - - PALAZZINA TASSO, - CAMPO S. POLO, - VENEZIA. - - October 3, 1903. - -DEAR MR. FLETCHER,--A. appears to me to have an exceedingly broad and -philosophic grasp of the problem of nutrition. - -He recognises that all present data are subject to criticism, and that -there are no scientifically accurate data available because - - (_a_) Observations are taken over too short a period. - - (_b_) They have mainly dealt with one side of the problem,--the output - of muscular work. - - (_c_) The observations are not sufficiently complete. - -He acknowledges that cleavage products from food broken down in the -intestines by bacteria are the cause of - - (_a_) Inefficiency - (_b_) Diseases - (_c_) Mental derangements. - (See Mott’s work.) - -He recognises that the majority of people eat far too much. He puts -this in the following way. If a “mediæval devil” had wished to discover -the most subtle and most effective way to destroy mankind mentally, -morally, and physically, he would have arranged for them to be supplied -with tasty, well-cooked foods, wines, etc.; in short, he would have -used every means to tempt, confuse, and pervert their appetite. He -would also have arranged every possible means to prevent their being in -the fresh air and taking exercise. He thinks one has here the picture -of modern civilisation. - -He talked in a very interesting and instructive manner about the -necessity and value of exercise and a muscular body for the maintenance -of good health. He has evidently worked at and thought a good deal -about this side of the subject. - -He regrets that there are not more people who realise the huge -importance of understanding the nutrition problem for the sake of -the progress of humanity. He would like to join all those who are -interested in forming an international society, as far as I understood -him. - -He is most keen on getting subjects, such as myself, for study over -a very long period of time,--two to three years,--as he very justly -observed “Muscular output is a very small part of the measure of a -man’s efficiency. Mental efficiency, manual dexterity, and other -psychological tests are necessary.” He seemed very much interested in -my idea of making a large number of curves of daily observations. He -said that it appeared to him to offer the best means of ultimately -measuring the degree of deviation from the subject’s optimum state of -health. - -He argues the necessity of getting some scientific definition of health. - - * * * * * - -The phrase that reduces all these people to contemplative silence is -this. - -“You acknowledge that the state of knowledge is insufficient to -prescribe a diet for any individual that he should take daily; or -in other words, that there is very little accurate knowledge of the -nutrition problem.” - -Reply. “Yes. I do not feel I could prescribe a diet for any one with -any degree of confidence.” - -“Very well, then. Why should not the body have or acquire the quality -that all animals have, in a free, natural state, of knowing what their -body wants by appetite and taste?” - -This is more or less how you put it to me when I first met you at -Cambridge. Its full significance did not dawn on me till much later; -till, in short, I commenced the study of my desires at Cambridge. - -Now this point of view is the rock on which we stand, and is the cause -of H.'s and A.'s interest, and as H. said, is the “most fascinating -idea” he ever heard. - -It had very much the same effect on A. He was reduced to silence. The -more you think of it the more you see there is no answer that could -contradict it. - -_He then admits that_ - - (_a_) The food should be finely divided. - - (_b_) That it should be thoroughly insalivated. - - (_c_) That in all probability most diseases are caused by dietetic - error. - - (_d_) That we have still to find the optimum health and the optimum - diet. - -He only kicks at the low proteid. Now I don’t care a “kuss” for the low -proteid, as such, or high proteid. Proteid like everything else will -be demanded by the appetite when it is wanted. - -Our great danger, to my mind, is the tendency so strongly exemplified -by some of prescribing diets and quantities and the length of time food -should be chewed.[1] Now the very errors we are fighting against are -the prescription of methods on insufficient information or knowledge. -_You have gone straight back to Nature._ _There is your strength_ in -convincing the scientific world, and we must study the problem from -that point of view if we are to get any great degree of success. - -A. had nothing to say when I told him that I did not hold by either -high or low proteid but only by my appetite and taste, developed by -ample mouth opportunity to discriminate, which I hoped, in time, to -understand more thoroughly than I do now. He told me that he feared -that there would be great physical deterioration after a long period -of low proteid. I said that I did not believe it would be the case by -your method. For instance, right in the midst of a long period of most -satisfactory low-proteid supply, I once ate nearly a whole chicken -with some ham at Penegal. I could not get saliva for anything else.[2] -In short, then, I insisted only on thorough mastication to protect -taste and appetite, and had no other theories. I was only concerned -in observing the factors determining my taste and appetite. I would -be more than contented to leave the question of minimum and maximum -quantity of proteid to be settled in the future after normality had -been established by practical demonstration. - - Yours faithfully, - HUBERT HIGGINS. - - - EXTRACTS FROM DR. KELLOGG’S LETTER - - BATTLE CREEK, MICH. - October 7, 1903. - MR. HORACE FLETCHER. - -DEAR FRIEND,--Yours of September 30th just reached my hands and I -hasten to reply. - -I saw a newspaper note in reference to the soldiers which the -government has selected for the dietetic experiments, and also read -an interesting article in the _Popular Science Monthly_. You have -accomplished a great good thing in enlisting these scientific and -military men and interesting them in the investigation of this -wonderful reform. The marvellous thing about it is that these busy men -of science should have so readily undertaken an investigation which -involves so much surrender and self-denial, at least, at the start. I -know you are absolutely right. My personal experiences and observations -confirm me. In the experiments you mention, which I made in reference -to the daily ration for ordinary persons, I simply sought to ascertain, -as have others, how much and what kinds of food people are in the habit -of using, taking no account of the possible excess or the careless -manner in which they eat. The figures I got were sixteen ounces of -starch; 1.2 ounces fat, and three ounces proteids,--approximately 2,500 -calories. In observation of patients I have seldom found one able to -eat this amount. Personally, I habitually eat scarcely half as much. My -breakfast to-day was the yolks of two eggs, two or three tablespoonfuls -of corn flakes, a moderate-sized potato, and a couple of peaches. At -dinner I shall take a little more. - -I have been so busy with my patients and the new building, getting -things organised, that I have not done as much as I ought to in the -way of promoting your splendid reform; but I am going at it now in -good earnest. I feel it is one of the greatest things in sight, and it -fits right in to all the other things I am trying to do. I feel that -I owe you continually a great debt for the efforts you have made and -the splendid work you are doing, which will accomplish more for the -uplifting of humanity than all that Carnegie and Rockefeller are doing -with their millions. What they are doing is mainly to perpetuate old -errors, while you are bringing out new truth of basic importance, and a -kind Providence has certainly inspired you to do this grand work. - -I thank you for all your good thoughts towards us, and assure you -the loving encouragement your letters always contain is very much -appreciated, and sometimes it gives us a mental uplift just when we -need it. The road we are travelling over is not altogether free from -thorns. All your suggestions are gratefully received. I remain, - - Faithfully yours, - - J. H. KELLOGG. - - - - - A. B.-Z. PRIMER - - - - - EXPLANATION - - -This is a condensed presentment of a subject of basic importance to -everyone, supported by numerous appendices of great scientific weight. - -The special object of such brevity and elementary treatment of the -subject is: - -=1.= To accentuate the facts showing how little we really have to know -and do in connection with our sustenance in order to have the NATURAL -AUTOMATIC PROCESSES done rightly and healthfully. - -=2.= To permit busy persons who will take our dictum as gospel and our -advice as sound to learn their necessary share in their own nutrition -in the least possible time, leaving the less credulous and more curious -to study the appendices at leisure and at will. - -=3.= For some ten years it has been the ambition and the aim of the -older and non-professional author to embody the fundamental essentials -of human responsibility in self-understanding and self-management in -not more than ten pages of coarse print that a child could understand -and that mothers and teachers might commit to memory and never forget. - -This is only a first trial-attempt to fulfil the ambition and the aim; -but the appendices show the assembling and concentration of scientific -and militant forces which will not allow this subject of primal -human interest to remain longer the most neglected of educational -departments. - - - - - SOME PERTINENT QUESTIONS - - -Will the reader not ask himself the following questions? - -=1.= How much do I know about my own nutrition? - -=2.= Do I know the particular need and purpose of my last meal and what -it is likely to accomplish? - -=3.= Considering my body as an engine, would I accept myself as a -competent engineer on my own examination and confession? - -=4.= Were I an iron and steel automobile, instead of a flesh and blood -automobile, which I really am, could I get a license for myself, as a -_chauffeur_, to run myself with safety, based upon my knowledge of my -own mechanism and the theory and development of my power? - -=5.= Were I an owner of valuable live-stock, would I employ a farm-hand -or a stable man, even at so low a wage as fifteen dollars a month, who -knew as little about the proper feeding of my animals as I know about -the proper feeding of myself and my children? - -=6.= Should I employ such an ignorant attendant for my live-stock, and -catch him worrying them during their feeding, and hurrying them away -from their fodder to hitch them up for work, would I not have the man -arrested for cruelty to animals? And yet this is what is habitually -done to children! - -=7.= Do I appreciate how important it is to learn sufficient of the -requirements of economic and healthy nutrition to enable me to escape -the depressing and debilitating effects of a faulty nutrition. - -=8.= How can I religiously “ask a blessing” upon food and then -immediately sin by treating it in a manner abhorrent to the natural -requirements? - -=9.= If “cleanliness is next to godliness” is it respectable for me to -slight my proper feeding in a manner that I know may induce putridity -of excreta through indigestion and that _may_ produce fatal disease? - -=10.= With All Eternity ahead of me, cannot I afford at least 1∕48[3] -of my time for careful feeding of my body in a manner known to favour -physical health; mental keenness; firmness of character; enjoyable -temperance; sexual vigour without morbidity. In fact, general -respectability and efficiency? - -Having duly reasoned out logical answers to the questions, may they not -seem sufficiently important to be remembered and respected as a DIETARY -TEN COMMANDMENTS? - - - - - A - - The Psychology of Nutrition - - APPETITE ATTENTION APPRECIATION - - -APPETITE is the most important factor in digestion (vide Pawlow). - -NORMAL APPETITE is indicated by a desire for _some particular_ simple -food accompanied by a “watering of the mouth.” - -FALSE APPETITE is a general discontent of the body, indefinite of -description. It is often expressed by “all gone-ness,” or stomach -craving, and calls for _something_, ANYTHING! to smother the discomfort -of present or recent indigestion. It is like the thirst which follows a -debauch. - -IGNORE FALSE APPETITE, and WAIT for a RETURN of NORMAL APPETITE. -It will come as soon as body repairs have been effected by natural -agencies and more material is required. No one was ever injured by -intelligently and calmly waiting for an appetite. No one ever starved -to death for lack of appetite. Most human ills come from forcing -appetite, anticipating appetite, abuse of appetite in some form. - -APPETITE is the most important factor in nutrition. This estimation is -based upon evidence given more fully in the various appendices, but the -measure of its importance may be briefly stated, as follows:— - - -_First_ - -In its normal state, Appetite is a perfect indicator of the bodily need -of nutriment and moisture, both as to quantity and as to the chemical -elements required at the moment. - - -_Second_ - -APPETITE is a creature of the mind and does not attach to a tissue. -It can be as easily changed, from abnormal to normal, by suggestion, -as can the mind itself, and is not like a solid, the form or habit -of which has been set in a mould. Whoever has once experienced a bad -oyster and has abhorred oysters ever after will substantiate this claim -regarding the caprices of appetite. - - -_Third_ - -APPETITE can be easily comprehended and read and the degrees of its -satisfaction understood by simple attention and study for a brief -period (vide Van Someren). - - -_Fourth_ - -ATTENTION is necessary to create APPRECIATION, and appreciation is -absolutely necessary to stimulate the secretion and flow of gastric and -other digestive juices (vide Pawlow). - - -_Fifth_ - -ANGER, or shock of any kind, and WORRY, or any of the pessimistic -depressants, stop digestive activity and cause indigestion (vide -Cannon). - - -_Sixth_ - -MENTICULTURE should begin with its application to selection (through -a normalised appetite) of nutriment for the body, and continue to aid -digestion by right thinking. - -It is very easy to cultivate calm and fortify against surprise, shock, -and anger if the nutrition of the body is carefully attended to. The -physical and the mental equipments are beautifully reciprocal and -necessary to each other in promoting MENTICULTURE. - - - - - B - - The Mechanical and Chemical Physiology of Nutrition - - BUCCAL DIGESTION - - THROUGH - - MOUTH THOROUGHNESS - - -Mouth treatment of food, which permits, aids, and includes insalivation -(mixing with saliva), and which is both actively digestive in its -functions and preparatory to final digestion, is the only _actual -mechanical responsibility_ we have in our nutrition; and, in connection -with favourable A conditions, insures perfect digestion. It has been -so fully and clearly explained in some recent articles, “Observations -on Mastication,” by Dr. Harry Campbell, F.R.C.P., physician to the -Northwest London Hospital, printed in the “Lancet” of July 11th, 18th, -25th, and August 8th, 1903, that reference to the articles, reprinted -herewith, is all that is necessary here. - -In giving attention to careful mouth-treatment of soft or liquid foods -until they are absorbed by the Swallowing Impulse the best health and -economic results are obtained. It should, at least, be tried. - -This will not be found to be a tedious operation after a little -practice, when the habit of attention and care has been formed. On the -contrary, a new appreciation and enjoyment of taste will be acquired, -the delight of which has to be experienced to be understood. - -Some hints on learning how to _read_ the appetite, _command_ the -attention, and _masticate_ and _swallow_ food material _properly_ -follow. - - - - - METHOD - - - _First; Last; and All the Time_ - -Be sure that you are really hungry and are not pampering False -Appetite. If true appetite that will relish plain bread alone is -not present, wait for it. Especially beware of the early-morning -habit-craving. Wait for an _earned_ appetite, if you have to wait till -noon. Then: “Chew,” “Masticate,” “Munch,” “Bite,” “Taste” everything -you take in your mouth (except water, _which has no taste_), until -it is not only thoroughly liquefied and made neutral or alkaline -by saliva, but until the reduced substance all settles back in the -(glosso-epiglottidean) folds at the back of the mouth and excites -the Swallowing Impulse into a strong inclination to swallow. Then -swallow what has collected and has excited the impulse, and continue -to chew _at_ the remainder, liquid though it be, until the last morsel -disappears in response to the Swallowing Impulse. Never forcibly -swallow anything that the instincts connected with the mouth show any -disposition to reject. It is safer to get rid of it beforehand than to -risk putting it into the stomach. - -Sip and taste milk and all liquids that have taste as the wine-tasters -do. They never drink wine and yet they get all the enjoyment there is -in it and waste none. In a very short time sipping and tasting liquids -and masticating and tasting solid food for “all they are worth” will -become an agreeable and profitable fixed habit. - -WHETHER WE “EAT TO LIVE OR LIVE TO EAT,” WHY NOT DO AS ABOVE? - - - - - Z - - The True Chemical End-Point of Digestion - - THE DIGESTION-ASH WHAT IT SHOULD BE LIKE WHEN IT IS NORMAL - - -_First_ - -In adults; or, in children after the eruption of teeth and the -ingestion of solid food: The non-liquid and non-gaseous waste of the -human body, which, in its normal state, is not offensive, should be -very small, in quantity, should be pillular in form, either separate or -massed together; should have no odour when released, should take on no -odour on standing, should be entirely aseptic (non-poisonous); should -drop freely from the exit, leaving nothing behind to wash or wipe away. -It _may_ not be collected in the intestines of full-grown and elderly -persons, when normal, as above, in sufficient quantity to require or -necessitate emptying oftener than from twice a week to once in two -weeks; according to age, activity, etc.; and should neither invite nor -justify the description “it is not that which goeth into a man that -defileth him but that which cometh out.” - - -_Second_ - -Economic Digestion-Ash (solid _excreta_), as a daily average for an -adult of 140 lbs. (10 stone; 63.5 kilos), including moisture, when -released, should not weigh more than two ounces (56.70 grams). An -average of less than one half this amount of waste has been secured in -test experiments. - - -_Third_ - -The true test of healthy Z is absence of odour and completeness, ease -and cleanliness of delivery. Frequency or otherwise, does not so much -matter. Quantity too, is not so important; but with foul odour there is -disturbance, strain and danger. - -The normal man is a cleanly being with all excreta inoffensive; and by -these tokens he may be his own private judge. - -Why is it that barn-yards are tolerable to the human senses while open -_dépôts_ of human excreta are fever-breeding nuisances and intolerable -to beasts and humans alike? - -This curse of putrid excreta caused more deaths from enteric fever -during the Boer War in South Africa than all other causes. It is -equally a menace to health and even to life while being formed and -carried in the body. - - -_Fourth_ - -Offensive excreta are quite certain evidence of neglect of the -self-controllable parts of our own nutrition. They are the tell-tale -condemnation of ignorance or carelessness. Each person should learn to -read the true bulletins of his health conditions in his waste-products -of digestion. - - -Z - -is the form the body _must_ assume to render emptying of the -digestion-ash natural and easy. Man was built to squat on his heels in -defecating, and sitting erect on a modern seat is like trying to force -a semi-solid through a kinked hose. HEALTHY HUMAN EXCRETA ARE NO MORE -OFFENSIVE THAN MOIST CLAY AND HAVE NO MORE ODOUR THAN A HOT BISCUIT. - - - - - A. B.-Z. FIGURE - - TO ILLUSTRATE THE “DIVISION OF LABOUR” - - -_First._ A - - Psychic Environment } This - Mental State } involves: - - APPETITE (to select for) } - ATTENTION (to prepare for) } DIGESTION - APPRECIATION (to assist in) } - -(Absolutely necessary to secure secretion and flow of the digestive -juices: Vide Pawlow and Cannon.) - - -_Second._ B - - BUCCAL-DIGESTION } This - MOUTH-TREATMENT } involves: - - MECHANICAL (teeth) } THOROUGHNESS - CHEMICAL (salival) } - -(Absolutely necessary to secure complete digestion and avoid the -putridity incident to bacterial decomposition: Vide Campbell and Van -Someren.) - - -INTERMEDIATE - -The twenty-three letters between “=B=” and “=Z=” represent but an -inadequate proportion for the spelling of the enormous share Nature -assumes in our welfare, marvellously performing her forty-seven -forty-eighths share in the secret laboratory of the alimentary canal. - - -_Third._ Z - -The true chemical end-point of digestion, by which each self-respecter -may know how well he has respected his “A” and his “B,” and how -faithfully he has performed his one forty-eighth share in the promotion -of his own most fundamental interest. - - - - - PREFACE TO 1906 EDITIONS - - -Since the former introductions were written much success has been -attained in further advancing the reforms advocated in the _A. B. C. -Life Series_. Professor Chittenden has published his report on the -Yale experiments in book form in both America[4] and England,[5] and -his results have been accepted in scientific circles the world over as -authoritatively conclusive. - -At the present writing the most important Health Boards of Europe[6] -are planning to put the new standards of dietary economy into practical -use among public charges in a manner that can only result in benefit -to the wards of the nations as well as make an important saving to -the tax-payers. In the most important of these foreign public health -departments the Health Officer of the Board has himself practised the -newly established economy for two years, and his plans are formulated -on personal experience which fully confirms Professor Chittenden’s -report and that of the author as herein related. - -At a missionary agricultural college, situated near Nashville, Tenn., -where the students earn their tuition and their board while pursuing -their studies, a six months' test of what is termed “Fletcherism” -resulted in a saving of about one half of the drafts on the commissary, -immunity from illness, increased energy, strength and endurance, and -general adoption of the suggestions published in the several books of -the author included in the _A. B. C. Life Series_. - -In the various departments and branches of the Battle Creek Sanitarium -in America, and widely scattered over the world, some eight hundred -employees and thousands of patients have been accumulating evidence of -the efficacy of “Fletcherism” for more than three years, and scarce a -month passes without a letter from Dr. Kellogg to the author containing -new testimony confirming the _A. B. C._ selections and suggestions. - -The author has received within the past two years more than a thousand -letters bearing the approval of the writers with report of benefits -received which seem almost miraculous, and these include the leaders in -many branches of human occupation--physiologists, surgeons, medical -practitioners, artists, business men, literary workers, athletes, -working men and women, and almost every degree of mental and physical -activity. - -One of the medical advisers of King Edward, of whom the King once said: -“He is a splendid doctor but a poor courtier,” follows the suggestions -of these books in prescribing to his sumptuous clients. - - - - - HISTORY OF DEVELOPMENT - - AND - - SUPPORTING EVIDENCE - - - - - SUMMARY OF THE FOREGOING PAGES BY AN EXPERIMENTER OF ONE MONTH’S - EXPERIENCE - - (_Requested and given as a test of effectiveness_) - - -The entire principle of economic nutrition is simple and practical. It -does not prescribe that we shall follow any special diet nor do away -with any of our meals. It simply requires you to throw present habits -and conventions to the winds, and for a little time try the experiment -of giving the matter of your every-day living honest, intelligent -thought. - -Eat all you crave, but do not eat more than this simply because you -have been in the habit of doing so. See to it that each morsel put into -your mouth is thoroughly masticated and mixed with the saliva before -going down into the stomach, which is not equipped to perform the work -which the teeth and salivary glands were given you for. The stomach -will struggle bravely to overcome the abuse which you heap upon it, but -in spite of all it can do to manage hastily chewed food, undigested -portions remain which clog the intestines and interfere with the -healthy conditions which Nature intended. - -The appetite is given as an indicator of what the body requires. If -you crave potato, the system needs starch, which the saliva makes -digestible, but which the acids of the stomach cannot dissolve. Other -needs of the system are similarly indicated. Take the trouble of asking -your appetite the question, instead of accepting the conventional -number of courses simply because they are set before you. The appetite -will close the valve when you have eaten enough, if you will give it a -chance. - -Suppose your time for eating is limited; in twenty minutes you could -not eat slowly the luncheon which you usually select. Then eat that -much less. The amount of food which you can eat and thoroughly -masticate in twenty minutes will give you more nourishment and will -sustain you better than twice the amount thrown into the stomach in the -same manner in which a man usually packs a trunk. - -Why is it that so many men require a “bracer” at eleven o’clock? -Because they have loaded their stomachs with a heavy breakfast, and -instead of gaining nourishment from it, the smothered organ is doing -its best to tear the undigested morsels to pieces, that they may pass -into the intestines and prevent sickness, or even death. The time -finally arrives when it finds itself unable to do this, and then comes -acute indigestion, or something worse, and the system becomes run down, -ready to receive typhoid, or any other germs which happen to come along. - -Do you know why griddle-cakes hurt you? Because the syrup, which is -cane-sugar,--and as such is indigestible,--is allowed to pass through -the mouth and down into the stomach, without being properly mixed with -the saliva, which makes it digestible. As soon as it enters the stomach -it becomes acid and interferes with everything it meets. Had the cakes -been properly masticated and mixed with the saliva, the cane-sugar -would have become grape-sugar, and in this form it is easily digested. - -Why is it that stout people are advised to avoid starchy foods? -Economic nutrition does not advise this. Potatoes, eaten too -hastily, when not craved by the appetite, supply the system with a -superabundance of starch, and this is fat-inducing. Potatoes are -supposed to produce fat; but if your appetite craves potato, and you -properly masticate it, eating only as much of it as satisfies your -appetite, the system absorbs it all, leaving nothing to produce fat. -On this same principle economic nutrition assures that the same food, -taken in accordance with its requirements, will add to one man’s -weight and decrease another’s, simply because proper care of the -stomach supplies the vital organs with the necessary materials to form -each individual person after the model which Nature intended for him. -If Nature intended him to be slight, economic nutrition will not make -him heavy; if Nature intended him to be muscularly strong and heavy, -economic nutrition will not reduce his weight. In each case he will -enjoy that perfect condition which Nature intended him to possess -without fat encumbrance. - -Did you ever try to reason out why it is necessary for athletes to go -into training? Simply because, in order to get the best use of their -strength, they are obliged to spend some number of weeks or months in -overcoming false conditions which they have brought upon themselves. -Any person who lives in accordance with the simple requirements of -economic nutrition has nothing of this kind to overcome, but is in -perfect condition all the time. - -The requirements of economic nutrition are not hardships but pleasures. -Proper mastication and insalivation (mixing with saliva), give your -sense of taste far greater gastronomic enjoyment than you have ever -before had. If you are a wine drinker, try insalivating a little port -wine; but it must be good wine, for this is a severe test. A sip will -quench your immediate desire and give you more pleasure than a whole -glass gulped down. The professional tea-taster does this in tasting -tea; he never allows himself to drink any tea at all, for drinking -anything that has taste destroys the delicacy of the sense of taste. -But he will tell you that he gets more real enjoyment out of the little -he takes than he previously gained from drinking a larger amount. The -same thing applies to the professional wine-tasters; they never drink -any wine, and yet they enjoy the taste of wine as drinkers never can -do. These men adopt this method as a business; is their commercial -advantage of greater importance than your health and happiness, and -even life itself? - -Is it not ridiculous that the average man is so ignorant of the engine -which supplies him with all his activity and upon which depends every -action of his life? Could you tell, were you asked, the particular need -and purpose of your last meal and what it is likely to accomplish? -Consider your body as an engine: would you accept yourself as a -competent engineer on your own examination and confession? Would you -employ a chauffeur to run your automobile who knew as little about its -mechanism and requirements as you do about your own stomach? Yet which -is of greater importance? Were you the owner of valuable live-stock, -would you dare entrust their care to a farm-hand or stableman who knew -as little about their proper feeding as you know about your own proper -feeding or that of your children? - -Have you ever stopped to think why the excrements are foul and odorous? -Simply because undigested food, which should have been so masticated -as to give the body nourishment, is thrown off by the stomach into the -intestines, there to decay and produce this unclean condition. If the -dead carcass of a cow is lying in the road, it is removed before it has -an opportunity to decay and thus become filthy and dangerous. Yet how -much more safe it would be for the carcass to lie where it was than -for you to take portions of it into your intestines and allow it to -decay there instead of in the road? In other words, food is intended -to be eaten that nourishment may be gained from it, and when you only -gain a part of the nourishment, you prostitute your stomach and take -tremendous risks of germ diseases in your body. - -These facts are set forward thus simply in the hope that they may -impress the reader as they have impressed the writer. Economic -nutrition is not a joke, is not a fad; it is solely an appeal to -self-examination and self-instruction in the most vital question of -all the world, since upon perfect nutrition depends not only health, -but strength, mental acuteness, moral tendencies, attractability to -others, happiness, and, in fact, life itself. - - - - - FIRST SCIENTIFIC RECOGNITION OF THE PRINCIPLES OF ECONOMIC NUTRITION - OUTLINED IN “GLUTTON OR EPICURE” - - -[With the exception of a brief review of _Glutton or Epicure_, by Dr. -Joseph Blumfield, of London, published in _The Lancet_, no scientific -or professional recognition of the principles of an economic nutrition -attained by means of thorough buccal digestion was gained until issue -of the following paper by Dr. Ernest Van Someren, of Venice, Italy. - -The previous autumn and winter had been devoted to experiments by -Dr. Van Someren and the writer, in co-operation with Dr. Professor -Leonardi, for twelve years Professor of Chemistry in the University of -Pavia, Italy. In the spring and summer of 1901 the field of experiments -was changed to Mendel Pass, _bei_ Bozen, Süd Tirol, Austria, and -related to endurance work in climbing mountains and bicycle runs among -the Dolomites. - -Dr. Van Someren’s paper attracted the attention of Sir Michael Foster, -Professor of Physiology at the University of Cambridge, England, -and Permanent Honorary President of the International Congress of -Physiologists. - -Professor Foster entered into correspondence with Dr. Van Someren, and -this was followed by an invitation to Dr. Van Someren and the writer to -attend the Congress which was to convene in Turin, Italy, during the -month of September following. At the Congress Dr. Van Someren presented -a technical thesis on the probable causes of the economy attained, -and gave a demonstration of the movement of his Swallowing Reflex -in relation to food in the process of liquefaction and preliminary -digestion in the mouth. - -Following the Congress we received an invitation to visit Cambridge, -England, and submit to tests of nitrogenous measurements in the -Physiological Laboratory of the University, under the direction of Dr. -F. Gowland Hopkins; and also to an examination of the bacterial flora -incident to the nitrogenous estimations, under the direction of Dr. -George H. F. Nuttall. - -The report of the experiments in the Chemical-Physiological Department -is given in the “NOTE” of Sir Michael Foster, which follows Dr. -Van Someren’s paper, but the bacterial examination was not carried -far enough to warrant a scientific report, owing to difficulty of -obtaining, at the time, sufficient data.—HORACE FLETCHER.] - - - - - WAS LUIGI CORNARO RIGHT? - - A PAPER READ BEFORE THE PHYSIOLOGICAL SECTION OF THE BRITISH MEDICAL - ASSOCIATION, AUGUST, 1901, BY ERNEST VAN SOMEREN - - -_Mr. President and Gentlemen:_ - -Being a general practitioner, it is with some trepidation and an -apology that I present myself before this section. The reasons for my -doing so are: First, that I believe that a hitherto unsuspected reflex -in deglutition has come to light which has an important bearing on -health, the prevention of disease and on metabolism. Second, that any -theory whatever, based on a possible physiological function, claiming -to diminish, as this does, the amount of sickness and suffering now -existent, should have serious investigation. Third, that I desire to -enlist your skilled help in the consideration of the theories I have -doubtless crudely erected on my premise. - -According to the “Encyclopædia Britannica,” “Luigi Cornaro (1467-1566) -was a Venetian nobleman, famous for his treatises on a temperate life. -From some dishonesty on the part of his relatives, he was deprived -of his rank and induced to retire to Padua, where he acquired the -experience in regard to food and regimen which he has detailed in his -work. In his youth he lived freely, but after a severe illness at -the age of forty, he began under medical advice gradually to reduce -his diet. For some time he restricted himself to a daily allowance -of 12 ozs. of solid food and 14 ozs. of wine. Later in life he still -farther reduced his bill of fare, and he found that he could support -his life and strength with no more solid meat than an egg a day. So -much habituated did he become to this simple diet that when he was -about seventy years of age the addition, by way of experiment, of 2 -ozs. a day had nearly proved fatal. At the age of eighty-three he -wrote his treatise on the ‘Sure and Certain Method of Attaining a -Long and Healthful Life.’ And this work was followed by three others -on the same subject, composed at the ages of eighty-six, ninety-one, -and ninety-five, respectively. ‘They are written,’ says Addison -(‘Spectator,’ No. 195), ‘with such a spirit of cheerfulness, religion, -and good sense, as are the natural concomitants of temperance and -sobriety.’ He died at the age of ninety-eight. Some say of 103! - -Now, was Luigi Cornaro right? Did he make use of a physiological -process unknown to us of the value of which he was not cognisant? To -live to an advanced age, must we be as temperate as he, reducing the -quantity of our food to a minimum required by Nature? - -That we all eat more than we can assimilate is unquestionable. How can -we determine the right quantity? Instinct _should_ guide us, but an -abnormal appetite often leads us astray. Nature’s plans are perfect -if her laws are obeyed. Disease follows disobedience. Wherein do we -disobey? - -We live _not_ upon what we eat, but upon what we digest; then why -should undigested food, recognisable as such, be deemed a normal -constituent of our solid egesta? - -Something like the following must be a common experience to general -practitioners, especially to those practising on the Continent. The -patient comes to see us and volunteers the information that he or she -has the “gout,” “rheumatic gout,” or “dyspepsia.” Symptoms are asked -for. The case is gone into carefully for causation. An appropriate -diet and an appropriate bottle of medicine prescribed. As the patient -leaves the room, we may, or may not, call attention to the fact that -both teeth and saliva are meant to be used. The patient returns, -better, _in statu quo_, or worse. If better, he remains so while -under treatment, and relapses when he returns to ordinary habits. If -unaffected, or worse, we try again and again, until we despair, then -take or send him to a consultant. Temporary benefit, possibly owing to -renewed hope, results; but finally the unfortunate gets used to his -sufferings and, if he can afford it, is sent to join the innumerable -hosts that wander from one _Bad_ to another, all Europe over, trying, -praising, and damning each in turn. Their manner of living is, of -course, at fault. Nature never intended that man should be perpetually -on a special diet and hugging a bottle of medicine, nor did she ordain -that he should go wandering over the map of Europe drinking purgative -and other waters. - -Though early yet to speak with certain voice, it would seem that we -are provided with a Guard, reliance on which protects us from the -results of mal-nutrition. There seems to be placed in the fauces and -the back of the mouth a Monitor to warn us what we ought to swallow and -when we ought to swallow it. The good offices of this Monitor we have -suppressed by habits of too rapid eating, acquired in infancy or youth. - -Last November my attention was called by Mr. Horace Fletcher, an -American author living in Venice, to the discovery in himself of a -curious inability to swallow, and a closing of the throat against food, -unless it had been completely masticated. My informant stated that he -noticed this peculiarity after he had begun to excessively insalivate -his food, both liquid and solid, until all its original taste had been -removed from it. Any tasteless residue in the mouth, being refused by -the fauces, required a _forced_ muscular effort to swallow. He further -told me that since adopting this method of eating he had been cured of -two maladies, adjudged chronic, the suffering from which rendered him -ineligible for Life Insurance. His weight now became reduced from 205 -lbs. to 165 lbs. He had practised no abstemiousness, had indulged his -appetite, both as to selection and to quantity, without restraint, and -for the last three years had enjoyed perfect health. - -After his cure, he was accepted without difficulty for insurance, the -last examination finding him an unusually healthy subject for his age. -Having leisure, he had spent three years in investigating the cause of -his cure, had pursued experiments upon others, and had extended his -inquiries, both in America and Europe, until our meeting in Venice. -He had also published a statement and inquiry in book form, entitled -“Glutton or Epicure,” which had been reviewed by the “Lancet.” - -For nearly a year I also had been experimenting on myself and others -with various diets, and was ready to believe that in the _manner_ of -taking food and not altogether in its varying _matter_ lay perhaps its -protean effects on our system. I at once adopted the same method of -eating. At the end of six weeks, I noticed that not only did the fauces -refuse to allow of the passage of imperfectly prepared food, but that -such food was returned from the back to the front of the mouth by an -involuntary, though eventually controllable, muscular effort taking -place in the reverse direction to that occurring at the inception of -deglutition. - -What actually happens is this: Food, as it is masticated, slowly passes -to the back of the mouth, and collects in the glosso-epiglottidean -folds, where it remains in contact with the mucous membrane containing -the sensory end-organs of taste. If it be properly reduced by the -saliva it is allowed to pass the fauces,--a truly involuntary act of -deglutition occurring. Let the food, however, be too rapidly passed -back to these folds, _i.e._, before complete reduction takes place, -and the reflex muscular movement above referred to occurs. The process -of this reflex is as follows: The tip of the tongue is involuntarily -fixed at the backs and bases of the lower central incisor teeth by the -anterior fibres of the geniohyoglossi muscles. With this fixed point -as fulcrum, the lower and middle fibres of these muscles, aided by -those of the stylohyoid and styloglossi muscles raise the hyoid bone, -straighten out the glosso-epiglottidean folds, passing their contents -forward, by the fauces, the opening of which is closed by approximation -of its pillars and contraction of the superior constrictor. The -tongue, arched postero-anteriorly by the geniohyoglossi, palato, and -styloglossi muscles, laterally, by its own intrinsic muscles, is -approximated to the fauces, soft and hard palates in turn, and thus, -the late contents of the glosso-epiglottidean folds are returned to the -front of the mouth for further reduction by the saliva preparatory to -deglutition. - -The word reduction is used for the reason that all foods tested, -without exception, give an acid reaction to litmus, when served at -table. The reflex muscular movement occurs in the writer’s case from -five to ten times during the mastication of each mouthful of food, -according to its quantity and its degree of sapidity. As often as it -recurs, the returned food continues to give an acid reaction, while -food allowed to pass the fauces is alkaline. - -Saliva, flowing in response to the stimulation of taste, seems more -alkaline than that secreted in answer to mechanical tasteless -stimulation. It is found that the removal of original taste from any -given bolus of food coincides with cessation of salivary flow and -complete alkaline reduction. The fibre of meat, gristle, connective -tissue, the husk of coarse bread and cellulose of vegetables are -carefully separated by the tongue and buccal muscles and rejected by -the fauces. To swallow any of these necessitates a _forced_ muscular -effort, which is abnormal. - -Adult man was not originally intended to take his nourishment in a -liquid form, consequently all liquids having taste, such as soup, milk, -tea, coffee, cocoa, and the various forms of alcohol, must be treated -as sapid solids and insalivated by holding them in the mouth, moving -the tongue gently, with straight up and down masticatory movements, -until their taste be removed. Water, not having taste, needs no -insalivation and is readily accepted by the fauces. - -In explanation of the phenomenon described, the following theory is -advanced: The fauces, back of the tongue, epiglottis, in short, those -mucous surfaces in which are placed the sensory end-organs of taste -and “taste-buds” (the distribution of which, by the way, has yet to -be explained), that these surfaces, readily becoming accustomed to -an alkaline contact by excessive insalivation and consequent complete -alkaline reduction of the food, afterwards resent an acid contact and -express their resentment by throwing off the cause of offence by the -muscles underlying them. - -This phenomenon must not be confused with the cases of rumination and -regurgitation, which from time to time are recorded. The food in this -case is not swallowed, nor does it pass any point from which it can -be regurgitated. Eighty-one individuals of different nationalities -and from several classes of society whom we have studied are now in -conscious possession of their reflexes. These seem readily educated -back to normal functions by all who seriously and patiently adopt the -habit of what seems only at first to be excessive insalivation. - -The dictum “bite your food well” that we so often use, has no -meaning to those suffering from the results of mal-assimilation and -mal-nutrition, especially should they have few or no teeth of their -own. I make so bold as to state that dyspepsia _et morbi hujus generis -omnis_ will cease to exist if patients be persuaded to bite their -food until its original taste disappears, and it is carried away by -involuntary deglutition. - -The important point of the whole question seems to be this alkaline -reduction of acid food before it passes on to meet subsequent -digestive processes elsewhere, which then become alternately acid and -alkaline. - -In the first few months of infant life, when saliva is not secreted, -Nature ordains that mammary secretion be alkaline. With the eruption -of teeth come an abundant flow of saliva and a synchronous infantile -capacity for managing other foods. This flow of saliva depends on a -thorough demand and use to maintain its generous supply. It is just -at this time that children learn to bolt their food,--the demand -fails, with a consequent detriment to the salivary glands, digestive -processes, and the system generally. - -A, B, C, and D were placed on an absolute milk diet. A drank his milk -in the ordinary way, and at the end of three days begged to discontinue -the experiment owing to disgust at the monotony of the diet. B, C, and -D continued the experiment for seventeen days, insalivating the milk, -but to a varying extent, B the least and D the most. Though D took most -milk, he excreted least solid egesta, C excreting less than B. Can one -infer that increased insalivation of a non-starchy food insured its -better digestion and assimilation? Each subject took as much milk only -as his appetite demanded, D taking the most, which never exceeded two -litres daily. The weights of the subjects after the usual sudden drop -of the first three days remained remarkably even until the end of the -experiment. B, C, and D all relished the diet, and it satisfied the -requirements of their appetites, but they experienced an increasing -monotony. - -As long ago as the seventeenth century, before the transformation of -matter into energy by the animal organism, known as Metabolism, was -understood, the fact was recognised that by the lungs, kidneys, skin, -and intestines, substances no longer useful to the organism were -eliminated, the retention of which proved harmful. The nature of these -substances was unknown, but it was noted that however much the food was -increased the weight of the body remained the same. In other words, a -state of complete nutritive equilibrium was maintained. - -The following table contains the _résumé_ of two experiments in which a -state of complete nutritive equilibrium was maintained by individuals -of about the same weight, on widely different quantities of food -similar in quality. The subjects of the experiments were a laboratory -assistant of Dr. Snyder, of the U. S. Department of Agriculture, and -the writer. The experiment of the former was made primarily to show -the relative digestibility of the several articles of diet, potatoes, -eggs, milk, and cream: - - ═════════════════════════╤══════════════════════════╤═══════════════ - │ Dr. Snyder’s │ - │ Experiment. │ Writer’s - │ Published in │ Experiment. - │ Bulletin 43 │ - —————————————————————————┼————─—─—─—─—─—────—─—─—─—─┼─—─—─—───—─—─—─ - Age of subject │ 22 years │ 30 years - Duration of experiment │ 4⅓ days │ 5 days - Number of meals │ 13 │ 10 - Weight at beginning │ 62.5 kilos. │ 57.3 kilos. - Weight at end │ 62.6 kilos. │ 57.5 kilos. - Potatoes (daily average) │ 1587.6 grammes │ 159.4 grammes - Eggs (daily average) │ 411.08 grammes │ 124.7 grammes - Milk (daily average) │ 710 c.c. │ 710 c.c. - Cream (daily average) │ 237 c.c. │ 237 c.c. - Daily urine │ 1108 grammes │ 1098 grammes - Daily fæces │ 204 grammes │ 18.9 grammes - —————————————————————————┴————─—─—─—─—─—────—─—─—─—─┴─—─—─—───—─—─—─ - -The daily diet of Dr. Snyder’s subject consisted of three and one-half -pounds of potatoes, eight eggs, a pint and a half of milk, and half a -pint of cream. The writer’s diet of twelve ounces of solid food (like -Luigi Cornaro) consisted of three eggs, the remainder of the twelve -ounces in potatoes, and an equal quantity of similar liquid food to -that taken by Dr. Snyder’s subject. The exercise of the laboratory -assistant comprised his daily routine of laboratory work, while that of -the writer consisted of six sets of tennis, or an hour and a half on -horseback, with an hour to an hour and a half’s walk or climb daily, in -addition to much reading and writing. - -In each case complete nutritive equilibrium was maintained, although -the author subsisted on three-seventeenths of the solid food taken by -the other subject. - -Again, cannot one infer that better assimilation and less waste -resulted from the better preparation of the smaller quantity of food -by insalivation? Surely, too, there must be less daily strain on the -intestinal canal, and body generally, in getting rid of 18.9 grammes -of inoffensive dry waste, than in getting rid of 204 grammes of humid, -decomposing, and offensive matter. - -“Considerable importance has been attached to the normal action of the -bacteria in the intestines; and it has even been supposed that the -presence of bacteria is essential to life. Such a view has recently -been shown to be erroneous by an elaborate and painstaking research -carried out by Nuttall and Thierfelder, who obtained ripe foetal -guinea-pigs by means of Caesarean section carried out under strict -antiseptic precautions. They introduced the animals immediately into an -aseptic chamber through which a current of filtered air was aspirated, -and fed them hourly on sterilised milk day and night for over eight -days. - -“The animals lived, and throve, and increased as much in weight as -healthy normal animals subjected to a similar diet for the purpose of -controlling the results. Microscopic examination at the end of the -experiment showed that the alimentary canal contained no bacteria of -any kind, nor could cultures of any kind be obtained from it. - -“The same authors, in a subsequent paper, described the extension of -their research to vegetable food. This was also digested in the absence -of bacteria. Under such conditions cellulose was not attacked. Hence -they consider that the chief function of this material is to give bulk -and proper consistency to the food so as to suit the conditions of -herbivorous digestion.” (Schäfer’s “Text-Book of Physiology,” vol i. p. -465.) - -Now, inasmuch as bacterial digestion has no place in the animal -economy, surely it can only occur at the expense of the organism? - -Can micro-organic action take place in the intestines without the -production of toxins and the consequent absorption of these toxins into -the blood? - -We know that the metabolism of a cell is determined by the general -physical environment of the whole organism, by supplies of oxygen and -water, on nervous impulses, and, what chiefly concerns this argument, -on the nature and amount of the pabulum supplied to it. This pabulum is -derived from the alimentary canal. - -Are not even those of us who may be enjoying seemingly the best of -health supplying to our tissues pabulum containing mild toxins, thus -causing an increased katabolic action to occur in each individual cell -of our bodies? - -Are not the blood elements, floating in a plasma containing such -toxins, rendered resistant, weaker, less capable of fulfilling their -functions as carriers and combatants of disease? - -Are not their and our lives, in consequence, more painful and shorter -than they need be? - -Would not the elimination of these toxins render us less liable -to disease? And is not their presence an important element in -predisposition to disease? - -When this reflex is restored micro-organisms get no further than the -stomach. They are destroyed there by the acid gastric juices, then -only stimulated to their full and normal secretion by the presence -of a sufficiency of alkaline substance. Undigested matter having -been eliminated, micro-organisms, still existing in the intestines, -deprived of their means of subsistence, decrease, and, in time, may -cease to exist. The body no longer absorbs the toxins these produced. -To this fact may be ascribed the increase of mental energy, the -general physical betterment, the cessation of morbid cravings for -food and drink and of those of a sexual nature, which are noticed and -experienced. - -What has just been stated is based not entirely on experimental -evidence but somewhat upon inference. The inference seems justified -because the excreta, more especially of the intestines, but also of the -kidneys and skin, become almost odourless and entirely inoffensive. -The solid egesta are voided thickly covered with mucus, leaving the -end of the bowel dry and clean. The sense of cleanliness can only -then be appreciated to the full, for it is internal as well external. -_Flatus_ is no longer produced. The urine is inoffensive and seems to -be materially changed in quality, as shown by chemical analysis. Uric -acid, the chlorides, and, more markedly, aromatic sulphates are reduced -in quantity. - -Owing to deliberation in eating, necessitated by this new habit, -satiety occurs on the ingestion of considerably less food. By carefully -studying one’s self I believe it possible to cultivate an instinct -which will regulate not only the quantity but the quality of food that -the body may need, and that in the _normal health_ of a full-grown -body, no more food either in quantity or quality should be supplied -than suffices to supply diurnal waste. Any excess must result in -pathological processes. - -Although there results enhanced pleasure in the taking of all foods, -rich and simple, and especially in the appreciation of good wines, the -quantities of these foods and beverages that suffice to fully satisfy -the appetite are much smaller than before, while there is a marked -preference for the simpler kinds of food. The writer now can imagine no -more pleasurable meal than one consisting of good brown bread, eggs, -butter, cheese, and cream. These, with fresh vegetables and a very -little fruit, form his staple diet. This tendency and preference for -simple foods is the general experience among those who have recovered -their reflexes of deglutition. - -Following on the ingestion of a lessened quantity of food and on its -better assimilation, there is less waste, the egesta are voided less -frequently, sometimes only once in five to eight days. - -The lower bowel is not the reservoir it formerly was. So hæmorrhoids -cease from troubling and constipation cannot exist. For this same -reason the body, at the beginning of the practice, commences to -approximate to its normal weight, increasing or decreasing as the -individual’s environment demands. - -A few more words only need be said. It has been easy to state the -results of experiments and observations: but the acquiring of this -new reflex, while pursuing daily occupations, is not easy, and needs -more than a little patience and much serious thought. The habits of a -lifetime cannot be changed in a few days or weeks. The shortest time in -which the reflex has been re-established is four weeks, and this only -by avoiding conversation at meal-time and concentrating the attention -on keeping the food in the mouth until complete alkaline reduction has -taken place and sapidity has disappeared. - -In closing I wish to maintain as a fact, gentlemen, of the truth of -which you will only be convinced by actual experience, that by the -restoration of this reflex and in complete dependence on its use, -there lies true health, the establishment of a condition of stable -nutrition and the possible abrogation of two great predisposing factors -of disease, mal-assimilation and mal-nutrition. Unless there be among -you, as in the “Cities of the Plain,” a parlous minority who possess -this reflex and take your food as you ought, none of you are in the -enjoyment of such health as you might have. A like punishment will be -meted out to you as was visited on those cities, for you will all be -consumed long before your day by the unnecessary combustion in your -bodies caused by the circulation in them of toxins, the product of -undigested and decomposing food. - -The writer, bearing in mind the warning suggested by the Frenchman -whose donkey died as soon as he had reduced his food to a single wisp -of straw, finds that he is taking less and less food. While his mind is -open as to his arriving at the final diet of Luigi Cornaro, yet it is -easily conceivable that living a similar life of retirement in a placid -environment, it would be quite possible to do as he did. Hence the -title of this paper and the queries at the commencement. - -The objects in publishing and distributing this paper are twofold: to -make the subject as widely known as possible, and to solicit the aid of -colleagues in investigating it more fully. - -There is ready at the service of the general practitioner an important -and potential therapeutic agent in the saliva of his patients and in -the use _ad finem_ of their salivary digestions. - -By any chance should readers of this paper wish to ask any questions, -the writer will be happy to communicate with them. - - 183, CALLE DEL CAPELLO NERO, - Piazza San Marco, - Venice, Italy. - -_Editor’s notes._ (1) Confirmatory evidence of the correctness of -the deductions made in this paper has begun to come in from many -professional sources and notably from a famous child specialist who -avers that children would follow the natural requirements in eating -were it not for artificial food, bad example, and bad teaching. - -(2) In a report of a paper read before the _Société de Biologie_, -Paris, France, March 15th, 1902, by M. Max Marckwald, of Kreuznach, “ON -DIGESTION OF MILK IN THE STOMACH OF FULL-GROWN DOGS,” the following -appears: “Hence these experiments confirm those of Horace Fletcher -and Ernest H. Van Someren on the importance of prolonged mastication” -(_translation_). Referring, as the latter statement does, to -mastication (insalivation) of liquid, it gives an important suggestion -relative to some probable causes of uncertain or defective digestion in -human nutrition. - - - - - THE CAMBRIDGE TESTS - - - [In connection with a report of the Cambridge Examination the writer - wishes to acknowledge the interest and assistance of Dr. Francis - Gowland Hopkins, head of the Physiological-Chemical Department of - the Physiological Laboratory of the University; Dr. George H. F. - Nuttall, in charge of the Bacteriological Section of the Pathological - Laboratory; Mr. Sidney W. Cole, Mr. Robert Barrett, and Dr. Hubert - Higgins, both for practical work in the laboratory and in serving as - test-subjects. To Dr. Higgins so much is due that it is difficult to - measure. Since our first meeting in Cambridge, Dr. Higgins has been - unremitting in his study of the subject and in consideration of its - application to human betterment. Having the altruistic temperament - inborn and not yet smothered by disappointment, the good doctor - has consecrated himself to the service of poorer humanity, and his - inspiration in so good a cause is wonderful motive power behind the - native desire to do good. The statement of Dr. Higgins' experiences in - pursuit of an Economic Nutrition is given in his own manner in the new - edition of _Glutton or Epicure_, which is being published coincidently - with this volume in the A. B. C. Life Series. - - At the time we were in Cambridge, Dr. Hopkins and Mr. Cole had just - published their paper in the _Journal of Physiology_ (English), - describing their isolation of the tryptophane element of the proteid - molecule which had eluded chemists from the beginning. In tryptophane - they found embodied the odourous indol and skatol which appear so - offensively in the putrid decomposition of proteid. In the excreta of - the test-subjects in our Economic-Nutrition-Inquiry these malodorous - substances did not appear, and hence another question is opened up - to investigation relative to the putridity of human excrement under - ordinary conditions of carelessness, and the absence of putridity in - the case of nutrition accomplished by aid of thorough buccal treatment - of food preparatory to digestion. - - It is a matter of interest, relative to the patience required in - science, to state that Dr. Hopkins and Mr. Cole were fourteen months - searching for the fugitive tryptophane element after they received - their first clew to its whereabouts. When isolated, tryptophane masses - in a substance having the appearance of silver, but not the solidity - of that metal.—HORACE FLETCHER.] - - - - - EXPERIMENTS UPON HUMAN NUTRITION - - NOTE BY SIR MICHAEL FOSTER, K.C.B., M.P., F.R.S. - - -In 1901 Dr. Ernest Van Someren submitted to the British Medical -Association, and afterwards to the Congress of Physiologists at Turin, -an account of some experiments initiated by Mr. Horace Fletcher. -These experiments went to show that the processes of bodily nutrition -are very profoundly affected by the preliminary treatment of the -food-stuffs in the mouth, and indicated that great advantages follow -from the adoption of certain methods in eating. The essentials of these -special methods, stated briefly and without regard to certain important -theoretical considerations discussed by Dr. Van Someren, consist of a -specially prolonged mastication which is necessarily associated with -an insalivation of the food-stuffs much more thorough than is obtained -with ordinary habits. - -The results brought to light by the preliminary experimental trials -went to show that such treatment of the food has a most important -effect upon the economy of the body, involving, in the first place, a -very notable reduction in the amount of food--and especially of proteid -food--necessary to maintain complete efficiency. - -In the second place this treatment produced, in the experience of its -originators, an increase in the subjective and objective well-being -of those who practise it, and, as they believe, in their power of -resistance to the inroads of disease. These secondary effects may -indeed be almost assumed as a corollary of the first mentioned; -because there can be little doubt that the ingestion of food--and -perhaps especially of proteid food--in excess of what is, under the -best conditions, sufficient for maintenance and activity, can only be -deleterious to the organism, clogging it with waste products which may -at times be of a directly toxic nature. - -In the autumn of 1901 Mr. Fletcher and Dr. Van Someren came to -Cambridge with the intention of having the matter more closely inquired -into, with the assistance of physiological experts. The matter evoked -considerable interest in Cambridge, and observations were made not only -upon those more immediately interested, but upon other individuals, -some of whom were themselves medical men and trained observers. - -Certain facts were established by these observations, which, however, -are to be looked upon as still of a preliminary nature. The adoption of -the habit of thorough insalivation of the food was found in a consensus -of opinion to have an immediate and very striking effect upon appetite, -making this more discriminating, and leading to the choice of a simple -dietary, and in particular reducing the craving for flesh food. The -appetite, too, is beyond all question fully satisfied with a dietary -considerably less in amount than with ordinary habits is demanded. - -Numerical data were obtained in several cases, but it is not proposed -to deal with these in detail here, as they need the supplementary study -which will be shortly referred to. - -In two individuals who pushed the method to its limits it was found -that complete bodily efficiency was maintained for some weeks upon a -dietary which had a total energy value of less than one-half of that -usually taken, and comprised little more than one-third of the proteid -consumed by the average man. - -It may be doubted if continued efficiency could be maintained with such -low values as these, and very prolonged observations would be necessary -to establish the facts. But all subjects of the experiments who -applied the principles intelligently agreed in finding a very marked -reduction in their needs, and experienced an increase in their sense of -well-being and an increase in their working powers. - -One fact, fully confirmed by the Cambridge observations, consists in -the effect of the special habits described upon the waste products of -the bowel. These are greatly reduced in amount, as might be expected; -but they are also markedly changed in character, becoming odourless and -inoffensive, and assuming a condition which suggests that the intestine -is in a healthier and more aseptic condition than is the case under -ordinary circumstances. - -Although the experiments hitherto made are, as already stated, only -preliminary in nature and limited in scope, they establish beyond all -question that a full and careful study of the matter is urgently called -for. - -For this fuller study the Cambridge laboratories do not possess at -present either the necessary equipment or the funds to provide it. For -the detailed study of the physical efficiency of a man under varying -conditions, elaborate and expensive apparatus is required; and the -advantages claimed for the special treatment of the food just discussed -can only be fully tested by prolonged and laborious experiments calling -for a considerable staff of workers. - -It is of great importance that the mind of the lay public should -be disabused of the idea that medical science is possessed of final -information concerning questions of nutrition. This is very far indeed -from being the case. Human nutrition involves highly complex factors, -and the scientific basis for our knowledge of the subject is but small; -where questions of diet are concerned, medical teaching, no less than -popular practice, is to a great extent based upon empiricism. - -But the scientific and social importance of the question is clearly -immense, and it is greatly to be desired that its study should be -encouraged. - - M. FOSTER. - - April 26th, 1902. - - - - - REPORT OF A PLAN FOR THE INSTITUTION OF AN INTERNATIONAL INQUIRY INTO - THE SUBJECT OF HUMAN NUTRITION - - - [Sir Michael Foster’s “Note” (preceding) and Professor Chittenden’s - article in the _Popular Science Monthly_ (following), which form a - part of this book, show a common want of exact knowledge relative to - human nutrition not at all creditable to human intelligence at the - beginning of the twentieth century; but they both offer hope of relief - from this discreditable stigma in systematic study of the question. - For this purpose an international inquiry was proposed, a plan was - drawn up under advice of Sir Michael Foster, and the matter was given - to the writer to promote by the best means available. - - The Carnegie Institution seemed, at the time, the most likely - supporter of such a scheme; but owing to an embarrassment of - applications for support of American science needs, it was considered - best not to attempt any foreign or even international benefaction, for - the present at least, and hence other means of furthering the inquiry - were sought. - - The invitation of Professor Chittenden to repeat the demonstration - of food-economy made by the author and Dr. Van Someren at Cambridge, - England, of which Sir Michael Foster’s “Note” treats, at the - laboratories of the Sheffield Scientific School of Yale University, - led to the discovery that New Haven already possessed an equipment - suitable for the inquiry much more complete than the plan Professor - Foster had outlined as being desirable. - - At Yale were found not only a very well-adapted chemico-physiological - laboratory with some of the most active and scientifically respected - research talent of the world in charge, but the laboratory stood only - three minutes away from one of the best furnished gymnasiums in the - world, under a director who is an M. D. of twenty years' experience, - as well as a famous athlete and author of an athletic manual. It so - happened that this gymnasium was especially suited for assisting in - a research into the very causes of human efficiency, or lack of it, - which nutrition is supposed to affect. - - Only forty minutes from New Haven by rail,--a distance not greater, - as measured by time separation, than from one side of London to the - other,--at Middletown, Conn., stood also the recently completed - calorimeter of Professors Atwater and Benedict ready for making a - calorimetric trial-balance measurement of metabolism attained and - chemically estimated in the tests at New Haven. - - After the Yale demonstration, of which Professor Chittenden’s article, - previously mentioned, treats, the author responded to an invitation - from Professor Atwater and submitted himself to a 32-hour confinement - in the calorimeter for confirmation of the results obtained at New - Haven. - - This experience in the calorimeter at Middletown was very significant - and instructive. The author was the first test-subject used in the - newly completed calorimeter. The oxygen-measuring attachment of Dr. - Benedict that completed the apparatus and gave a complete trial - balance of the metabolism of the subject under examination was as - yet untried, but it proved its integrity within the fraction of one - per cent and registered as accurately as necessary for all practical - purposes. So much for the machine; but it measured a result which is - of the greatest importance to the human race. The author had just - demonstrated the possibility of running the human machine on half the - heat, on one-third of the fuel, and with only one-tenth of the waste, - as represented by the waste, or ashes of digestion. Not only was this - done while in pursuit of the ordinary activity of present-day life, - but under stress of 'Varsity-Crew exercise, as reported by Professor - Chittenden and Dr. Anderson. Had this demonstration been made relative - to steam engines or electrical motors, the information would have been - revolutionary in establishing new values for things industrial and - commercial. - - Its significance relative to human profitable possibilities is even - more important than if related to steam or electrical power. The - possibility of economy in the human machine gives also a hope of - immunity from the common diseases which now afflict mankind. - - The trial of the calorimeter as a measuring machine and the trial - balance of the economic metabolism which the author had attained - by five years of careful attention to the natural requirements of - nutrition were epoch-making events coincidently related, and for them - the author here makes this distinguished claim--not on account of any - accomplishment of himself, but as a promise of great possibilities for - human betterment. - - Here follows a reproduction of the plan just referred to, with - _fac-simile_ of the signatures of the distinguished physiologists - who approved the plan and consented to serve as “Assessors.” To this - list should have been added the name of Professor Ozawa, professor of - physiology at the University of Tokio, Japan; but time and distance - did not permit gaining the required understanding and assent. - Professor Ozawa’s connection with the inquiry would make it not only - international but interhemispherical and interracial as well, and this - possibility of scientific coördination and coöperation is typical of - the harmonising wave that is fast enveloping the earth for the benefit - of mankind. - - I give a copy of the document entire, with estimates of cost, - etc., just as it was originally drawn and intended only as a trial - suggestion, to be modified by circumstances.—HORACE FLETCHER.] - - - - - PROPOSAL TO FOUND AN INTERNATIONAL LABORATORY OF RESEARCH FOR THE - STUDY OF NUTRITION IN ALL ITS ASPECTS - - -Notwithstanding the enormous development which the study of -Experimental Physiology has undergone during the last half-century, and -the constant multiplication of physiological laboratories fitted in -a manner which enables them to be used as places of research as well -as of instruction in the methods of physiological inquiry, it has -appeared to many physiologists that a great need remains to be supplied -by the establishment of an International Laboratory of Research, -devoted primarily, if not exclusively, to the investigation of problems -connected with the Nutrition of the Animal, and particularly of Human -Organisms,--studies particularly, and in the first instance, from the -point of view of the relation of the food consumed by the animal body -to its output of energy, either in the form of heat or mechanical work. - -The reason for establishing such a laboratory, available for the use -of investigations of all nations, is to be found in the fact that the -researches which are now called for, in order to place upon a firm -foundation our knowledge of food and its relations to the activity of -the organism, necessitates an assemblage of apparatus and machinery -so specialised and so costly that they are not to be found collected -together even in the best equipped of the physiological laboratories -of Europe or America, which all subserve in the first instance the -purposes of systematic instruction. Undoubtedly, unquestionably, -certain of the great and costly appliances of research are to be found -in particular laboratories, as, for instance, in those of Berlin, -Munich, Paris, and Turin, but there certainly exists no laboratory -in which the investigator can find assembled under one roof all -the specially fitted chemical, physical, and even bacteriological -appliances which he may need to employ in the investigation of the -Phenomena of Nutrition. - -A more precise conception of the nature of the proposed laboratory -may be formed if reference is made to certain groups of appliances -which such a laboratory should possess and be able to place at the -disposal of the scientific men coming to it for facilities which may be -denied them at home. It should possess a complete set of respiration -chambers of various types, and especially should be provided with the -“Atwater Respiration Apparatus;” the most perfect appliances for the -analyses of gases should be available; it should be provided with the -most perfect calorimeters of various types, both for the investigation -of the calorimetric value of the foods experimented on, and for the -determination of the heat produced by man or by the lower animals,--the -subjects of observation. The laboratory should possess, besides, the -most perfect appliances for the measurement of work done by man and -by animals (“ergostat,” “ergograph”), and a set of balances of the -highest perfection capable of weighing with accuracy very heavy loads. -These characteristic appliances of a laboratory specially designed for -placing our knowledge of Animal Nutrition on a thoroughly sound basis -must be superadded to the ordinary means for pursuing with success -researches in Pure Organic, Physiological, and Physical Chemistry, as -well as in Bacteriology. - - - OUTLINE OF THE PROPOSED SUBJECTS OF RESEARCH TO BE UNDERTAKEN IN THE - PROPOSED INTERNATIONAL LABORATORY - -1. To determine with greater precision than has yet been possible the -efficiency of the animal organism considered as a machine in which -potential energy of the organic constituents of food is converted -into mechanical work. The knowledge that we already possess has shown -that in the animal we have an engine infinitely more efficient as a -utiliser of the potential energy supplied to it than any appliance yet -constructed, or which we can, in the present state of physical science, -construct. A still more precise study of the actual efficiency of the -animal as a whole, as well as of certain of the vital organs which are -mainly concerned in mechanical work, and a more thorough investigation -of the processes whereby--for instance, in the muscles--the potential -energy of stored-up chemical compounds is, as appears certain, directly -converted into mechanical work, is not only desirable in the interest -of the ultimate object of the work of the Laboratory, but possesses a -high degree of theoretical interest, even from the point of view of -Pure Physics. To sum up: One of the first objects of the investigations -to be carried out in the projected Laboratory should be “the more -precise determination of the minimum transformation of energy which -corresponds to mean and accurately determined conditions of the animal -body, and of that of man in particular.” - -2. We are acquainted with the fact that the potential energy which -is utilised by the animal is supplied to it with the least wear and -tear to, or strain upon, its mechanism by non-nitrogenous organic -constituents of food which must belong to the groups of starches and -sugars or fats, but that the continued existence of the organism -demands, as an essential condition, the introduction of a certain -proportion of albuminous matter. In spite of numerous very fine -investigations on this subject, the yet more precise determination -of the minimum quantity of the albuminous constituents which are -absolutely necessary or desirable, under the most varying conditions, -is eminently desirable, especially in the light of recently recorded -facts, amongst which are those to be referred to under 3 (following):— - -3. Certain very noteworthy observations made by Messrs. Horace Fletcher -and Ernest H. Van Someren have shown that an excessively prolonged -mastication and insalivation of food leads to remarkable results in -respect to the diminution of the total quantity of food necessary to -keep the body in a state of health, and to, as is alleged, a remarkable -improvement in the digestive functions as well as of the general -health of the individual. It appears highly important thoroughly to -investigate the remarkable phenomena discovered by Messrs. Fletcher and -Van Someren, and to determine how far they may lead to a modification -of or improvement in the dietary of healthy individuals and of persons -in a state of disease. - -4. Indeed, it may truly be said that the average diet of man, that is -to say, the absolute and relative amount of certain food-stuffs on -which an average man should live, is at present, to a large extent, -determined in an empirical manner. It is most necessary that this -should be determined in an exact manner, since it is at least possible -that a more complete knowledge may reveal that the good results -thus obtained empirically are only reached by means of an excess of -one element being counterbalanced by excess of another element, and -thus open up a way to considerable economy. The changes needed for -variations from the average, to meet certain conditions, are also at -present, to a very large extent, determined empirically, and these also -most certainly ought to be determined in an absolutely exact manner. - -5. The researches of Pawlow on the conditions which influence the -activity of the secreting glands of the organs of digestion, upon the -relation of their activity to the nature of the food ingested, upon -the influence exerted by the secretion of the glands situated in one -part of the alimentary canal, upon the activity of glands situated -lower down, indicate lines of research only recently opened out, but -the importance of which in reference to the problems of nutrition is -probably great. - -6. Similarly, the facts which have in recent times been ascertained -in reference to the remarkable influence exerted by the so-called -“internal secretion” of certain ductless glands on the general -metabolism, the part played by the pancreas in reference to the -transformations of sugar in the body indicate yet other lines of -research to be carried out in connection with the main inquiry. - -In conclusion: The final problem of the work of the proposed Laboratory -will be to ascertain the conditions which will “render it possible to -obtain from the human machine, under varying conditions, the highest -efficiency at the least cost.” - -The value of results which may be thus obtained, considered from the -point of view of social, political, and administrative economy, is -hardly to be exaggerated. - - - SUGGESTIONS AS TO STAFF AND PERSONNEL OF THE PROPOSED INTERNATIONAL - LABORATORY - -For the coördination and general direction of the several -investigations, the services of an eminent physiological chemist -(preferably one having the principal European languages at his command) -is essential. - -Such a director would need at least two efficient permanent technical -assistants, as for instance, one to deal with the problems of Organic -Chemistry, and another competent to deal with the problems of Physical -Chemistry. Other assistants might be necessary, but it would probably -be desirable that the Institute should have the power of subsidising, -for a longer or shorter period, men who would undertake special -investigations in coördination with the general work, and who would -thus be, as it were, temporary assistants. This would be quite apart -from the general hospitality of the Laboratory offered by the Institute -to other investigators. - - - ESTIMATES FOR THE PROPOSED LABORATORY - - INITIAL OUTLAY - - Director $5,000 $5,000 - Permanent and Temporary Assistants 7,500 to 10,000 - Other General Maintenance 5,000 to 7,500 - ——————— —————— -— $17,500 $22,500 - -With regard to the second item, the permanent assistants would be -required at the outset, but the temporary assistants would be taken on -as opportunity offered. Less than even the lower estimate might suffice -at first. - -Regarding the third item, also, the maximum might not be required in -the beginning. - - - SUGGESTIONS AS TO DESIRABILITY OF LOCATION - -The place fitted for the establishment of an International Institute -should be one which can be reached with comparative facility by -investigators of the different nationalities. It must be one free -from the objections due to national susceptibilities. It should also -be, if possible, a place agreeable to live in; a place where work can -be carried on through the year; and a place where expenses, both the -personal expenses of the investigators, and the general expenses of -the Institute, are not excessive. Venice has been suggested as a place -fulfilling the above requirements. It can be reached readily from -all parts of Europe, and is as accessible to Americans as any other -European city. Living is very cheap, and, indeed, all expenses are very -moderate. - -On sea level itself, Venice is within near distance of very high -altitude, and hence offers facilities for the study of the effects -of climatic influence on nutrition. It is also sufficiently near the -Regina Margherita Laboratory, on Monte Rosa, to enable the observations -made at the two places to be coördinated. Venice is, moreover, a -cosmopolitan centre; and persons of many different nations and races -might readily be obtained as subjects for observation and experiment. - -On the other hand, it may be regarded as essential to the complete -success of the proposed Institute that both the director and those -engaged in investigation should have ample opportunities of ready and -frequent intercourse with eminent men engaged in investigation in -Physics, Chemistry, and the allied sciences. The help which is thus -gained by intercourse with men at the very head of various scientific -inquiry cannot be supplied in any other way. There is also an urgent -reason for ready access to a most thoroughly equipped scientific -library. It is also essential that the Institute should have facility -of obtaining, or of getting constructed, with the least possible delay -such apparatus as it might need. These essentials cannot be supplied -otherwhere than in great centres of scientific activity. A small -university cannot supply them. If they are insisted on, the Institute -must be located in a place which has metropolitan distinction and holds -not only a large but an active university. The choice of a situation, -from this point of view, in Europe, is thus almost limited to such -places as Paris, Berlin, Vienna, or London. Of these London probably -best recommends itself for international purposes. - -But, on the other hand, London is distinctly an expensive place to live -in. Indeed, all expenses there are great, and the same may be said of -any great metropolitan centre. Moreover, London cannot be reached from -the countries of Europe without sea transit. - -The choice between such a place as London and such a place as Venice -must depend upon the relative weight attached, on the one hand, to the -scientific advantages dwelt on above, and, on the other hand, to the -advantages other than scientific. - - - SUGGESTIONS AS TO MANAGEMENT OF THE PROPOSED INTERNATIONAL INSTITUTE - -It is proposed that: First, there should be a small body of trustees -who should undertake the financial responsibility; and, Second, a -board of scientific assessors, representing several nations, who, in -conjunction with the director, should exercise general supervision -of the work of the Institute. Such a board need meet only at rare -intervals, much being done by way of correspondence. The expenses which -the members incur in the exercise of their functions ought to be met -out of the funds of the Institute. - - -The following have expressed willingness to act as scientific -assessors:— - -[Illustration: Signatures] - - - - - NATIONALITY AND SCIENTIFIC TITLES OF OUR BOARD OF SCIENTIFIC ASSESSORS - - - SIR MICHAEL FOSTER, M.D., K.C.B., F.R.S., M.P., etc. Late Professor of - Physiology, University of Cambridge, England; Secretary of the Royal - Society; Permanent Honorary President of the International Congress of - Physiologists, etc. - - DR. PROFESSOR ANGELO MOSSO. Professor of Physiology, University of - Turin, Italy; Director of the Regina Margherita Biological Station on - the summit of Monte Rosa, etc. - - DR. PROFESSOR HUGO KRONECKER. Professor of Physiology, University of - Berne, Berne, Switzerland, etc. - - DR. PROFESSOR N. ZUNTZ. Professor of Physiology, Berlin, Germany, etc. - - DR. PROFESSOR PAUL HEGER. Professor of Physiology, Brussels, Belgium; - Director of the Solvay Sociological Institute, Brussels. - - DR. PROFESSOR A. DASTRE. Professor of Physiology, Universitie de la - Sorbonne, Paris, France, etc. - - DR. PROFESSOR HENRY PICKERING BOWDITCH, Professor of Physiology, - Harvard Medical School; Second President American Physiological - Society; President of the Children’s Aid Society, Boston, Mass., etc. - - PROFESSOR RUSSELL H. CHITTENDEN. Director Sheffield Scientific School - of Yale University; Professor of Physiological Chemistry in Yale; - Present President of the American Physiological Society, etc. - - DR. PROFESSOR WILLIAM H. WELCH. Professor of Pathology in Johns - Hopkins University, Baltimore, Maryland; President of the Rockefeller - Institute of Preventive Medicine, etc. - - DR. PROFESSOR J. P. PAWLOW. Director of the Department of Experimental - Physiology in the Russian Imperial Military School of Medicine, etc. - - - - - PERSISTENT SCIENTIFIC DOUBTS - - - [Notwithstanding the report of the Cambridge examination of the - claims for an economic nutrition advanced by the authors, American - physiologists were still doubtful if a nitrogenous economy like that - reported could be maintained, and the writer was invited to submit - to further tests at the Physiological Laboratory of Yale University, - under direction of Professor Russell H. Chittenden, Director of - the Sheffield Scientific School, and President of the American - Physiological Society, and Dr. Lafayette B. Mendel. - - The following article, first published in the _Popular Science - Monthly_, June, 1903, is a report of that test, and indicates a - desire to carry the investigation further to include a variety of - test-subjects. - - In response to Professor Chittenden’s request, the Trustees of the - Bache Fund of the National Academy of Sciences appropriated $1000 - towards a more extended inquiry; and other means having been assured, - a project of experiments was taken under consideration. - - One of the difficulties encountered was the control of test-subjects - for a sufficiently long time to make conclusive estimates relative - to the minimum needs of nitrogenous food in relation to the common - occupations of life. Few if any volunteers, with the leisure and - interest fortunately possessed by the writer, were available outside - the laboratory force itself, and there were serious objections to - using for test-subjects the same persons who did the chemical analyses - and estimated the results. - - In this dilemma the good fortune of a meeting with Surgeon-General - O’Reilly of the United States Army and with General Leonard Wood--the - former on his way to Madrid to attend a medical congress, and the - latter _en route_ to the Philippines to take command there--happened - to the writer on the S. S. _Commonwealth_, on a voyage to Italy in - April, 1903. - - Both these officers are medical men and research enthusiasts. They had - fought yellow fever together, in coöperation with martyr Dr. Major - Walter Reed, in Cuba, and the fame of their success was being talked - of as one of the great triumphs of pathologic, or hygienic, science at - the time of the meeting. - - There was ample time on the steamer to discuss a subject of such - mutual and general interest, and both officers had had, in service, - experiences that led them to believe that the results obtained by the - writer and his colleagues were the common possibilities of all persons - under right conditions of alimentation. - - General O’Reilly was of the opinion that the corps he commanded - could furnish intelligent and earnest test-subjects for nutrition - investigation, as it did in the yellow fever case. In the yellow fever - investigation privates and officers alike had volunteered to act as - test-subjects, even though their lives were at stake and many had - already been sacrificed. It is to their great honour, also, that they - refused to receive the bounty that was offered for test-subjects, - preferring to serve science and humanity freely as volunteers rather - than sell themselves as experimental risks. From such material General - O’Reilly was sure that capable assistants could be secured to test the - not at all dangerous or disagreeable economies of nutrition that the - projected inquiry wished to solve. - - Armed with letters of recommendation to the President and to - the Secretary of War from General Wood, and an invitation from - Surgeon-General O’Reilly to call on him if coöperation on his part - were desired, the writer returned to the United States and consulted - with Professors Chittenden and Bowditch relative to the desirability - of army coöperation. It was believed to be just the thing wanted to - facilitate the inquiry, and the writer proceeded to Washington to - effect the combination. - - General O’Reilly had already had the matter under consideration and - was quite ready to draw up a project for presentation to the Secretary - of War when Mr. Root should return to Washington from his summer - vacation. - - Twenty privates and three non-commissioned officers of the Hospital - Corps of the United States Army under command of Dr. Lieutenant - Wallace DeWitt are now quartered at New Haven in coöperation with - the staff of the Sheffield Scientific School. It is the intention - to learn, if possible, how little nitrogen is necessary to secure - the best human efficiency; and also, if possible, to ascertain some - measure of the evil effects of an excess of nitrogenous food as well - as excess of food in general upon human efficiency. - - The writer is grateful for the good fortune of being able to be of - service in a development of interest in a subject which is of vital - importance to the human race. He has enjoyed the benefits of an - economic nutrition and knows its value. - - The practical proof of a subject of personal application must come - from such personal application. Each person must be his own doctor and - his own scientist in the matter of his alimentation or he runs the - risk of running amuck in his health economy. There is not so much to - learn, neither is there very much to do to insure right alimentation, - perfect digestion, and continuous good health; but the little required - of us must be attended to with no lapses of attention.—HORACE - FLETCHER.] - - - - - PHYSIOLOGICAL ECONOMY IN NUTRITION - - BY RUSSELL H. CHITTENDEN - - _Director of the Sheffield Scientific School of Yale University_ - - -Among the many problems awaiting solution, none is of greater -importance for the welfare of the individual and of the race than -that which relates to the proper nutrition of the body. Man eats to -live and to gain strength for his daily work, and without sufficient -nutriment the machinery of the body cannot be run smoothly or with -proper efficiency. The taking of an excess of food, on the other hand, -is just as harmful as insufficient nourishment, involving, as it does, -not only wasteful expenditure but, what is even of greater moment, an -expenditure of energy on the part of the body, which may in the long -run prove disastrous. While it is the function of food to supply the -material from which the body can derive the necessary energy for its -varied activities, any excess of food over and above what is needed to -make good the loss incidental to life and daily activity is just so -much of an incubus, which is bound to detract from the smooth running -of the machinery and to diminish the fitness of the body for performing -its normal functions. - -A proper physiological condition begets a moral, mental, and physical -fitness which cannot be attained in any other way. Further, it must be -remembered that lack of a proper physiological condition of the body -is more broadly responsible for moral, social, mental, and physical -ills than any other factor that can be named. Poverty and vice on -ultimate analysis may often be traced to a perversion of nutrition. -A healthy state of the body is a necessary concomitant of mental and -moral vigour, as well as of physical strength. Abnormal methods of -living are often the accompaniment or forerunner of vicious tastes -that might never have been developed under more strictly physiological -conditions. Health, strength (mental and physical), and moral tone -alike depend upon the proper fulfilment of the laws of nature, and it -is the manifest duty of a people hoping for the fullest development -of physical, mental, and moral strength to ascertain the character of -these laws with a view to their proper observance. Poverty, crime, -physical ills, and a blunted or perverted moral sense are the penalties -we may be called upon to pay for the disobedience to Nature’s laws; -penalties which not only _we_ may have to pay, but which may be passed -down to succeeding generations, thereby influencing the lives of those -yet unborn. - -There is to-day great need for a thorough physiological study of those -laws of nutrition which constitute the foundation of good living. -It is a subject full of interest and promise for the sociologist -and economist, as well as for the physiologist. We need a far more -complete knowledge than we possess at present of the laws governing -nutrition; we need fuller knowledge of the methods by which the most -complete, satisfactory, and economical utilisation of the diet can be -obtained; we need to know more concerning the minimum diet and the -minimum amount of proteid or albuminous foods on which health, mental -and physical vigour can be permanently maintained; we need to know -more fully concerning the influence of various forms of food on growth -and recuperative power; we need more complete knowledge regarding the -rôle of various dietetic and digestive habits, fixed or acquired; the -effects of thorough mastication, insalivation, and the influence of -two versus three meals a day upon the utilisation of food and hence -upon the bodily health. Further, we need more concise information as -to the effect of the mental state upon digestion and nutrition. These -and many other problems of a like nature confront us when we attempt -to trace the influence of a proper nutrition upon the condition of the -body. These problems, however, all admit of solution, and in their -solution undoubtedly lies the remedy for many of the personal ills of -mankind. - -The foregoing thoughts have been suggested by observations recently -made in the writer’s laboratory on the amount and character of the -food actually required by a healthy man in the maintenance of bodily -equilibrium in periods of rest and physical work. Our ideas at present -are based primarily upon observations as to what civilised peoples are -accustomed to do, and not upon what they need to do in order to meet -the demands made upon the body. Sir William Roberts has well said that -the palate is the dietetic conscience, but he adds that there are many -misfit palates, and we may well query whether our dietetic consciences -have not become generally perverted through a false mode of living. The -well-nigh universal habit of catering to our appetite on all occasions, -of bowing to the fancied dictates of our palates even to the extent of -satiety, and without regard to the physiological needs of the body, -may quite naturally have resulted in a false standard of living, in -which we have departed widely from the proper laws of nutrition. -Statistical studies carried out on large groups of individuals by -various physiologists have led to the general acceptance of dietary -standards, such as those proposed by Voit, of Munich, and Atwater in -this country. Thus the Voit diet for a man doing moderate work is 118 -grams of proteid or albuminous food, 56 grams of fat, and 500 grams -of carbohydrates, such as sugar and starch, with a total fuel value -of 3,055 large calories or heat units per day. With hard work, Voit -increases the daily requirement to 145 grams of proteid, 160 grams of -fat, and 450 grams of carbohydrates, with a total fuel value of 3,370 -large calories. Atwater, on the other hand, from his large number of -observations, is inclined to place the daily proteid requirement at -125 grams, with sufficient fat and carbohydrate to equal a total fuel -value of 3,500 large calories for a man doing a moderate amount of -work; while for a man at hard work the daily diet is increased to 150 -grams of proteid, and with fats and carbohydrates to yield a total -fuel value of 4,500 large calories. These standards are very generally -accepted as being the requirement for the average individual under the -given conditions of work, and it may be that these figures actually -represent the daily needs of the body. Suppose, on the other hand, that -we have in these figures false standards, or, in other words, that the -quantities of food-stuffs called for are altogether larger than the -actual demands of the body require. In this case there is a positive -waste of valuable food material which we may calculate in dollars -and cents; a loss of income incurred daily which might be expended -more profitably in other directions. To the wage-earner with a large -family, who must of necessity husband his resources, there is in our -hypothesis a suggestion of material gain not to be disregarded. The -money thus saved might be expended for the education of the children, -for the purchase of household treasures tending to elevate the moral -and mental state of the occupants, or in many other ways that the -imagination can easily supply. This kind of saving, however, is purely -a question of economy, and in some strata of society would be objected -to as indicative of a condition of sordidness. It has come to be a -part of our personal pride to have a well-supplied table, and to eat -largely and freely of the good things provided. The poorer man takes -pride in furnishing his family with a diet rich in expensive articles -of food, and imagines that by so doing he is inciting them to heartier -consumption and to increased health and strength. He would be ashamed -to save in this way, under the honest belief that by so doing he -might endanger the health of his dear ones. But let us suppose that -this hypothetical waste of food is not merely uneconomical, that it is -undesirable for other and weightier reasons. Indeed, let us suppose -that this unnecessary consumption of food is distinctly harmful to the -body, that it is physiologically uneconomical, and that in our efforts -to maintain a high degree of efficiency we are in reality putting upon -the machinery of the body a heavy and entirely uncalled-for strain, -which is bound to prove more or less detrimental. If there is truth in -this assumption, our hypothesis takes on a deeper significance, and we -may well inquire whether there are any reasonable grounds for doubting -the accuracy of our present dietary standards. - -In this connection it is to be remembered that the food of mankind may -be classified under three heads, viz., _proteid or albuminous_, such -as meat, eggs, casein of milk, gluten of bread, and various vegetable -proteids; _carbohydrates_, as sugar and the starches of our cereals, -and _fats_, including those of both animal and vegetable origin. The -proteids are characterised by containing nitrogen (about 16 per cent), -while the fats and carbohydrates contain only carbon, hydrogen, and -oxygen. The two latter classes of food-stuffs are burned up in the -body, when completely utilised, to carbonic acid (a gas) and water, -while the proteid foods, beside yielding carbonic acid and water, -give off practically all of their nitrogen in the form of crystalline -nitrogenous products in the excreta of the body. Proteid foods have a -particular function to perform, viz., to supply the waste of proteid -matter from the active tissues of the body, and this function can be -performed only by the proteid foods; hence the latter are essential -food-stuffs without which the body cannot long survive. Fats and -carbohydrates, on the other hand, are mainly of value for the energy -they yield on oxidation, and in this connection it is to be remembered -that the fuel value of fats per gram is much larger than that of -carbohydrates, viz., 9.3: 4.1, or more than twice as great. Further, -it is to be noted that the various food-stuffs cannot be utilised -directly by the body, but they must first be digested, then absorbed -and assimilated, after which they gradually, in their changed form, -undergo decomposition with liberation of their contained energy, which -may manifest itself in the form of heat or of mechanical work. The -thoroughness with which foods are digested and utilised in the body -must therefore count for a great deal in determining their dietetic or -nutritive value. Moreover, it is easy to see how an excess of proteid -food will give rise to a large proportion of nitrogenous waste matter, -which, floating through the system prior to excretion, may, by acting -on the nervous system and other parts of the body, produce disagreeable -results. A mere excess of food, even of the non-nitrogenous variety, -must entail a large amount of unnecessary work, thereby using up -a proportional amount of energy for its own disposal, since once -introduced into the body it must be digested and absorbed, otherwise it -undergoes fermentation and putrefaction in the stomach and intestines, -causing countless troubles. When absorbed in quantities beyond the real -needs of the body, it may be temporarily deposited as fat; but why -load up the system with unnecessary material, thereby interfering with -the free running of the machinery? In other words, it is very evident -that the taking in of food in quantities beyond the physiological -requirements is undesirable, and may prove exceedingly injurious. It -is truly uneconomical, and defeats the very ends we aim to attain. -Instead of adding to the bodily vigour and increasing the fitness of -the organism to do its daily work, we are really hampering the delicate -mechanism, upon the smooth running of which so much depends. - -Why, now, should we assume that a daily diet of over 100 grams of -proteid, with fats and carbohydrates sufficient to make up a fuel -value of over 3,000 large calories, is a necessary requisite for -bodily vigour and physical and mental fitness? Mainly because of the -supposition that true dietary standards may be learned by observing -the relative amounts of nutrients actually consumed by a large number -of individuals so situated that the choice of food is unrestricted. -But this does not constitute very sound evidence. It certainly is not -above criticism. We may well ask ourselves whether man has yet learned -wisdom with regard to himself, and whether his instincts or appetites -are to be entirely trusted as safe guides to follow in the matter -of his own nutrition. The experiments of Kumagawa, Sivén, and other -physiologists, have certainly shown that men may live and thrive, for -a time at least, on amounts of proteid per day equal to only one-half -and one-quarter the amount called for in the Voit standard. Sivén’s -experiments, in particular, certainly indicate that the human organism -can maintain itself in nitrogenous equilibrium with far smaller amounts -of proteid in the diet than is ordinarily taught, and, further, that -this condition can be attained without unduly increasing the total -calories of the food intake. Such investigations, however, have always -called forth critical comment from writers on nutrition, indicating -a reluctance to depart from the current doctrines of the Voit or -Munich school; and, indeed, it may justly be claimed that the ordinary -nutrition experiments, extending over short periods of time, are not -entirely adequate to prove the effect of a given set of conditions when -the latter are continued for months or years. Thus, Schäfer writes: -“It may be doubted whether a diet which includes considerably less -proteid than 100 grams for the twenty-four hours could maintain a man -of average size and weight for an indefinite time. It has frequently -been asserted that many Asiatics consume a very much smaller proportion -of proteid than is the case with Europeans. The inhabitants of India, -Japan, and China chiefly consume rice as the normal constituent of -their diet, which contains relatively little proteid; and this has -been advanced as an argument in favour of the view that the minimal -amount of proteid is much less than that ordinarily given as essential -to the maintenance of nutritive equilibrium. It must, however, be -stated that we have no definite statistics to show that, in proportion -to their body-weight, Asiatics doing the same amount of work as -Europeans require a less amount of proteids; indeed such evidence as is -forthcoming is rather in favor of the opposite view.” This statement is -typical of the attitude of physiologists in general on this important -subject. Why not candidly admit that the matter is in doubt, and, -with a due recognition of the importance of the subject, attempt to -ascertain the real truth of the matter? - -The writer has had in his laboratory for several months past a -gentleman (H. F.) who has for some five years, in pursuit of a study -of the subject of human nutrition, practised a certain degree of -abstinence in the taking of food and attained important economy with, -as he believes, great gain in bodily and mental vigour, and with marked -improvement in his general health. Under his new method of living he -finds himself possessed of a peculiar fitness for work of all kinds, -and with freedom from the ordinary fatigue incidental to extra physical -exertion. In using the word abstinence possibly a wrong impression -is given, for the habits of life now followed have resulted in the -disappearance of the ordinary craving for food. In other words, the -gentleman in question fully satisfies his appetite, but no longer -desires the amount of food consumed by most individuals. - -For a period of thirteen days, in January, he was under observation in -the writer’s laboratory, his excretions being analysed daily with a -view to ascertaining the exact amount of proteid consumed. The results -showed that the average daily amount of proteid metabolised was 41.25 -grams, the body-weight (165 pounds) remaining practically constant. -Especially noteworthy, also, was the very complete utilisation of the -proteid food during this period of observation. It will be observed -here that the daily amount of proteid food taken was less than one half -that of the minimum Voit standard, and it should also be mentioned that -this apparent deficiency in proteid food was not made good by any large -consumption of fats or carbohydrates. Further, there was no restriction -in diet. On the contrary, there was perfect freedom of choice, and the -instructions given were to follow his usual dietetic habits. Analysis -of the excretions showed an output of nitrogen equal to the breaking -down of 41.25 grams of proteid per day as an average, the extremes -being 33.06 grams and 47.05 grams of proteid. - -In February a more thorough series of observations was made, involving -a careful analysis of the daily diet, together with analysis of -the excreta, so that not alone the proteid consumption might be -ascertained, but likewise the total intake of fats and carbohydrates. -The diet consumed was quite simple, and consisted merely of a prepared -cereal food, milk, and maple sugar. This diet was taken twice a day -for seven days, and was selected by the subject as giving sufficient -variety for his needs and quite in accord with his taste. No attempt -was made to conform to any given standard of quantity, but the subject -took each day such amounts of the above foods as his appetite craved. -Each portion taken, however, was carefully weighed in the laboratory, -the chemical composition of the food determined, and the fuel value -calculated by the usual methods. - -The following table gives the daily intake of proteids, fats, and -carbohydrates for six days, together with the calculated fuel value, -and also the nitrogen intake, together with the nitrogen output through -the excreta. Many other data were obtained showing diminished excretion -of uric acid, ethereal sulphates, phosphoric acid, etc., but they need -not be discussed here. - - ═════════╤════════════════════════════════════════╤═══════════════════ - │ Intake │ Output of Nitrogen - ├————————┬————-┬——————-┬————————┬————————┼—————┼——————-┼————— - │Proteids│Fats │Carbohy│Calories│Nitrogen│Urine│ Fæces │Total - ————————-┼————————┼—————┼——————-┼————————┼————————┼————-┼——————-┼————- - │ Grams │Grams│ Grams │ │ Grams │Grams│ Grams │Grams - Feb. 2 │ 31.3 │25.3 │ 125.4 │ 900 │ 5.02 │5.27 │0.18 │5.45 - 3 │ 46.8 │40.4 │ 266.2 │ 1690 │ 7.50 │6.24 │0.81* │7.05 - 4 │ 48.0 │38.1 │ 283.0 │ 1747 │ 7.70 │5.53 │0.81* │6.34 - 5 │ 50.0 │40.6 │ 269.0 │ 1711 │ 8.00 │6.44 │0.81* │7.25 - 6 │ 47.0 │41.5 │ 267.0 │ 1737 │ 7.49 │6.83 │0.81* │7.64 - 7 │ 46.5 │39.8 │ 307.3 │ 1852 │ 7.44 │7.50 │0.17 │7.67 - ————————-┼————————┼—————┼——————-┼————————┼————————┼————-┼——————-┼————— - Daily Av.│ 44.9 │38.0 │ 253.0 │ 1606 │ 7.19 │6.30 │0.60 │6.90 - ═════════╧════════╧═════╧═══════╧════════╧════════╧═════╧═══════╧═════ - *Average of the four days. - -The main things to be noted in these results are, first, that the -total daily consumption of proteid amounted on an average to only 45 -grams, and that the fat and carbohydrate were taken in quantities -only sufficient to bring the total fuel value of the daily food up to -a little more than 1,600 large calories. If, however, we eliminate -the first day, when for some reason the subject took an unusually -small amount of food, these figures are increased somewhat, but they -are ridiculously low compared with the ordinarily accepted dietary -standards. When we recall that the Voit standard demands at least 118 -grams of proteid and a total fuel value of 3,000 large calories daily, -we appreciate at once the full significance of the above figures. But -it may be asked, was this diet at all adequate for the needs of the -body--sufficient for a man weighing 165 pounds? In reply, it may be -said that the appetite was satisfied, and that the subject had full -freedom to take more food if he so desired. To give a physiological -answer, it may be said that the body-weight remained practically -constant throughout the seven days' period, and further, it will be -observed by comparing the figures of the table that the nitrogen of -the intake and the total nitrogen of the output were not far apart. -In other words, there was a close approach to what the physiologist -calls nitrogenous equilibrium. In fact, it will be noted that on -several days the nitrogen output was slightly less than the nitrogen -taken in. We are, therefore, apparently justified in saying that the -above diet, simple though it was in variety, and in quantity far below -the usually accepted requirement, was quite adequate for the needs -of the body. In this connection it may be asked, what were the needs -of the body during this seven days' period? This is obviously a very -important point. Can a man on such a diet, even though it suffices to -keep up body-weight and apparently also physiological equilibrium, -do work to any extent? Will there be under such condition a proper -degree of fitness for physical work of any kind? In order to ascertain -this point, the subject was invited to do physical work at the Yale -University Gymnasium, and placed under the guidance of the director of -the gymnasium, Dr. William G. Anderson. The results of the observations -there made are here given, taken verbatim from Dr. Anderson’s report to -the writer. - - On the 4th, 5th, 6th, and 7th of February, 1903, I gave to Mr. Horace - Fletcher the same kind of exercises we give to the Varsity Crew. They - are drastic and fatiguing and cannot be done by beginners without - soreness and pain resulting. The exercises he was asked to take were - of a character to tax the heart and lungs, as well as to try the - muscles of the limbs and trunk. I should not give these exercises to - Freshmen on account of their severity. - - Mr. Fletcher has taken these movements with an ease that is unlooked - for. He gives evidence of no soreness or lameness, and the large - groups of muscles respond the second day without evidence of being - poisoned by Carbon dioxide. There is no evidence of distress after or - during the endurance test, _i. e._, the long run. The heart is fast - but regular. It comes back to its normal beat quicker than does the - heart of other men of his weight and age. - - The case is unusual, and I am surprised that Mr. Fletcher can do - the work of trained athletes and not give marked evidences of - over-exertion. As I am in almost constant training I have gone over - the same exercises, and in about the same way, and have given the - results for a standard of comparison. [The figures are not given here.] - - My conclusion, given in condensed form, is this: Mr. Fletcher performs - this work with greater ease and with fewer noticeable bad results than - any man of his age and condition I have ever worked with. - -To appreciate the full significance of this report, it must be -remembered that Mr. Fletcher had for several months past taken -practically no exercise other than that involved in daily walks about -town. - -In view of the strenuous work imposed during the above four days, it is -quite evident that the body had need of a certain amount of nutritive -material. Yet the work was done without apparently drawing upon any -reserve the body may have possessed. The diet, small though it was, and -with only half the accepted requirement in fuel value, still sufficed -to furnish the requisite energy. The work was accomplished with perfect -ease, without strain, without the usual resultant lameness, without -taxing the heart or lungs, and without loss of body-weight. In other -words, in Mr. Fletcher’s case at least, the body machinery was kept in -perfect fitness without the consumption of any such quantities of fuel -as has generally been considered necessary. - -Just here it may be instructive to observe that the food consumed -by Mr. Fletcher during this seven days' period--and which has been -shown to be entirely adequate for his bodily needs during strenuous -activity--cost eleven cents daily, thus making the total cost for -the seven days seventy-seven cents! If we contrast this figure with -the amounts generally paid for average nourishment for a like period -of time, there is certainly food for serious thought. Mr. Fletcher -avers that he has followed his present plan of living for nearly five -years; he usually takes two meals a day; has been led to a strong -liking for sugar and carbohydrates in general and away from a meat -diet; is always in perfect health, and is constantly in a condition of -fitness for work. He practises thorough mastication, with more complete -insalivation of the food (liquid as well as solid) than is usual, -thereby insuring more complete and ready digestion and a more thorough -utilisation of the nutritive portions of the food. - -In view of these results, are we not justified in asking ourselves -whether we have yet attained a clear comprehension of the real -requirements of the body in the matter of daily nutriment? Whether we -fully comprehend the best and most economical method of maintaining the -body in a state of physiological fitness? The case of Mr. Fletcher, -just described; the results noted in connection with certain Asiatic -peoples; the fruitarians and _nut_arians in our own country recently -studied by Professor Jaffa, of the University of California; all -suggest the possibility of much greater physiological economy than we -as a race are wont to practise. If these are merely exceptional cases, -we need to know it; but if, on the other hand, it is possible for -mankind in general to maintain proper nutritive conditions on dietary -standards far below those now accepted as necessary, it is time for us -to ascertain that fact. For, if our standards are now unnecessarily -high, then surely we are not only practising an uneconomical method -of sustaining life, but we are subjecting ourselves to conditions the -reverse of physiological, and which must of necessity be inimical to -our well-being. The possibility of more scientific knowledge of the -natural requirements of a healthy nutrition is made brighter by the -fact that the economic results noted in connection with our metabolism -examination of Mr. Fletcher is confirmatory of similar results -obtained under the direction and scrutiny of Sir Michael Foster at the -University of Cambridge, England, during the autumn and winter of last -year; and by Dr. Ernest Van Someren, Mr. Fletcher’s _collaborateur_, -in Venice, on subjects of various ages and of both sexes, some account -of which has already been presented to the British Medical Association -and to the International Congress of Physiologists at its last meeting -at Turin, Italy. At the same time emphasis must be laid upon the fact -that no definite and positive conclusions can be arrived at, except as -the result of careful experiments and observations on many individuals -covering long periods of time. This, however, the writer hopes to do -in the very near future, with the coöperation of a corps of interested -observers. - -The problem is far-reaching. It involves not alone the individual, but -society as a whole, for beyond the individual lies the broader field -of the community, and what proves helpful for the one will eventually -react for the betterment of society, and for the improvement of mankind -in general. - - - - - INTRODUCTION TO DR. HARRY CAMPBELL’S CONTRIBUTION ON THE IMPORTANCE - - OF MASTICATION - - - [Since the publication of Van Someren’s paper, “Was Luigi Cornaro - Right?”, read before the British Medical Association, and reprinted - elsewhere in this volume, much more attention has been given to - the study of mastication than had been previously reported. Mr. - Gladstone’s advice to his children, which was commonly current and was - repeated whenever mastication was mentioned, was usually accompanied - and met by an amused smile that showed that the full importance of - better mouth-treatment of food was not appreciated. _Glutton or - Epicure_, a little book by the present writer, published in 1898, - insisted on thorough use of the functions of the mouth in alimentation - but did not go into the anatomical, physiological and dental details. - - Dr. Harry Campbell of Northwest London Hospital has performed this - latter service to science and humanity, with splendid carefulness, and - must have devoted much time and study to the collection of evidence - and suggestion which is given here following in full, reprinted from - the _London Lancet_. - - The authors acknowledge with much gratitude, the courteous permission - of both Dr. Campbell and of the editor of the _Lancet_, to reprint all - four articles which composed the series. - - In our own study of the subject of mouth-treatment of food we have - been led to give more credit to the chemical feature of preparation - than Dr. Campbell yet attributes to the chemical side of the problem. - Comminution of hard food is of first importance, undoubtedly, but - insalivation and neutralisation or alkalinisation are, seemingly, - much more easily and quickly accomplished in the mouth than farther - on in the alimentary canal. The intestines _can_ do all in the way - of digestion, even if the mouth and stomach are passed and their - assistance in the digestive process is entirely neglected, but it is - done at tremendous disadvantage in the supplementary digestive tract - of the intestines. We have proven the economy of letting the mouth - do _all it can_, by the insalivation (sipping and tasting) of liquids - that have taste up to the point of compulsory swallowing (a sucking-up - by the Swallowing Impulse which naturally occurs in the course of - treatment in the mouth if not fought against too strongly). If Dr. - Campbell will extend his observations to liquids, say milk, and for - a sufficiently long time to measure results by continued economy of - assimilation and saving of solid excreta, he will find that it pays - to let the mouth do all it can do, and that while it _cannot do too - much_ it _may do too little_. The natural instincts of the mouth, or - those that attach to the mouth, become much more discriminating also - if exercised on liquids as well as on solids. This they do not learn - to do so well if sapid liquids are habitually rushed past their field - of discrimination. - - Taste enjoyed in the mouth is good, and a good part of the pleasure of - living comes from taste gratification, but taste that returns from the - stomach and is belched by eructation or is lingeringly reminiscent in - the mouth or nose is indicative of indigestion. - - Hence it is better to dissipate taste in the mouth, which is the sole - region of taste. Spirits tasted into absorption in this way leave - no odour upon the breath, and asparagus munched and tasted to the - limit in the mouth, carries no odour to the urine. Even the stale and - disagreeable odour of onion or garlic can be neutralised by saliva and - killed in the mouth. - - It is extremely difficult to get observers to practise tasting taste - out of liquids as the wine tasters do, and as the tea tasters _have to - do or die_; or, at least, become useless in their profession. Once the - efficacy of the liquid-tasting precaution in digestion is understood, - however, to swallow anything but pure water without tasting it into - absorption produces a shock. This care becomes instinctive quite - easily and regulates itself automatically. It is also a distinct gain - to the gustatory possibilities, which are very limited at best. - - When the body will tolerate spirits tasted into it--not poured into - it--at all, which is not often when the nutrition is normal (only in - damp or cold weather, as a general thing, and then in the case of - the writer only at rare intervals, say two or three times a year), - the spirit will mix quickly with the saliva and become neutralised - sufficiently to excite the Swallowing Impulse. Continue sipping the - spirit for a time and you will note that there comes a point where the - saliva and the spirit do not mix, do not neutralise; the mouth becomes - unduly full of liquid without any relaxation or invitation of the - Swallowing Impulse; and the really instinctive inclination will be to - _spit it out_. It is a clear indication that the body-_toleration_ has - been fully taxed; there is no longer any bodily need for alcohol--in - fact, there is no longer natural toleration--and the secretion sent - down into the mouth is evidently mucous for a washing-out process, and - is not alkaline saliva for assisting in a utilisation function. - - It is quite uncanny to observe the nicety of mouth-discrimination and - the consistency of it as related to similar substances under similar - conditions, if one learn to read it with precision and intelligence. - - With increased ease of digestion, which comes with more thorough - attention to solid foods alone, the ordinary observer will think - that he has accomplished the whole of the possible benefit. It is - only when he gives sufficient time to liquids also, to get the added - delight and relief that salivary respect of them brings, that the - whole of the beneficence of mouth-service is realised. Follow this - discrimination and care to a comparative measurement of the waste of - digestion, the solid excreta, and note the increased proportionate - gain in assimilation and the value of the economy will be appreciated. - Try the different treatments on milk for a month; fifteen days with - drinking and fifteen days insalivating (sipping and tasting) the milk - to the limit, and keep account of quantity of intake required to - satisfy appetite and maintain body-weight; and also note carefully the - condition and quantity of the fæces. In the one case you will find - the waste to be _fæces_ indeed, and unmistakably worthy of the name; - but in the case of sipping, tasting and insalivating the milk to the - full satisfaction of the appetite, the _digestion-ash_ will assume - quite a different amount and character and deserve a change of name. - The proportions of the saving in our own experiments have approximated - the difference between three and ten; that is, on a reduction of only - one-third the quantity of food commonly ingested, but fully satisfying - the sipping and tasting appetite, the quantity of solid excreta was - only one-tenth of the other and of quite a different character, - æsthetically considered. - - While these suggestions do not discredit or affect the value of the - purely mechanical side of the treatment as given by Dr. Campbell, - and are not intended to be controversial, they are ventured as an - amendment to be worked out in regard to liquids, which are, in fact, - only an extreme of the pultaceous foods against which Dr. Campbell - warns us as being subtly dangerous. - - There is another point in our experiences and observations of the - largest importance that may appropriately be introduced here: The - treatment of all liquids in the manner suggested prevents intemperance - of drinking as effectively as it does intemperance of eating. - - When food is filtered into the body after having become liquified - and made alkaline, or, at least neutral, by saliva, the appetite is - given a chance to measure the needs of the body and to discriminate - against excess. As soon as the point of complete saturation of any one - deficiency is reached, the appetite is cut off, as short as possible - to imagine, with no indication of stomach fullness. It will welcome - a little of proteid in beans, cheese, eggs, or in some other of its - richer forms, and then turn to sugar or fat in some of their numerous - forms. Thirst for water will assert itself for a moment, sometimes - asking but for a drop and again for a full glass, and afterwards, when - near the point of complete saturation, appetite will hesitate for a - moment, as if searching around for some rare substance, and may find - its final satisfaction in a single spoonful of a sweet or a sip of - something in sight. - - The appetite satisfied by the infiltering process is a sweetly - appeased appetite, calm, rested, contented, normal. There is no danger - from the flooding of intemperance, for there is not even toleration - of excess either of more food or of more drink, and this contented - appetite will remain in the condition of contentment until another - need has really been earned by evaporation or destructive katabolism. - - In the teaching of this physiology and psychology of alimentation to - the children of England, lies the only true solution of the drink - question, which is now the curse of the nation. - - Dr. Campbell has made such a splendid case for the mechanical side - of mouth work, that it is the hope of the writer that he will give - equally careful consideration to the chemical and psychological - sides, and in a completeness of observation render inestimable service - to his country, to science, and humanity. A decade of trial on the - inmates of an infant orphan asylum will show the possibilities for the - nation in a single generation, if broadly applied. It might lead to - an effective intemperance, inhibition, or quarantine, and that is all - any nation needs of advantage to make it independent of the world and - truly great.—HORACE FLETCHER.] - - - - - OBSERVATIONS ON MASTICATION - - BY HARRY CAMPBELL, M.D., F.R.C.P. (Lond.) - - _Physician to the Northwest London Hospital_ - - [London _Lancet_, July 11, 18, 25, and August 8, 1903] - - - SECTION I. From _London Lancet_, July 11, 1903 - - THE EFFECTS OF MASTICATION - -The primary object of mastication is to break up the food so as (1) -to facilitate the swallowing of it, and (2), still more important, -to insure its intimate admixture with the digestive juices, not -only within the mouth, but throughout the entire digestive tract. -Mastication has, however, other important and far-reaching effects. -Thus it promotes the flow of saliva and, when properly performed, -secures a due insalivation of the food; it increases the quantity of -alkaline saliva passing into the stomach; it stimulates the heart and -circulation; and it finally influences the nutrition of the jaws and -their appendages by stimulating the local blood and lymph circulation. -Now to consider these various objects and effects of mastication. - -_Mastication facilitates swallowing._--Many foods cannot be swallowed -without first going through some preparation in the mouth. Soft, moist, -pultaceous foods, such as milk pudding and porridge, can be and often, -indeed, are swallowed with little or no preliminary chewing. On the -other hand, it is a mechanical impossibility to swallow large lumps -of tough food, or very dry food, even though, like flour, it be in a -finely divided state. Dry food needs first to be well moistened; and -it is not surprising that it promotes a more abundant flow of saliva -than moist food, though the secretion thus excited may be poor in -ferment. Hence it follows that if we desire to give foods which compel -mastication, they should be tough or dry. On the whole, vegetable foods -necessitate more thorough mastication than animal. The carnivora can -scarcely be said to masticate at all the flesh which they consume; they -simply tear off portions, and forthwith swallow them whole. Cooked -flesh, however, does require mastication, owing to the coagulation of -its proteids. The herbivora, on the other hand, unlike the carnivora, -have to subject their food to considerable mastication before it can be -swallowed; but they generally masticate it far more than is needful to -render swallowing mechanically possible, as is exemplified in the act -of rumination, the object here being to facilitate the admixture of the -digestive juices with the food. - -According to Van Someren, if the habit of masticating efficiently -is once acquired, the food is not swallowed before it is converted -into the liquid state, the swallowing of unmasticated lumps being -effectually prevented by a pharyngeal reflex. - -_Mastication, by breaking the food up into small particles, enables it -to be brought into intimate contact with the digestive juices._--Such -comminution is especially needful in the case of raw vegetable foods -of the tougher kind, in order to break up their cellulose framework, -and to set free the contained starch, proteids, and fats. Foods of -this kind, unless masticated, yield practically no nutriment to the -organism. I cannot too strongly emphasise the fact that before man -learned to break up the cellulose framework of his vegetable food by -cooking he was compelled to subject it to laborious mastication. But, -while thorough comminution is especially needed for vegetable food -when raw, it is also needed for many cooked forms of it also,--as, for -example, solid batter pudding and new underbaked bread, heavy lumps -of which, passing into the stomach, may seriously hamper the work of -that organ. Such substances are indigestible essentially by virtue -of their impermeability to the digestive juices, and they gain in -digestibility in proportion as they are comminuted. The indigestibility -of new bread would appear to be wholly due, not to any peculiarity -of chemical composition, but to its tendency to elude the teeth and -form a sodden mass impermeable to the digestive juices, while the more -powdery stale bread is more easily broken up both in the mouth and -within the stomach. Cabbage, again, owes its indigestibility to the -fact that it is allowed to pass into the stomach in large masses, while -the well-known digestibility of cauliflower and minced spinach is due -to the fineness of their division; were cabbage as finely minced as -spinach usually is it would be equally digestible. - -Turning now to animal food it has to be remarked that while in the -raw state it may be readily digestible with little or no previous -mastication, since massive pieces of it are readily attacked by the -digestive juices, the like is much less true of animal food the -proteids of which have been coagulated and rendered less permeable by -cooking. Large lumps of hard-boiled egg or overdone meat, for instance, -may obstinately resist gastric digestion; indeed, as with vegetable -so with animal foods, their relative digestibility depends more upon -physical consistence than chemical composition; beef is generally more -indigestible than mutton and pork or veal than either, not so much -by virtue of chemical composition as of physical consistence; the -indigestibility of cheese illustrates the same truth; the individual -nutritive ingredients of this substance--the proteids and fats--are not -in themselves indigestible; casein in the form of protein or plasmon is -known to be easy of digestion, and butter is one of the most digestible -of fats; but in cheese the two are welded together into a comparatively -impermeable mass, which is apt to escape comminution by the teeth and -to pass down into the stomach in the form of solid lumps. A plain, -wholesome cheese well masticated or intimately mixed with other foods, -as in macaroni cheese, is quite easily digested by the majority. - -I do not, of course, deny the influence of the chemical factor. -Undoubtedly food may disturb digestion by virtue of its chemical -composition, apart altogether from its physical characters; thus, while -cooked goose-fat sets up violent irritation in some, others cannot -tolerate eggs in any shape or form, and innumerable idiosyncrasies in -respect of special articles of diet are met with which are essentially -referable to chemical composition; but making due allowance for -this chemical influence there can, I think, be little doubt that the -digestibility of the more common articles of diet, both animal and -vegetable, depends in the main upon their physical constitution, _all -of them tending to be equally digestible when reduced to the same -degree of comminution_. This, if true, is, I need scarcely say, a fact -of the greatest practical importance, for it amounts to this: that we -may often allow to those with very weak digestions foods which are -generally considered indigestible, provided that they be thoroughly -comminuted, whether by mastication or artificial means. - -_Mastication promotes the flow of saliva and the insalivation of the -food._--The more efficiently food is masticated the greater is the -salivary flow, and the more intimately is it mixed with the saliva, -or, as we say, insalivated. The saliva has apparently no effect on -fats; whether it acts on proteids seems more doubtful, though by some -authorities the penetration of these by the alkali of this fluid is -said to aid in their subsequent digestion; on starch, however, the -saliva acts very potently, and hence mastication plays a special -part in promoting the digestion of starchy foods. Indeed, if only -mastication be persisted in long enough, starch may be wholly converted -into maltose within the mouth, and it need scarcely be said that it is -better for the individual himself to manufacture his maltose in this -way than that he should take it ready made for him in the form of one -of the many “malt extracts” on the market. Patients are often forbidden -starchy food, while they are allowed the maltose which they can quite -well manufacture in their own mouths. Provided they be sufficiently -insalivated, there are few starchy foods which are indigestible, not -even excepting the proverbially indigestible new potato. These remarks -are especially applicable to children, as will be more particularly -insisted on later. - -_Mastication increases the amount of alkaline saliva passing into the -stomach_, and this not only prolongs the period of starch digestion -within this organ but, by its influence upon the reaction of the -gastric contents, influences all the digestive processes taking place -there. I shall have occasion to point out later that a deficient supply -of alkaline saliva in the stomach predisposes to certain forms of -indigestion. - -_Mastication acts reflexly upon the stomach._--It is now known that -the act of mastication influences the stomach reflexly, promoting the -flow of gastric juice and thus preparing the stomach for the entrance -of food into it. If the œsophagus of a dog is cut so as to allow the -swallowed food to escape instead of passing into the stomach, it is -found that the mastication of food causes a considerable flow of -gastric juice. Food introduced into the stomach unaccompanied by -mastication is less effective in promoting the gastric flow. It is -probable that the influence of mastication on the flow of gastric juice -is largely produced through the medium of psychic influences, for the -more efficient the mastication the more is the sense of taste affected. - -_Mastication stimulates the heart and so promotes the general -circulation._--This stimulating action may be partly due to its local -action on the flow of blood and lymph in the jaws and accessory parts, -and partly to a reflex influence, but whatever the explanation there -can be no doubt of the fact. Hence the mere chewing of a non-nutritive -substance, such as gum arabic, is stimulating, and, doubtless, the -stimulating effects induced by the chewing of such articles as tobacco -and betel are largely to be explained in this way. - - -THE INFLUENCE OF MASTICATION ON THE JAWS AND ADJACENT STRUCTURES - -This subject is of such importance that it needs to be dealt with in -some detail. By “adjacent structures” I mean the masticatory muscles, -tongue, teeth, salivary glands, the nasal passages and sinuses -pertaining thereto, the naso-pharynx, soft palate, and tonsils. - -_The muscles of mastication._--Let me at the outset draw attention -to certain anatomical points, in connection with the muscles of -mastication. These are (_a_) their massiveness; (_b_) the very close -relation of the pterygoids to the naso-pharynx; and (_c_) the outward -direction of the pterygoids. - -(_a_) It is not until one studies the muscles of mastication closely -that one comes to realise their massiveness. Their large size, in -relation to the bony structures in connection with them, is well shown -in a vertical transverse section of the head carried through the -ascending ramus of the mandible[7] (see Fig. 1). It is evident that -the functional activity of so large a mass of muscle tissue cannot but -exercise considerable influence on the nutrition of the neighbouring -parts. - -[Illustration: - - FIGURE 1.--Vertical transverse (slightly oblique) section through the - head on a level with the epiglottis. The massiveness of the system of - masticatory muscles is apparent.] - -(_b_) The pterygoid muscles, springing as they do from the internal -pterygoid plates, must necessarily be in close relation with the -naso-pharynx, especially the internal pair, which take their origin -from the internal aspect of the internal plates. I would further -point out that the external pair, although they diverge from the -naso-pharynx on their way to the mandibular condyles, yet remain on a -level with that cavity. This close relation of the pterygoids to the -naso-pharynx is, if I mistake not, of great importance in relation to -the etiology of “adenoids.” - -(_c_) Of the two pairs of pterygoids the external pair pass in the more -outward direction, forming with the sagittal plane of the head an angle -of 45° (see Figs. 1 and 2). In consequence of this direction they tend -by their contraction to pull the pterygoid plates and posterior parts -of the maxilla away from the sagittal plane of the head, and thus to -secure the normal width of the posterior nares. It is these muscles -which bring about the lateral movements of the mandible, causing the -lower teeth to move laterally and sagittally across the upper, the food -being in this way far more effectually ground than by a mere vertical -pressure of the teeth against one another. These lateral movements are, -as we shall see, less pronounced among the moderns than among primitive -peoples. - -[Illustration: - FIGURE 2.--Portion of horizontal section of head about an inch below - the condyles of the lower jaw. The outward direction of the external - pterygoids is well shown; also the close relation of the levatores and - tensores palati with the internal pterygoids.] - -_The influence of the contraction of the masticatory muscles on the -local circulation of blood and lymph._--When a muscle is at rest the -blood flows sluggishly through it, while there is a complete, or -all but complete, stagnation of the lymph current; if a lymphatic -trunk of a limb at rest be cut no lymph escapes from it. Rhythmic -muscle contractions, however, stimulate the flow both of blood and -lymph (_a_), in the contracting muscles themselves and (_b_) in the -neighbouring parts. (_a_) Not only are the muscle arteries dilated -during rhythmic contractions, but the blood is vigorously squirted out -of the muscle veins, so that much more blood flows through a muscle -during its rhythmic contraction than during rest. The flow of lymph is -even more markedly stimulated,--this fluid, which, while the muscle is -at rest, is stagnant or all but so, being during contraction driven -actively along the lymphatic trunks. (_b_) How greatly rhythmic muscle -contractions influence the circulation of fluids in the neighbouring -parts is shown by the flushing of the skin and the swelling of the soft -parts generally of a limb which is being exercised. We thus see how -profoundly the exercise of the masticatory muscles--and among these we -must not forget to include the tongue--influences not only their own -nutrition but that of the important structures adjacent to them--that -is to say, of the jaw-bones, salivary glands, buccal mucous membrane, -soft palate, faucial tonsils, pharynx, and naso-pharynx, as well as -of the nasal cavities and their accessory sinuses. All these parts -are during mastication copiously flushed with blood and lymph, from -which it is evident that efficient mastication must stimulate their -nutrition and favour their proper development. Hence, in one who has -from childhood upwards been accustomed to masticate efficiently, we -generally find these parts well developed, the jaws large and shapely, -the teeth regular and straight, the tongue and salivary glands large, -the nasal and naso-pharyngeal passages spacious, and the mucous -membrane of the buccal and adjoining cavities healthy. - -_Influence of mastication on the jaw-bones._--It is well known that the -size of a bone is largely determined by the degree to which the muscles -attached to it are exercised. That the jaws do not grow to their normal -size, if not adequately exercised during their period of growth, is -strikingly shown by the overcrowding of the teeth, which takes place -in those brought up on soft foods, and this even though there be no -contraction of the jaws resulting from mouth-breathing. The dependence -of the size of the jaws upon the degree to which they are exercised is -also shown by the smallness of the modern jaw, as compared with that -of primitive peoples, a difference which, as we shall see, is in part -congenital and in part due to the comparative disuse of the former. -Mastication influences not only the size but also the shape of the -jaws (_a_), through its influence on the size of the tongue, which by -pressing against the teeth tends, as Sim Wallace has shown, to expand -the jaws; (_b_) by the pressure of opposing teeth against one another, -which has a similar effect; and (_c_) by the outward pull of the -pterygoids, which tends to widen the maxilla posteriorly and to broaden -the posterior nares. - -_Influence of mastication on the teeth._--The teeth being developed -within the jaw-bones and remaining, even after eruption, in close -anatomical and physiological association with them, must necessarily -share in their nutritive tendencies. If these bones are efficiently -exercised during the formation of the teeth--and my remarks apply -especially to the permanent set--the tooth-germs will be abundantly -flushed with blood, while the ample growth of the jaws themselves -will provide the germs with plenty of room in which to grow and to -develop, and the more perfect their growth and development the more -resistant should we expect them to be to the ravages of caries. Who can -contemplate the jaw-bones of a six-years-old child, dissected so as to -display all the imbedded teeth, without being assured of the effect of -mastication upon dental development? Fifty-two teeth meet the view: -the whole region from the orbital rims to the inferior border of the -mandible is literally paved with them, and I can hardly doubt that -they collectively weigh more than the bone in which they are imbedded. -Surely no one can examine such a dissection without being convinced of -the urgent necessity, if the teeth are to grow and to develop normally, -of giving the child’s jaws from infancy onwards plenty of work to do. - -The ample development of the jaws, which efficient mastication brings -about, has a further beneficial effect as regards the teeth, in that -it enables them to take up their proper places in the alveolar ridges, -thus securing all the advantages of a good “bite.” These I now proceed -to consider. The teeth during mastication, and especially when the bite -is good and the food of a kind necessitating vigorous and sustained -mastication, are made to move in their sockets both vertically and -horizontally; the effect of this is to stimulate the circulation in the -tooth-pulp, the alveolar periosteum (and hence also in the cementum and -alveolar walls which are supplied by it), and the circumjacent mucous -membrane of the gum. All this makes for the health of the teeth; not -only does it promote the nutrition of the tooth itself and of its bony -socket, thus maintaining a firm dental setting, but it also tends to -secure a healthy environment for the exposed part of the tooth--that -part, namely, wherein caries begins--by maintaining a healthy state of -the surrounding and, indeed, of the entire buccal mucous membrane, as -well as of the various secretions which bathe the mouth. Wherefore it -is not surprising to find that those who masticate efficiently suffer -much less from dental caries and its complications (such as abscess at -the root) and disease of the periodontal membrane (_e.g._, pyorrhœa -alveolaris and loosening of the teeth) than those who are accustomed to -bolt their food. - -A few words as to the influence of mastication in wearing down the -teeth. In those races which masticate vigorously the teeth in quite -early adult life show signs of wearing away, while in later life it is -quite common for the biting surfaces to be worn flat; sometimes the -crown of the molars is worn away so that its surface shelves downwards -and inwards and not infrequently it is concave, having a scooped-out -appearance; often the dentine is exposed in this way; and yet among -many hundreds of skulls examined I do not remember to have seen one -single case where caries has started on the biting surface thus worn -down. - -I had always attributed this wearing down of the teeth to the friction -of coarse food against them. Primitive races eat coarse vegetable -food, which frequently contains grit, and this doubtless helps to grind -the teeth down, but they may be markedly ground down even in those -living on soft food, and in such cases the grinding away can obviously -only be due to the friction of opposing teeth against one another. -I, indeed, believe this to be the essential cause of the phenomenon, -both in civilised races living on soft food and in primitive races -whose coarse food necessitates prolonged and vigorous mastication and -a corresponding amount of attrition between the biting surfaces of -opposing teeth. In order that this attrition may occur two things are -requisite: the upper and lower teeth must be well opposed--there must -be a good bite--and mastication must be vigorous and of the right kind. -Mere vertical pressure of the teeth against one another will not wear -away the opposing surfaces; there must be friction of these surfaces -against one another--a transverse and sagittal movement of the lower -teeth against the upper by means of the pterygoids. Mainly to this do -I attribute the marked wearing down of the teeth observed in primitive -peoples, and I am gratified to know that so competent an authority on -dental pathology as Sim Wallace is a convert to this view. - -That all the teeth may be worn down just as we observe in primitive -people, even in those who have lived all their lives on the ordinary -fare of the moderns, is proved by a case I have under observation. It -is that of a man in his fiftieth year, who was brought up in Belgium -but who has resided in London for the last thirty years. When he came -to my out-patient room I was not a little surprised to find that -all his teeth were sound--a very unusual occurrence, I need hardly -say, among the London poor at his age. In seeking for an explanation -I elicited the fact that he was unable to swallow his food without -chewing it very thoroughly, and on giving him a moderate-sized piece -of bread, with the request that he should chew it in the ordinary way, -I found that he subjected it to one hundred and twenty separate bites -before swallowing it, and in the steady, deliberate way he went to work -and in his extensive lateral movements of the mandible he reminded one -for all the world of a cow chewing its cud. The temporals and masseters -of this man are enormous, and the like is no doubt true of the -pterygoids; he has well-developed nasal passages, has never suffered -from nasal obstruction, while his buccal mucous membrane is unusually -healthy for one of his years and circumstances. May we not attribute -this healthy state of the mouth, teeth, and nose to the good effects -upon them of efficient chewing? Here is a man who has lived for thirty -years in London on the same kind of food as the average poor Londoner, -but instead of finding his mouth full of carious, tartar-coated teeth, -and spongy, receding, pus-exuding gums, we find thirty-two sound teeth -firmly set in healthy gums and all but devoid of tartar. - -A word as to the wearing down of the teeth in the anthropoid apes. -In this respect the gorilla differs markedly from the orang and the -chimpanzee. In all the skulls of these latter which I have examined the -teeth show signs of wearing away, while I have found the teeth of the -gorilla, with the exception of the tusk-like canines, but little worn. -From this we should expect the latter animal to be mainly carnivorous, -and the orang and chimpanzee to be largely herbivorous. - - - SECTION II. From _London Lancet_, July 18, 1903 - - CHANGES WHICH THE JAWS AND TEETH OF MAN HAVE UNDERGONE DURING MAN’S - EVOLUTION FROM HIS ANTHROPOID ANCESTORS - -During man’s progress upwards from the anthropoid his diet has -undergone a progressive change, and a parallel adaptation has taken -place in his jaws and teeth. Dietetically considered, we may divide -his evolutionary career into the following epochs[8]: (1) the -anthropoid stage; (2) the pre-cooking human stage; (3) the cooking -pre-agricultural stage; (4) the early agricultural stage; and (5) the -late agricultural stage. - -1. _The anthropoid stage._--The diet of man’s anthropoid ancestors -was probably much the same as is that of existing anthropoid apes; it -consisted, namely, of raw vegetable and animal food, necessitating a -vigorous use of the maxillary apparatus. This latter, we may assume, -was of the type belonging to the anthropoids--_i. e._, the jaws were -massive and markedly prognathic; the denture was the same as it is in -existing man, but the teeth were larger, especially the upper canines, -which served as weapons of offence and defence; the third molars (the -wisdom teeth) were as large as the other molars and were provided with -three fangs, and there was an ample portion of alveolar ridge behind -them; there was no chin. No doubt the massiveness and the marked -prognathism, which characterised the jaws at this stage, served other -ends than that of mastication; it is obvious that projecting jaws and -teeth are much more effectual for seizing and lacerating prey than are -the orthognathic jaws of modern man. - -2. _The pre-cooking human stage_ extends from the time man’s ancestors -first assumed the human form till they learned to apply fire in the -preparation of their food. During all this period the jaws and teeth -were probably used as much, or almost as much, for mastication as -during the anthropoid stage; raw animal food had to be torn from -the bones, the latter had to be crunched, while the bulk of the -raw vegetable food needed then no less than it needs now prolonged -and vigorous mastication in order to liberate the starch and other -nutritive ingredients from their undigestible cellulose envelopes.[9] -Nevertheless, the jaws and teeth underwent considerable change during -this period, for not only were they with every advance in intelligence -called less and less into requisition for purposes of offence and -defence, but the jaws, at least, became materially modified in -correlation with the expanding cranial cavity and in connection with -the assumption of the erect posture. It is, I think, rather for these -reasons than in consequence of alterations in the nature of the food -that the masticatory apparatus now gradually lost its more bestial -aspect and assumed an essentially human type, becoming towards the -close of the period much the same as may be observed among the most -primitive peoples now living. - -3. _The pre-agricultural cooking period._--The characters of the -maxillary apparatus belonging to this period are still available for -study, the aboriginal Australians, the Bushmen, Negritos, and many -Esquimaux not having yet emerged from it. So far as mastication is -concerned, cooking influences vegetable far more than animal food, for -it not only softens it but by rupturing the undigestible cellulose -chambers and liberating their contents relieves mastication of one -of its essential functions. Wherefore, with the advent of cooking, -man’s jaws and teeth began to get smaller, and they have continued to -diminish in size up to the present time. No great diminution, however, -took place at first, inasmuch as the diet still continued to be largely -animal (and prior to the use of knives and forks such food had to be -torn by the teeth), while the coarse vegetable food of this date, even -when cooked, still needed laborious mastication. The chief differences -between the maxillary apparatus of this early cooking age as compared -with that of the present day are as follows: the jaws of the earlier -period--_e. g._, in the aboriginal Australian--are more massive, and -their sagittal diameter is greater, giving rise to decided prognathism, -the teeth for the most part are larger and stronger, the third molars -being nearly, if not quite, as big as the other molars, and provided -with three fangs, while there is a considerable portion of alveolar -ridge behind them. The third molars, however, show a decided tendency -to be smaller than the rest, and the alveolar ridge behind them is less -marked than in the previous period, features, I doubt not, attributable -to the influence of cooking in diminishing mastication. Dental caries -is rare and is chiefly met with in the third molars. - -4. _The early agricultural age._--All the existing primitive races -which have attained to the cultivation of the soil may be regarded as -belonging to this period. Previously to it man was mainly carnivorous, -owing to the comparatively limited quantity of vegetable food -available, so long as the supply was left to nature alone; but when by -cultivation this supply was increased and, at the same time, rendered -more constant and certain, he gradually became less carnivorous and -more vegetarian in his diet. The result of agriculture, however, is -not only to increase the supply of vegetable food, but to diminish its -fibrous, cellulosic ingredients, and thus to render it more easily -masticated. Hence at this stage we find the maxillary apparatus -becoming smaller than in the previous period, although the difference -as shown--_e. g._, by the examinations of the skulls of the African -negroes and the Melanesians--is less pronounced than we might perhaps -have anticipated; prognathism is not so decided, the jaws are smaller, -also the teeth, especially the third molars, which now for the first -time show a tendency to be furnished with two instead of three fangs, -while the alveolar ridge behind them is distinctly shorter than in -the preceding period. Dental caries, hitherto rare, now becomes more -frequent. - -5. _The late agricultural period._--A mid-agricultural period might be -described, but I shall take no account of it here, but pass on to a -consideration of the late agricultural period--that, namely, in which -we ourselves live. The chief characteristic of the food of this period -is its softness. Cooked animal food requires, indeed, more mastication -than raw, but the vegetable food of to-day, owing to the combined -effects of improved agriculture, and skilful milling and cooking, is so -soft as to excite comparatively little mastication. The present may, -in fact, be described as the _age of pap_. Hence the jaws and teeth -are now called upon to perform far less work than in any earlier stage -of our evolution, and there has taken place in consequence a great -diminution in their size, more especially in the size of the jaws, so -that there is now often no room for the teeth to take up their normal -positions, and there is generally a complete absence of alveolar ridge -behind the last molars. The latter are, moreover, apt to be very small -or even absent, while dental caries is alarmingly frequent. - -It will thus be seen that from the period of the anthropoids to the -present time, a progressive change in the size and shape of the jaws -and teeth has been taking place, a change which is to be explained -by (1) the cessation of the need for using them for offensive and -defensive purposes; (2) the growing capacity of the cranium and the -assumption of the erect position; (3) the progressive alteration in -man’s diet; and probably also (4) considerations of beauty. The first -three factors have operated through natural selection, the last through -sexual selection, which has come into play, I would suggest, chiefly -within recent times. Probably the most pronounced change which has -taken place in the jaws during the agricultural periods has been the -suppression of prognathism which, in the woman especially, is very -unsightly, and tends to diminish the likelihood of marriage. - - -INSTANCES OF THE VIGOROUS USE TO WHICH THE JAWS AND TEETH ARE PUT AMONG - EXISTING PRIMITIVE PEOPLES - -A study of existing primitive peoples brings forcibly home to the -mind how laboriously the jaws and teeth of our primitive ancestors -were used. I have already shown how in pre-agricultural and early -agricultural times the nature of the food compelled a sustained and -vigorous exercise of these structures, and I wish here only to refer -to a few specific and peculiar instances of laborious mastication -exercised by primitive races now or recently living.[10] Among some -of these mastication has been promoted almost to the position of an -industrial art. - -_The chewing of very tough substances in order to extract therefrom -liquid or nourishment._--The recently extinct Tasmanians included -among their articles of diet a species of sea-weed which, even when -cooked, was so tough as to require long-sustained mastication in order -to extract its nutrient elements. The Indians of North California chew -kelp, which is “as tough as white leather” (_i. e._, leather dressed -with alum). “A young fellow with good teeth will masticate a piece -of it a whole day.” Again Featherman[11] tells how when the Bushmen -are short of food in the winter they steep an old dried gnu-skin in -water and, having rubbed off the hair, boil it, and proceed to gnaw the -tough morsel until their very jaws ache. The Modoc Indians are said to -munch the raw kais root all day long.[12] Among the Esquimaux it is a -universal custom to chew the raw skin of the whale, the porpoise, and -the seal for the blubber it contains, and the skin being as tough as -india-rubber, it requires, as may be imagined, a good deal of chewing. -The Lower Californians also chew deer-skin and ox-skin (Bayert). The -more southern Esquimaux, according to Nansen, preserve the stalks of -_angelica_ by steeping them in a mixture of chewed blubber and saliva. -Finally, I may refer to the habit of chewing the sugar-cane, a practice -which is prevalent among the natives in all countries where the cane -grows, and affords, it need scarcely be said, abundant exercise for the -jaws and teeth. - -_Mastication in the preparation of beverages._--I find that among -widely separated aboriginal peoples chewing is resorted to in the -preparation of beverages, both intoxicating and non-intoxicating. -The Gran Chaco Indians make an intoxicating drink by chewing the -algarroba bean and then spitting into a receptacle. In other parts of -South America berries are chewed with the same object. In some of the -Pacific Islands boys and girls with good teeth are selected to chew a -root (kava), from which they then prepare a drink. In New Guinea drinks -are similarly prepared from roots. Boiled cassava root is chewed by -the Indians of Nicaragua for the same purpose. In British Guiana the -natives make a drink by adding chewed maize and saliva to sweet potato, -maize, and sugar-cane. The Indians in Honduras, after steeping cassava -cake or carbonised bread in hot water, chew a portion and mix it with -the rest. - -_Mastication in the industries._--Even among moderns teeth are used -for many purposes other than mastication--_e. g._, for holding pins -and needles and for severing cotton; also in some industries--_e. -g._, among diamond workers--where it is the custom for girls to hold -the diamond between their front teeth, which in consequence get much -worn away, as I have myself seen. It is only among primitive peoples, -however, that the jaws and teeth actually play the part of implements -for use in the arts. The Australian women make lines, nets, and bags -by chewing various kinds of fibre, a process which wears down their -teeth considerably and may cause them to be tender.[13] The Esquimaux -are still more dependent upon the use of their teeth as implements, -especially in the preparation of skins for their clothing, boats, and -lines. The teeth are used to hold the skins, while the latter are -being scraped, the mouth constituting, in fact, “a third hand;” and -the front teeth of Esquimaux women are often by this means worn away -to the merest stumps.[14] The garments of the Esquimaux, even to the -boots, are made up of skins which have been laboriously chewed for this -purpose by the women “inch by inch,” till they acquire a beautiful -softness and flexibility, and are often, indeed, chewed again after -having been dried. And we are told that the women have no objection -to the task, while the children are eager to help in it on account of -the blubber the skin contains; also, that in bad times the men do not -object to join in the work. The lines for harpooning are prepared in -a similar way from the skin of the bearded seal, and in very large -quantities.[15] When we think of the quantity of skins needed for these -lines, for their dress, including boots and gloves, and for their -boats (although for the latter some skins are used without having -first undergone chewing), it is clear that enormous quantities must be -chewed. The Esquimaux men also use their teeth considerably in other -work--_e. g._, in lashing the sledges together.[16] The Indians of -North California use their teeth for stripping the bark from the fresh -shoots employed in making their wickerwork utensils, and they also -employ their teeth in making strings, cords, and nets. - - - THE INSTINCT TO MASTICATE - -Seeing that the maxillary apparatus of man has for long ages past been -put to vigorous use, it is not surprising that the need to exercise it -should express itself as a powerful instinct. This instinct manifests -itself in many and curious ways, some of which I will now consider. -During the early months of life the natural function of feeding at -the breast provides the infant’s jaws, tongue, and lips with all the -needful exercise. This bottle-feeding fails to do, and we frequently -find bottle-fed children seeking to satisfy the natural instinct by -sucking their thumb, fingers, or any convenient object to hand. The -teeth are a provision for biting hard foods, but even before they -actually appear we find the child seeking to exercise his toothless -gums on any hard substance he can lay hold of, and there can be no -doubt that exercise of this kind tends to facilitate the eruption of -the teeth, a truth, indeed, recognised universally, whether by the -primitive mother who strings the tooth of some wild animal round the -neck of her infant, or the up-to-date parent who provides her child -with a bejewelled ivory or coral bauble. When the teeth have erupted, -the masticatory instinct finds among primitive peoples abundant -satisfaction in the chewing of the coarse, hard foods which constitute -their dietary; but among us moderns, subsisting as we do mainly on soft -foods, affording but little exercise for the masticatory apparatus, -it does not find its proper expression, and thus tends to die out. -Nevertheless, it dies a hard death, and long continues to assert -itself; witness the tendency of children to bite their pencils and -pen-holders; I have known a child to gnaw through a bone pen-holder, -much in the same way as a carnivorous animal gnaws at a bone. - -This instinct to chew for chewing’s sake manifests itself all over -the world. In our own country not only do children bite pencils and -pen-holders, but they will chew small pieces of india-rubber for hours -together. The practice of gum-chewing, so common among our American -cousins, evidently comes down from far-off times, for the primitive -Australians chew several kinds of gum, attributing to them nutrient -qualities,[17] and the Patagonians are said to keep their teeth white -and clean by chewing _matri_, a gum which exudes from the incense bush, -and is carefully collected by the women and children.[18] - -A widespread custom in the East is betel-chewing, which is met with in -India, Malay, Melanesia, and Polynesia, and even among the primitive -Veddahs of Ceylon. This article is composed of the pungent leaf of -the betel plant, the areca nut and lime rolled together, and when -chewed yields a reddish juice which stains the mouth and teeth. The -Veddahs, failing to get the genuine article, manufacture a quid from -the leaves of an aromatic plant, the barks of one or two kinds of tree, -and calcined small shells.[19] The compound must possess some strange -attraction, for otherwise such pains would not be taken to secure it. -What is the attraction? Doubtless betel has stimulating properties, -and it must, moreover, be remembered that the mere mechanical act -of mastication stimulates the circulation, a fact which helps to -explain the tendency for man, all the world over, to chew non-nutrient -substances. Tobacco-chewing is common in many parts of the world, and -here, again, the effect for the time is stimulating. Pitcherie is -extensively chewed among the aboriginal Australians; it consists of -twigs of about the thickness of rye-grass stems, which are first chewed -into a mass, then mixed with the ash of gum trees, and made into a -paste, which is chewed for its stimulating and narcotic effects.[20] - -I may allude in passing to the grinding of the teeth, which takes -place during sleep in disturbed states of the nervous system. It is -a true masticatory act, in which the normal lateral movement of the -mandible is well marked, and it may thus be regarded as a perverted -manifestation of the masticatory instinct. - - - THE CAUSATION OF INEFFICIENT MASTICATION - -The effects for good upon the organism of efficient mastication being -profound and far-reaching, it follows that inefficient mastication must -lead to many evils. What these are we have now to consider; but first -it will be well to inquire into the causes of the defective mastication -which prevails among moderns. - -1. _Softness of food._--By far the most important of these lies -in the nature of the food taken. The food of to-day--of the late -agricultural age period, as I have termed it--is for the most part -soft and pappy, of a kind which does not compel thorough mastication; -so much so, indeed, that, as I have already said, we may speak of this -as the age of pap. This feature is especially noticeable in the case -of children’s diet: under the modern system children are kept on a -liquid, or semi-liquid, diet, not merely during the first months, but -during the first years of life, and at the seventh or eighth month all -kinds of artificial saccharide foods in liquid or semi-liquid form are -poured into the child’s stomach; thereafter he is fed on such viands -as mashed potatoes and gravy, rusks soaked in milk, milk puddings, -bread dipped in bacon fat, pounded mutton, thin bread-and-butter, -and the like; and we are told that this is the kind of diet best -suited to the young human, from the time of weaning to the end of the -second year! The same pernicious methods are adopted subsequently. -“Perhaps the great majority of children after they have got their -complete set of temporary teeth have,” writes Dr. Sim Wallace,[21] -“a dietary such as the following. Breakfast: bread-and-milk or -porridge, milk, tea, coffee, or cocoa, bread-and-butter, perhaps an -egg. Dinner: potatoes and gravy, or meat, milk pudding. Tea: milk -or tea with bread-and-butter, jam, cakes. Supper: bread or biscuit -and milk.” Now food of this kind does not invite mastication, and it -finds its way into the stomach all too readily. Hence the instinct to -masticate has little opportunity of exercise and, not being properly -exercised, tends, as I have said, to die out. Small wonder that the -child nourished on such pappy food acquires the habit of bolting -it, and learns to reject hard, coarse foods in favour of the softer -kinds; everything nowadays must be tender, pultaceous, or “short.” -Given a choice between a food compelling little or no mastication -and one necessitating prolonged mastication--as between, say, fresh -Vienna bread and an Abernethy biscuit--and in nineteen cases out of -twenty the one which gives the least trouble in eating will be chosen. -To such absurd lengths has this harmful custom been pushed that -even bread crust is avoided by many. Witness the fashion of eating -bread-and-butter with a minimum of crust; order bread-and-butter at -any place of refreshment, and the last thing you will be served with -is a plateful of crusts of bread. Many establishments, indeed, make -a regular practice of giving away their crusts as unsaleable. Thus, -the rectangular loaves used for bread-and-butter in the “Aërated -bread-shops” are cut transversely into slices, each loaf thus yielding -two end crusts which are put into baskets for the poor, only the soft -crumby pieces being reserved for the customers, to be, in due course, -no doubt washed down by copious libations of tea and coffee. - -When we trace the diet of the modern from childhood upwards we find the -same story: it tends to remain soft and pappy to the end. Animal food, -especially as it comes to the tables of the well-to-do, necessitates -very little mastication. It is the coarser varieties of vegetable food -alone which call out the full functional activity of the masticatory -apparatus, but the vegetable food of to-day is rarely of a kind to do -this; cooked vegetables, such as potatoes, greens, peas, and beans, -can be, and generally are, swallowed after little or no preliminary -mastication, and our flour is so carefully deprived of its fibrous -portions and so cunningly dealt with in the bakehouse and kitchen in -the making of bread, cakes, and pastry which shall eat light and short -that these articles get very little chewing; while such vegetable -products as rice, vermicelli, tapioca, and macaroni are, as served at -table, so soft that they slip down into the stomach almost as readily -as simple milk. Let any one run through his dietary of any one day, -and he will realise how very little work his masticatory apparatus is -called upon to perform. It will read something like the following. -Breakfast: porridge and milk, eggs, bacon, bread, and marmalade. Lunch: -fish, tender meat, boiled vegetables, bread, some “sweet,” and cheese. -Tea: bread, butter, and cake. Dinner: much the same as lunch. What -opportunity, I ask, does such a bill-of-fare afford for the development -of teeth and jaws, and for the proper functional activity of the -salivary glands? - -2. _Defective masticatory apparatus._--Another potent cause of -inefficient mastication is some defect in the masticatory apparatus, -and defects of this kind are very common in those who have not been -accustomed to masticate thoroughly in early life. Foremost among these -are irregularities of the teeth leading to faulty “bite” and caries of -the teeth which causes them to be tender or to break away, if it does -not lead to their actual extraction. Mastication cannot be thorough -where the bite is defective, for this not only leads to imperfect -opposition of the upper and lower teeth, but renders the lower ones -incapable of that ample lateral movement, against the upper which is -needful to normal mastication. - -3. _Idiosyncrasy._--Some are temperamentally more disposed to hurry -over their meals than others. The katabolic, restless, nervous -individual is more apt to swallow his food hastily than is his more -deliberate and phlegmatic brother. Individual differences in this -respect are even observed among the lower animals. Thus, one of a pair -of horses of about the same age and build is nervous and excitable -and inclined to bolt its food, while its companion of more stolid -temperament is a thorough and efficient masticator. The former shows -comparatively little wearing down of the teeth, and often suffers -from indigestion, a large portion of corn grains passing through -his digestive canal intact; in the latter the teeth are well worn, -indigestion never occurs, and but very few grains pass through the -digestive tract unchanged. It may be objected here that we cannot -help temperament, and to a large extent this is true; but much can be -done towards modifying it, and it is something to know where dangers, -temperamental dangers, among others, lie. - -4. _Circumstances of life._--Again, in this hurrying, strenuous age -people are much less deliberate than in the easy, slow-going days of -long ago. A meal is too often regarded as something to be got through -quickly, as taking up time which might be devoted to something more -profitable. Especially is this true of breakfast and lunch; it is no -uncommon thing for a business man to hurry through his breakfast in a -few minutes, preparatory to rushing off to his train, and his lunch -as likely as not is as hastily swallowed in his office or at a bar. -Tradesmen are apt to take their meals in mere snatches; apprentices, -shop girls, and other “hands” are often not allowed sufficient time -for their meals; while, to come to the professions, we all know how -the busy medical man, for instance, is often obliged to take a hurried -snack in the short intervals between seeing his patients. No wonder -that thus circumstanced people acquire the habit of bolting their food. -A meal should be regarded as an end, and an important end, in itself. -It should be taken at leisure, body and mind being, for the time being, -given up to it, and to agreeable social intercourse. If this rule were -always observed a most important source of inefficient mastication -would be removed. - - - SECTION III. From _London Lancet_, July 25, 1903 - - EVILS RESULTING FROM INEFFICIENT MASTICATION - -_Too much food is eaten._--Inefficient mastication conduces to -excessive eating. Now it is obvious that soft foods, and these -constitute the bulk of our modern dietary, pass much more readily into -the stomach than coarse, hard foods which compel a certain amount of -preliminary mastication, and for this reason the former predispose to -excessive eating: hence a danger at all periods of life, not only in -grown-ups but in children, even infants; brought up as the latter are, -mainly on liquid and pappy foods, many of them consume not only far -more than is needful, but far more than is healthful, their stomachs -being literally deluged with nutriment. - -When the food is of a kind necessitating abundant mastication it is -much less likely to be taken in excess, for the longer the time spent -in mastication the less will the individual be tempted to consume; -even in the case of soft food, less will probably be eaten if it be -thoroughly masticated and insalivated than if it be bolted. Thorough -mastication, however, not only tends to diminish the amount of food -consumed on account of the time and labour which it entails; it -actually reduces the amount needful to constitute a sufficiency, for -the more perfectly the food is chewed the more perfectly is it digested -and the more economically is it disposed of in the system; the less, -moreover, is the tendency to that morbid craving for food which is so -frequent an accompaniment of defective digestion. It is certain that -appetite and the needs of the system are sooner satisfied when food is -well masticated and digested than when it is swallowed whole. - -_A mass of unmasticated food may lodge in the throat and cause fatal -suffocation._--This may seem to be a very exceptional kind of evil, -but I am informed by one whose experience makes him an authority -on the ways of the British soldier that it is by no means uncommon -for soldiers in barracks to die from this cause. Usually it is when -they are under the influence of alcohol that fatal results occur, -post-mortem examination disclosing large undigested masses of food in -the stomach. A like experience is also frequently met with in the case -of men killed by accident. - -_The presence of masses of imperfectly masticated food in the stomach -may cause disturbance either mechanically or by reason of their -imperviousness to the gastric juices._--We have already seen that the -digestibility of a food is largely determined by its consistence, and -that many articles of diet, such as cheese, hard-boiled egg, cocoa-nut, -lobster, and new bread, which have the reputation of being very -indigestible, can, if finely comminuted by chewing or otherwise, be -rendered quite digestible. Such articles are indigestible essentially -by reason of their compactness; the compact lumps, but little pervious -to the gastric juice, tend to undergo abnormal chemical change in the -stomach, and may in this way cause violent local irritation, even to -the extent of setting up acute gastritis; or they may paralyse the -nerves of the stomach and check gastric secretion and movement, and -thus remain _in loco_ wholly undigested for hours or even days; or, -again, more distant nervous effects may be produced, such as frontal -headache, which may be felt almost immediately after ingestion of -the peccant substance, being of reflex rather than toxic origin, -and presumably in some cases, at least, due to the mere mechanical -irritation of the stomach. The passage of imperfectly digested food -into the bowel may still further aggravate matters. It does not seem -improbable that the habitual bolting of food, by the prolonged local -irritation to which it gives rise, may predispose to cancer of the -stomach: Napoleon was a notorious fast eater and it is well known that -he died from this disease. - -While, however, the bolting of food readily sets up disturbance in -some, it must be conceded that in many it seems to cause little or no -inconvenience; especially is this the case in the young with vigorous -muscular stomachs capable of triturating the food, and thus doing duty -for the teeth. The human stomach is, indeed, a long-suffering organ, -and wonderfully tolerant of ill-treatment, sometimes almost rivalling -in its hardiness the gizzard of the bird. Nor is this surprising when -we reflect that it is, in the ordinary course of nature, constantly -exposed to the entrance of noxious substances. In this respect it -stands in marked contrast to the intestines, for not only are highly -irritant substances often vomited rather than passed onwards, but in -ordinary circumstances the gastric contents are not allowed to pass -the pylorus, until they have been duly prepared by the stomach; the -pylorus, in fact, stands guard over the entrance to the bowel and is -jealous of anything passing it which is likely to injure that canal. - -And just as the pylorus protects the bowel so, in exceptional cases, -may the œsophagus protect the stomach, regurgitating, after the fashion -of the ruminants, insufficiently masticated bits of food, in order -that they may be re-masticated. I have myself met with cases in point. -Sometimes, in cases of this kind, the œsophagus may be dilated into a -sort of proventriculus, which is capable of temporarily lodging a large -quantity of food. Such a proventriculus is said to have developed in -an apprentice who, not being allowed sufficient time for his dinner, -rapidly bolted it, to regurgitate it after working hours and to chew -the cud at leisure. Whether in these cases the food is ever returned -from the stomach itself I am unable to say. - -While the stomach is the organ especially liable to be injured by the -swallowing of lumps of unmasticated food, the bowel may also suffer, -especially the cæcum and vermiform appendix. And here we come to one of -the most serious indictments against the bolting of food; though man -has doubtless always suffered from appendicitis, there can be little -doubt that this malady is more common now than it used to be; and -there is equally little doubt, in my own mind at least, that the cause -of its greater frequency is related to his food. I do not propose to -discuss here in detail how food is capable of causing appendicitis, -but will merely refer to one of the ways in which it may do so. I had -already come to the conclusion that the habit of bolting food is a -potent cause, when I read Sir Frederick Treves’s Cavendish Lecture in -which he makes that contention. Sir Frederick Treves points out that -in this rushing age people, especially business men, are apt to hurry -over their meals and to take them at irregular times and often while -standing at a bar; even when there is more leisure, food is rarely -masticated nowadays in the same thorough way that it was in the old -time, when it was of a coarser nature: hence solid lumps, especially -in the case of such articles as pine-apple, preserved ginger, nuts, -tough meat, and lobster, are apt to pass beyond the pylorus and, -escaping intestinal digestion, to lodge in the cæcum and precipitate an -attack of appendicitis, the most common predisposing cause of which is -a loaded cæcum, often preceded by constipation. Sir Frederick Treves -contends that this distended state of the cæcum encourages catarrh of -the appendix by dragging upon it and blocking its orifice, as well as -by twisting it and thus interfering with its blood-supply.[22] - -_An excess of starch is apt to pass into the stomach._--We have just -seen that inefficient mastication tends to promote over-eating, and -what has been said on this head applies to all kinds of food, starchy -foods among others. It leads, however, to a further evil as regards -these latter; not only does it tend unduly to increase the quantity of -them consumed, but it too often causes the stomach and intestines to -become flooded with starch in a wholly undigested form. I cannot too -frequently repeat that in ancient times, especially in the pre-cooking -age, laborious mastication was needed in the case of all starchy -foods, partly because they were coarse and fibrous, but chiefly because -the starch and other nutritive ingredients had, in order to become -available for nutrition, to be liberated from their undigestible -cellulose envelopes. In these days of prepared, soft, starchy foods, -however, mastication is very little required for these purposes, but in -other respects it is as needful as ever, indeed more needful, if the -large quantities of starch which are now consumed are to be insalivated -effectually. The laborious and sustained mastication to which primitive -man was compelled to subject _his limited supplies of uncooked starchy -food, went far to effect complete digestion of the starch within the -mouth_, for raw starch is freely digested by the saliva,[23] and hence -in his case _very little passed into the stomach in a wholly undigested -form_. How different is the case with us moderns. Since the opening -of the era of agriculture and cooking, man has enormously multiplied -his supplies of saccharide, and he now consumes large quantities of -starch which has been freed from its cellulose framework by cooking, -milling, grinding, and the like, and reduced to a soft or pappy form, -such as milk puddings, porridge, boiled potatoes, and new bread, all -of which can be swallowed with little or no preliminary chewing; and -when food can be swallowed easily, without mastication, few will take -the trouble to masticate it. In these circumstances the starch does not -undergo adequate salivary digestion, and a large quantity passes wholly -undigested into, and out of, the stomach, not beginning to be digested -until it reaches the bowel. Small wonder that the latter should rebel -again this invasion and that flatulence, pain, and other dyspeptic -evils should result. - -It is especially in young children that these evils are observed. Too -often the stomach of the child, semi-carnivorous, remember, by its -ancestry, is literally deluged with pure starch. At the seventh or -eighth month, or even earlier, for many of the patent infant foods -contain it, this substance is poured into the stomach without being -afforded any opportunity of undergoing salivary digestion; and for a -long time after infancy large quantities are given in the liquid or -pultaceous form, such as rusks soaked in milk, puddings, and mashed -potatoes. This practice of deluging the digestive organs with starch, -besides leading to the more immediate troubles connected with flatulent -dyspepsia, gives rise to abundant formation of toxins which, by -irritating the alimentary mucous membrane, set up gastro-intestinal -catarrh; this, again, intensifies the dyspepsia already existing and -causes a still further production of toxins, so that the motions -become intensely fœtid. These poisons being absorbed into the blood -the tissues become saturated with them and the nutrition of the entire -organism is disturbed, the faulty metabolism manifesting itself by a -diminished resistance to pathogenic agencies, by a tendency on the part -of the tissues to inflame (as shown by a liability in children thus fed -to bronchitis, rhinitis, naso-pharyngitis, and tonsillitis), by their -proneness to tuberculosis, and finally by a disposition to rickets, -which I little doubt is essentially of toxæmic origin. - -Besides the above-mentioned troubles an excess of starch in the stomach -may set up hyperchlorhydria--_i. e._, that form of dyspepsia in which -there is excessive secretion of hydrochloric acid. This affection -occurs during the most vigorous years of life and is apparently due -to excessive activity on the part of the gastric glands. The excess -of acid does not give rise to any symptoms so long as there is any -unsatisfied proteid in the stomach to unite with it, but directly all -the proteid is satisfied and free acid is present in the stomach, pain, -heartburn, and distention are apt to be felt; hence these symptoms -are generally removed temporarily by a meal, the food ingested seizing -upon the free acid, and tend to recur in the course of an hour or -two. Other symptoms are mental and bodily lassitude and great mental -depression, while, if the condition is long-continued, gastric catarrh -and dilatation ensue. Eructation of the acrid mass, its removal with a -tube, or its dilution or neutralisation by an alkali, causes relief of -the symptoms. Now Dr. William Russell, who has recently studied this -form of dyspepsia, has shown, and the fact is most significant from -our present point of view, that in it starch is the last constituent -to leave the stomach; that when this organ has so far emptied itself -as to contain but one or two ounces of very acrid material the -residue consists chiefly of finely divided undigested starch, which -continues to stimulate the gastric secretion; “and, there being no more -proteid with which to combine, the secretion accumulates and leads to -hyperacidity.”[24] Inasmuch, then, as inefficient mastication leads to -an excess of starch in the stomach, we see how it may predispose to -hyperchlorhydria and we shall presently see that there is yet another -reason why it should do so. - -It will be gathered from the foregoing that thorough mastication is -the most effective way of securing efficient starch digestion. This -simple fact has been most strangely overlooked. Thus “van Valzah -considers that not a little of the difficulty of the digestion of -starches and cereals can be overcome by more thorough cooking. Patients -who cannot eat potatoes after ordinary cooking are [he urges] often -able to digest them very readily if they are doubly cooked before -being served. Cereals, as a rule, should [he contends] be allowed to -simmer all night and then be thoroughly cooked for a half hour in the -morning before being eaten.”[25] This is an admirable illustration of -the modern tendency to cheat the mouth of its proper work. A much more -rational way of facilitating starch digestion in those who experience a -difficulty in this respect is by efficient mastication. - -_Evils resulting from an insufficient quantity of alkali in the -stomach._--I doubt if it is adequately realised what a large amount -of alkaline saliva passes into the stomach as the result of prolonged -mastication. Its presence there serves the useful purpose of prolonging -the period of starch digestion within the stomach, while it further -aids gastric digestion not only by exciting the secretion of gastric -juice, but also by its influence on the reaction of the gastric -contents; it can scarcely be doubted that the effect is on the -whole one favourable to digestion in general. We have just seen that -defective mastication may predispose to hyperchlorhydria by allowing an -excess of pure starch to pass into the stomach, and I suggest that it -may further operate in the same direction by cheating the stomach of -its due supply of alkaline saliva. Now the saliva in this affection is -apt, as was pointed out by Sir William Roberts, to be superalkaline, -and for this reason he recommended his acid-dyspeptics to excite the -flow of it by chewing gum-mastic with the object of neutralising the -gastric hyperacidity. That relief can thus be obtained there can be no -doubt; but it is surely more rational to get the patient to stimulate -his salivary glands by masticating actual food, by which we secure -the additional advantages accruing from its complete insalivation and -comminution as well as from the reflex gastric effects. Actuated by -these considerations, I have long been in the habit of recommending -hyperchlorhydriacs to subject their food to prolonged mastication, this -being, in my belief, the most rational and effective way of breaking -the stomach of its vicious habit. In extreme cases we must insist that -each morsel of food should be chewed at least one hundred times and not -permit any relaxation of this severe discipline, until the stomach has -been schooled into healthier ways. _Evils in connection with the jaws -and their appendages and the adjacent structures: the nasal passages, -naso-pharynx, and faucial tonsils._--In those who do not masticate -properly in early life these parts fail to develop as they should, -and they are on this account alone predisposed to disease; their -resistance to disease is still further lowered by the fact of their -blood and lymph flow not being adequately stimulated by the vigorous -exercise of the masticatory muscles. Now we have seen that the great -cause of defective mastication in children is the softness of the food -given them and that the feeding of them upon an excess of soft food, -especially the starchy kind, disturbs digestion, induces toxæmia, and -in this way evokes a catarrhal tendency. In children thus fed we have -therefore several conditions which make for disease in the parts under -consideration--defective development, sluggish circulation, and toxic -saturation. Is it any wonder that the modern child should be liable -to disease in these regions, that he should so frequently suffer from -rhinitis, naso-pharyngitis, tonsillitis, and from hypertrophy of the -pharyngeal tonsil (“adenoids”) and of the faucial tonsils? - -It is in this way that I would explain the frequency of adenoids among -the children of civilised communities. I claim, in fact, that this -disease is largely dietetic in origin. I submit that a child whose -nasal apparatus and naso-pharynx are well-grown and habitually bathed -by a stream of pure blood and lymph, periodically accelerated by an -ample and vigorous use of the masticatory muscles, is unlikely to -contract adenoids. On the other hand, I contend that a child in whom -these parts are ill-developed and bathed by an habitually sluggish -stream of tainted blood and lymph--one, _i. e._, that is not only -poisoned, but rarely, if ever, hurried along its lazy course by due -exercise of the muscles of mastication--I submit that such a child -runs great risk of contracting the disease. The influence in setting -up adenoids of toxic saturation with its resulting catarrhal tendency -is shown by the frequency with which this affection follows upon the -rhinitis and naso-pharyngitis of measles and diphtheria, and in order -to realise how greatly the circulation of blood and lymph in the walls -of the naso-pharynx must be influenced by mastication, one has but to -remember how very closely the pterygoids are related to this region; in -exploring it for adenoids they can, indeed, often be felt to stand out -prominently.[26] - -This, then, is my explanation of the truly fearful prevalence of -adenoids among the moderns. It is essentially a disease of pap-fed -peoples. A child may, with the one exception that he is fed on a pappy, -super-saccharide diet, be brought up under ideal health conditions. He -may live in the heart of a dry, open country, far from the darkness, -dust, and tainted atmosphere of the town, sleep with the windows open -all night, live out of doors all day, be fed on the most nourishing -(too nourishing, it may be) food, be clothed after the most approved -methods, and yet, in spite of all this, we may find his naso-pharynx -packed with adenoids. This disease is, in fact, scarcely less prevalent -in the country than in the towns, scarcely less common among the rich -than among the poor. Yet in primitive communities it is practically -unknown. And what, I would ask, is the one condition in the material -environment of my supposititious child differing from that of the -primitive child? What but the factor of diet? Therefore, I say, the -prevalence of adenoids among moderns must be the result of the modern -system of feeding children, and the defective mastication which goes -along with it. - -That the foregoing is a grave indictment against that system, it -need scarcely be said. For adenoid disease is fraught with many -evils, among them mental hebetude, blocking of the Eustachian tubes, -and manifold other auditory troubles, gastro-intestinal disturbances -from the passage into the stomach of unhealthy discharges, and, most -serious of all, nasal obstruction and consequent mouth-breathing. -So serious are the evils connected with this latter habit that they -demand more than a passing reference. Pronounced adenoid disease is -always associated with mouth-breathing, and there can be no doubt that -in the majority of these cases, the nasal obstruction is not in the -nasal passages primarily, but is due to a blockage of the posterior -nares by the adenoid growths, for it generally happens that nasal -breathing is rapidly re-established after their removal, though in a -certain proportion of cases the obstruction still persists, and has to -be dealt with by treatment directed to the nasal passages themselves. -Some have, indeed, contended that a primary nasal obstruction is one -important factor in the induction of adenoids, leading as it does to a -dry-cupping of the naso-pharynx during inspiration and to a consequent -congestion of its lining membrane. I am quite ready to allow that this -mechanism may play some part in causation, and such an assumption is -in entire harmony with my main contention that adenoid disease is of -dietetic origin, for nasal obstruction in children, other than that -caused by adenoids, is mainly due to defective development of the nasal -passages coupled with inflammation of their lining membrane, both of -which conditions may, as we have seen, be essentially the outcome of -defective diet. - -Coming now to the evils resulting from mouth-breathing, we have first -to remember that normally the air is inhaled through the nose, and -is thus warmed, moistened, and filtered before being allowed to pass -into the lungs; but in the mouth-breather the air, which may be dry, -cold, and dust-laden, passes at once unprepared through the mouth into -the lungs, impinging in its passage against the pharynx, thus drying -and mechanically irritating the mouth, pharynx, larynx, and bronchial -tubes, all of which are thereby predisposed to disease. In this way -laryngitis and bronchitis, nay, even phthisis, may be induced. Dental -caries is also predisposed to by the habit of breathing through the -mouth. Mouth-breathing further interferes with the proper development -of the cranial bones, but especially of the maxilla, giving rise to -what may be termed the “mouth-breather’s jaw,” so characteristic is -it I do not propose to discuss here the mechanism by which this -deformity is produced, interesting though the question is; suffice it -to say that nasal breathing is essential to the normal development of -the jaws. The deformity in question, though it involves the maxilla -chiefly, affects also the mandible from the fact of its being, to a -large extent, moulded on the maxilla; in typical cases the maxilla is -small and its alveolar ridge does not attain its normal length, but is -compressed laterally towards the sagittal plane, giving rise to the -false appearance of a “high arch” and often thrusting the anterior -portion of the ridge forwards; the teeth, the growth of which is not so -much interfered with as that of the imbedding bone, are thus prevented -from taking up their proper positions and show irregularity, sometimes -extreme. Dental irregularity may also, as we shall see, result from -inadequate use of the jaws in mastication, but not to the extent which -is frequently observed in the mouth-breather’s jaws, and therefore -pronounced dental irregularity always shows that there has been -protracted nasal obstruction, and this in the vast majority of cases -implies the existence of adenoids, past or present; I say in the “vast -majority,” for in a few rare cases long-continued nasal obstruction in -children originates primarily in the nose and may lead to the typical -mouth-breather’s jaw, with the resulting dental irregularity. - -_The tongue._--If the tongue is not properly exercised in childhood -and youth, we find it imperfectly developed; hence in inefficient -masticators it is generally small. It must not be forgotten in this -connection that this organ is considerably exercised when the infant -is at the breast, from which the milk is obtained, not by suction, -but by a vigorous tugging and squeezing of the nipple (in which the -tongue takes considerable part), whereby the gland is reflexly excited -to secrete. When, on the other hand, the child feeds at the bottle he -obtains his milk by actual suction, and generally through an orifice -of such ample dimensions as to allow the bottle to be rapidly emptied -with comparatively little exercise of the lips and tongue. In short, -the breast-fed infant has to do some work for his living, and that of a -sort calculated to promote the health of the jaws and their appendages, -while the bottle-fed child can glut himself by doing very little more -than opening his mouth; wherefore we find the tongue and adjacent parts -less developed in the latter than in the former. It may be thought to -be a matter of indifference whether the tongue develops to its normal -proportions or remains small, but such is by no means the case, for, as -Dr. J. Sim Wallace has shown, the pressure of this structure against -the teeth promotes the normal development of the jaws, especially of -the mandible, and when it is small they are apt to be so too. - -_The salivary glands._--Just as mastication increases the functional -activity of the salivary glands and buccal glands and favours their -normal development, so, contrariwise, inefficient mastication during -early life fails to call forth their normal functional activity and -to secure their adequate development. Thus we find that a child who -has been brought up on hard, starchy foods, necessitating abundant -mastication has much larger and more active salivary glands than -one who has been fed on soft foods which slip down into the stomach -before they have had the chance of being properly masticated, and it -is needless to say that the more efficient these glands are the more -likely is digestion to be carried out satisfactorily. - -_The jaw-bones._--If the jaws are not adequately exercised in youth -by mastication they fail to grow to their normal size and shape, and -there is apt in consequence to be overcrowding of the teeth. The main -defect of the jaws in such cases is their smallness; they do not -present that pronounced lateral compression and anterior protrusion -which characterise the mouth-breather’s jaw, nor such extreme dental -irregularity, the most common being overlapping of the incisors, -displacement of the canines, and difficulties in regard to the eruption -of the wisdom teeth from shortness of the alveolar ridge. I have -already referred to the progressive shortening in the post-molar ridge, -which has been taking place during man’s evolution from the anthropoid -in correspondence with the alteration in his diet. - -We thus see that defective use of the jaws leads to irregularity of -the teeth (1) directly and (2) indirectly through the induction of -adenoids. This irregularity is not only unsightly but leads to certain -evils which thus primarily owe their origin, in large measure at least, -to defective mastication. What, then, are these evils? In the first -place, dental irregularity predisposes to dental caries by favouring -the lodgement of food between the teeth; in the next place, it leads to -defective “bite.” Now when the bite is defective adequate mastication -is impossible, for not only is it impossible in these circumstances -to oppose the teeth properly, but also, owing to their interlocking, -to accomplish that free lateral movement of the lower teeth against -the upper, which belongs to normal mastication. I do not say that -defective bite is the sole cause of this imperfect lateral movement; -it may, indeed, be observed in most moderns brought up on soft pappy -food, whether the bite be good or not. Normal mastication is, in fact, -becoming a lost art; the average modern masticates mainly by a vertical -compression of the lower teeth against the upper, and in only a small -degree by a lateral frictional movement which, it is needless to say, -is the more effective method for grinding purposes; and it is, I doubt -not, chiefly for this reason that the teeth of modern man are so much -less worn down than those of primitive peoples. - -_The teeth._--Imperfect use of the teeth leads to many ills. When -adequately exercised and made to execute for one or two hours every day -a lively dance in their sockets, during which the circulation of blood -and lymph in the tooth-pulp, periodontal membrane, and surrounding -tissue of the gum is vigorously stimulated, and the cavity of the mouth -is bathed in a copious flow of salivary and other buccal secretions, we -have conditions which make alike for the health of the buccal mucous -membrane, of the teeth, and of the periodontal membrane and alveoli; -but when the circulation is not duly stimulated in this way the teeth -do not develop properly, while the secretions of the mouth are apt to -be scanty and unhealthy, both of which conditions predispose to caries. -How far dental caries is due to inherent dental weakness and how far -to faulty conditions outside the teeth we need not stop to inquire; Dr. -Wallace attributes little influence to the former factor, contending -that caries depends essentially upon faulty dental environment; and -one can scarcely doubt that the state of the gums and of the oral -secretions profoundly influences the growth of bacteria in the mouth, -upon the acid yielded by which organisms the corrosion of the dental -enamel essentially depends. Faulty conditions of the oral secretions -likewise favour the deposit of tartar. - -Another result of imperfect use of the teeth is undue thinness of -the alveolar walls and periodontal membrane, in consequence of which -the teeth are not so firmly held in their sockets as they should be. -This is, I believe, one of the reasons why they are prone to fall -out prematurely among the moderns: we know that the teeth tend to -drop out in old people owing to a senile atrophy of the alveolar -walls; the Haversian canals get smaller and may, indeed, disappear -entirely, and it stands to reason that this atrophy must be hastened by -inefficient exercise of the teeth. So far as I am able to gather from -an examination of skulls in museums, the teeth are rarely shed among -primitive peoples before extreme old age, while among moderns they -frequently fall out long ere this is attained. - -A still worse evil attaching to insufficient use of the teeth is -pyorrhœa alveolaris or Riggs’s disease, which, in conjunction with the -deposit of tartar, is the great cause of the premature loosening and -shedding of the teeth observed among latter-day civilised peoples. -This affection consists of a purulent inflammation of the periodontal -membrane, owing to the invasion of it by pyogenic cocci, so that pus -wells up on pressing the gum against the teeth. Now, when by a vigorous -use of the teeth the buccal cavity is kept well flushed with healthy -secretions, the growth of micro-organisms within this chamber is kept -down, and when, by the same means, the vitality of the periodontal -membrane and adjacent tissues of the gum is periodically stimulated, -these tissues offer stout resistance to the invasion of pathogenic -organisms; but when, contrariwise, the teeth are little used, the -secretions of the mouth are in consequence defective both as to -quality and quantity, and the growth of organisms in the buccal cavity -is promoted; and when, further, the circulation in the periodontal -membrane and adjacent soft tissues is not adequately stimulated by -vigorous mastication, their vitality is poor and they offer but a -feeble resistance to parasitic invasion. We can thus, I think, safely -infer that inefficient mastication is a potent cause of pyorrhœa -alveolaris; and the chief cause of inefficient mastication being the -eating of soft foods, we must also conclude that the latter practice -is chiefly responsible for the disease in question; such foods further -predispose to this affection in that they are apt to lodge between -the teeth and by undergoing decomposition there to favour the growth -of micro-organisms within the mouth. The condition of the teeth and -gums among the civilised poor is, alas, little calculated to make us -proud of our boasted civilisation--the spongy pus-exuding gums, the -lengthening, loose, tartar-covered, carious teeth, and the putrescent -breath constitute a damning indictment against our modern system of -living on a soft, pappy diet, and not giving the teeth the work for -which they are designed. I never examine such a mouth without being -impressed with, and I may add oppressed by, this fact. - -I am not, of course, contending that pyorrhœa alveolaris only occurs -in those who masticate inefficiently; whatever causes an unhealthy -condition of the gums and saliva predisposes to it, but it is surely -much less common in those who masticate well than in those who -masticate ill. Confirmatory of this statement is the fact that it is -more frequent in those with irregular teeth than in those with a good -bite, who are thus able to put their teeth to more effective use. This -affection is very common among the carnivora of menageries as well as -among dogs and cats; indeed, one seldom fails to find it in dogs over -four years of age, and in old dogs it is generally rampant. Doubtless -in all these cases the general conditions of life play some part in -the causation of the disease, but I do not think that we can eliminate -from it the factor of defective use of the jaws and teeth, for it is -certain that dogs and cats are fed largely on pappy foods and are often -insufficiently supplied with bones. - -_The causation of dental caries._--Dr. Wallace, in his philosophical -work on “The Cause and Prevention of Decay in Teeth,” contends that -the cause of the prevalence of dental caries is that the natural -food-stuffs are, to a large extent, ridded of their accompanying -fibrous parts and consumed in a form which renders them liable to -lodge and to undergo acid fermentation in the mouth; while from the -same cause and the induced conditions the micro-organisms of the mouth -lodge and multiply and augment the rapidity and intensity of the acid -fermentation. I am perfectly at one with Dr. Wallace in believing -that the removal of the fibrous portions of food is the main cause of -the prevalence of caries among moderns, and I can hardly doubt that -foods so prepared tend to promote caries in the way indicated, but I -venture to think that they do this even more by failing to call forth -the normal degree of mastication. I cannot but think that if these same -soft foods were as laboriously masticated as they would need to be if -they retained their fibrous ingredients, dental caries would be much -less common than it actually is. I have endeavoured to show how very -different the local conditions are in the efficient from what they are -in the inefficient masticator--how in the former the jaws and teeth -are wont to be well developed, the bite to be good, and the secretions -which bathe the teeth to be of a kind calculated to promote their -health; and how in the latter an entirely opposite set of conditions is -wont to prevail. That it is possible to maintain a fine set of healthy -teeth till past middle life on ordinary civilised diet, provided the -food be habitually subjected to efficient mastication, is shown in the -case of the man already referred to, and by numerous other cases which -I have observed. - -Since the application of cooking to food there has been a progressive -lessening in the work of the jaws and teeth and, parallel with this, -a diminution in their size and an incursion of dental caries. Among -the anthropoids in their natural state caries is practically unknown, -and I think we may conclude that the same was true of man before he -learnt to cook. In the pre-agricultural races, such as the aboriginal -Australians, the effect of cooking the food is shown in the lessening -in the size of the wisdom teeth and of the post-wisdom alveolar -ridge; dental caries, though rare among these people, does occur, and -especially in the wisdom teeth.[27] In the early agricultural period, -owing to the increasing softness of the vegetable food, the jaws and -teeth show a tendency to be smaller than in the previous periods; the -wisdom teeth are decidedly smaller and more prone to caries, while -caries of the other teeth is by no means rare. In the late agricultural -period the jaws and teeth often show very decided defects of -development, while dental caries is, as we know but too well, rampant. - -What has been said concerning the relative prevalence of caries in -different diet epochs applies to many other diseases of the teeth; -thus, along with the increase of caries, there has been a parallel -increase in the prevalence of pyorrhœa alveolaris. - - - - - CONCLUDING REMARKS - - -I have now set forth some of the evils resulting from inefficient -mastication. They are many and serious. The immediate evils, such -as over-eating, indigestion, adenoids, dental caries, and pyorrhœa -alveolaris, are bad enough, but when we consider the secondary evils -to which these primary ones give rise,--and I have only mentioned a -few of them,--we must come to the conclusion that an appalling amount -of misery and suffering may be saved by the simple expedient of -inculcating the habit of efficient mastication. How this end can best -be accomplished will be considered in the next section. - - - SECTION IV. From _London Lancet_, August 8, 1903 - - MEANS OF INSURING ADEQUATE MASTICATION - - -In order to secure the full advantages accruing from the use of the -jaws and their appendages, it is, above all, necessary for them to be -adequately exercised during the period of development. If this is done, -not only will the tendency to dental caries, adenoids, indigestion, -and other evils be greatly diminished, but the masticatory instinct -will establish itself as a permanent force, so that the individual -will tend for the rest of his life to subject even soft foods to -thorough mastication. The tongue, the lips, and the jaws of the newly -born child find their natural exercise at the mother’s breast, and -we should, therefore, do our utmost to get the mother to suckle her -child, the bottle affording neither the same kind nor the same amount -of exercise. If, unhappily, we fail in this, we must see that the teat -of the feeding-bottle is so constructed as to compel the child to -earn his meal by, at any rate, some exercise. This kind of exercise -promotes the growth of the tongue and thus of the jaws, especially of -the mandible. Directly the infant shows a disposition to bite hard -things the instinct should be gratified. We may observe a tendency in -this direction as early as the third or fourth month, and it becomes -more and more pronounced when, the time for the eruption of the teeth -approaching, the gums begin to swell up and to get tender, and saliva -begins to flow from the mouth; it is now, more than ever, necessary to -provide the child with hard substances on which to exercise the jaws -and the gums, and a great deal of the trouble of teething is due to -the failure to recognise this fact. What, then, are we to employ for -this purpose? I am convinced that it is a mistake to rely solely, or -even mainly, upon baubles of ivory, coral, and the like useful though -these may be in their way; it is far better to give the child something -which is not only hard but nutrient and pleasant to the taste, -something which will at one and the same time exercise the maxillary -apparatus, excite the gustatory organs, and provide a certain amount -of nutriment. To this end we may, as the teething time approaches, -give a chop or chicken bone, from which most of the meat has been -removed; by powdering the bone with white sugar or salt we may increase -its attractiveness. From such bones a good deal of nutriment can be -extracted, and this of a kind which is most acceptable to the infant -stomach, for it must be remembered that the young human is in the -main carnivorous. Indeed, since milk is a purely animal diet, all the -mammals must be regarded as essentially carnivorous during the period -of suckling, while man, as already observed, from the time he emerged -from the anthropoid until he learned to cook his food, was throughout -life mainly an animal feeder. Therefore we should not hesitate to allow -the teething infant animal food in the form suggested. Chicken and -chop bones, yielding as they do before the pressure on the gums, are, -moreover, just of the right degree of consistence for the purpose in -view, while they afford abundant exercise for the tongue; ivory, coral, -and the like are, on the other hand, too hard and unyielding, and lack, -moreover, the attractiveness belonging to sapidity. - -By thus providing the maxillary apparatus with suitable exercise we -shall do much to facilitate the eruption of the teeth and to favour the -growth of the jaws and their appendages, including the salivary glands, -and so to prepare the mouth for the reception of vegetable food. This -should, of course, not be given till the teeth appear. The order in -which these make their appearance gives some indication as to the -order in which vegetable food should be administered to the child. The -first teeth to penetrate the gums are the lower incisors which appear -from the seventh to the eighth month; then follow the upper incisors -from the seventh to the tenth month. These teeth enable the child to -_bite_, but not, be it observed, to _masticate_, for which function -the molars are necessary. Now the first molars do not appear till the -twelfth or fourteenth month; the second molars not till between the -fourteenth and the twentieth month; and it seems to me certain that -our primitive ancestors could not have obtained starch in any quantity -until they reached this age; at the best, pre-cooking man was but -scantily supplied with starch, and such slender supply as he had -could only be rendered accessible to the digestive juices by vigorous -mastication, which broke up the indigestible cellulose framework in -which all vegetable starch is contained; hence, until the young human -cut his molars, he had little opportunity of securing any starch. -These considerations strongly suggest the desirability of giving but -small quantities of starch before the twelfth month, and though the -facts, that ptyaline appears in the saliva about the time the first -incisors are cut, and that pancreatic juice develops its amylolytic -ferment at the same time, show that the digestive organs are ready for -the reception of some starch at the seventh or eighth month, yet I -believe the quantity should be strictly limited. I am ready to admit -that the modern child may have, indeed probably has, a greater power of -digesting starch than his remote pre-agricultural ancestor; but even -so, I am convinced that we should be on our guard not to over-gorge -infants with this substance. Only a small quantity should be given -before the twelfth month, and it should be gradually increased up to -the twentieth month. - -I have said that the pre-agricultural infant was unable to secure -starch in any quantity by means of his incisors. These teeth enabled -him, however, to obtain some soluble nutriment from fruits, and -Dr. Sim Wallace has suggested that the early eruption of the lower -incisors is for the purpose of enabling the infant to pierce the -outer covering of fruits so as to permit him to extract the soluble -contents by suction; and, accordingly, when these teeth are cut we -may allow the child to bite at such vegetable substances as apples, -oranges, and sugar-cane. The latter is a useful article of diet for -children, for it provides soluble saccharide in a diluted form, and -it is advisable that the child should receive his cane sugar well -diluted, for it must be remembered that before the agricultural period -man’s supply of pure sugar was limited to wild honey which, consisting -as it does almost entirely of mono-saccharide (grape sugar and fruit -sugar), is very easily disposed of by the digestive organs. Nowadays, -the less digestible cane sugar (which is a di-saccharide) is very -largely consumed in the undiluted state, in which it is apt to set up -disturbance. When, however, it is obtained by chewing the sugar-cane, -it is diluted both by the water in the cane and by the saliva, and I -should like to see children obtain most of their cane sugar in this way. - -The consideration of the conditions obtaining for pre-agricultural man -not only strongly suggests that the young human of to-day should be -given starch in very moderate quantities up to the twelfth month, but -it points an even more important lesson--viz., that this substance -should be given not, as is the custom, as liquid or pap, but in a form -compelling vigorous mastication, for it is certain that early man, from -the time he emerged from the ape till he discovered how to cook his -vegetable food, obtained practically all his starch in such a form; -it cannot too often be repeated that uncooked starch in the natural -state, locked up as it is in chambers of indigestible cellulose, has no -nutritive value; these chambers need first to be broken up by prolonged -and energetic chewing, and in this way much or most of the starch is -converted in the mouth into dextrines and maltose, very little passing -into the stomach in the crude state to set up disturbance in that -organ and later in the bowel. If it is given as liquid or pap it will -pass down as starch into the stomach, while if it is administered in -a form which obliges the child to chew it properly, not only will the -jaws, the teeth, and the gums obtain the exercise which they crave, -and without which they cannot develop normally, but the starch will be -so thoroughly insalivated that much of it will be converted within the -mouth into maltose. How foolish to upset the child’s digestive system -by deluging it with liquid starch, and then to endeavour to correct -matters by giving the malt extract which the child can and should -himself manufacture within the laboratory of his buccal cavity. - -Clearly, then, the child should make his first acquaintance with -starch, not in the form of a liquid or pappy patent food, but in a -solid and somewhat tough form. The best means of achieving this end -is occupying my attention, and I hope soon to publish the results of -my investigation. Meanwhile, I would point out that hard, well-baked -crusts constitute a convenient form in which to administer starch to -children. A piece of crust may be put in the oven and re-baked; this -not only hardens it but helps to convert the starch into dextrine, -which is a stage on the road to maltose. If the crust be then cut -into a suitable shape and spread with bacon fat or fresh butter, it -constitutes a most agreeable morsel. Later, we may give hard plain -biscuits. The same principle should be acted upon during later -childhood and youth: we should always give, as far as possible, the -starch in a form compelling abundant mastication. Loaves should be -shaped so as to give a maximum of crust and a minimum of crumb, -and should be baked hard. Such loaves are quite as nutritious as -the ordinary ones, and much more digestible, containing as they do -an abundance of dextrine and not a little maltose, and compelling -efficient mastication, especially if eaten, as they should be, without -any fluid. A lady who has the catering for a large number of girls -gives the bread in this way, and she tells me that there is keen -competition for the most crusty portions. - -I do not say that starch in the liquid and pappy form should find no -place whatever in man’s dietary at the present day, for this would -imply the prohibition of porridge, boiled potatoes, milk puddings, -and the like. We cannot put back the hand of time and return to the -food of our primitive ancestors, nor is it desirable that we should; -but we can, at least, arrange matters so that a large proportion -of the starch we consume shall be in a form inviting mastication, -such as crusts, stale bread, stale cake, biscuits, and so forth. The -less children eat of pastry, or, indeed, of any luxurious foods, the -better; if brought up on a healthy dietary and under healthy conditions -generally, they will relish their simple fare more than the choicest -dishes of the epicure. I do not, I say, object to the child consuming -a certain proportion of starch in the liquid or pultaceous form, for -if, by bringing him up on a rational dietary, his instinct to masticate -be afforded due opportunity to develop he will be likely to subject -even soft vegetable food to something like adequate mastication; this -will tend to mitigate the evils associated with such food, not only by -facilitating the digestion of starch, but by flushing the mouth and -promoting the health of the teeth and buccal mucous membrane. - -The question how far children should be allowed to crack nuts may here -be considered. If the child has been brought up on pappy food, and has -in consequence brittle and ill-developed teeth, the cracking of hard -nuts will be likely to injure them, and this is _a fortiori_ true if -any of the teeth are carious or “filled.” And not only nuts but hard -food of any kind, such as ship’s biscuits, may in these circumstances -injure the teeth, as many of those who went through the recent South -African campaign can testify. But if, on the other hand, the child has -from the beginning been fed on coarse, hard foods, so that the teeth -have been allowed to grow dense and strong, no harm is likely to ensue -from cracking such nuts as filberts and Spanish nuts. If a squirrel -or a monkey weighing a few pounds can do so with impunity, surely the -young human should be able to also. The cracking should, however, be -done by the molars, while such hard nuts as Brazils had best not be -tackled at all. - -Animal food does not need the same amount of mastication as vegetable -food, since it is not digested in the mouth, though some contend that -the mixture of proteid with alkaline saliva facilitates its subsequent -peptonisation. Cooked animal food is, however, all the better for some -mastication, owing to the coagulation of the proteids, and, in order -to insure the efficient mastication of meat, fish, and poultry, Dr. -Sim Wallace recommends that they should be given in large pieces cut -thin. “Flat pieces about one inch square generally _necessitate_ a -certain amount of mastication. It is difficult to swallow large flat -pieces of meat without mastication, but when finely minced little or no -mastication is called forth.” The younger the child the more underdone -should the meat be. - - - EXAMINATION OF THE MOUTH AND ADJACENT PARTS - -If a child be brought up on the lines indicated and under healthy -conditions generally, it is tolerably certain that the maxillary -apparatus will develop normally, that the teeth will be strong and -well opposed, and show little tendency to disease; but, inasmuch as -the methods advocated are but seldom put into practice, disorders of -the teeth, more especially caries and irregularities, are common, and -hence with a view to promote more efficient mastication it is always -advisable to examine our patient’s teeth. - -Each individual tooth should be inspected in a good light for the -presence of caries, and careful note should be taken of the “bite,” -a normal bite implying not only a proper opposition of the two rows -of teeth but the capacity of the lower ones to move freely across the -upper; mere vertical movement of the mandible does not constitute -efficient mastication. In this connection it must not be forgotten that -an unopposed molar is useless for purposes of mastication, and it is by -no means rare to find in a mouth several sound unopposed molars which -are for this reason absolutely functionless. Nay, more than this, it -may happen that teeth, perfectly sound ones, too, far from helping, may -actually interfere with mastication; thus, among the poor, we sometimes -find all the teeth gone save the upper canines and the lower incisors, -and the teeth and gums being alike unable to come into contact, nothing -worthy of the name of mastication is possible; it would be far better -to be without any teeth whatever, for the toothless gums would then be -permitted to come into contact along their entire extent, under which -condition they gradually harden and come to be quite efficient grinding -agents. - -Next the gums, the alveoli, and the roots of the teeth must be -examined, especially for the presence of erosion, tartar, and pyorrhœa -alveolaris, this latter condition being evidenced by the welling-up of -pus upon pressing the gums against the sides of the teeth. - -If our examination of the mouth discloses anything likely to interfere -with mastication the aid of the dentist should at once be sought, but -every physician should be so far acquainted with disorders of the -teeth as to be able to say, in the majority of cases, at all events, -when this is necessary. I am convinced that far more illness than is -generally supposed is attributable to dental defects, and this even -among the more leisured classes. With regard to pyorrhœa alveolaris, it -has to be remembered that it not only does harm by causing loosening, -lengthening, and shedding of the teeth, and thus interfering with -mastication, but also by contaminating the stomach and the blood and -thus upsetting the digestion and causing constitutional diseases, such -as anæmia and arthritis; and inasmuch as poisonous discharges from -the nose, the naso-pharynx, the pharynx, and the tonsils may act in a -similar way, these parts also should be inspected in connection with -the examination of the teeth. In the dust-laden atmosphere of towns -they are very liable to disease, and even when healthy are necessarily -dirtied; some go so far as to advise all town dwellers daily to wash -out the nasal passages and to gargle the throat; but, whatever may be -thought of this, it is certain that under existing dietetic conditions -special means are needed in order to keep the mouth and teeth clean. -When man fed on raw food this was not necessary, the food itself -and the copious flow of saliva, induced by prolonged mastication, -effectually cleansing these parts; but, under present conditions, food -tends to remain within the mouth, especially between the teeth and in -their crevices, and therefore special means are needed to remove it. -This is done by “cleaning the teeth” and by rinsing the mouth. - -_The tooth-brush._--Probably the ideal method of cleaning the teeth -is that adopted by many primitive and not a few semi-civilised -peoples--viz., rubbing them with a twig of wood which has been teased -out at one end so as to form a sort of brush by means of which the -teeth can be burnished and food dislodged from them. The modern -tooth-brush requires to be used with great caution, as it is capable of -doing much harm, not only by removing the mucoid film, which, according -to Dr. Wallace, protects the teeth from corroding agencies,[28] but -probably also by injuring the edge of the gum and the neck of the -teeth, and thus setting up the condition known as “erosion.” Certain -it is that some of the best sets of teeth I have encountered have been -wholly unacquainted with the tooth-brush. In any case the brush should -be employed with great care; it should be soft, and should always be -drawn away from the gums both on the inner and outer aspect of the -teeth towards the biting surface, as well as across the latter, never -transversely across the outer surfaces, as so frequently is done. The -object of these procedures is to dislodge any particles of food that -may have collected between the teeth or in their crevices. For this -purpose the toothpick may also be employed judiciously. In order to -render the enamel of the teeth white it is better to rub each tooth -carefully with some soft material, such as chamois leather, rather -than to scrub them with a brush. Tooth-powders should not be used as -a matter of routine, but only occasionally and for appearance rather -than for cleanliness, and should consist of some simple non-irritant -material. Antiseptic powders and washes are to be scrupulously avoided, -for it is neither desirable nor possible to render the buccal cavity -aseptic; myriads of bacteria flourish within it, many of which play -a useful part as scavengers. The time of all others for cleaning -the teeth is just before going to bed, so that the food shall not be -allowed to decompose in the mouth during the night. There will then be -no need to use the tooth-brush in the morning. - -_Rinsing the mouth._--The mouth should be rinsed out as a matter of -routine after each meal and on rising, and care should be taken to do -this before the early cup of tea, so as not to contaminate the stomach -with the buccal secretions which have accumulated during the night. -Inasmuch as raw vegetable food has a cleansing effect on the teeth, it -is often a wise plan, especially in the case of children, to finish a -meal with some kind of fruit, such as an apple or an orange. It hardly -seems necessary to insist upon the necessity for keeping all artificial -dentures thoroughly clean. - - - - - PROFESSOR PAWLOW’S DEMONSTRATIONS OF PSYCHIC INFLUENCE IN DIGESTION - - - [In presenting a theory of human alimentation involving mental or - nervous as well as mechanical and chemical factors which influence - it for good, it is not often that an author is able to enlist the - assistance of a complete battery of scientific confirmation to fortify - his own crude observations taken direct from personal experience in - the study of natural requirements. - - Professor Pawlow, with his marvellously skilful investigation of the - workings of the digestive secretions, and Dr. Cannon of the Harvard - Medical School, by aid of persistent and patient X-ray studies, - explain how it is that earned appetite and thorough mouth-treatment - of food are preliminary necessities of easy digestion, and that - disturbance or shock of any sort during the process stop digestive - proceedings and endanger health. They show also that when the mouth is - used to do _all that it can do_ in the work of digestion all the rest - is easily accomplished by the NATURAL AUTOMATIC PROCESSES within the - body. - - They both show that we have, each of us, a certain responsibility in - the matter of right digestion and healthy nutrition, and that all - this personal responsibility is located in the head, in the mind, and - in the mouth, and that while the alimentation is proceeding it is a - sacred duty to do our part _right_, according to the intelligence that - these most valuable demonstrations teach. - - Professor Pawlow has allowed publication of his lectures in Russian - and German, and recently Professor W. H. Thompson of the Physiological - Department of Trinity College, Dublin, has made an English translation - which is issued by Charles Griffin & Company of London and J. B. - Lippincott of Philadelphia. - - The author has to express special gratitude to Professor Pawlow, - Professor Thompson, Messrs Griffin and Lippincott for permission to - reprint herein some entire lectures and extracts that bear especially - on the practical understanding of our subject. - - Professor Pawlow is one of the Board of Scientific Assessors mentioned - in the REPORT of a PLAN for an INTERNATIONAL INQUIRY into the subject - of HUMAN NUTRITION. - - In one of the lectures, not here reprinted, Professor Pawlow gives - merited recognition of the early statements of the French physiologist - Blondlot relative to psychic influence on the digestive secretions - made some half century ago, but discredited by physiologists since - that time, owing to insufficiency of evidence brought forward in - support of the statements. - - Professor Pawlow’s acknowledgment is so gracefully rendered that it is - here given as a model of scientific courtesy. - - “I have depicted the work of the gastric glands as we have seen it - in our experiments, and as it has developed under our hands. Is the - picture a new one? In its details, yes; but not in its fundamental - features. However singular it may appear, the sketch of this - picture was more than fifty years ago outlined by physiology. May - this constitute another reason for our science relinquishing its - characteristic shyness of new things and for its conversion to our - interpretation of the phenomena under consideration! - - “The talented author of the _Traité Analytique de la - Digestion_--Blondlot--spoke in plain words of the importance of taking - food, and of the specific excitability of the gastric mucous membrane. - The facts adduced in the working up of his theory were naturally - insufficient, but we must not forget that the first experiments on - dogs with artificial gastric fistulæ had only just been performed. - It is truly incomprehensible that the researches of Blondlot and his - views upon the secretion of gastric juice have experienced during the - past fifty years no completion, no additions, but, on the contrary, - have passed out of sight, thanks to the faulty experiments and - erroneous representations of later authors. Only in the works of a - few writers--and those mostly French--has Blondlot’s theory survived. - Of other investigators we must give mention to Heidenhain, who has - enriched the physiology of absorption in general, but more especially, - in connection with the secretory work of the stomach, has discovered - many important facts and has given birth to many fruitful ideas. From - him proceed the subdivision of the secretory process according to - periods and exciting agencies, as well as the suggestion that it would - be important to investigate the individual food-stuffs in relation - to the work of the stomach. Heidenhain’s results are contained in - his well-known article on the secretion of the cardiac glands of the - stomach, published in the year 1879 in PFLÜGER’S ARCHIVES. The work of - Blondlot and the additions of Heidenhain comprise almost everything - of importance which was accomplished by physiology in fifty years - concerning the conditions and mechanism of the secretory work of the - stomach during digestion. Full of moment, however, for our subject was - the obvious error that mechanical stimulation constituted an effective - excitant of the gastric glands, and this error was in its turn a - result of faulty methods.”—HORACE FLETCHER.] - - - - - LECTURE IV - - GENERAL SCHEME OF AN INNERVATION MECHANISM--THE WORK OF THE NERVOUS - APPARATUS OF THE SALIVARY GLANDS--APPETITE, THE FIRST AND MOST POTENT - EXCITER OF THE GASTRIC SECRETION - - Constituent parts of a complete innervation mechanism--The special - duty of the peripheral terminations of afferent nerves--The specific - qualities of nerve cells--Analogy between the innervation mechanism - of the salivary glands and that of the deeper-lying glands of - digestion--The exciting agencies of the nervous mechanism of the - salivary glands; their particular properties--Differences between - the exciting agencies of the different salivary glands--Discussion - of the sham feeding experiment--Mechanical and chemical stimulation - of the cavity of the mouth has no effect on the gastric glands--The - experiment of Bidder and Schmidt relative to psychic excitation of - the gastric secretion--Conditions for success in this experiment--The - passionate longing for food--the appetite--alone brings on the - secretory effect in the sham feeding experiment. - - -GENTLEMEN,--As you have learned in the last lecture, and also in part -have seen by direct experiment, the nervous system can influence the -work of our glands in the most diverse ways. The vagus nerve, already -burdened with many duties, has, in addition, proved itself to be an -undoubted exciter of the gastric glands and of the pancreas. But we -must also assign to the sympathetic nerve a similar _rôle_. This is a -matter which cannot be doubted, so far as the pancreas is concerned, -and is highly probable as regards the stomach. We also saw good reason -for believing that these two nerves contained two different classes -of fibres, secretory and trophic, a condition which had already been -proved to exist by Heidenhain for the nerves of the salivary glands. -As a hypothesis we might even have proceeded a step farther and have -divided Heidenhain’s trophic nerves into separate classes of secretory -fibres. Lastly, we advanced important experimental evidence to show -the existence of special inhibitory fibres to the glands, and these -fibres also run in the vagus, the list of whose functions seems almost -interminable. - -We obtained these results by division and artificial excitation of -the nerves which run to the glands. But when, how, and by what means -these nerves are thrown into activity during the normal course of -physiological events remains a question. - -In order to avoid repetition, and at the same time impart the utmost -clearness to our representation, it may be useful to bring before your -minds at once the plan of innervation of a given organ, all the more -since this scheme is seldom completely followed out or adequately -described in physiological text-books. Consequently, it is not borne in -mind with sufficient precision by the majority of medical men. - -A complete innervation mechanism consists of the peripheral endings of -the centripetal (afferent) nerves, the centripetal nerves themselves, -the nerve cells (a group of nerve cells connected with each other is -termed a “nerve centre”), the centrifugal (efferent) nerves, and, -lastly, their peripheral terminations. Physiology now accepts it as a -settled fact, that nerve fibres serve only as _conductors_ of nervous -impulses, which come in from contiguous links of the nervous chain. -Only the peripheral endings of nerves and the nerve cells themselves -have the power of transforming the external stimulus[29] into a -nervous impulse. In other words, in the intact organism these alone -constitute the normal receiving apparatus of the nervous system. -Whether the peripheral ends of centrifugal (efferent) nerves are -likewise able to function as normal sites for the application of -external stimuli has still to be answered. Consequently, when any -external agency excites the peripheral terminations--the receiving -stations--of centripetal nerves in this or that organ, the effect -of the stimulus will be conveyed through the centripetal nerves, as -through a receiving wire, to the central station--the nerve cells. Here -it becomes changed into a definite impulse and now comes back along the -centrifugal nerves--the outgoing wires. - -The utmost importance is to be attached to the fact that only the -peripheral endings of centripetal (afferent) nerves, in contrast to -nerve fibres themselves, respond to _specific_ stimuli; that is to -say, are able to transform definite kinds of external stimuli into -nervous impulses. The function of the end organs with which they are -connected is therefore of a purposive nature; in other words, these -organs are only called into play by certain definite conditions, and -impart the idea of being aware of their purpose, of being conscious -of their duty. We have long known that the peripheral endings of -sensory nerves are possessed of a high degree of speciality, and cannot -therefore have any doubt regarding the specific nature of the end -organs of other centripetal nerves. This is a sore point in present-day -physiology. But, notwithstanding our knowledge of the separate parts -of the animal body, we shall only be able to form a true conception -of the motive agencies of the whole complicated machine, when we have -established the specific excitability of the end apparatus of every -centripetal nerve, and have discovered all the mechanical, chemical, -and other factors which throw this or that end apparatus into an active -condition. I always look upon it as a period of scientific inadequacy -so long as the effects of the most diverse external agencies upon any -normal physiological process are admitted to be indistinguishable. As -the work of the digestive canal is now represented in the majority of -text-books, and consequently presented to the mind of the physician, -it bears the impress of this period. To impart to the physician a more -correct conception of this matter was my chief object in giving these -lectures. I hope, indeed, to furnish you with evidence sufficiently -convincing, that the alimentary canal is endowed not with mere general -excitability; that is to say, does not respond to every conceivable -form of agency, but only to special conditions which are different -for the different portions of its length. Just as men and animals in -the world are only able to maintain their existence and constantly -adapt themselves to changing circumstances by aid of the peripheral -endings of their sensory nerves, so every organ, indeed every cell -of every organ, can only maintain its place in the animal microcosm, -and adapt itself to the activity of innumerable associates, as well -as to the general life of the whole, by virtue of the fact that the -peripheral end apparatus of its centripetal nerves possesses a specific -excitability. - -The same applies to the nerve cells: obviously they are endowed -with specific sensibility. Irrespective of the excitations which -are communicated to them from centripetal nerves, they respond, as -originators of nervous impulses, only or at least mainly to definite -forms of mechanical, chemical, or other stimuli arising in the -organism. This follows not alone from a number of physiological facts -but also from various pharmacological data. Thus we learn that various -drugs excite or annul the activity of definite portions of the nervous -system, at least in the earlier phases of their effects. This specific -excitability of nerve cells, just as much as the same property of -peripheral end organs, lies at the bottom of the purposive action of -these organs. - -Hence, our next duty is to endeavour to discover the normal exciting -conditions of the centripetal nerves belonging to the glands which -we had under consideration in our last lecture, or, more correctly, -to find out the conditions which excite the centres, as well as the -peripheral endings of the different nerves, which form parts of the -nervous apparatus of these glands. We have, therefore, for each phase -of the work of secretion, to find out that portion of the nervous -mechanism which is for the time being under excitation, and to -discover the primary agency by which this condition is elicited. This -would include an exact analysis of the stimulating influence which -mastication and food exert upon the nervous mechanism of these glands. -We shall also be able more fully to comprehend the inner mechanism -underlying the facts which formed the subject of the second lecture. -This, of course, is an ideal programme which we can only follow out -as far as the present state of physiology permits. It may now be -instructive, and, for our further conclusions, advantageous, to glance -shortly at the nervous control of the salivary glands. - -The salivary glands, whose innervation has long ago been investigated, -have generally been accepted as types of the deeper-lying digestive -glands, and when it became necessary to form a conception of the mode -of activity of the latter, medical science resorted to a bold analogy -and thought of the nervous apparatus of the salivary glands. But -the attempts of investigators to apply rigidly to others the scheme -of innervation which holds good for the salivary glands, have done -considerable harm to the usefulness of the analogy and have prevented -our arriving at a correct idea of the plan of innervation of the -abdominal glands. We have already had an example of this nature before -us. In the salivary glands we have no clearly marked indications of -nervous inhibition, and this circumstance has decidedly retarded -the due development of our knowledge of the nervous control of the -abdominal glands. Authors naturally expected to see a simple and -prompt stimulation-effect from the same conditions of experiment which -sufficed for the salivary glands, and the failure of this gave them, -as they thought, the right to deny the existence of any extrinsic -nervous influence upon the abdominal glands. The error is now obvious; -the abdominal glands behave in some ways different from the salivary -glands, and for their successful investigation, other conditions of -experiment are necessary than those which held good for the former. In -the working of the abdominal glands nervous inhibitory processes play -a large part, but they are almost wholly absent in the case of the -salivary glands. This is an additional warning that one must never push -the conclusions drawn from analogy too far, but must constantly bear in -mind that the life-functions of all organs are extremely complicated, -and that the work of even the most apparently similar organs should -be submitted to separate and careful observation. To me it appears -that the unjustified analogy drawn between the abdominal and salivary -glands has to be credited with another important misapprehension. -And precisely for this reason I think it desirable to bring under -consideration, if only in brief fashion, the conditions of work of the -salivary glands, especially since Dr. Glinski has instituted in the -laboratory some easily performed experiments which bear upon the matter. - -The experiences of daily life teach us from the outset, that the -activity of the salivary glands begins even before the introduction -of food into the mouth. With an empty stomach, the sight of food or -even the thought of it is sufficient to set the salivary glands at -once into activity; indeed, the well-known expression, “to make one’s -mouth water,” is based upon this fact. Hence a psychic event, the eager -longing for food, must be accepted as an undoubted excitant of the -nervous centre for the salivary glands. On the other hand, the same -every-day experience, as well as numerous experiments upon animals, -teach us that a number of substances, when brought into contact with -the mucous membrane of the mouth, are likewise able to call forth a -secretion of saliva. One even acquires the impression that everything -brought into the mouth may reflexly influence these glands, the only -difference being a gradual shading off in the effect, dependent upon -the strength of the stimulation which the substance introduced is able -to exert, and it appears to me that it is precisely this impression -which has driven the idea into the background, that the peripheral -end apparatus of the centripetal nerves of the digestive canal are -specifically excitable. The facts were here correctly observed, but -their indications erroneously interpreted. - -The great multiplicity of excitants of salivary secretion, has without -doubt, some connection with the complicated physiological functions -of the saliva. This is the first fluid encountered by everything -which enters the alimentary canal. It must, therefore, in a sense -play the part of host to every substance taken in--moisten the dry, -dissolve the soluble, envelop the hard and bulky with mucus in order to -facilitate its passage down the narrow œsophagus; and submit certain -forms of food material, such as starch, to a process of chemical -elaboration. Nor is its duty by any means ended here. The saliva is -secreted in the first compartment of the alimentary canal, which is at -the same time the sorting-room of the organism. Much of what enters the -mouth may prove in the testing process to be useless, or even noxious, -and must either have its deleterious properties neutralised or be -completely rejected. The saliva is secreted in the first instance to -obviate injurious effects in some way; thus, for example, a strong acid -is to a certain degree neutralised, while other corroding substances -may be simply diluted, and by mere reduction of concentration have -their harmfulness diminished. - -In the second place, when the injurious substances have to be wholly -removed, the saliva plays the _rôle_ of a washing-out fluid; otherwise -the material, by clinging to the mucous membrane of the mouth, might in -longer or shorter time gain entry into the blood and there develop its -noxious influence. This last function of the fluid is hardly taken into -account at all in physiology, and yet it is evident that the saliva, -as a cleansing fluid, must have a wide importance. If you only think -of how often we are impelled to expectorate, that is, to wash out the -mouth with saliva after something unpleasant, this will be clear. -Such a view finds additional support when we reflect that a feeling -of disgust produces almost as strong a flow of saliva as the sight -of a tasty meal. In both cases the secretion performs the office of -forerunner: in the first it prepares for the washing out of the mouth, -in the second for the requisite elaboration of the food. Think how -often, when something disagreeable enters the mouth, with what rapidity -the saliva is poured out, even after the unpleasant substance has been -for a considerable time removed, and not a trace more is apparent to -the sense of taste. Indeed, long afterwards one has only to recall -the circumstances to mind in order to bring on anew the secretion of -saliva. Apparently the psychic excitation of the nerves of salivary -secretion also ushers in the act of vomiting, which, as is well known, -can be called forth by mental influence. Further, the function of the -saliva just mentioned is probably the true physiological explanation of -the feeling of disgust which many persons experience at the sight of -the secretion itself. - -Hence I hold that substances which obtain entry to the mouth set up a -secretion of saliva only because we have here the seat of a definite -physiological sense, and not because the peripheral terminations of the -buccal nerves are devoid of specific excitability, and capable of being -thrown into action by every desired form of stimulus. In other words, -the specific excitability of the peripheral endings of the salivary -nerves is very comprehensive and widely extended. This is no picture -of the imagination, for it can be supported by facts. To say nothing -of the testimony of earlier authors, that the salivary glands have -each particular exciting agencies to which they specially respond, we -can demonstrate the following facts from the material collected in our -laboratory. - -Dr. Glinski isolated the orifices of the salivary glands in dogs with -portions of the adjoining mucous membrane, brought them out of the oral -cavity, and caused them to heal into the edges of the skin wounds. In -his first animal the ducts of the submaxillary gland were thus led -outwards. By means of a Mendeljeff’s clip, the wide end of a conical -funnel of waterproof material was attached to the skin surrounding -the orifice. To the narrow end a small test-tube, which served to -collect the saliva, was attached by a wire. I now offer such an animal -a piece of flesh, and, as you see, the tube fills up at once with -saliva. I stop tempting the dog, hang on a new test-tube, and give it -a few pieces of flesh to eat; once more a strong secretion of saliva -results. A new tube is now attached to the funnel, the dog’s mouth is -opened, and a pinch of fine sand thrown in; again there is a flow of -saliva. Once more a new test-tube; and now I apply to the buccal mucous -membrane, the plume of a feather dipped in acid solution, with the -result that I obtain a strong flow of saliva. One may employ a number -of substances in this way, when a similar effect is always produced. -You see, in this, such a comprehensive excitability of the innervation -apparatus of the salivary glands that you might readily interpret it as -meaning the power of response to all and sundry forms of stimulation. -We now proceed, however, to another dog, whose parotid duct has in -a similar manner been diverted outwards. The saliva is collected in -the same way. We tempt the dog with a piece of flesh, but to our -astonishment no saliva flows, and yet the animal is most eager for the -savoury meal offered. Now we give it some raw flesh to eat; again the -secretion of saliva is as good as absent; only when I come near can I -detect one or two drops of saliva running down the sides of the tube. -Probably you will say there is something wrong, either with the method -or with the glands of the animal. But wait a little. I now give the dog -finely powdered dry flesh, and obtain at once an abundant secretion. -Should any one happen to think that the variation in the result is -dependent, not on a different specific activity of the glands, but on -individual differences in the dogs, I respond that Dr. Glinski has had -an animal with double parotid and submaxillary fistulæ, and was able to -observe on one and the same dog, a like behaviour on the part of the -glands to that which we have just seen in two different individuals. An -analogous experiment with bread was also carried out by Dr. Glinski. -The eating of fresh moist bread produced no secretion worth mentioning, -while dry bread, on the other hand, caused the saliva to flow in large -quantities. The results of this experiment permit us to draw extremely -instructive conclusions. In the first place, the several salivary -glands are, as a matter of fact, very sharply differentiated in the -conditions necessary for their activity--that is to say, in respect -to the agencies which excite their nervous mechanisms. Secondly, the -innervation apparatus of the parotid manifests a very sharp selective -power in the choice, so to speak, of an adequate stimulus. The -mechanical effect of large pieces of flesh is naturally much greater -than that of the finely powdered material, and yet it was precisely -to the latter that the glands responded. The stimulus is, therefore, -not due to the mechanical, but to some other property of the food. -This other property is obviously the dryness of the material. Our -example illustrates how that which we may term “purposiveness” comes -into play in the working of our glands and also how erroneous is the -opinion that the mechanical stimulus is all potent. Indeed, previous -authors have already pointed out that dry substances cause a specially -free secretion of saliva, and yet physiological opinion throughout the -length and breadth of the land, as expressed in text-books, has chosen -to recognise a _universal_ instead of a _specific_ excitability. Dr. -Wulfson, who is at present carrying on the investigation of salivary -secretion in our laboratory, has added a very interesting observation -to the results of Dr. Glinski already related. The parotid gland, which -is hardly, if at all, excited when one offers fresh meat to the animal, -responds with a very active secretion, when dry food (bread or powdered -meat) is offered. This phenomenon is all the more surprising since the -desire of the animal for eating is much more strongly excited by flesh -than by dry bread. I am quite convinced that an exact study of the -exciting agencies of the three salivary glands will furnish a number of -new data bearing upon the question in hand. - -The second reagent which is poured out on the raw material in the -digestive canal is the gastric juice. How, in the normal course of -events, is the work of the gastric glands, which prepare this juice, -called into play? With the first, and manifestly important factor, -which has a relation thereto, you are already acquainted, and, indeed, -have already seen. I refer to the production of gastric juice in the -empty stomach, as a result merely of the swallowing of food in the -so-called sham feeding of an œsophagotomised dog. When one takes -into consideration the absolute independence of this factor, and the -intensity of the effect, which makes itself evident in the secretion of -a large quantity of juice of high digestive power, the exciting agency -which brings about such secretion must be recognised as one of the most -important and effective processes in gastric digestion. But in what -does it consist? At first sight it appears--and when I previously drew -your attention to the fact I expressed the opinion--that there is here -a simple reflex effect from the cavity of the mouth upon the secretory -nerves of the stomach, similar to the reflex excitation, _e.g._, of the -parotid gland, by finely powdered flesh thrown into the mouth. Now, -however, I assert quite emphatically that this is not the case. We -have, it is true, in the activity of the salivary glands an analogous -phenomenon to indicate--not, however, that of which we have just -spoken. We might apply every conceivable form of stimulus which could -possibly come into play in the act of eating, and yet would not obtain -the slightest indication of secretory activity in the stomach. In this -dog with a gastric fistula, and with also a divided œsophagus, I will -try such an experiment, using the most effective chemical stimulus to -the buccal mucous membrane, viz., acid solution. - -The secretion of saliva begins at once, as you see; the acid is, -therefore, effective. From the stomach, however, in spite of continued -excitation, no secretion results, although the acid, mixed with the -saliva, is swallowed and flows out again from the upper segment of the -œsophagus--that is to say, passes along precisely the same path that -the food takes in sham feeding. - -We could experiment in the same way with a number of other substances: -saline, bitters, pepper (strong local excitation), mustard, and so -on, and always with the same results; a free secretion of saliva, but -perfect quiescence of the gastric glands. We may even, with the same -object, employ the soluble constituents of flesh in the form of a -decoction, and likewise observe, in most cases at least, no sign of -activity on the part of the gastric glands. - -With the chemical we may also combine a mechanical stimulus. We can, -for example, wipe out the mouth with a sponge soaked in the solution -to be experimented with, but always with the same negative result. -We may finally give such pieces of sponge, or even smooth stones of -considerable size, to the dog to swallow, passing them back behind the -anterior pillars of the fauces and allowing them to fall out again, -from the upper portion of œsophagus. It may be added that a well-taught -dog puts up with all these procedures without the slightest protest. -You see that all the manipulations in this case are carried out with -bare hands and without instrumental aid. One can easily train a dog -to swallow stones which are placed in the anterior part of the buccal -cavity. It simply makes a few chewing movements and swallows them down. -The dog on which the acid experiment has just been made serves also for -the swallowing of the stones. The attendant now places some pebbles in -the front part of the mouth, when the animal rolls them round, as if -chewing and gnawing them, and then swallows them. The stones fall out, -as you see, from the œsophagus, and drop with an audible sound upon -the table. This play with the stones has now lasted fifteen or twenty -minutes (in the laboratory we have often kept it up for hours), and yet -not a drop of gastric juice is to be seen. - -In order to prove that the dog is perfectly healthy and normal, we lay -aside the stones and proceed to our old experiment of sham feeding. As -you see, the first drop of gastric juice makes its appearance precisely -at the end of five minutes, and after a further five minutes we have -collected more than 15 c.c. of the fluid; consequently there can be no -doubt that in this dog both gastric glands and nerves are uninjured -and function in normal manner. At one time we even had a dog which -voluntarily took the stones out of one’s hand and swallowed them; the -sagacious creature had seen our object in previous experiments and -learned to perform it of its own accord! But in this case also the -result was negative. - -Clearly, therefore, neither chemical nor mechanical stimulation of -the buccal mucous membrane is capable of reflexly exciting the nerves -of the stomach. Further, it is obvious that the excitation of these -nerves in sham feeding is not the result of a stimulation coincidently -produced; that is to say, the excitement of the chewing and swallowing -centres does not imply simultaneous action of the secretory centre of -the gastric glands. In what, then, does this influence consist which -is intrinsic to the sham feeding, but which we have not been able to -reproduce in our analytical investigation? There is only one thing -to think of, namely, the eager desire for food, and the feeling of -satisfaction and contentment derived from its enjoyment. - -It has, indeed, been known for forty years, thanks to the experiments -of Bidder and Schmidt, that at times, the offering of food to a -hungry dog, in other words, the excitement of a keen desire for -it, is sufficient to cause a flow of gastric juice from the empty -stomach. We shall presently have occasion to observe the force of this -physiological factor. Here I bring before you another dog, likewise -having a gastric fistula with divided œsophagus. The stomach has been -washed out half an hour ago, and since then not a drop of gastric juice -has escaped. We begin to get ready a meal of flesh and sausage before -the animal as if we meant to feed it. We take the pieces of flesh from -one place, chop them up, and lay them in another, passing them in front -of the dog’s nose, and so on. The animal, as you see, manifests the -liveliest interest in our proceedings, stretches and distends itself, -endeavours to get out of its cage and come to the food, chatters its -teeth together, swallows saliva, and so on. Precisely five minutes -after we began to tease the animal in this way the first drops of -gastric juice appear in the fistula The secretion grows ever stronger -and stronger, till it flows in a considerable stream. After the -lapse of a few minutes we can count the number of cubic centimetres -by tens. The meaning of this experiment is so clear as to require no -explanation; the passionate longing for food, and this alone, has -called forth under our eyes a most intense activity of the gastric -glands. If the experiment be frequently repeated, one can easily -observe that the keener and more eager the desire on the part of the -dog for the food, the more certain and intense is the secretory effect. -In extreme cases there is even a quantitative relationship between this -effect and that of the sham feeding. - -Here is an experiment of Professor Ssanozki, in which the secretory -effect of the mere tempting of the animal with the sight of food is -compared with that of sham feeding. A few threads of alkaline mucus -had just escaped from the stomach, and then the excitation of the dog -with flesh was begun. After six minutes the secretion commenced and -continued as follows: - - Duration of the flow. Quantity of the juice. - 8 minutes 10 c.c. - 4 ” 10 ” - 4 ” 10 ” - 10 ” 10 ” - 10 ” 10 ” - 8 ” 10 ” - 8 ” 10 ” - 19 ” 10 ” - 19 ” 3 ” - -Then followed a sham feeding for six minutes. - - Duration of the flow. Quantity of the juice. - 17 minutes 10 c.c. - 9 ” 10 ” - 8 ” 10 ” - -It is clear that in this case the tempting, instead of being less -effective than the sham feeding, on the contrary excelled it. - -Consequently, the observation of Bidder and Schmidt was perfectly -correct. It cannot, however, be said that it received general -recognition in physiology, or that it was sufficiently appreciated. -There are authors who could never convince themselves of its reality, -and in many physiological text-books it is not once mentioned. By -way of explanation, we shall now consider how this matter must be -dealt with by those who wish to observe the effect. It is only under -certain conditions that it can be seen. Firstly, the animal must be -healthy and vigorous; it must have a perfectly uninjured gastric -mucous membrane; and this, from the description in the case of many -authors who obtained a negative result, was not the case. Secondly, -the success of the experiment, as stated above, is dependent upon the -intensity of the desire for eating, and this, again, is dependent -upon how freely and how long beforehand the dog had eaten, and also -upon what it is tempted with, whether with a dish that excites its -desire or leaves its interest unawakened. It is known that dogs have -very different tastes, just as men have. Thirdly, one may find among -the dogs positively careless, indifferent creatures, incapable of -being perturbed in this way by anything which has not actually reached -their mouths, and patiently waiting till the food is given them. Hence -for success in the experiment, eager, impressionable, and excitable -animals are necessary. Fourthly, one has to reckon with the sense and -cunning of the dog, a factor which is not lightly to be disregarded. -Often the animals perceive at once that they are only being teased -with the food, become annoyed thereat, and turn away offended at what -is being done before them. We must, therefore, so arrange matters as -if the animals were not going to be disappointed but fed in reality. -If attention be paid to these conditions the experiment of “psychic -excitation of the gastric secretion,” as we usually term it, will be -found to be as reliable as the experiment of sham feeding. When one is -occupied for a length of time with the study of the gastric secretion -under different conditions, one becomes convinced of what a dangerous -source of error this psychic excitability may become in the different -experiments. We must constantly fight, so to speak, against this -factor, keep it ever in view, and guard against it. If the dog has not -eaten for a long time, every movement,--the going out of the room, the -appearance of the attendant who ordinarily feeds the animal--in word, -every little triviality may give rise to excitation of the gastric -glands. The minutest attention is necessary in order to avoid such -sources of error, and we should not be far wrong if we said that much -which has been ascribed in former investigations to the effect of this -or that agency was in reality a result of unobserved psychic influence. -Consequently, in order to verify our own conclusions concerning the -effects of this or that condition, we have performed many of our -experiments on sleeping animals, having beforehand convinced ourselves -by frequent repetition that sleep exercises no restraining influence on -the working of the gastric glands. - -When we recall to mind the failure of our attempts to obtain a -secretion of gastric juice by any stimulation whatever of the buccal -mucous membrane, and at the same time see how constant and intense the -action of this psychic impression is, we are forced to the inevitable -conclusion that in our sham feeding experiment the whole secretory -effect is due to the psychic stimulus, that is to say, to the keen -desire on the part of the animal for food and the satisfaction of -enjoying it. - -In view of the importance of the act of eating, which even now is -apparent, but which will become still more obvious when the succeeding -periods of secretion are investigated, we have spared neither time nor -trouble to arrive at a correct explanation of the mechanism of this -factor. We have, therefore, taken in hand a number of modifications of -the sham feeding experiment, and these investigations have confirmed -the opinion at which we had arrived. If, for instance, the dog has -been prepared by a long fast of two to three days, a very intense -secretion of gastric juice will always be obtained by the sham feeding -experiment, no matter what may be given it to eat, whether boiled or -raw flesh, bread or coagulated egg-white, etc. The dog, however, which -has not fasted, that is to say has been fed fifteen to twenty hours -before, will pick and choose amongst the different foods, eating one -with great greed, tolerating another, and refusing altogether a third, -and, corresponding therewith, the amount and quality of the gastric -juice will manifest wide variations. The more eagerly the dog eats -the more juice will be secreted and the greater the digestive power -which it possesses. The majority of dogs prefer flesh to bread, and -correspondingly less juice will be produced by sham feeding with bread -than with flesh. Sometimes, however, we find dogs which will devour -bread with greater appetite than flesh. In these cases one obtains -more and stronger juice in sham feeding with bread than with flesh. -Here is a case in point: a dog is given boiled meat which has been -cut into pieces of definite size, and the pieces follow each other -at regular intervals of time. The animal eats, but soon, from its -behaviour, you see that it develops no particular greed for the meal, -and this observation is confirmed by the fact that after fifteen to -twenty minutes it ceases taking the flesh. The secretion of juice has -meanwhile either not begun at all, or only after a longer interval -than five minutes, and remains scanty to the end. Now wait till the -secretion has stopped and give the same dog raw flesh, either forthwith -or next day, in pieces of the same size and at the same rate as -before. The raw meat tastes excellently to the dog; it eats for hours -at a time; the secretion of gastric juice begins precisely after five -minutes and is very active. With another dog which prefers boiled to -raw meat exactly the reverse occurs. Broth, soup, milk--towards which -dogs are usually more indifferent than towards solid food--often -produce in sham feeding either no secretion at all or only very little, -although broth, for instance has essentially the same taste as flesh. - -It is therefore clear that in sham feeding the psychic effect may -readily become an absolute and independent factor. All the conditions -which we enumerated above, and which are necessary for the successful -production of the psychic effect, hold good in combined form for the -sham feeding experiment. The dog eats with greed before one’s eyes; -the food which it receives is pleasant; it not only imagines food but -actually eats it, and has therefore no reason to feel offended, for -naturally the idea does not occur to any of the dogs that all their -trouble is in vain. - -Consequently, in the sham feeding experiment, by the act of eating, -the excitation of the nerves of the gastric glands depends upon a -psychical factor which has here grown into a physiological one, that -is to say, is just as much a matter of course, and appears quite as -regularly under given conditions as any other physiological result. -Regarded from the purely physiological side, the process may be said -to be a complicated reflex act. Its complexity arises from this, that -the ultimate object is attained by the joint working of many separate -organic functions. The material to be digested--the food--is only found -outside the organism in the surrounding world. It is acquired not -alone by the exercise of muscular force, but also by the intervention -of higher functions, such as judgment, will, desire. Hence the -simultaneous excitation of the different sense organs, of sight, of -hearing, of smell and taste, is the first and strongest impulse towards -the activity of the gastric glands. This especially applies to the two -latter senses, since they are only excited when the food has already -entered the organism, or at least has arrived very near it. It is by -the establishment of this passionate desire for eating that unerring -and untiring nature has linked the seeking and finding of food with the -commencement of the work of digestion. That this factor, which we have -now carefully analysed, stands in closest connection with an every-day -phenomenon of human life, namely, appetite, may easily be predicated. -This agency, which is so important to life and so full of mystery to -science, becomes here at length incorporated into flesh and blood, -transformed from a subjective sensation into a concrete factor of the -physiological laboratory. - -We are therefore justified in saying that the appetite is the first -and mightiest exciter of the secretory nerves of the stomach, a factor -which embodies in itself a something capable of impelling the empty -stomach of the dog in the sham feeding experiment to secrete large -quantities of the strongest juice. A good appetite in eating is -equivalent from the outset to a vigorous secretion of the strongest -juice; where there is no appetite this juice is also absent. To restore -appetite to a man means to secure him a large stock of gastric juice -wherewith to begin the digestion of the meal. - - - - - LECTURE V - - PERIOD OF OCCURRENCE AND IMPORTANCE OF THE PSYCHIC OR APPETITE JUICE - IN THE SECRETORY WORK OF THE STOMACH--THE INEFFICIENCY OF MECHANICAL - STIMULATION OF THE NERVOUS APPARATUS OF THE GASTRIC GLANDS - - The psychic secretion is the normal commencement, in the majority of - cases, of secretory activity on the part of the gastric glands. If - the meal be subdivided and administered at intervals, the psychic - juice appears each time--Demonstration of “appetite juice” in a dog - with an isolated gastric _cul-de-sac_. The work of the gastric glands - if appetite juice be avoided by introducing food through a gastric - fistula unperceived by the animal--Digestion of flesh by the stomach - with and without sham feeding--Duration of the secretory influence of - sham feeding--After the cessation of the psychic effect, how is the - secretory work of the stomach maintained?--Experiments to prove the - ineffectiveness of mechanical stimulation: excitation of the mucous - membrane by means of a glass rod, a feather, a puff of sand, and by - rhythmic dilatation of an india-rubber ball--Contact between the food - and the stomach-wall may indirectly call the activity of the glands - into play by awakening or increasing the desire for food. - - -GENTLEMEN,--On the last occasion we made ourselves acquainted with -the first normal impulse which, in the natural course of events, -calls into activity the innervation apparatus of the gastric glands. -This impulse is a mental one, and consists in a passionate longing -for food, that which in every-day life, and in the practice of the -physician, is called “appetite,” and which everybody, both medical -and lay, endeavours carefully to promote. We may now venture to say -explicitly, APPETITE IS JUICE, a fact which at once displays the -pre-eminent importance of the sensation. Medical science endeavours to -assist the debilitated stomach by introducing the active constituent of -gastric juice--pepsin--from without, or by prescribing other remedies -believed to promote its secretion. It is, however, of interest to -follow our experimental investigation still farther. What position is -to be assigned to the “psychic” or “appetite-juice”[30] in the course -of normal gastric digestion? Is any definite _rôle_ to be attributed -to it? What course does gastric digestion take when it is absent? -Fortunately to all these important questions satisfactory answers are -forthcoming by experiment. We have only to regret that these answers -come so late. - -Let us recall to memory how the secretion of gastric juice proceeded -after feeding with flesh or bread in the case of our dog with the -isolated miniature stomach. The following are the quantities and -digestive capabilities of the first two hourly portions of juice after -the administration of 200 grams of flesh or bread (experiments by Dr. -Chigin): - - ═════╤═══════════════════╦═══════════════════ - │ Flesh. ║ Bread. - Hour.├————————-┬————————-╫—————————┬————————— - │Quantity │Digestive║Quantity │Digestive - │of juice.│ power. ║of juice.│ power. - —————┼————————-┼————————-╫————————-┼————————— - 1st │12.4 c.c.│ 5.43 mm.║13.4 c.c.│ 5.37 mm. - 2nd │13.5 ” │ 3.63 ” ║ 7.4 ” │ 6.50 ” - ————-┴—————————┴————————-╨—————————┴————————— - -You see at once that the secretion of the first hour is identical in -the two cases both as regards quantity and digestive power, and only in -the second is the secretory work differentiated according to the nature -of the food. How are we to explain the secretion which takes place at -the commencement? Is it not the same which we have already seen in the -sham feeding experiments? Is not this first onrush of the stream of -secretion the preliminary psychic juice? Unquestionably, gentlemen, -this is the case, and we may convince ourselves of the fact in the -most diverse ways. Above all, the following is clear: whatever occurs -in the so-called sham feeding cannot wholly be absent in the case of -normal feeding, since the former is nothing else than the isolated -commencement of normal digestion. This justifiable inference is fully -confirmed, if the secretion of the first hours after the administration -of flesh and bread be compared with that after simple sham feeding. In -the case of feeding with flesh and bread, the identically similar and -high digestive power of the first hourly portions is striking, and this -power coincides with what we have met in sham feeding. Further, if the -quantity of juice from the miniature stomach during the first hour be -compared with that produced by the non-resected part of the organ,--to -do which we must multiply it by ten, since the resected _cul-de-sac_ -is approximately one-tenth of the whole organ,--it is here again found -that the quantity approximately corresponds to the mean values obtained -by sham feeding. Finally, the depression in digestive power or quantity -of juice (with flesh, decrease of digestive power; with bread, decline -in the quantity of juice), which sets in soon after the taking of food, -indicates that the two conditions are connected with the ingestion -of food--_i. e._, with a transitory factor which soon passes away -and gives place to other conditions. Our explanation becomes still -more convincing when we take into consideration the effects of other -foods. If you give the dog, for example, something else to eat which -does not interest it to the same degree as flesh or bread, you will -find the initial increase in quantity and strength of juice does not -appear. Offer the animal milk, for example, which in sham feeding, -especially if it does not last long, calls forth, as a rule, no -secretion, or at all events only very little, and the rapid flow of the -commencement--the already-mentioned initial rise--absolutely fails to -appear. You have already seen the figures which deal with this matter; -I think it necessary, however, to bring them forward again in order -that you may be better able to compare them with the secretion after -flesh and bread. - -The dog was given 600 c.c. of milk (experiment by Dr. Chigin). - - Hour. Quantity of juice. Digestive power. - 1st 4.2 c.c. 3.57 mm. - 2nd 12.4 ” 2.63 ” - -We have now begun the analytical examination of the variations of our -secretory curve. But owing to the importance of the matter we did not -confine ourselves to conclusions which might be drawn from earlier -investigations. We turned to new forms of experiment for further proof. - -Thus we divided the ordinary ration of flesh given to our dogs--400 -grams--into four equal parts, which were administered at intervals of -an hour and a half. (Experiments by Privat docent Kotljar and Dr. -Lobassoff.) Each time after the dog received its 100 grams of flesh we -were able to detect a rise both in the quantity and in the digestive -power of the juice. The following table shows the figures in question: - - ══════════╤═══════════╤═══════════╤═══════════════════════ - Half-hour │ Quantity │ Digestive │ - periods. │ of juice. │ power. │ Remarks. - ——————————┼———————————┼——————————-┼——————————————————————— - 1st │ 3.1 c.c. │ 5.13 mm. │ 100 grms. flesh given. - 2nd │ 5.0 ” │ 4.63 ” │ - 3rd │ 4.7 ” │ 4.50 ” │ - 4th │ 5.4 ” │ 4.88 ” │ 100 grms. ” ” - 5th │ 5.5 ” │ 3.38 ” │ - 6th │ 4.7 ” │ 2.75 ” │ - 7th │ 6.0 ” │ 3.75 ” │ 100 grms. ” ” - 8th │ 5.4 ” │ 2.50 ” │ - 9th │ 5.9 ” │ 2.50 ” │ - 10th │ 5.4 ” │ 3.88 ” │ 100 grms. ” ” - 11th │ 5.3 ” │ 3.0 ” │ - 12th │ 4.2 ” │ 2.5 ” │ - ——————————┴———————————┴——————————-┴————————————————————————— - -In the curve which follows, only the variations of digestive power are -represented. - -It is clear that the increase, both of digestive power and of juice -volume, is connected with the act of taking in food. - -It appeared of interest definitely to determine the volume and -properties of the secretion called forth by the act of eating in the -dog with the isolated stomach. We endeavoured, therefore, at the -beginning, to imitate the conditions of sham feeding as they occurred -in the case of the dog with divided œsophagus. In addition to the -fistular orifice leading into the isolated miniature stomach, another -was opened into the main portion of the organ. If we now fed the dog -in the ordinary way with small pieces of flesh, these were received -back again at the orifice of the latter fistula, covered with saliva. -Precisely as in sham feeding, after five minutes the juice began to -flow simultaneously, from both the large and small stomachs. The -secretion ran a corresponding course in the two cavities and ceased at -the same length of time in both after the administration of food was -stopped. Here is an instance taken from such an experiment performed by -Dr. Lobassoff. - -[Illustration: FIGURE 1.--Curve of digestive power constructed from the -foregoing table.] - -In five minutes the dog had eaten eighty pieces of flesh (weighing 172 -grams), all of which soon afterwards dropped out at the fistula. The -secretion began in both stomachs after the lapse of seven minutes from -the commencement of the feeding, and proceeded as follows: - - - ══════╤═══════════════════════╦══════════════════════════════════ - │ Miniature stomach. ║ Main stomach. - ├——————————-┬———————————╫—————————————┬———————————————————— - Hour. │ Quantity │ Digestive ║ Quantity of │ Digestive power. - │ of juice. │ power. ║ juice. │ - ——————┼——————————-┼——————————-╫—————————————┼———————————————————— - 1 │ 7.7 c.c. │ ║ 83.2 c.c. │ 5.35 mm. - │ │ ║ │} In consequence of - │ │ ║ │} a mixture with - 2 │ 4.5 ” │} ║ 58.1 ” │ } bile (10-15 c.c.) - │ │ }6.25 mm ║ │ } the digestive - 2½ │ 0.6 ” │} ║ 8.5 ” │} power was greatly - │ │ ║ │} reduced. - ——————┴——————————-┴——————————-╨—————————————┴———————————————————— - -The secretion from both cavities also came to an end at the same time. - -This experiment proves to us, first, that the main and miniature -stomachs work in perfectly parallel manner with each other. The -beginning, the end, and the intermediate variations of the secretion -correspond in both cases. Secondly, the digestive power of the -secretion coincides in both, and is the same which was observed in the -so-called sham feeding. It has here remained at the same height till -the cessation of the secretion, without falling to the lower value -which we observed from the beginning of the second hour onwards, after -normal flesh feeding. - -This was also confirmed later, when we performed an œsophagotomy on the -dog, and carried out sham feeding in typical form. Here follows one of -these experiments taken from Dr. Lobassoff’s article. - -The first drop of juice appeared from both cavities during the sixth -minute after commencing the feeding, which was kept up for half an -hour. The further course of the secretion was as follows: - - ══════╤══════════════════════════╦══════════════════════════ - │ Miniature stomach. ║ Main stomach. - ├————————————-┬————————————╫———————————————┬—————————— - Hour. │ Quantity │ Digestive ║ Quantity │ Digestive - │ of juice. │ power. ║ of juice. │ power. - ——————┼————————————─┼————————————╫——————————————─┼—————————— - 1st │ 7.6 c.c. │ 5.88 mm. ║ 68.25 c.c. │ 5.5 mm. - 2nd │ 4.7 ” │ 5.75 ” ║ 41.5 ” │ 5.5 ” - 3rd │ 1.1 ” │ 5.5 ” ║ 14.0 ” │ 5.38 ” - │———— │ ———— ║ ————— │ ———— - │13.5 (total) │ 5.75 (mean)║123.75 (total) │ 5.5 (mean) - ——————┴—————————————┴————————————╨———————————————┴——————————— - -The secretion came to an end in both stomachs at the same time. - -The above is represented in curves in Figs. 2 and 3, the scale on which -that for the main stomach is drawn being ten times less than that for -the small. As you see, the progress of secretion is identical in both. - -The existence of a fistula leading into the large stomach affords us -also the possibility of performing an experiment upon our dog which -is exactly the converse of the sham feeding experiment, and which -constitutes a real _experimentum crucis_. While in sham feeding, we -had only, so to speak, the beginning of digestion before us, we are -now able in our cross experiment to start at the continuation of this -beginning. For this purpose it is only necessary to bring the food -into the stomach through the fistula, without attracting the dog’s -attention. Since in this experiment it is above all necessary not to -excite the dog’s appetite, it is best to carry out the procedure on the -sleeping animal. I may add at once, however, that the same result can -be obtained on the waking animal, only the process must be performed -unnoticed, and the animal’s attention must be diverted from thoughts of -food. - -[Illustration: FIGURE 2.--Curve of secretion from the miniature -stomach.] - -[Illustration: - FIGURE 3.--The same from the main stomach reduced ten times.] - -The results of this experiment are striking, and do not in any way -resemble the secretion after normal feeding. Some kinds of food, for -instance bread and coagulated white of the hen’s egg, when directly -introduced into the stomach, do not yield a single drop of juice -during the first hour or more afterwards. This holds good both for -the small and large stomachs. When a glass rod is introduced into the -food contained in the organ it remains dry. Flesh, if introduced at -this stage, is able to excite a secretion, but the appearance of the -juice is considerably retarded. It begins from fifteen to forty-five -minutes after the feeding, instead of from six to ten, is under normal -circumstances extremely scanty during the first hour (3 c.c. to 5 c.c. -instead of 12 c.c. to 15 c.c.), and possesses a very low digestive -power. - -Here is an experiment by Dr. Lobassoff: - - 400 grms. of flesh were brought into the stomach. - - Hour. Quantity of juice. Digestive power. - 1st 3.7 c.c. 2.0 mm. - 2nd 10.6 ” 1.63 ” - 3rd 9.2 ” 1.5 ” - 4th 7.0 ” 1.88 ” - 5th 5.6 ” 2.25 ” - 6th 6.6 ” 2.63 ” - 7th 7.5 ” 1.88 ” - 8th 5.3 ” 2.0 ” - 9th 3.0 ” 5.0 ” - 10th 0.2 ” — ” - -The secretion began twenty-five minutes after introducing the food. I -now ask you to compare the following tables: - - - ┌────—┬——————————————————╥——————————————————╥——————————————————┬———————┐ - │ │Fed with 200 grms.║Flesh (150 grms.) ║ Sham feeding │ Total │ - │ │of flesh (Chigin).║brought into ║ (Lobassoff). │ quan- │ - │ │ ║stomach(Lobassoff)║ │ tity │ - │Hour.├————————┬—————————╫————————┬—————————╫————————┬————————-┤ in two│ - │ │Quantity│Digestive║Quantity│Digestive║Quantity│Digestive│experi-│ - │ │of juice│ power. ║of juice│ power. ║of juice│ power. │ ments.│ - │ │ c.c. │ mm. ║ c.c. │ mm. ║ c.c. │ mm. │ │ - ├—————┼————————┼————————-╫————————┼—————————╫————————┼————————-┼———————┤ - │ 1st │ 12.4 │ 5.43 ║ 5.0 │ 2.5 ║ 7.7 │ 6.4 │ 12.7 │ - │ 2nd │ 13.5 │ 3.63 ║ 7.8 │ 2.75 ║ 4.5 │ 5.3 │ 12.3 │ - │ 3rd │ 7.5 │ 3.5 ║ 6.4 │ 3.75 ║ 0.6 │ 5.75 │ 7.0 │ - │ 4th │ 4.2 │ 3.12 ║ 5.0 │ 3.75 ║ — │ — │ 5.0 │ - └—————┴————————┴—————————╨————————┴—————————╨———————-┴—————————┴———————┘ - -The progress of juice secretion in the above is also represented in the -following curves: - -[Illustration: - FIGURES 4-7.—A. Ordinary curve of gastric secretion (200 grms. - flesh). B. Curve from direct introduction of food (150 grms. flesh). - C. Sham feeding with same. D. Summation of B and C.] - -As you see, the curve which represents the results of the direct -introduction of flesh ascends much more slowly and does not attain -anything like the height of that caused by normal feeding with the same -food. But if the quantities obtained by direct introduction of the -flesh be added to those of sham feeding, the resulting curve is almost -identical with the normal. - -In like manner the digestive power of the secretion in the foregoing -experiments can be dealt with, and with the same result. It is a good -instance of how a secretion curve can be synthetically constructed from -its constituent factors. - -Finally, I am able to demonstrate to you the following instructive -experiment. In the presence of some of my listeners, whom I had invited -to attend an hour before the lecture, I carried out the following -procedures on two dogs, both of which had ordinary gastric fistulæ and -were, besides, œsophagotomised. Into the stomach of one, while its -attention was distracted by patting and speaking kindly to it in order -to avoid arousing any thoughts of feeding, a definite number of pieces -of flesh were introduced through the fistula. The morsels were threaded -on a string, the free end of which was fastened to the fistular cannula -by inserting a cork. The dog was then brought into a separate room and -left to itself. A like number of pieces was introduced into the stomach -of the other dog in the same way, but during the process a vigorous -sham feeding was kept up, the animal being afterwards left alone. Each -dog received 100 grams of flesh. Since then an hour and a half have -elapsed, and now we may draw the pieces of flesh out by means of the -thread and weigh them. The loss of weight, and consequently the amount -of flesh digested, is very different in the two cases. In that of the -dog without sham feeding the loss of weight amounts to merely 6 grams, -while the flesh withdrawn from the stomach of the other dog weighs only -70 grams, that is to say, was reduced by 30 grams. This, therefore, -represents the digestive value of the passage of food through the -mouth, the value of an eager desire for food, the value of an appetite. - -I give also a series of figures obtained by Dr. Lobassoff in analogous -experiments. Into the dog’s stomach 25 pieces of flesh (100 grams) -were brought. The flesh remained two hours in the cavity. Without sham -feeding 6.5 per cent, with eight minutes' sham feeding 31.6 per cent, -of the quantity was digested. - -Again: the flesh remained an hour and a half in the stomach; without -sham feeding 5.6 per cent, with five minutes' sham feeding 15 per cent, -was digested. - -Once more: the flesh remained five hours in the stomach; without sham -feeding 58 per cent, with sham feeding 85 per cent, was digested, the -balance of undigested food being 42 per cent in the one case and 15 per -cent in the other. - -I must, however, add that from the nature of this experiment it is not -well adapted for class demonstration, and may often fail. On the one -hand, it is not at all easy to conceal the introduction of the flesh -from the dog; on the other, the unusual and distracting surroundings -of the animal often causes a short period of sham feeding to have less -effect than would otherwise pertain. In order to avoid such failures -it is better before an audience to carry out this experiment only -on dogs accustomed to appear in the lecture theatre, and of whose -temperament the experimenter is well assured. - -I hope you have now been convinced of the great importance which is to -be attached to the passage of food through the mouth and œsophagus, or, -in other words--and this, according to our former experiences, means -the same thing--to the eager desire for food. Without this longing, -without the assistance of appetite, many forms of food-stuffs which -gain entry to the stomach remain wholly devoid of gastric juice. -Others, it is true, excite a secretion, but the juice poured out is -scanty and weak. - -It is only later, when we have still more fully recognised the -conditions upon which the secretory work of the gastric glands depends, -that we shall be able to grasp the meaning of these facts in a more -comprehensive manner. For instance, why does bread brought unnoticed -into the stomach of the dog cause no secretion for hours, while flesh -tolerably soon (after twenty to forty minutes) provokes this act? This -will be explained in the next lecture; now, however, we must consider -other questions. - -How long does the after-effect, the echo of the first impulse to the -secretory nerves of the stomach, continue to last? How long does -appetite juice continue to flow after the normal act of eating, which, -especially in the case of animals, is not of long duration? We have -already determined many times, not only on our dog with the isolated -stomach, but also on other animals, how long the after-effect of sham -feeding is continued. - -Here, for example, is an experiment from the article of Professor -Ssanozki which deals with the point. The dog had a gastric fistula and -also an opening leading into the œsophagus. After a sham feeding of -five minutes the secretion began, and was continued as follows: - - Time in minutes. Quantity. Digestive power. - 10 25.5 c.c. 8.1 mm. - 10 20.0 ” 8.0 ” - 10 13.5 ” 6.8 ” - 10 11.0 ” 7.5 ” - 10 8.5 ” 8.1 ” - 10 6.5 ” 9.0 ” - 20 13.5 ” 7.4 ” - 20 11.0 ” 7.2 ” - 20 7.0 ” 7.2 ” - 20 11.5 ” 6.8 ” - 20 11.0 ” 6.5 ” - 30 6.5 ” 7.6 ” - 20 5.5 ” 7.2 ” - -The effect, therefore, even after a short period of sham feeding, -stretches over a length of time. Naturally the same holds good for the -taking of food in the normal way. One must, however, bear in mind that -in sham feeding, with all the force and reality of a hunger sensation -not satisfied, the eager desire for food, the effective agency, becomes -more and more accentuated, and therefore the secretory influence is -prolonged and more powerful. In normal feeding, however, the quelling -of the longing, the feeling of satisfaction which, as is well known, -sets in long before the termination of the digestive period from the -mere filling and distension of the stomach, must diminish the desire -for food, and, consequently, bring the secretory effect to an end. - -It is, therefore, improbable that the whole secretory process in the -stomach, which, in the case of certain kinds and quantities of food, -lasts from ten to twelve hours, is dependent on the factors which we -have up to the present investigated. This is all the more obvious -since a sham feeding of five minutes, even under the most favourable -circumstances, does not call forth a secretion for longer than three to -four hours. We must, therefore, seek for other exciting agencies of the -innervation apparatus of the gastric glands. - -Why and wherefore is the secretion instituted by psychic influence -maintained? What would first occur to all your minds is naturally -the immediate influence which the food exerts upon the walls of the -stomach. And this is true, but it does not happen in the simple, direct -fashion current in the minds of many physiologists and physicians. When -I said that bread or boiled white of egg, introduced directly into the -stomach, may not for hours produce a trace of secretion, probably many -of my hearers may have asked themselves with natural astonishment, -“How, then, is the effect of the forced feeding of phthisical and -insane patients, and the artificial feeding of those with gastric -fistulæ (performed on account of stricture of the œsophagus) to -be explained?” I will introduce my answer by a very unexpected -pronouncement relative to the assertion that mechanical stimulation of -the stomach wall by food constitutes a reliable and effective means -of calling forth the secretory work of the glands. This assertion, -which is so categorically set forth in many text-books of physiology, -and which consequently has gained hold of the mind of the physician, -is nothing else than a sad misconception degenerated into a stubborn -prejudice. My own statement, repeated in many published articles, and -at the meetings of various medical societies, that this dictum is only -a picture of the imagination, has met, for the most part, either with -an unbelieving shake of the head or else with a direct avowal that “it -cannot be so.” I regret exceedingly that these steadfast unbelievers -are not here, so that we might together bring the matter before the -tribunal of fact, to the demonstration of which we will now proceed. To -this matter I attribute very great importance. It is on this ground, -according to my opinion, that the whole battle must be fought out -between the generally accepted view that every agency is capable of -exciting the gastric mucous membrane and the theory that it is only -excitable by specific and selected stimuli. If once the defenders of -the old opinion are driven from their position and obliged to admit -the inefficiency of mechanical stimulation, there would be nothing -further left for them than to build up new theories and search out -old facts concerning gland work which have hitherto been rigidly kept -in the shade. We may take it that it is mainly because people were so -seized with the belief in the direct and simple mechanical explanation -that Bidder and Schmidt’s experiment of the excitation of gastric -secretion by mental effect has been so little taken into consideration, -notwithstanding that it appeared so thoroughly reliable and convincing. - -I will now repeat the experiment of mechanical stimulation of the -gastric mucous membrane before you in the well-known, traditional, -and classic manner. Here is a dog with a gastric fistula on which -a cervical œsophagotomy has in addition been performed. I open the -fistula; as you see, nothing flows out of the stomach; it was washed -out clean with water an hour ago. We take the celebrated feather and -also a tolerably strong glass rod. Folds of blotting-paper saturated -with red and blue tincture of litmus are placed at hand. I now ask my -assistant to continuously move the feather and glass rod, alternately, -in all possible directions in the stomach, changing from one to the -other every five minutes. On removal from the stomach each is carefully -dried with red and blue blotting-paper. You have all seen, gentlemen, -that this procedure has now been kept up for half an hour. From the -fistular orifice not even a single drop has escaped, and, moreover, the -drops of moisture on all the pieces of red blotting-paper I have been -able to hand to you have assumed a distinct blue tinge, caused by the -moisture of the alkaline mucous membrane. The blue pieces, however, -have merely been made wet without altering their colour. Consequently, -with the most thorough mechanical stimulation of the whole cavity of -the stomach, we have not been able to find a single spot possessing a -noticeable acid reaction. Where, then, are the streams of pure gastric -juice of which we read in text-books! What objection can be raised -against the conclusiveness of this experiment? In my opinion only one: -that we are dealing with a dog out of health, whose gastric glands from -some possible cause are unable to react normally. This single objection -can be set aside before your eyes. After failing with the mechanical -stimulation, we proceed forthwith to the sham feeding of the same -animal. The dog takes the food offered it with keen appetite, and you -see that, exactly five minutes after beginning the feeding, the first -drops of juice appear from the stomach, followed by others faster and -faster. I catch a couple of drops on the blue litmus paper, and you see -that they produce bright red specks on the blue sheet. After thirty -minutes' sham feeding we have collected 150 c.c. of juice, which, -without filtering, looks as clear and transparent as water. - -We cannot, therefore, possibly doubt that, when the proper stimulus is -used, the gastric glands react to it in a perfectly normal fashion, -furnishing a healthy gastric juice. From this it irrefutably follows -that only one explanation is to be found for the negative result in -the first half of our experiment, viz., that the mucous membrane -of the stomach, so far as secretory activity goes, is perfectly -indifferent to mechanical excitation. And yet this mechanical stimulus -is demonstrated as an exciting agency in the physiological lecture -theatre. I venture to think that this lecture experiment from now -onwards will quit the field, and give place to the one I have just -shown you. This apparently simple experiment of mechanical stimulation -can, however, only be successfully performed when certain very obvious -rules are followed. These, however, physiologists have not observed, -probably on account of a preconceived belief in the effectiveness of -the mechanical stimulus. These rules are two. First, it is necessary -that the stomach should be clean, and that nothing shall gain entry -to it from without. Such conditions were not formerly fulfilled. It -is true the stomach was emptied by removing the stopper from the -fistular cannula, but it was not washed out till an acid reaction -was no longer given, and consequently preformed gastric juice was -left behind between the folds of the mucous membrane. At the same -time saliva from the cavity of the mouth could gain entry, which -quickly became acidified in the incompletely emptied and imperfectly -washed-out organ. It is, therefore, not surprising that the glass -tube, by setting up contractions of the stomach, was the means of -expressing small quantities of acid fluid from the fistula-tube. (The -relationship between mechanical stimulation and the motor functions -of the stomach is not to be confounded with what we are here speaking -of.) That matters are as I state, and that the facts correspond to -the explanation is proved by this; namely, that nobody till now -has obtained genuinely pure gastric juice of an acidity amounting -to 0.5 or 0.6 per cent. It is only necessary to call to mind that -Heidenhain, when determining the acidity of the juice first obtained -from the resected stomach, was placed in no little doubt as to whether -his results (0.5 to 0.6) were correct, and his assistant at the -time (Gscheidlen) was set to verify the correctness of his standard -solutions. The acidity of the “purest” juice known at that time was -scarcely 0.3 per cent. As a further proof that none of the older -observers ever really obtained a secretion from mechanical stimulation -pure and simple, we may adduce the fact that none of them made mention -of the constant and precise period of five minutes' latency. To -overlook this was not possible if a genuine excitation of the glands -had been obtained. - -Of no less importance is the second condition when we wish to perform -the experiment of mechanical stimulation in the correct way. It is -very necessary that the gastric glands be not already in activity at -the beginning of the experiment, and also that during the experiment -no impulse comes into play, which of itself, apart from mechanical -excitation, could excite the glands to secretion. Nor have we any -proof that observers formerly waited for hours before commencing -the experiment and convinced themselves that the gastric glands had -ceased working. On the contrary, we have not the slightest evidence to -indicate that the authors had attempted to guard against accidental -psychical stimulation of the glands--a matter which we have seen is of -considerable difficulty. And some dogs are so easily excited in this -way that it is almost impossible to bring their glands to rest, or at -least it is necessary to wait for hours. The experimenter must strain -his whole attention to preserve such an experiment free from objection. -It is only necessary that some food be near the dog, or that the hands -of the attendant who has prepared the food should smell of it, or that -some other similar circumstance should come into play, and the glass -tube, quite undeservedly, will be made answerable for the excitation of -the gastric glands. As you have just seen, both of our conditions have -been fulfilled on the dog before you, and the result of the experiment -stands in irreconcilable contradiction to those of the laboratory and -lecture experiment of former times. - -The importance of the experiment, which I have already dwelt upon, -justifies me in making still further demands upon your attention in -order to show you two modifications of it. Nobody has as yet said, with -regard to mechanical stimulation, that in order to obtain results the -mechanical agency must simultaneously come into contact with numerous -points of the inner surface of the stomach. But in order to meet this -possible objection I will now show you two new modifications. Again -a similar dog is used, that is to say, one on which both gastrotomy -and œsophagotomy have been performed. The stomach has been washed out -clean and is at present in a state of complete rest. Into the fistula -I bring a thick glass tube containing a number of small openings (2 -to 3 mm. diameter) at its rounded end. The other end of the tube is -connected with a glass ball containing tolerably coarse sand. Leading -into the ball is a second tube, with which an india-rubber pump can be -connected and a blast of sand blown through. By rhythmic compression -of the india-rubber ball I inject sand with considerable force into -the stomach, and this play is kept up for ten to fifteen minutes; -nevertheless, we see no trace of gastric juice. The sand falls out -again between the side of the cannula and the glass tube, and it -is either dry or scarcely moistened, but in no case is it able to -turn blue litmus red. And yet we are here dealing with a strong and -widely diffused stimulus. Look for a moment at the performance of the -bellows outside the stomach. From every opening of the tube--numbering -considerably more than ten--a strong stream of sand is ejected. If you -hold your hand against it, you feel quite distinctly that the grains -of sand strike with considerable force. And now, when our experiment -is ended, we may convince ourselves by sham feeding, in easy and -unquestionable fashion, that the innervation of the dog’s stomach is -perfectly normal. - -Yet another experiment on a similar dog. Into its empty and resting -stomach an india-rubber ball is introduced. This is distended with -air by means of a syringe till it is as large as a child’s head and -maintained in this condition for a time, afterwards being allowed -to collapse. The procedure is kept up for ten to fifteen minutes. -During this time not a single drop of juice has appeared from the -stomach. The surface of the ball taken out of the organ is everywhere -alkaline. And here also subsequent sham feeding shows that the dog is -in a suitable condition for the experiment. I must add that in making -this observation the dog must not be too hungry, that is to say, must -have been fed within ten to twelve hours before, otherwise a psychic -excitation of the secretion can readily be induced. - -If one dispassionately regards this question, and if any of our methods -for the study of gastric secretion are reliable, one must be convinced -step by step in the laboratory of the uselessness of mechanical -stimulation. In the case of dogs with an ordinary gastric fistula, and -failing some special reason, not a drop of gastric juice ever escapes -from the stomach other than during the digestive period. How could -this be the case if the mechanical stimulus were effective, since the -inner rim of the fistula-tube is continuously in contact with the -gastric mucous membrane? The same holds good for the dog with resected -stomach. During the experiment a glass or india-rubber tube is brought -sufficiently far into the _cul-de-sac_ to catch the juice, and yet not -a drop flows through the tube, nor does its inner surface ever become -acid, so long as true secretory conditions are absent. Moreover, the -tube has tolerably often to be taken out and set right. - -In the ordinary gastric fistula in dogs, when the operation has lasted -a long time--over a year--folds of mucous membrane are often formed -in the neighbourhood of its inner orifice which completely close the -tube. In these cases a long, thick, perforated metal tube has to be -passed in deeply, and yet the manipulation of itself never calls forth -a secretion. Further, it is a daily occurrence to find in the stomach -of the dog thick rolls of hair, and yet their presence in no way -hinders the arrest of the secretion, which occurs when digestion has -ceased. Such an occurrence would have been specially obvious in our dog -with the isolated stomach, since it was bedded with sawdust in order -to guard against maceration of the wound by juice trickling out. Very -often we found enormous quantities of sawdust in the stomach, as much -as half a pound weight; obviously the dog had licked the wound from -adherent sawdust, which it then swallowed, together with that sticking -to its nose. And yet these particles of sawdust of themselves, which -certainly acted as mechanical stimuli, never caused a secretion. It -appears to me that this long series of facts ought to suffice to carry -the supposition to its grave that by direct mechanical stimulation -one is able to set the neuro-secretory apparatus of the stomach into -activity. - -And yet the feather and the glass tube continue the even tenor of -their ways to this moment and function in some text-books, yea, even -in articles which specially treat of gastric secretion as exciters of -the gastric glands. There are, it is true, a few physiologists who -hold mechanical stimulation, in relation to gastric secretion, not to -be very effective, and give it a subordinate position in the series of -exciting agencies, but as yet I know of no other physiologist who has -wholly denied its influence, and who has not held it possible to obtain -at least some juice by it. - -To conclude this lecture, we will take into consideration a question -connected with the matter we have just discussed. Since the contact of -food with the gastric mucous membrane has no direct influence on the -secretion, is its entry into the stomach devoid of all connection with -the secretory process? - -It can hardly be doubted that, under normal conditions, the stomach is -the seat of certain definite sensations, that is to say, its surface -has a certain degree of tactile sensibility. This sensation is, as a -rule, very weak, and the majority of people become accustomed to pay -no heed to it in the normal course of digestion. They obtain their -sensations of general well-being, and especially of satisfaction -from the enjoyment of food, without taking cognisance of the factors -contributing to them. The feeling of general hunger, however, is -referred solely to the stomach. - -On the other hand, all of us have met with men who could describe -exactly, and with gusto, how they were able to follow a special -tit-bit, or a mouthful of a favourite wine, the whole way through the -œsophagus down to the stomach, especially when the latter happened -to be empty. Naturally the gourmand, who directs his attention -continuously to the act of eating, can in the end distinctly perceive -sensations, and even call them up to the consciousness, which in other -people are normally masked by other sensations and impressions. We may -therefore take it that the satisfaction derived from eating is caused -not only by stimulation of the mouth and throat, but also by impulses -awakened by the passage of the food along the deeper portions of the -œsophagus and by its entry into the stomach. In other words, food which -merely passes through the mouth and throat produces less enjoyment -and excites, therefore, a less feeling of appetite than the food -which passes the whole way into the stomach. The appetite, the eager -craving after food, is, indeed, a very complex sensation, and often -not merely the need of the organism for food material is necessary for -its excitement, but also a condition of thorough well-being, together -with a normal healthy feeling in all parts of the digestive tract. For -this reason it is easy to understand how patients who have diseased -sensations in these organs, and who have no feeling of appetite, -no desire for food, remember the sensations, whether consciously or -unconsciously, even when they are no longer present. Cases are known -to neuro-pathologists where people with gastric anæsthesia suffered -from this loss of appetite. Such patients are no longer conscious of -having stomachs, and dislike the idea of eating because the food, as -they express it, appears to fall into a strange empty sack. In this -way one can also conceive how the appetite becomes lost in cases of -long-continued obstruction of the alimentary tube. The patients forget -their stomachs, and in such instances direct introduction of food into -the organ, after an operation, may suddenly bring back the appetite. - -As a further illustration, I may be permitted to give an instance from -my own personal experience. After an illness with which a transient but -high fever was associated, although otherwise fully recovered, I had -lost all desire for food. There was something curious in this complete -indifference towards eating. Perfectly well, I only differed from -others in that I could with ease abstain from all food. Fearing that I -should collapse, I resolved on the second or third day to endeavour to -create an appetite by swallowing a mouthful of wine. I felt it quite -distinctly pass along the œsophagus into the stomach, and literally at -that moment perceived the onset of a strong appetite. This observation -teaches that the tactile sensation of the stomach at the moment of -entry of food is capable of awakening or increasing the appetite. It is -known that withholding food from the organism, or in other words the -creation of a necessity for food, does not lead immediately, nor in -all cases, to the production of an appetite, to a passionate craving -for food. How often does it happen that the ordinary hour for a meal -has struck, and yet, owing to some keenly interesting occupation, not -the least desire for food is felt? It is known to everybody, indeed it -has become a proverb, that real appetite first sets in with eating. -If this be true, the initial impulse towards awakening an appetite -may originate in the stomach and not in the buccal cavity. When we -spoke above of the desire for food being the excitant of the secretory -nerves of the stomach, we naturally meant the passionate and conscious -longing for food, that which is called “appetite,” and not the latent -need of the organism for nourishment, the lack of nutrition, which -has not yet been transformed into a concrete passionate desire. A -good example which enables us to differentiate between these two -factors is furnished by our dogs with sham feeding. The necessity for -food exists in such cases even before the experiment; the juice, -however, only begins to flow as soon as this need has taken the form -of a passionate longing. It is therefore quite possible that in the -case of some dogs, and at a certain stage of hunger, the touching of -the gastric mucous membrane with any object at hand, its mechanical -excitation, its distension by the food mass, may give the impulse which -excites the appetite, and when the appetite is awakened the juice -flows. This is possibly a third reason why, in the old experiment, -the mechanical stimulus came to be considered effective. Viewed from -this point it may, to a certain degree, lead to a reconciliation -between my assertion concerning the inefficiency of the mechanical -stimulus and the generally prevailing belief. I further also admit that -mechanical excitation will at times call into play the work of the -gastric glands, not however directly by means of a simple physiological -reflex, but indirectly, after it has first awakened and enlivened the -idea of food in the dog’s consciousness, and thereby called forth the -passionate desire. I hope that the foregoing will in no way lead to a -confusion of ideas in your minds, but will assist you to an exact and -concrete analysis of the previous simple explanation of the facts. This -representation, which bears more or less of a hypothetical character, -could, of course, be submitted to experimental proof. For such it is -only necessary to compare the influence which sham feeding exercises -in an œsophagotomised dog with that in one having a simple gastric -fistula. - - - - - LECTURE VIII - - PHYSIOLOGICAL ACTION AND THE TEACHING OF INSTINCT: EXPERIENCES OF THE - PHYSICIAN - - It would be desirable, in the interests of medicine, that the methods - described in these lectures should be employed in experimental - investigations into the pathology and therapeutics of the digestive - canal on the lines laid down--The fact that the beginning of the - secretory work in the stomach depends upon a psychic effect harmonises - with the experiences of every-day life, namely, that food should - be eaten with attention and relish--To restore the appetite has - from all ages been the endeavour of the physician--The indifference - of the present-day physician towards appetite--Probable causes of - this--Curative remedies based upon a restoration of appetite--The - therapeutic effects of bitters depend upon the excitation of - appetite--The usages of the mid-day meal are in agreement with - physiological requirements--Physiological reasons for certain - instinctive customs and empirical regulations--Importance of an - acid reaction of the food--Dietetics of fat and its therapeutic - application--The peculiar position of milk among food-stuffs is - based on physiological reasons--Explanation of the curative effects - of sodium bicarbonate and sodium chloride--The causes of individual - differences in the work of the digestive glands--Participation of - the inhibitory nerves of secretion in the production of pathological - effects. - - -GENTLEMEN,--To-day we shall endeavour to bring the previously -communicated results of our laboratory investigations into -reconciliation with the customs observed in the ingestion of food, -and with the regulations prescribed by the physician in disorders of -the digestive apparatus. To bring our knowledge to full fruition, and -so secure for it the most useful application, the same methods should -be applied from the same standpoint to the experimental investigation -of the pathology and therapeutics of the alimentary canal. Nor should -we be likely to encounter insuperable difficulties. Thanks to the -advances of bacteriology, many of the pathological processes can now -be experimentally produced in the laboratory. Moreover, we would, -in a sense, have to deal with external ailments, since our present -methods enable us to obtain access to any desired part of the inner -surface of the digestive canal. In such pathological animals the -functional diseases of the apparatus could be studied in a precise -and detailed manner; that is to say, the alterations of secretory -activity, the properties of the fluids, and the conditions under which -they appear could be examined. On such animals therapeutic remedies -could also be tested, the whole process of healing and the final result -experimentally observed, while the conditions of secretory activity -during every phase of the healing process could be investigated. It can -hardly be doubted that scientific, that is to say ideal, medicine, -can only take its proper position as a science when, in addition to an -Experimental Physiology and Pathology, there has also been built up an -Experimental Therapeutics. A proof that this is possible is furnished -by the recent vigorous strides made by the science of bacteriology. - -I have already described one of such pathological therapeutic -experiments; namely, on the dog whose vagi nerves were divided in the -neck. Other similar cases I can also call to mind. Our dog with the -two stomachs suffered at one time from a slight and transitory gastric -catarrh. It was then very interesting to observe that the pathological -process (which we were usually able to wholly guard against) spread -from the large to the small stomach. It manifested itself here in -an almost continuous slimy secretion of very slight acidity, but of -strong digestive power. At the beginning of the ailment, indeed before -it became fully established, the psychic stimulation was remarkably -effective (that is to say, still furnished juice in appropriate -quantity), while local excitants almost completely failed. One may -conceive that the deeper layers of the mucous membrane with the gastric -glands were still healthy, and thus easily thrown into activity by -central impulses, whilst the surface of the membrane with the end -apparatus of the centripetal nerves was already distinctly damaged. -I mention these, which I may call impressions rather than precise -observations, because I wish to point out what a fruitful field awaits -the investigator who wishes to study, with the aid of our present -methods, the pathological conditions of the digestive organs and their -treatment. Such an investigation is all the more desirable because -clinical study of the same subject (notwithstanding the zeal devoted to -it during the last ten years and the results derived therefrom) has to -contend with serious difficulties. We must not forget that the sound or -stomach-tube, the chief clinical instrument, is more uncomfortable than -the ordinary form of gastric fistula which was previously practised on -animals, and yet the physiology of the stomach, even with the aid of -the latter, made no material progress for many long years. Nor is this -difficult to understand. The investigator obtained through the fistula -a mixture of substances from which it was difficult, or even at times -impossible, to decide anything. - -Hence the exact scientific study of therapeutic questions in this -region still belongs to the future. But this does not exclude the -probability that the newer acquirements of physiology may fruitfully -influence the work of the physician. But physiology naturally can make -no pretence to guide the field of medicine, since the knowledge at its -disposal is incomplete and is much more restricted than that of the -broad world of clinical reality. As a recompense for this, however, -physiological knowledge is often able to explain the causation of an -illness and the meaning of empirical curative methods. To employ a -remedy the mode of action of which is not clear is quite a different -thing from knowing precisely what we are doing. In the latter case -the treatment of the diseased organ will be more effective because it -will be better adapted to the special needs of the case. It is thus -that medicine, being daily enriched by new physiological facts, will -at length grow into what it ideally must become; namely, the art of -repairing the damaged machinery of the human body, based upon _exact_ -knowledge, or, in other words, applied physiology. - -We may now return to our subject. If it be at all admitted that human -instinct is the outcome of an every-day experience, which has led to -the unconscious adoption of the most favourable conditions for life, -it is particularly so with regard to the phenomena of digestion. The -expression that physiology merely confirms the precepts of instinct -is justified here more than anywhere else. It appears to me also -that, in relation to the foregoing facts, instinct has often made -out a brilliant case when brought before the tribunal of physiology. -Perhaps the old and empirical requirement, that food should be eaten -with interest and enjoyment, is the most imperatively emphasised and -strengthened of all. In every land the act of eating is connected -with certain customs designed to distract from the business of daily -life. A suitable time of day is chosen, a company of relatives, -acquaintances, or comrades assemble. Certain preparations are carried -out (in England a change of raiment is usually effected, and often a -blessing is asked upon the meal by the oldest of the family). In the -case of the well-to-do a special room for meals is set apart, musical -and other guests are invited to while away the time at meals--in a -word, everything is directed to take away the thoughts from the cares -of daily life, and to concentrate them on the repast. From this point -of view it is also plain why heated discussions and serious readings -are held to be unsuitable during meal-times. Probably this also -explains the use of alcoholic beverages at meals, for alcohol, even -in the lighter phases of its action, induces a mild narcosis, which -contributes towards distraction from the pressing burden of the daily -work. Naturally this highly developed hygiene of eating is only found -in the intelligent and well-to-do classes, first, because here the -mental activity is more strained and the various questions of life more -burning; and secondly, because here also the food is served in greater -quantity than is required for the wants of the organism. In the case of -the poorer classes, where mental activity is less highly developed, the -greater amount of muscular activity and the constant lack of more than -sufficient nourishment insure a strong and lively desire for food in a -normal manner, without recourse to any special regulations or customs. -The same conditions explain why the preparation of food is so choice -in the case of the upper classes and so simple in that of the lower. -Further, all the accessories of the meal, which are foretastes of the -actual repast, are obviously designed to awaken the curiosity and -interest, and to augment the desire for food. How often do we see that -a person who begins his customary meal with indifference afterwards -enjoys it with obvious pleasure when his taste has been awakened by -something piquant or, as we say, appetising. It was here only necessary -to give an impulse to the organs of taste, that is, to excite them, in -order that their activity might be later maintained by less powerful -excitants, for a person who feels hungry such extra inducements are, -of course, not necessary. The quelling of hunger in his case affords of -itself sufficient enjoyment. It is not, therefore, without reason that -it is often said that “Hunger is the best sauce.” This dictum, however, -is only right up to a certain point, for some degree of appetising -taste is desired by everybody, even by animals. Thus, a dog which has -not fasted for more than some hours will not eat everything with equal -pleasure which dogs usually eat, but will seek out the food which it -relishes best. Hence the presence of a certain kind of spice is a -general requirement, although naturally individual tastes differ. - -This short discussion as to how different people behave with regard -to the act of eating is of itself testimony that care should ever be -taken to keep alive the attention and interest for food and to promote -enjoyment of the repast--that is to say, that care should be taken of -the appetite. Every one knows that a normal, useful food is a food -eaten with appetite, with perceptible enjoyment. Every other form of -eating, eating to order or from conviction, soon becomes worse than -useless, and the instinct strives against it. One of the most frequent -requests addressed to the physician is to restore the appetite. Medical -men of all times and of every land have held it to be a pressing -duty, after overcoming the fundamental illnesses of their patients, to -pay special attention to the restoration of the appetite. I believe -that in this they are not only animated by an endeavour to free their -patients from troublesome symptoms, but also by the conviction that -the return of appetite of itself will favour the restitution of normal -digestive conditions. It may be said that to the same extent to which -the patient wishes back his appetite the physician has effectively -employed measures to restore it. Hence we have not a few remedies which -are specially named “gastric tonics,” and whose action is to promote -appetite. Unfortunately medical science has latterly deviated from -this, the correct treatment of the appetite, and that which corresponds -to the real conditions. If one reads current text-books on disorders of -digestion, it is remarkable how little attention is paid to appetite -as a symptom or to its special therapy. Only in a few of them is its -importance indicated, and then merely in short, parenthetic phrases. -On the other hand, one may meet statements in which the physician is -recommended to adopt no special means for counteracting so unimportant -a subjective symptom as a bad appetite! After what I have said and -demonstrated to you in these lectures, one can only designate such -views as gross misconceptions. If anywhere, it is precisely here -that symptomatic treatment is essential. When the physician finds it -necessary, in disorders of digestion, to promote secretory activity by -different remedies, this object can most certainly and completely be -achieved by endeavouring to restore the appetite. We have already seen -that no other excitant of gastric secretion, so far as quantity and -quality of the juice are concerned, can compare with the passionate -craving for food. - -To a certain degree we can understand--and this contributes to an -explanation of matters--how medical science of our time has come -to regard so lightly the loss of appetite as a special object for -treatment. Now, however, the experimental method has penetrated more -and more into medical science, with the result that many pathological -factors and therapeutic agents are judged of according to whether they -hold good in the laboratory or not--that is to say, they are valued -only in so far as they can be verified by laboratory experiments. -Naturally we do not doubt that a movement in this direction indicates -a great advance, but even here, as with every undertaking of mankind, -things do not proceed without mistakes and exaggerations. We must not -consider an event to be a mere picture of the imagination because -it is not realisable under given experimental conditions. We often -do not know all the essential conditions for the production of the -phenomenon in question, nor are we yet able to grasp the connection -between all the separate functions of life as fully as may be desired. -Thus in the clinical treatment and pathology of digestion assistance -was sought for in the laboratory, but nothing was there met with which -had a relation to appetite, and consequently this factor was overlooked -in medical practice. As stated above, the psychic gastric juice -obtained only cursory mention in physiology, and this not even by all -authors; and when it was noticed it was related more as a curiosity. -Great importance was, on the other hand, assigned to the mechanical -stimulus, the efficiency of which, now that our knowledge is more -complete, has been shown to be purely imaginary. Each of the contending -factors has at length been assigned its proper place, and if clinical -medicine maintains her worthy desire of following out the experimental -investigation of her problems, she must in actual practice accord to -appetite its old claim for consideration and treatment. - -But notwithstanding the indifference of physicians to appetite in -itself, many therapeutic measures are based on the promotion of it. -And in this the truth of empiricism makes itself irresistibly felt. -When the patient is enjoined to eat sparingly, or when he is restrained -from eating at all till the physician expressly permits, or again, when -he is (for instance, during convalescence) removed from his ordinary -surroundings and sent to an establishment where the whole life, and -particularly the eating, is regulated according to physiological -needs--in all these cases the physician seeks to awaken appetite, and -relies upon it as a factor in the cure. In the first case, where the -food is prescribed in small portions, in addition to preventing the -overfilling of a weak stomach, the oft-recurrence of appetite juice, -which is so rich in quantity and so strong in digestive power, is of -great importance. I ask you here to call to mind one of our experiments -in which food was given in small portions to a dog, and thus led to -a secretion of much stronger juice than if the whole ration had been -eaten at once. This was an exact experimental reproduction of the -customary treatment of a weak stomach. And such a regulation of diet -is all the more necessary, since, in the commonest disorders of the -stomach, only the surface layers of the mucous membrane are affected. -It may, consequently, happen that the sensory surface of the stomach, -which should take up the stimulus of the chemical excitant, is not -able to fulfil its duty, and the period of chemical secretion, which -ordinarily lasts for a long time, is for the most part disturbed, or -even wholly absent. A strong psychic excitation, a keen feeling of -appetite, may evoke the secretory impulse in the central nervous system -and send it unhindered to the glands which lie in the deeper as yet -unaffected layers of the mucous membrane. - -An instance of this, taken from the pathological material of the -laboratory, I have already related at the beginning of this lecture. It -is obvious in these cases that the indication is to promote digestion -by exciting a flow of appetite juice, and not to rely upon that excited -by chemical stimuli. From this point of view the meaning of removing -a patient, the subject of chronic weakness of the stomach, from his -customary surroundings is also plain. Take, for instance, a mentally -overstrained individual, or a responsible official; how often does -it happen that he cannot for a moment distract his thoughts from his -daily work. He eats without noticing it, or eats and carries on his -work at the same time. This often happens, particularly in the case of -people who live in the midst of the incessant turmoil of great cities. -The systematic inattention to the act of eating prepares the way for -digestive disturbances in the near future, with all their consequences. -There is no appetite juice, no “igniting juice,” or, at most, very -little. The secretory activity comes slowly into play; the food remains -much longer in the digestive canal than is necessary, or passes, for -want of sufficient digestive juices, into a state of decomposition -which irritates the mucous membrane of the alimentary canal and brings -it into a condition of disease. No medicinal treatment can help -such a patient while he remains surrounded by his old conditions. -The fundamental cause of his illness still continues in progress. -There is only one course to pursue; namely, to take him completely -away, to free him from his occupation, to interrupt the interminable -train of thought, and to substitute for a time, as his only object -in life, the care of his health, and a regard for what he eats. This -is attained by sending the patient to travel, or by placing him in a -hydropathic establishment. It is the duty of the physician to regulate -not only the life of individual patients according to such rules, -but also to have a care that in wider circles of the community a due -conception of the importance of eating should be disseminated. This -is particularly so with the Russian physician. It is precisely in the -so-called intelligent classes of Russians that a proper conception -of life generally is often found wanting, and where an absolutely -unphysiological indifference towards eating often exists. More -methodical nations, like the English, have made a species of cult of -the art of eating. It is, of course, degrading to indulge excessively -and exclusively in culinary enjoyments, but, on the other hand, a lofty -contempt for eating is also reprehensible. As so often is the case, the -best course here also lies between the two extremes. - -With the establishment of mental effect upon the secretion of juice the -influence of condiments enters upon a new phase. The conclusion had -already been empirically arrived at that it was not alone sufficient -for the food to be composed exclusively of nutrient substances, but -that it should also be tasty. Now, however, we know why this is so. -For this reason the physician, who has often to express an opinion -upon the suitability of the dietaries of different persons, or even -of whole communities, should constantly bear in mind the question of -psychic secretion; that is to say, he should inquire after and learn -how the food has been eaten, whether with or without enjoyment. But how -often do the people who have charge of the commissariat pay attention -solely to the nutritive value of the food, or place a higher value on -everything else than taste? We must, further, in the interest of the -public weal, direct attention especially to the feeding of children. -If this or that inclination of the taste ultimately determines the -relation of grown-up individuals towards food, a matter with which -the commencing phase of digestion is closely linked, it would seem -undesirable to habituate children solely to a nicety and uniformity of -gustatory sensations. Such might effect their capabilities of adapting -themselves to other conditions in after life. - -The question of the therapeutic influence of the so-called bitters, -it appears to me, bears the closest connection with that of appetite. -After a long period of high repute these substances have been almost -expelled from the list of pharmaceutic remedies. When tested in -the laboratory, they were unable to justify their old and valued -reputation; when directly introduced into the stomach, many of them -were unable to produce a flow of gastric juice. Consequently, in the -eyes of the clinician, they became greatly discredited, so that many -were quite ready to discard their use altogether. Obviously, the simple -conclusion was drawn that a weak digestion could only be assisted by -a remedy which directly excites secretory activity. In this, however, -it was forgotten that the conditions of the experiment possibly had -not corresponded with the actual state of affairs. The whole question -of the therapeutic importance of the bitters, however, acquires a -different significance when we link it with another question, such, for -instance, as how do bitters affect the appetite? It is the universal -opinion of the earlier and later physicians that bitters increase -the appetite, and if this be so everything is said. They are, in -consequence, real secretory stimulants, since the appetite, as has many -times been repeated in these lectures, is the strongest of all stimuli -to the digestive glands. It is, however, not by any means strange -that this had not previously been observed in the laboratory. The -substances were either introduced directly into the stomachs of normal -dogs or else injected into the circulation. But their action is chiefly -bound up with their effect upon the gustatory nerves, and it was not, -therefore, without some reason that this large group of remedies, -consisting of substances of the most varied chemical composition, were -grouped together mainly on account of a certain bitter taste common -to them all. A person who suffers from digestive disturbance has, -moreover, a blunted taste, a certain degree of gustatory indifference. -The ordinary foods, which are agreeable to other people, and also to -himself when in health, now appear tasteless. They not only arouse no -desire for eating, but may even cause a feeling of dislike; there -is no sense of taste, or at best a perverse one. It is necessary, -therefore, that the gustatory apparatus should receive a strong -stimulus in order to restore a normal sensation. As experience teaches, -this object is most quickly attained by exciting sharp, unpleasant, -gustatory impressions, which by contrast awaken the idea of pleasant -ones. In either case there is no longer indifference, and this is the -foundation upon which an appetite for this or that kind of food may -be awakened, and here a general physiological law is illustrated. The -light appears brighter after darkness, a sound louder after silence, -the enjoyment of blithesome health more intense after illness, and so -on. This explanation of the appetising effects of bitters proceeding -from the mouth does not exclude the possibility of some such similar -influence coming also from the stomach. As has been already stated in -the fifth lecture, there is some reason for believing that certain -impulses from the cavity of the stomach are likewise necessary for -the excitation of appetite. It is possible that bitters not only act -directly on the gustatory nerves in the mouth, but that they also act -on the mucous membrane of the stomach in such a way that sensations -are generated which contribute to the passionate craving for food. As -a matter of fact, it has been confirmed by many clinicians that after -the administration of bitters some such special sensations do arise -in the stomach. The effect of these remedies consists, therefore, not -merely in the generation of a simple reflex, but in the production of -a certain psychic effect, which indirectly excites a physiological -secretory activity. The same probably applies to other substances, such -as condiments. In any case, whether our explanation corresponds to the -actuality or not, the question of the therapeutic effect of bitters -is settled in the affirmative the moment we acknowledge that these -substances awaken appetite. The problem, therefore, of an experimental -investigation of bitters consists in establishing the fact that they -have an effect upon the appetite. The question is a difficult one, -and has not hitherto been attempted in the laboratory. It is not -sufficient to hand over clinical observations to the laboratory as -experimental proofs. One must have, in addition, the assurance that the -investigation has been correctly carried out; that is to say, that it -dealt exactly with the point under consideration. It is interesting to -observe that the connection between appetite and gastric juice is by -many physicians, and in many text-books of medicine, exactly reversed. -Thus it is represented that some medicinal remedy calls forth a -secretion of gastric juice, and this, by its presence in the stomach, -awakens an appetite. Here we have to deal with a false explanation of -a true fact, and that because it was not recognised that a psychic -effect could by any possibility be a powerful excitant of secretory -nerves. The customs of the chief meal of the day also correspond with -our physiological results. After this or that _hors d’œuvre_, perhaps -also with a liqueur of brandy (especially customary in Russia), both of -which are designed to awaken the appetite, the repast proper begins, -and, in the majority of cases, with something hot, consisting mostly of -meat broth (_bouillon_, different soups, and so on). After this comes -the really nourishing food--meat of different kinds served in various -ways, or, in the case of poorer people, stews made with vegetables, -and therefore rich in carbohydrate material. This sequence of foods, -from the standpoint of physiology, is quite rational. Meat broth, as -we have already seen, is an important chemical excitant of gastric -secretion. An attempt is therefore made in two ways to secure a free -secretion of gastric juice to act on the chief food; first, in the -excitement of the appetite juice by the _hors d’œuvre_, and secondly, -in the promotion of the flow by the action of the meat broth. It is in -this way that human instinct has made provisions for the digestion of -the chief meal. A good meat broth can only be afforded by well-to-do -people, and consequently with the poorer classes a less expensive, -and, indeed, also a less effective, chemical excitant is used for -awakening the early secretion. For example, _kwas_[31] serves in this -way with the Russian population, while in Germany, where the price -of meat is high, different kinds of soups are used, consisting of -water mixed with flour, bread, etc. It is further to be borne in mind -that the quantity of the digestive juices in general stands in close -connection with the content of water in the organism. This has been -shown by the experiments of Dr. Walther for the pancreatic juice, and -by my own for the gastric juice. If this sequence of foods, therefore, -holds good for healthy people, it must be even more strictly adhered -to in pathological conditions. Thus, when a person has no appetite, -or only a weak one, he has no psychic juice or only very little; -consequently, the meal must in every case be begun with a strong -chemical excitant--for example, with a solution of the extractives of -flesh. Otherwise solid foods, particularly if they do not consist of -meat, would remain long in the stomach without any digestion whatever. -It is, therefore, in every way desirable to prescribe meat juice, -strong broth, or meat extract to people who have no appetite. The same -applies also to forced feeding, for instance, of the insane. It is true -that the method of introduction in this case necessarily secures the -presence of a chemical excitant, since the food can only be introduced -in a fluid form. In any case the addition of meat extract would be very -useful. If one arranged the ordinary fluid foods in descending order, -according to the influence of the chemical excitants, the following -would be the series: first, the preparations of the flesh, such as meat -juice and the like; secondly, milk; thirdly, water. - -The usual termination of the repast is also, from the physiological -standpoint, easy to be understood. The chief meal is generally ended -with something sweet, and everybody knows that sweets are pleasant. -The meaning of this is easy to guess. The repast, begun with pleasure, -consequent on the pressing need for food, must also, notwithstanding -the stilling of hunger, be terminated with an agreeable sensation. At -the same time the digestive canal must not be burdened with work at -this stage; it is only the gustatory nerves which should be agreeably -excited. After thus dealing in general with the usual arrangement of -our meals, we may now speak of some special points. - -Above all comes the acid reaction of the food. It is apparent that -acidity enjoys a special preference in the human taste. We use quite -a number of acid substances. Thus, for example, one of the commonest -seasoning substances is vinegar, which figures in a number of sauces -and such like. Further, many kinds of wine have a somewhat acid -taste. In Russia, _kwas_, especially in the acid form, is consumed in -great quantities. Moreover, acid fruits and green vegetables are used -as food, and they are either of themselves acid, or made so in the -preparation. In medicine this instinct is likewise often made use of, -and acid solutions, especially of hydrochloric and phosphoric acids, -are prescribed in digestive disturbances. Finally, Nature itself -constantly endeavours to prepare lactic acid in the stomach in addition -to the hydrochloric acid. The former arises from the food introduced, -and is consequently always present. These facts are all physiologically -comprehensible when we know that an acid reaction is not only necessary -for an efficient action of the peptic ferment, but is at the same time -the strongest excitant of the pancreatic gland. It is even conceivable -that in certain cases the whole digestion may depend upon the -stimulating properties of acids, since the pancreatic juice exerts a -ferment action upon all the constituents of the food. In this way acids -may either assist digestion in the stomach where too little gastric -juice is present, or bring about vicarious digestion by the pancreas -where it is wholly absent. It is easy, therefore, to understand why the -Russian peasant enjoys his _kwas_ with bread. The enormous quantity -of starch which he consumes, either as bread or porridge, demands a -greater activity upon the part of the pancreatic gland, and this is -directly brought about by the acid. Further, in certain affections of -the stomach, associated with loss of appetite, we make use of acids, -both from instinct as well as medical direction, the explanation being -that they excite an increased activity of the pancreatic gland, and -thus supplement the weak action of the stomach. It appears to me that a -knowledge of the special relations of acids to the pancreas ought to be -very useful in medicine, since it brings the gland--a digestive organ -at once so powerful and so difficult of access--under the control of -the physician. We could, for instance, intentionally discard digestion -in the stomach, and thus transfer it to the bowel, by prescribing -substances which do not excite the gastric glands. On the other hand, -by lessening the acidity of the gastric juice we could reduce the -activity of the pancreas, and these are matters which might be made use -of in various special diseases, or even in some general disturbances of -the digestive apparatus. - -No less instructive is a comparison of the results of our experiments -upon fat, with the demands of instinct and also with the precepts of -dietetics and therapeutics. Everybody knows that fatty foods are heavy, -that is, difficult of digestion, and in the case of weak stomachs -they are usually avoided. We are now in a position to understand this -physiologically. The existence of fat in large quantities in the chyme -restrains in its own interest the further secretion of gastric juice, -and thus impedes the digestion of proteid substances; consequently, a -combination of fat and proteid-holding foods is particularly difficult -to digest, and can only be borne by those who have good stomachs -and keen appetites. The combination of bread and butter is less -difficult, as might _a priori_ be inferred from its wide employment. -Bread requires for itself, especially when calculated per unit, but -little gastric juice and but little acid, while the fat which excites -the pancreatic gland insures a rich production of ferment both for -itself and also for the starch and proteid of bread. Fat alone does -not count by any means as a heavy food, as may be seen from the fact -that large quantities of lard are consumed in certain districts of -Russia with impunity. This also is comprehensible, since the inhibitory -influence of the fat in this case does not prevent the digestion of -any other food-stuff, and is conducive to the assimilation of the -fat itself. There is no struggle in this case between the several -food constituents, and therefore no one of them suffers. In harmony -also with daily experience the physician, in cases of weakness of the -stomach, totally excludes fatty food and recommends meat of a fat-free -kind; for example, game, etc. In pathological cases, however, where an -excessive activity of the gastric glands is manifested, fatty food, -or fat as emulsion, is prescribed. And here medicine has empirically -brought to its aid the restraining action of fat, which we have so -strikingly seen in our experiments. - -Amongst all the articles of human food, milk takes a special position, -and this is unanimously recognised, both in daily experience and in the -practice of medicine. By everybody milk is considered a light food, -and is given in cases of weak digestion as well as in a whole series -of severe illnesses; for example, in heart and kidney affections. The -extreme importance of this substance, a food prepared by Nature itself, -we can now well understand. There are three properties of milk which -secure it an exceptional position. As we already know, in comparison -with nitrogenous equivalents of other foods, the weakest gastric juice -and the smallest quantity of pancreatic fluid are poured out on milk; -consequently, the secretory activity requisite for its assimilation is -much less than with any other food-stuff. In addition, milk possesses -a further important property. Thus, when it is introduced unobserved -into the stomach of an animal it causes a secretion both in the stomach -and also one from the pancreas; consequently, it appears to be an -independent chemical excitant of the digestive canal; and in this -action it is remarkable that we perceive no essential difference in -the effect when the milk is brought unnoticed into the stomach from -that which occurs when it is given to the animal to lap. Although -flesh is a better chemical excitant, it is by no means a matter of -indifference how it gets into the stomach. It must, therefore, be -accepted that milk excites not only a really effective, but at the same -time a very economic, secretion, and also that the appetite is unable -to stimulate this secretion into a more active or abundant flow. The -secret of the relation of milk to the secretion of the digestive juices -can, unfortunately, at present be submitted to no further analysis or -investigation. We are at liberty, however, to suppose that the fat on -the one hand is of importance for the inhibition of the gastric glands, -and the alkalinity on the other for the restraint of the pancreas. Thus -the gastric glands and the pancreas, notwithstanding the presence of -excitants, are maintained by milk at a certain but not too high degree -of activity, a matter which is in every way desirable in consideration -of the easy digestibility of its constituents. Finally, the third -characteristic which is observed to belong to milk, and which is -probably only an expression of the first, consists in the following. -When one administers to an animal equivalent quantities of nitrogen, in -the one case as milk, in the other as bread, and afterwards estimates -the hourly output of nitrogen in the urine, it results that the -increase during the first seven to ten hours after the milk (compared -with the excretion beforehand) amounts only to from 12 per cent to 15 -per cent of the nitrogen taken in, while after bread it amounts to 50 -per cent. If the hourly rate of absorption and the extent to which -milk and bread are respectively used up be taken into consideration, -it has to be admitted that these augmentations of urinary nitrogen -which appear soon after feeding must be expressions of the functional -activity of the digestive canal itself, and that this activity in the -case of bread is three or four times greater than in the case of milk -(_Experiments of Prof. Rjasanzew_); consequently, in the case of milk -a much larger fraction of its nitrogen is free to be used up by the -organism at large (irrespective of the organs of digestion) than in -that of any other kind of food. In other words, the price which the -organism pays for the nitrogen of milk, in the form of work on the part -of its digestive apparatus, is much less than that for other foods. How -admirably, therefore, the food prepared by Nature distinguishes itself -when compared with all others! - -The facts just related bring forward a new aspect from which the -relative nutritive values of different foods may be judged. The older -criteria must frankly make room for the new or else be displaced by -them. Experiments upon the utilisation of food-stuffs, in which what -remains undigested is determined as well as what is absorbed into -the body fluids, cannot alone be trusted to solve the question in a -satisfactory manner. Suppose, for instance, that in the digestion of -a given food the alimentary canal has been given a certain work to -perform; if it be in health the work will be accomplished in the -best possible manner--that is to say, with complete abstraction of -everything nutrient. You will thus learn how much nutrient material was -contained in the food, but the question of its digestibility remains -as obscure as before. In your experiment you do not know how great an -effort it has cost the alimentary canal to extract all the nourishment -from the food. Nor can artificial digestion experiments settle the -question of digestibility, for experiments in which food is normally -partaken of are quite different from those in the test-tube, where -we have to deal with only one juice, and not with the interaction of -different juices and different food constituents. That one must here, -as a matter of fact, make a distinction is clear from the observation -of Dr. Walther in our laboratory. Fibrin, which is regarded by all as -the most easily digested proteid, proved, when compared with a nitrogen -equivalent of milk, to be a much stronger excitant of the pancreas, -although milk contains, in addition to nitrogenous substances, a good -deal of other non-nitrogenous material. The digestibility and nutritive -value of foods must obviously be decided by an estimation of the real -work which they entail upon the digestive apparatus, both in regard to -the quantity and quality of the juices poured out on a given amount -of nutrient material. The energy used up in gland metabolism must be -deducted from that of food taken in. The remainder will then indicate -the value of the food to the organism; that is to say, will give the -amount available for use by all the other organs exclusive of the -digestive apparatus. From this point of view those materials must be -taken as less nourishing and less digestible which are in large part -used up to make good the expenditure entailed by their digestion on -the part of the alimentary canal; that is to say, those food-stuffs -are less useful whose nutritive value little more than covers the cost -of their digestion; consequently, it is of great practical importance -to compare from this aspect the same foods differently prepared--for -example, boiled and roast meat, hard and soft boiled eggs, boiled and -unboiled milk, etc. - -A discussion of some further medical questions may here be taken up. -The first concerns the therapeutic use of the neutral and alkaline -salts of sodium. In clinical, pharmacological, and physiological -text-books it is stated now, as ever, that these salts promote a flow -of gastric juice. We may look in vain, however, for any experimental -foundation to support this doctrine. The experiments brought forward -cannot be regarded as conclusive. When Blondlot sprinkled sodium -bicarbonate upon flesh, or Braun and Grützner introduced sodium -chloride solutions directly into the blood, they began with methods -either false in themselves or far removed from normal conditions. In -this case, however, the gaps in the experiment were happily made good -by the clinician, for the experiment appeared to be confirmatory of -clinical experience. That sodium salts (the chloride and bicarbonate) -are useful in disorders of the digestive apparatus there can be no -doubt. How do they act, however? It appears to me that here, as in -some other cases, medical science has fallen into error. When we -know that an effect takes place it does not by any means imply that -we know the mechanism by which it occurs; and although medicine is -broad enough and comprehensive enough to make free use of empiricism -in practice, yet it often thinks in narrow grooves when it turns to -the explanation of facts. It frequently tries to explain complicated -healing processes in the simplest way, on supposed physiological -data. And this is true in the present case, which affords an example -of prevalent medical reasoning; the alkalies work favourably in -digestive disturbances--therefore they are succagogues. Naturally -the stomach, under the influence of alkalies, sometimes begins to -secrete a greater quantity of juice. This means, however, that it -has recovered from a disordered state and has returned to normal -conditions. Consequently, the effect is due to the fact of recovery, -and not to a direct influence of the alkalies. This latter, however, -must be specially proved. The assistance afforded by the alkalies to -the organism might be capable of another explanation; for example, -that which is ordinarily given. In this case, however, I venture to -offer a reason for the effects of sodium chloride, and of the alkaline -salts of sodium, which is exactly the opposite of that generally -accepted. We were unable to convince ourselves of any succagogue -influence on the part of these salts. Indeed, both on the stomach -and pancreas they proved in our hands to have an inhibitory effect. -In addition to the experiments which I previously brought forward -concerning the relation of alkalies to gastric and pancreatic juice, -I may relate the following observation. A dog which fortunately had -survived the performance, one after the other, of a gastric fistula, -a pancreatic fistula, and an œsophagotomy, received daily during the -course of several weeks an addition of soda to its food. The animal -enjoyed good health and had an excellent appetite. When the first sham -feeding experiment was carried out, the relatively small effect of -this otherwise very active juice-exciting procedure at once struck -us. At the same time we observed that the pieces of flesh which fell -from the upper end of the œsophagus, contrary to the ordinary rule, -were hardly at all insalivated. In this dog, therefore, a greatly -lowered activity of several digestive glands--viz., of the gastric, -pancreatic, and salivary glands--simultaneously existed. With regard -to the salivary glands the circumstance was naturally submitted to -closer investigation. I believe that the inhibitory influence of the -alkalies on the digestive glands, which was here proved experimentally, -may furnish a basis for the following representation of their mode -of action in producing healing effects. Catarrhal affections of -the stomach are characterised by an incessant or very protracted -secretion of slimy, weakly acid gastric juice. Further, in many cases -the affection begins with a hypersecretion, that is an abnormal -excitability, of the secretory apparatus which makes itself evident in -a superfluous and useless flow. The same must be conceived to happen -in disorders of the pancreatic gland; at least such a condition sets -in after operations performed for physiological purposes. It is, -further, justifiable to suppose that, when an affection is once set -up by this or that cause, it may later maintain itself independently; -for continuous activity has undoubtedly a harmful influence on the -glands. The due nourishment, and the restoration of organs after -activity, proceeds best during rest. In the normal course of events, -after a period of active work follows a pause, during which the -latent work of restoration is accomplished. When, therefore, a remedy -effectively restrains the excessive work of a diseased organ, it may -in this way contribute to the removal of the pathological condition, -and thus to a restoration of the normal state. In this consists, in my -opinion, the healing effects of the alkalies. One might draw a parallel -between the action of these substances in digestive disturbances -and that of digitalis in compensatory disturbances of the heart. An -uncompensated heart beats rapidly, and thereby only aggravates its -condition. Its time of rest, that is of recovery, of restitution of -the organ, is shortened. A vicious cycle is set up. The weak action -of the heart lowers blood pressure; the lowering of this leads (from -known physiological causes) to an increase in the number of beats; -the quickening leads to weakening of the organ. Without doubt the -digitalis aids by breaking through this vicious cycle, in that it -greatly slows the pulse, and thereby gives new power to the heart. With -our explanation of the action of the alkalies harmonises the further -circumstance that, with the use of the salts in question, a strict diet -is generally prescribed, which means that a certain amount of rest is -secured for the digestive glands. It is interesting that in clinical -investigations with the stomach-tube, after a period when the alkalies -were looked upon as succagogues, a new phase has also set in, mention -being now more frequently made of a restraining effect. - -The cause of the erroneous belief that alkalies promote a flow of juice -obviously lies in this, that people omitted to compare the effects -of the saline solutions with those of like quantities of water (_Dr. -Chigin_). - -The second point which we may consider is the following. The chief -difficulty of the physician who wishes to regulate the diet of patients -when they suffer from digestive disturbances consists in the fact -that idiosyncrasy plays a very important _rôle_. In one and the same -illness, different patients react to the same diet in wholly different -ways. That which is agreeable to one, and is well borne and useful, -may be rank poison to another. Consequently, the golden rule in -dietetics is to give no directions with regard to food till one has -made inquiries concerning the inclinations and habits of the patient. -What does all this indicate? Till now physiology had no experimental -answer to the question. But our facts, it appears to me, contribute -to a clearing up of the situation. Every food determines a certain -amount of digestive work, and when a given dietary is long continued, -definite and fixed types of glands are set up which can only slowly -and with difficulty be altered. In consequence, digestive disturbances -are often instituted if a change be suddenly made from one dietetic -_régime_ to another, especially from a sparse to a rich diet; such, for -instance, as happens after the long Russian fasts. These disturbances -are expressions of the temporary insufficiency of the digestive glands -to meet the new demands made upon them. - -Finally, it may be of some use to relate the following here. There -are often cases of sudden and unaccountable digestive disturbances. -From the standpoint of modern physiology they might be explained by -an activity of the secreto-inhibitory nervous system, which from some -cause or other has been excessively and abnormally stimulated. In any -case this system is now a factor of which the physician has to take due -account. - - - - - SWALLOWING AND MOVEMENTS OF THE STOMACH AND INTESTINES - - BY W. B. CANNON, M.D. - -_Of the Physiological Laboratory of the Harvard Medical School Boston, - Mass., U. S. A._ - - - [NOTE.--In the beginning of 1896 Dr. Professor Henry Pickering - Bowditch, one of our Board of Scientific Assessors in the Nutrition - Case suggested the use of the Röntgen ray as a means of learning more - than was then known about the mechanism of swallowing. There was - much difference of opinion among research physiologists about this - important function, and the question was far from settled. Magendie - published a theory of deglutition, in Paris, in 1836, which was - practically accepted until 1876, when Dr. Professor Angelo Mosso, of - the University of Turin, Turin, Italy, established the theory of sole - peristaltic assistance in swallowing. Again in 1880 Dr. Professor - Kronecker, of Berne, Switzerland, in connection with Dr. Falk, and - later in connection with Dr. Meltzer, of New York, produced evidence - to prove a more complicated process in deglutition than that of - peristalsis alone. But even Kronecker and Meltzer found, as they went - on, evidence to modify their earlier beliefs, and hence the subject - was not cleared up to a point of general agreement. - - The suggestion made by Dr. Bowditch was taken up in the Harvard - Physiological Laboratory and formed the beginning of a series of - studies of the mechanical factors in digestion. The reports of these - studies, presented by Dr. W. B. Cannon and collaborators, in the - _American Journal of Physiology_, in the volumes of 1898 and 1903, - are so understandable, even to the layman ignorant of physiological - nomenclature, that we are prompted to give them, almost entire, - leaving out only the technical description of the methods employed, - which are only interesting to research students who have access to the - _Journal_. - - - It will be noted that three of the professors of physiology - mentioned in connection with this preliminary study of the nutrition - problem--Bowditch, Mosso, and Kronecker--are members of our presently - organised Board.—HORACE FLETCHER.] - - - - - THE MOVEMENTS OF THE FOOD IN THE ŒSOPHAGUS - - BY W. B. CANNON AND A. MOSER - - _From the Laboratory of Physiology in the Harvard Medical School_ - - Extracts from _American Journal of Physiology_, 1898 - - -The movements of deglutition, in common with many other physiological -processes, were explained by the older physiologists on anatomical -grounds. Thus, Magendie divided the act into three parts, corresponding -to the anatomical regions of the mouth, pharynx, and œsophagus. The -muscles of each of these divisions were considered the active agents -in propelling the food onward. The function of moving the mass to the -pharynx was variously ascribed to the tongue itself, to the mylohyoid -muscles, and to gravity. For the second part, the movement through the -pharynx, there was more unanimity of opinion, since the constrictors, -especially the middle and lower, were evidently concerned. - -Direct observations on the movement of swallowed masses in the -œsophagus were first made by Mosso. The œsophagus of a dog was laid -bare, and a transverse incision made through it, or a piece of it -excised. A small wooden ball was placed in the canal below the excised -part, and the animal was then stimulated to swallow. One or two seconds -after the contraction of the pharyngeal muscles a peristaltic wave -began to traverse the œsophagus. This wave did not stop at the point of -excision, but in due time reappeared below, and carried the ball to the -stomach. Thus the act was shown to be controlled by the central nervous -system. Peristalsis was so plainly the motive power that the action was -never doubted. Yet this belief was soon to be questioned. - -In 1880 Falk and Kronecker studied the movements in the mouth and -pharynx, and advanced the theory that deglutition was accomplished by -the rapid contraction of the muscles of the mouth. During the act of -swallowing the air-tight buccal cavity shows a manometric pressure of -twenty centimetres of water. The same pressure was demonstrated to be -present also in the œsophagus, but not in the stomach. This pressure -was considered sufficient to force food through the œsophagus before -the peristaltic wave traversed it. Another argument for rapid descent -was found in the fact that cold water can be felt in the epigastric -region almost immediately after being swallowed. Further, when strong -acids pass through the gullet, they corrode but small parts of it, and -not the entire mucous membrane, as would be the case were the acid -carried to the stomach by peristalsis. - -Over a year and a half ago it was suggested by Prof. H. P. Bowditch -that if some substance opaque to the Röntgen rays were swallowed, -it could be seen in its passage to the stomach, and the nature of -its movement thus determined. Anæsthesia could be dispensed with,--a -desirable condition, since observers had found that it interfered -greatly with the deglutition reflex. It would be unnecessary to open -either the abdominal or the pleural cavity. The reflex stimulus of -food, moreover, would be better than electrical stimulation of the -superior laryngeal nerve. In short, the animal would swallow normal -food under practically normal conditions. At Dr. Bowditch’s suggestion -and with his valuable assistance--which we gratefully acknowledge--we -made the following series of experiments. - -To render the swallowed mass opaque, subnitrate of bismuth was used. -The salt is tasteless, practically inert, and can be fed in large -quantities without harm. In order that observations could be made by -more than one person, all experiments were conducted in a dark room. On -the side of the animal opposite the Crookes tube was placed an open -fluorescent screen, on which the different tissues of the animal were -outlined with varying degrees of light and shade. Among these shadows -the swallowed mass appeared as a darker object, and thus its motion -could be studied. - -For the first experiments the goose was selected. The head and neck -were held stationary by a tall pasteboard collar, which allowed free -movement of the head without constriction of the neck. The fluorescent -screen was placed against this collar at a uniform distance of thirty -centimetres from the tube. When a bolus of corn-meal mush mixed with -bismuth was placed in the pharynx, it descended slowly and regularly, -and occupied about twelve seconds in passing over a distance of fifteen -centimetres. The screen was marked at intervals of two centimetres with -cross lines, by means of which the relative rate in different parts of -the œsophagus could be studied. A vibrator marking tenths of a second -was interrupted whenever the bolus crossed a line. An average of over -one hundred such observations showed that the rate became slightly -slower as the bolus proceeded. - -In order to test liquids, molasses was mixed with bismuth to such a -consistency as to drop easily from a glass rod. When this was fed -with a pipette, it passed slowly and regularly down the œsophagus, -clearly by peristalsis. The rate was about the same as for solid food. -In both these experiments the addition of water would sometimes cause -irregularities in the descent. Microscopic sections from four different -parts of the œsophagus of the goose showed no histological difference. - -In the experiments on the cat, the animal was placed on its back and -left side on a holder. The extremities were secured by straps. The -head was held between two upright rods, connected above by a thong; -this allowed free movement of the head, without resistance to the -passage of food. Shreds of meat dipped in bismuth were ordinarily -masticated and swallowed without difficulty. For soft solids, bread and -milk were used, so fluid as to be easily drawn up into a pipette. The -insolubility of the bismuth salt rendered the study of liquids more -difficult. Strong solutions of potassic iodide and other salts, and -suspension of bismuth, in acacia and molasses were tried; but a simple -mixture of milk and bismuth, shaken in a test tube and immediately -drawn up into a pipette, was found most practicable. - -Inasmuch as the movement of these different foods varied in different -parts of the œsophagus, it will be convenient to divide the latter into -three sections. The first or cervical portion extends from the pharynx -to the thorax; the second or thoracic, from here to the lower half of -the heart; and the third comprises the rest of the canal. The relative -length of these three parts is about in the ratio of 9:8:6. - -The beginning of deglutition was noted by one observer by a finger on -the larynx; the same observer called out when the bolus arrived at -the thorax, heart, and stomach respectively, while the other observer -noted the time. The movement of solids will first be considered. The -descent the entire way was by peristalsis, but the rapidity varied. The -duration of the movement in the cervical portion was two and a half -seconds, and in the thoracic region a little less than two seconds. -At the lower end of the heart there was sometimes a slight pause. In -the lower section, from the heart to the stomach, the movement was -decidedly different; the rate was always very slow. The distance was -less than one-third of the entire canal, yet the time consumed in this -part ranged from six to seven seconds, or three-fifths of the entire -time of descent. The character of the movement here was also peculiar. -Whereas in the upper sections the passage was uniform and regular, with -a slight acceleration in the thoracic region, here it was apparently -irregular, for the bolus descended about one centimetre with each -inspiratory movement of the diaphragm, and remained stationary or -descended very slightly during expiration. Thus a series of hitches -seemed to carry the bolus to the cardia. A probable explanation of this -peculiar movement is that the stomach and lower œsophagus were pulled -down with each descent of the diaphragm. This would make the movement -appear irregular, although it was really a slow peristalsis. It may be -well to remark here that this movement was invariably observed in the -cat with every kind of food. - -Semi-solids, namely, a mush of bread and milk, descended in the same -way as solids; but the rate was slightly faster in the upper œsophagus, -for the bolus took about a second less to reach the cardiac level. From -here the rate was the same as with solids. - -For liquids, one and a half to two seconds sufficed for the descent to -the midheart region. Here there often occurred a long pause, from a few -seconds to a minute or more. Then the œsophagus apparently contracted -above the liquid, which slowly passed on to the stomach, as already -described. Sometimes it seemed as if a swallowing movement, evidenced -by a rise of the larynx, started the peristaltic wave. Again, several -swallows would succeed one another before the liquid passed on. A few -times the bismuth and milk seemed strung out along the œsophagus; -some more liquid descending would gather this up, and the whole mass, -assuming an ovoid form, would move into the stomach. - -Thus in the cat the total time for deglutition varies from nine to -twelve seconds. The lowest section presents no change ascribable to a -difference in consistency, while in the upper sections the rate does -slightly increase with the more liquid character of the food. - -In experiments on the dog, bismuth enclosed in capsules or wrapped in -shreds of meat was fed as the solid. The general phenomena were as -follows: With the rise of the larynx there was a quick, propulsive -movement of the bolus, which descended rapidly for a few centimetres, -sometimes as far as the clavicle. From this point the rapidity -was diminished, yet no pause was observed; the bolus simply moved -more slowly. This rate was then continued to the stomach without a -slackening of speed in the diaphragmatic region, as was observed in the -cat. Semi-solids moved in the same way as solids. The total time of -descent from larynx to stomach was from four to five seconds. - -Liquids gave even a more decided squirt in the beginning of the -movement. To render the œsophagus as lax and free as possible, the -head of the dog was released from the upright rods and held by the -hands after the food was placed in the mouth. Sometimes the liquid -descended rather rapidly as far as the heart, at other times no further -than the clavicle; then without a pause it passed on slowly and -regularly, reaching the stomach in about the same time as solids and -semi-solids. - -Thus in the dog and cat but little variation was seen in the swallowing -of liquids and solids. The liquids pass somewhat faster in the upper -œsophagus. But in some animals the difference of rate with foods of -varying consistency is much more marked. In the horse, for instance, -mere observation shows a decided variation in the rate of movement -in the œsophagus. Liquids shoot along the gullet, while solids move -clearly by peristalsis. To determine the rate of solids, one hand was -placed on the larynx of a horse to note the beginning of swallowing, -and the other hand near the shoulders, where the bolus could be easily -felt in its passage. The time consumed by the bolus in passing over a -certain distance was measured by a stop watch. The rate obtained for -solids, such as hay or grain, was from thirty-five to forty centimetres -a second. - -For semi-solids, a mixture of bran and water was made, thin enough to -run easily between the fingers. Each bolus was watched by a separate -observer with a separate watch. The average rate obtained was the same -as for solids. - -Liquids in the horse pass with a rapidity too great to be affected -by peristalsis. Another force must be sought. Among the various -muscles supposed to be effectual in moving food into the pharynx, the -mylohyoids were shown by Meltzer to be essential. The styloglossi were -cut by him without much interference with deglutition, but section of -the mylohyoid nerves rendered the act impossible. The activity of these -muscles in the horse during swallowing is easily perceived by the hand. -Their energetic contraction is a sufficient explanation of the rapid -passage of water through the œsophagus. The motion here is more than -five times as rapid as that of solids and semi-solids. - -Meltzer’s experiment to measure the rate of liquids in man by -passing a stomach tube containing litmus paper was repeated by us -with some modifications. Congo red paper was used, since it is more -sensitive than litmus; it also furnishes a means of differentiating -between mineral and organic acids, as the discolouration produced -on Congo red by mineral acids is removed by ether. It was thus -possible to distinguish between the discolouration produced by -gastric regurgitation and that produced by the swallowed liquid. For -the swallowed liquid, one-half per cent lactic acid was found most -satisfactory, as the colour produced by it on Congo red test paper is -almost instantly discharged in ether. By this method the paper was -found discoloured within half a second after the rise of the larynx, -certainly too short a period for a peristaltic wave to carry the liquid -to the neighbourhood of the cardia. - -The X-ray method lends itself less successfully to the study of -deglutition in man than in the other animals we have studied. The -thickness of the thorax, the distance of the œsophagus from the -surface, and the relation to dense tissues render the observation of a -swallowed mass difficult, especially when the mass is in rather rapid -motion. The few observations which we have to report were made on a -seven-year-old girl, placed in the sitting posture. Gelatine capsules -containing bismuth were used for solids, and were traced to a point -below the heart. The motion was very regular, and apparently due to -peristalsis, for the bolus descended without a hitch or irregularity of -any kind. Sometimes the capsule became fixed in the upper œsophagus, -at about the level of the second rib. Repeated swallows of water would -fail to dislodge it. An interesting point was noted here. With each -attempt at swallowing, the capsule would rise slightly, as if the -œsophagus was pulled up with the rise of the larynx; then the capsule -would descend to its former position. - -Semi-solids--a mush of bread and milk--could be seen about as far as -solids; that is, to just below the heart. The motion of the mushy bolus -was the same as with solids, except that the rapidity was perhaps -slightly greater. - -It should be noted here that with the human subject, as well as with -the horse, our results for semi-solids differ from those derived by -Meltzer’s method; for according to his statements semi-solids, like -liquids, are squirted down the œsophagus, and are not propelled by -peristalsis, as has been the case in our observations. - -Liquids--bismuth and water--were seen only in the neck and upper -thorax. Here there was a decided squirt. With the rise of the larynx -the liquid was seen to pass rapidly through the pharynx and well down -into the thoracic œsophagus before it was lost to observation. The -rate, however, by estimation was less than that of liquids in the horse. - -There remains to be considered Meltzer’s latest investigation, in -which he endeavoured to ascertain whether liquids remain above the -cardia till the arrival of the peristalsis, or ooze down before. An -experimental answer was secured by Meltzer by the following method. The -abdominal and gastric walls of an anæsthetised dog were incised, and a -tube (vaginal speculum) introduced. Through this the entrance of food -into the stomach could be observed directly. In repeated experiments no -liquid was seen to pass through the cardia before the arrival of the -peristaltic wave. An incision through the diaphragm near its anterior -origin showed that the swallowed liquid was not squirted as far as a -point an inch above the diaphragm. To observe the œsophagus nearer its -beginning, the upper three ribs were resected on the left side. Thus -the swallowed liquid was seen to shoot along the œsophagus before any -peristalsis reached this point. The resection of the fifth rib exposed -the œsophagus half-way between the bifurcation of the trachea and the -diaphragm. Here a bulging was sometimes observed immediately after -the beginning of the act, and the swallowed mass remained there until -a peristaltic wave carried it down. If the mass swallowed was small, -or was projected with moderate force, it might not even reach as far -as the bifurcation. From these experiments Meltzer concluded that in -animals, as in man, liquid food is not carried down the œsophagus by -peristalsis, but is thrown rapidly into a deep part of the canal. The -depth reached depends on the quantity swallowed, the force used, and -the tonicity of the lower part of the œsophagus. - -The difference between these methods of Meltzer and those employed in -our experiments has already been mentioned; and merely his results, -which were obtained with liquids alone, need be considered here. -According to our observations on the dog, there was no distinct pause -at any part of the canal. The movement simply became slower, and -continued at this rate until the stomach was reached. Neither was -the rate through the diaphragmatic part of the œsophagus slower than -through the thoracic. The quick propulsive movement noticed in the -dog was observed with solids and semi-solids as well as with liquids, -but the liquids descended further down the canal before the movement -changed to the slower peristalsis. While this difference was evident to -the eye, the total time consumed by liquids in passing from pharynx to -stomach was not enough shorter than the time for solids and semi-solids -to be determined by our measurements. - - - SUMMARY. - -The phenomena of œsophageal deglutition as determined by our -experiments may then be described as follows:— - -There is a difference in swallowing according to the animal and the -food which is used. - -In fowls the rate is slow and the movement always peristaltic, without -regard to consistency. A squirt-movement with liquids is manifestly -impossible, as the parts forming the mouth are too hard and rigid. With -this diminution of propulsive power in the mouth there is observed a -greater reliance on the force of gravity. The head is raised each time -after the mouth is filled, and the fluid by its own weight trickles -into the œsophagus, through which it is carried by peristalsis. - -In the cat the movement is always peristaltic, and slightly faster than -in fowls. A bolus takes from nine to twelve seconds in reaching the -stomach. Liquids move somewhat more rapidly than semi-solids in the -upper œsophagus. In the lower or diaphragmatic part the rate is very -much slower than above, and is the same for liquids as for solids. - -In the dog the total time for the descent of a bolus is from four -to five seconds. The food is always propelled rapidly in the upper -œsophagus, and moves more slowly below. This rapid movement is -frequently continued further with liquid food. No distinct pause was -observed when the movement of the bolus changed from the rapid to the -slower rate. - -In man and the horse liquids are propelled deep into the œsophagus at a -rate of several feet a second by the rapid contraction of the mylohyoid -muscles. Solids and semi-solids are slowly carried through the entire -œsophagus by peristalsis alone. - - - - - THE MOVEMENTS OF THE STOMACH STUDIED BY MEANS OF THE RÖNTGEN RAYS - - BY W. B. CANNON, M.D. - - _From the Laboratory of Physiology in the Harvard Medical School_ - - Extracts from _American Journal of Physiology_, 1898 - - -Since the stomach gives no obvious external sign of its workings, -investigators of gastric movements have hitherto been obliged to -confine their studies to pathological subjects or to animals subjected -to serious operative interference. Observations made under these -necessarily abnormal conditions have yielded a literature which is -full of conflicting statements and uncertain results. The only sure -conclusion to be drawn from this material is that when the stomach -receives food obscure peristaltic contractions are set going, which -in some way churn the food to a liquid chyme and force it into the -intestines. How imperfectly this describes the real workings of the -stomach will appear from the following account of the actions of the -organ studied by a new method. The mixing of a small quantity of -subnitrate of bismuth with the food allows not only the contractions -of the gastric wall, but also the movements of the gastric contents -to be seen with the Röntgen rays in the uninjured animal during normal -digestion. An unsuspected nicety of mechanical action and a surprising -sensitiveness to nervous conditions have thereby been disclosed. - - - INTRODUCTORY LITERATURE - -The early writings on the subject of gastric movements are -characterised by general inferences from physical laws and from the -anatomical structure of the stomach. According to Galen the stomach -had four functions: to draw the food from the mouth (_facultas -attractrix_), to retain the food (_facultas retentrix_) during the -process of chemical digestion (_facultas alteratrix_), and, finally, -to pass the changed material onward (_facultas expultrix_). In later -writings the _facultas attractrix_ failed to appear as one of the -functions of the stomach. Fallopius, in the sixteenth century, changed -the notion of the _facultas retentrix_ by suggesting that the pylorus -alone performed this office, and that the muscles of the gastric wall -could help only by remaining quiet. Thus the _facultas alteratrix_ and -the _facultas expultrix_ are left as true gastric functions. It is with -the latter activity and its effects that this paper is concerned. - -The ideas of the early writers concerning the pylorus and cardia are -of interest. The cardia, they were agreed, is closed during normal -digestion in order to keep the food from re-entering the œsophagus. The -pylorus they looked upon as the ruler of the actions of the stomach. -Such names as pylorus (keeper of the gate), janitor justus, and rector, -which the first investigators gave to the sphincter, indicate their -theories of its functions. The passage of chyme into the duodenum, the -keeping of undigested food in the stomach, the act of vomiting, were -all dependent, they believed, on the “will” of the pylorus. - -No substantial advance was made beyond these hypotheses until the -beginning of the eighteenth century, when Wepfer and Schwartz applied -the experimental method to the study of the gastric movements and laid -the foundation of a more accurate knowledge. Wepfer vivisected wolves, -dogs, and cats, and observed constrictions following stimulation of -the stomach. He remarked a general contraction of the pyloric part in -vomiting and noted peristaltic and antiperistaltic movements passing -over the organ. About the middle of the stomach he frequently saw a -deep constriction. The investigations of Schwartz are more valuable in -that his search was for the normal action of the muscular coats. The -movements, as he observed them, were generally only slight. They began -either at the pylorus and passed to the left, half-way to the cardia, -or started at the fundus and went to the pylorus. The contractions -and relaxations, following one another, formed larger or smaller -depressions and elevations, _i. e._, more or less definite waves. - -Near the middle of the last century Haller, after confirming the -results obtained by Schwartz and Wepfer, summarised his knowledge of -the motor functions of the stomach as follows. In general, contraction -alternates with relaxation, so that the stomach is, now here, now -there, made narrower by longitudinal or transverse depressions; then -in these same places relaxation and bulging occur. So long as both -apertures are closed the food is driven hither and thither by the -shifting movements. It first takes a definite direction when the cardia -or the pylorus opens. If the cardia opens, there is an antiperistalsis -followed by regurgitation and vomiting. If, on the contrary, the -pylorus relaxes, a contraction, starting at the œsophagus, pushes the -contents of the stomach into the duodenum. The pylorus allows the -passage of fluids, but if it be stimulated by over distention or by -hard pieces of food, it closes tightly. - -Such was the knowledge of gastric movements in Haller’s time. A -comparison of his descriptions with those in any standard work on -physiology published ten or fifteen years ago will show that, despite -very many researches, little advance had been made. Examinations -of animals and men with gastric fistulas, studies of the stomach -through the atrophied abdominal wall, and vivisection have yielded -numerous results; but these have not been harmonious, and have led to -much controversy. Prominent in this mass of material as a valuable -contribution are Beaumont’s careful observations through the gastric -fistula of Alexis St. Martin. Beaumont’s work has recently been -confirmed by Hofmeister and Schütz, who, with Rossbach, Hirsch, -Openchowski, and others, have presented during the last twelve years -much new and interesting information. Since, however, it will conduce -to clearness to set forth the results of these investigations in -connection with my own work, their consideration will be deferred until -later. - -It will then appear that these later investigations, like the earlier -researches, disagree as to the details of the stomach movements. -Such differences in results are the proper outcome of the abnormal -conditions under which the studies have been conducted. Obviously, in -order to see the natural movements of the stomach, the organ should be -observed in its natural state, and not after it has been disturbed by -removal from the abdomen, or by the adhesions and losses of substance -incident to gastric fistulas. - -As a means of watching the gastric motor activities under normal -circumstances, Dr. H. P. Bowditch, in the autumn of 1896, suggested the -use of the Röntgen rays. The present paper is the result of the work -thus far completed. The kind assistance and stimulating counsel of Dr. -Bowditch throughout the investigation are gratefully acknowledged. - - - THE ANATOMY OF THE STOMACH AND ITS RELATIONS TO THE SHADOW - -It must be constantly borne in mind that the shadows described in this -research are cast by the gastric contents, not by the stomach itself. -Therefore the movements of the organ are not seen directly, but are -indicated by their effect on the contained food. Variations in the -length and breadth of the stomach can be inferred from changes in the -outline of the shadow, but variations in the front-to-back diameter of -the organ must be judged from changes in the intensity of the shadow. - -The form of the active stomach soon after food has been taken is shown -in outline in Figure 1. Since the several parts of the stomach are -to be mentioned frequently, it will be well to recall them here in -their relations to the outline. The larger, cardiac part of the organ -lies to the left of a line through _w x_. Into it the œsophagus opens -through the cardiac sphincter, or cardia, at _c_. The pyloric part, -which includes all of the stomach situated at the right of a line _w -x_, is closed by the pylorus at _p_. This part has two divisions: the -antrum at the right of the line _y z_, and the preantral part of the -pyloric portion, or middle region of the stomach, between the lines _w -x_ and _y z_. The lesser curvature corresponds approximately to the -anterior border of the shadow _c w p_; the greater curvature to the -more extensive sweep, _c p_, along the posterior border. - -[Illustration: FIGURE 1.] - -The wall of the cat’s stomach consists of three coats, but as this -paper deals only with the functions of the muscular coat, that alone -will be described. The gastric muscular fibres are disposed in three -sets: an outer longitudinal layer, a middle circular layer, and a set -of inner oblique fibres. The longitudinal fibres continue those of the -œsophagus, and, radiating over the cardiac end, become more marked -along the curvatures than on the front and back surfaces. Over the -antrum they lie in a thick, uniform layer. The circular fibres form a -complete investment, and are arranged in rings at right angles to the -curved axis of the stomach. Towards the pyloric end they become denser -and stronger, and at the pylorus form a thick bundle, the pyloric -sphincter. Separating the antrum from the rest of the stomach, at _y -z_, is a special thickening of the circular fibres, called by the -early writers the “transverse band,” and described by Hofmeister and -Schütz as the “sphincter antri pylorici.” The oblique fibres start -from the left of the cardiac orifice and pass as two strong bands -along the anterior part of the dorsal and ventral surfaces, giving off -fine fasciculi to the circular musculature; towards the antrum they -gradually disappear. - -The musculature of the stomach consists of smooth muscle fibres, -the chief physiological characteristics of which are slowness of -contraction, rhythmic alternation of contraction and relaxation, and -a very great tonicity, or power of prolonged contraction. The action -of these muscles in the process of gastric digestion is now to be -considered. - - - THE NORMAL MOVEMENTS OF THE STOMACH - -Since the time of Haller the chief contributors to the knowledge of the -mechanics of the stomach have been Beaumont, Hofmeister and Schütz, and -Rossbach. - -Beaumont’s famous investigations on Alexis St. Martin are recorded in -almost all general works on physiology. Through a gastric fistula he -introduced a thermometer-tube and observed how it was affected by the -motions of the stomach. His conclusions are as follows: “The circular -or transverse muscles contract progressively from left to right. When -the impulse arrives at the _transverse band_, this is excited to a more -forcible contraction, and closing upon the alimentary matter and fluids -contained in the pyloric end, prevents their regurgitation. The muscles -of the pyloric end, now contracting upon the contents detained there, -separate and expel some portion of the chyme.... After the contractile -impulse is carried to the pyloric extremity, the circular band and all -the transverse muscles become relaxed, and a contraction commences in a -reversed direction, from right to left, and carries the contents again -to the splenic extremity to undergo similar revolutions.” - -In close accord with Beaumont’s description of the activities of the -human stomach are the records of the investigations on the stomach -of dogs by Hofmeister and Schütz. They removed the stomach from the -body and placed it in a moist chamber, kept at body-heat and covered -with glass. Under such conditions the organ remained active for from -sixty to ninety minutes. A typical movement is described by these -observers as composed of two phases. In the first phase a constriction -of the circular fibres, deeper on the greater curvature, starts a -few centimetres from the cardia and passes towards the pylorus. As -the constriction proceeds it increases in strength until a maximum -is reached about two centimetres in front of the antrum. This -annular contraction, called by Hofmeister and Schütz the “preantral -constriction,” closes the first phase. Immediately thereafter the -strong sphincter antri pylorici, or transverse band, contracts. Now, -while the preantral constriction is relaxing, the sphincter antri -pylorici tightens still more, and the antrum is shut off from the rest -of the stomach. As soon as this has occurred a general contraction of -the muscles of the antrum follows. Relaxation begins at the sphincter -antri pylorici and progresses slowly towards the pylorus; it is -sometimes accompanied by an antiperistaltic movement. - -Although Rossbach also used dogs, his results vary considerably from -those of Hofmeister and Schütz. This discrepancy is possibly accounted -for by a difference in method, for Rossbach left the stomach in the -body. The dogs were treated with morphia and curare, and the abdomen -was then widely opened, so that the movements could be clearly seen. -When the stomach was full Rossbach saw deep constrictions begin near -the middle and pass in waves to the pylorus. At first these movements -were weak; later, however, they became more vigorous. The fundus -remained in tonic contraction about its contents and took no part in -the peristalsis. - -Before attempting to explain the difference in the records of these -observers I shall give an account of what may be seen in a cat by use -of bismuth subnitrate and the Röntgen rays. - -1. _Movements of the pyloric part._--Within five minutes after a cat -has finished a meal of bread, there is visible near the duodenal end -of the antrum a slight annular contraction which moves peristaltically -to the pylorus; this is followed by several waves recurring at regular -intervals. Two or three minutes after the first movement is seen very -slight constrictions appear near the middle of the stomach, and -pressing deeper into the greater curvature, course slowly towards the -pyloric end. As new regions enter into constriction, the fibres just -previously contracted become relaxed, so that there is a true moving -wave, with a trough between two crests. When a wave swings round the -bend in the pyloric part the indentation made by it deepens; and as -digestion goes on the antrum elongates and the constrictions running -over it grow stronger, but until the stomach is nearly empty they do -not entirely divide the cavity. After the antrum has lengthened, a -wave takes about thirty-six seconds to move from the middle of the -stomach to the pylorus. At all periods of digestion the waves recur at -intervals of almost exactly ten seconds. So regular is this rhythm that -many times I have been able to determine within two or three seconds -when a minute had elapsed simply by counting six similar phases of the -undulations as they passed a given point. It results from this rhythm -that when one wave is just beginning several others are already running -in order before it. Between the rings of constriction the stomach is -bulged out, as shown in the various outlines in Figures 2, 3, 4, and 5. -The number of waves during a single period of digestion is larger than -might possibly at first be supposed. In a cat that finished eating -fifteen grams of bread at 10.52 A.M., the waves were running regularly -at 11.00 o’clock. The stomach was not free from food until 6.12 P.M. -During that time the cat was fastened to the holder at intervals of -half an hour, and the waves were always observed following one another -in slow and monotonous succession. At the rate of three hundred and -sixty an hour, approximately two thousand six hundred waves passed over -the antrum during that single digestive period. - -From the above review it will be manifest that my observations of the -movements of the pyloric part agree closely with those of Rossbach, -but differ considerably from the harmonious results of the work of -Beaumont, and Hofmeister and Schütz. Beaumont’s methods, however, may -be justly criticised on the ground that the thermometer-tube which he -held in the stomach was wholly unlike food and very liable to bring -about unwonted contractions in so sensitive an organ as the stomach. -Further, the movements observed by Hofmeister and Schütz, as Ewald has -pointed out, may easily have resulted from the abnormal stimulus due -to lack of blood--a potent cause of peristalsis. And it will be shown -later that the accounts given by these investigators describe very well -the actions of the stomach when stimulated by an unusual irritant. -In this connection it may be added that since the publication of the -preliminary notice of my work, Roux and Balthazard, using the Röntgen -rays, have published the results of observations on the stomachs of the -dog and man similar to those thus far described in this paper. - -The fact that my observations and those of Roux and Balthazard -were conducted under normal conditions, and that the conditions of -Rossbach’s experiments were more nearly normal than those of the other -observers mentioned, warrants the conclusion that the pyloric part has -a more important function than that of merely expelling the contents -of the stomach into the intestines. After summarising the description -given by Hofmeister and Schütz, Ewald, for _a priori_ reasons, -declares: “I cannot accept this view. The plain fact that the pyloric -portion secretes a strongly digesting fluid containing pepsin and -hydrochloric acid proves it to be an important part for the peptonising -function of the stomach.” The account of the remarkable manner in which -the pyloric portion performs this function must be deferred until the -movements of other parts of the stomach have been considered. - -2. _Movements of the pyloric sphincter._--Rossbach mars his otherwise -careful work by declaring that the pylorus is tightly closed during -the whole digestive period of from four to eight hours, and that then -the sphincter relaxes and the peristaltic waves empty the stomach. -That this is not the normal action of the sphincter has been shown -by several observers. Hirsch watched dogs with duodenal fistulas and -saw food come from the stomach at intervals of one-fourth of a minute -to several minutes. Roux and Balthazard maintain that in dogs food -enters the duodenum at the completion of each wave of constriction. -Observations on the cat, however, do not support their view, but agree -rather with the statement of Hirsch. - -In cats fed with bread mixed with subnitrate of bismuth, ten or -fifteen minutes elapse after the first constriction in the antrum -before any food can be seen in the duodenum. When food does appear -it is spurted through the pylorus and shoots along the intestine for -two or three centimetres. Not every constriction-wave forces food -from the antrum. On one occasion, about an hour after the movements -began, three consecutive waves were seen, each of which squirted food -into the duodenum. The pylorus remained closed against the next eight -waves, opened for the ninth, but closed once more against the tenth and -eleventh. For each of the four succeeding waves the sphincter relaxed, -but blocked the food brought by three constrictions that followed; and -in this irregular way the food continued passing from the stomach. Near -the end of gastric digestion, when the constrictions are very deep, it -may be that the pylorus opens for every wave. - -When a hard bit of food reaches the pylorus, the sphincter closes -tightly and remains closed longer than when the food is soft. This -action of the sphincter was shown by giving with the regular food of -the cat a dry, hard pellet of equal parts of starch paste and bismuth -subnitrate about the size of a pea. The food itself contained merely -enough bismuth to throw a dim shadow, near the centre of which the -pellet could be clearly seen as a dark object. The continual passing of -the contraction-waves finally brought the little ball to the pylorus. -When it arrived there, five grams of bismuth subnitrate were introduced -into the stomach through a tube in the œsophagus. This was done in -order that the food passing into the intestines after the ball came to -the pylorus might be distinguished from that which had gone on before. -By kneading the stomach the bismuth was distributed, as shown by the -uniformly black shadow. The pellet could still be seen near the end of -the antrum when the constrictions passed over it. Now, although the -waves continued to run regularly, the very black food did not gather in -the intestines in sufficient amount to be recognised until forty-two -minutes after it had been introduced. And when, finally, the food did -show itself in the intestines, its shadow contrasted strongly with that -of the food which had already passed on. The slowness of the expulsion -is not to be regarded as wholly due to the hard mass. No doubt the -kneading of the stomach mixed the contents of different parts of the -organ and brought to the pylorus food not yet sufficiently digested -to be passed by that selective sphincter. But this does not explain -the whole delay. Food similar to that given here, except that it -contained no hard particles, has usually been seen as small masses in -the intestines within fifteen minutes after being swallowed. A part of -the delay was evidently, therefore, caused by the hard pellet. Further -evidence on this point was secured when, on one occasion, the sphincter -was seen to open only seven times in twenty minutes following the -arrival of a hard particle of food at the pylorus. The conclusion may -therefore be drawn that hard morsels keep the pylorus closed and hinder -the passage of the food into the duodenum. - -3. _Activity of the cardiac portion._--The part played by the fundus -apparently has not hitherto been properly appreciated. It has been -regarded as the place for peptic digestion, or as a passive reservoir -for food; but it is in fact a most interestingly active reservoir. - -[Illustration: FIGURE 2.] - -[Illustration: FIGURE 3.] - -[Illustration: FIGURE 4.] - -[Illustration: - FIGURE 5.--Figures 2, 3, 4, and 5 present outlines of the shadow - of the contents of the stomach cast on a fluorescent screen by the - Röntgen rays. The drawings were made by tracing the outline of the - shadow on tissue paper laid upon the fluorescent surface, and are - about one-half the actual size. They show the change in the appearance - of the stomach at intervals for half an hour, from the time of eating - until the stomach is nearly empty. -] - -The action of the cardiac portion will be best understood by comparing -the appearances the stomach presents at various stages in a digestive -period. In order to show these stages I carefully made a set of three -tracings of the outlines of the stomach as soon as possible after a -cat had finished eating, and another set of three every half hour -thereafter, until the contents had disappeared (Figs. 2, 3, 4, and -5). These tracings were made by placing white tissue paper over the -fluorescent screen, and drawing with a thick lead pencil, easily seen, -as much of the boundary of the stomach as I could at the end of each -expiration. Between the times for making the drawings the cat was -allowed to rest quietly on a mat, but care was taken to lay her in the -same position on the holder for every drawing. The drawings of each set -were afterwards fastened over one another, so that the lines coincided -as closely as possible. Another piece of tissue paper was then put over -these, and all four sheets were laid on an illuminated pane of glass. -It was thus easy to get a composite tracing which, considering the -movement imparted to the stomach by respiration, and the dimness of -the shadows in the later stages of digestion, probably represents more -exactly than any single drawing the outline of the stomach for each -successive period. - -A comparison of these drawings shows that as digestion proceeds the -antrum appears gradually to elongate and acquire a greater capacity, -and that the constrictions make deeper indentations in it. But when the -fundus has lost most of its contents, the longitudinal and circular -fibres of the antrum contract to make it again shorter and smaller. -Its change of form, however, compared with the rest of the stomach, is -slight. - -The first region to decrease markedly in size is the preantral part -of the pyloric portion. The peristaltic undulations, caused by the -circular fibres, start at the beginning of this portion, and gradually, -by their rhythmic recurrence, press some of the contents into the -antrum. As the process continues, the smooth muscle fibres with their -remarkable tonicity contract closely about the food that remains, so -that the middle region comes to have the shape of a tube (Figs. 3 and -4--1.30 P.M. to 2.30 P.M.), with the rounded fundus at one end and the -active antrum at the other. Along the tube very shallow constrictions -may be seen following one another to the pylorus. - -At this juncture the longitudinal fibres which cover the fundus like -radiating fingers, and the circular and oblique fibres reaching in -all directions about this spherical region, begin to contract. Thus -the contents of the fundus are squeezed into the tubular portion. -This process, accompanied by a slight shortening of the tube, goes on -until the shadow cast by the fundus is almost wholly obliterated (Fig. -5--5.30 P.M.). - -The waves of constriction moving along the tubular portion press the -food onward as fast as they receive it from the contracting fundus, and -when the fundus is at last emptied they sweep the contents of the tube -into the antrum (Fig. 5--5.00 P.M. to 6.00 P.M.). Here the operation is -continued by the deeper constrictions till, finally (in this instance -at 6.12 P.M.), with the exception of a slight trace of food in the -fundus, nothing is to be seen in the stomach at all. - -The food in the fundus may possibly be slightly affected by the -to-and-fro movements of the diaphragm in respiration. With normal -breathing the upper border of the cardiac portion swings through about -one centimetre; with dyspnœa, or deep breathing, through one and a half -or two centimetres. Since the lower border does not move so much, the -contents are gently pressed, and then released from pressure, at each -respiration. The pyloric portion is moved very little by the diaphragm, -the oscillation being less than a half centimetre. - -Moritz has pointed out the value of an organ like the stomach for -holding the bulk of the food and serving it out a little at a time, so -that the intestines may not become congested during their digestive and -absorptive processes. All of the advantages supposed to be thus secured -to the intestines may be claimed also for the stomach itself. For -the preceding description indicates, and experiments to be described -later prove, that the stomach is composed of two physiologically -distinct portions: the busy antrum, over which during digestion -constriction-waves are running in continuous rhythm; and the cardiac -part, which is an active reservoir, pressing out its contents a little -at a time as the antral mechanism is ready to receive them. - - - THE MOVEMENTS OF THE STOMACH IN VOMITING - -The appearance of the stomach during vomiting has been studied -particularly by Openchowski. He says that when an emetic is given -there follows a quivering of the stomach-wall, which, beginning near -the pylorus, shows itself later in the antral and middle regions of -the stomach. The quivering afterwards passes into a contraction, most -strongly marked in the antral part, since the peristaltic waves running -down to the antrum from above are continually growing deeper. At the -same time the fundus expands spherically. The increased contraction in -the pyloric part drives the contents towards the more dilated portion, -and thence they are forced into the œsophagus by abdominal pressure. - -The same phenomena occur when a cat is given apomorphine -hypodermatically. First the upper circular muscles relax and become so -flaccid that the slightest movement of the abdomen changes the form -of the fundus. Then there are apparently irregular twitchings of the -fundus wall. Soon a deep constriction starts about three centimetres -below the cardia and, growing in strength, moves towards the pylorus. -When it reaches the transverse band the constriction tightens and holds -fast, while a wave of contraction sweeps over the antrum. Another -similar constriction follows. In the interval the transverse band -relaxes slightly, but tightens again when the second wave reaches -it. Perhaps a dozen such waves pass; then a firm contraction at the -beginning of the antrum completely divides the gastric cavity into -two parts. This same division of the stomach into two parts at the -transverse band is to be seen when mustard is given. Now, although -the waves are still running over the antrum, the whole preantral part -of the stomach is fully relaxed. A flattening of the diaphragm and a -quick jerk of the abdominal muscles, accompanied by the opening of the -cardia, now force the contents of the fundus into the œsophagus. As -the spasmodic contractions of the abdominal muscles are repeated, the -gastric wall again tightens around the contained food. Antiperistalsis -I have seen only once; then, while the cat was retching, a constriction -started at the pylorus and ran back, over the antrum, completely -obliterating the antral cavity. - -It will be recalled that the principal difference between the -movements of the stomach and their effects as described by Beaumont, -and Hofmeister and Schütz on the one hand, and Rossbach, Roux and -Balthazard, and myself on the other hand, is that the former observed -constrictions completely dividing the stomach at the transverse band, -and the antrum then squeezing its contents into the intestines; whereas -the latter have seen the constrictions moving forward as narrowing -rings, but not separating the gastric cavity into two parts. - -With the exception of peristalsis in the antrum, the gastric -movements at the beginning of emesis are almost exactly the same as -those Beaumont, and Hofmeister and Schütz, declare to be the normal -contractions of the stomach. Their observations were made, however, -when the organ was subjected to unnatural stimulation. In the excised -stomach, observed by Hofmeister and Schütz, not only were all nervous -connections severed, but likewise all flow of blood to the organ was -entirely stopped, and the cutting off of the blood supply is regarded -as one of the most powerful predisposing causes of peristaltic action. -The thermometer-tube used by Beaumont was an irritant to the stomach, -as he himself admits. “If the bulb of the thermometer,” he writes, “be -suffered to be drawn down to the pyloric extremity, and retained there -for a short time, or if the experiments be repeated too frequently, it -causes severe distress and a sensation like cramp, or spasm, which -ceases on withdrawing the tube, but leaves a sense of soreness and -tenderness at the pit of the stomach.” Moritz also noticed that a -rubber sound introduced into the human stomach proved to be a source -of irritation. It seems reasonable to suppose, therefore, that these -observers did not see the normal movements, but the actions resulting -from abnormal irritation. - - - THE EFFECT OF THE MOVEMENTS OF THE STOMACH ON THE FOOD - -In my first observations on the active stomach a bulging of the -stomach-wall was to be seen in front of the passing waves. But as -food did not immediately appear in the intestine, and as, after the -pylorus relaxed, the gastric contents did not diminish rapidly enough -to allow the supposition that all of the food squeezed forward by the -waves was immediately forced through the pylorus, it was assumed that -a part, at least, of the food under pressure was forced back towards -the cardia through the constriction-ring. This inference was stated in -the preliminary notice of my work. Roux and Balthazard also observed -the passage of the undulations over the pyloric part, but state merely -that the function of the constrictions is the propulsion of food into -the intestine, without mentioning what must be regarded as a very -important function; namely, the mixing effect of the waves. - -Most writers have agreed that the result of the active and passive -movements of the stomach is to force the contents hither and thither, -thus mixing them and the gastric juice together. Two observers, -Beaumont and Brinton, have attempted to explain the manner of the -mixing. Beaumont, after noting how the thermometer-tube, used by him to -indicate the gastric motions, was affected, describes the circulation -of the food as follows: “The bolus as it enters the cardia turns to the -left, passes the aperture, descends into the splenic extremity, and -follows the great curvature towards the pyloric end. It then returns, -in the course of the small curvature, makes its appearance again at -the aperture, in its descent into the great curvature, to perform -similar revolutions.” Brinton bases his theory of the circulation of -the food on an analogy between the movement of a constriction over the -stomach and the passage of a septum with a central perforation along -the interior of a cylinder full of liquid. The result in both cases, -he declares, must be a peripheral current of advance, and a central -current of return. Thus in the stomach there would be peripheral -currents from the cardia along the walls of the stomach to the -pylorus, where they would unite and run as an axial current back to the -cardia. - -Certain _a priori_ objections may be urged against each of these -conclusions. In the first place Beaumont’s observations were made on -a subject having a gastric fistula, and the adhesions between the -stomach and the abdominal wall would prevent the fundus from acting -quite normally in relation to its contents. Beaumont’s conclusions, -furthermore, are based on the movements of a thermometer-tube -introduced through the fistula, and on the recognition of particles of -food which he had seen before as they passed the fistulous opening: the -first method, as has been shown, made the conditions in the stomach -more abnormal than they were previously; the second gave uncertain -knowledge of the course of the food when out of the observer’s sight. -Brinton’s hypothesis states the probable movements of fluid contents -acted on by a passing constriction. But it may be objected that the -conditions assumed by him do not exist in all parts of the stomach. -For not only is there no peristalsis visible in the fundus, but with -the usual food the fundus contents are not liquid. Moreover, the -constrictions at the beginning of the pyloric portion are very slight -and move slowly. The food in front of them is, accordingly, not under -much greater pressure than the food behind them. The axial current -which might result, therefore, could not be strong enough to go far -into the cardiac portion. - -It is easily possible to test experimentally the validity of these -two theories by watching the action of pieces of food which throw a -black shadow in a dimly outlined stomach. For this purpose little -paste pellets of bismuth subnitrate, with starch enough to keep the -form, were given with the customary meal. These pellets, it was found, -did not break up in the stomach during the gastric digestion of soft -bread. Several times I have been fortunate in getting two of the little -balls in the axis of the stomach and about a centimetre apart. As the -constriction-wave approached them, both moved forward, but not so -rapidly as the wave. Now when the constriction overtook the first ball, -the ball moved backward through the constricted ring, in the direction -of least resistance. The wave then overtook the second ball, and it -also passed backward to join its fellow. At the approach of the next -wave they were both pushed forward once more, only to be again forced -backward, one at a time, through the narrow orifice. As the waves -recurred in their persistent rhythm, the balls were seen to be making -progress--an oscillating progress--towards the pylorus; for they went -forward each time a little farther than they retreated. This to-and-fro -movement of the pellets was much more marked in the antrum, where the -waves were deep, than in the middle region. On different occasions from -nine to twelve minutes have elapsed while the balls were passing from -where the waves first affected them to the pylorus; which means that -on the way they were moved back and forth by more than a half hundred -constrictions. - -If the pylorus does not relax, it is evident that a wave approaching it -pushes the food into a blind, elastic pouch, the only exit from which -is through the advancing constricted ring. The constrictions are deeper -near the end of the antrum, and the rings are small; consequently, -the food is squirted back through them with considerable violence. As -has been noted, the pylorus opens less frequently for a while after a -solid piece of food comes to it. In such a case the slow driving waves -squeeze the hard morsel and the soft food about it up to the sphincter, -only to have the whole mass shoot back, sometimes half-way along the -antrum. Over and over again the process is repeated till the sphincter -at last opens and allows the more fluid parts to pass. Hofmeister and -Schütz, and Moritz have disclaimed any selective action of the pylorus, -and declare that solids are driven from the pylorus to the fundus by -antiperistalsis. The action of the pylorus which I have seen, however, -is more like that described by the earlier investigators; for during -digestion there was no antiperistalsis, and the sphincter, separating -the fluids from the solids, caused the solids to remain and undergo a -tireless rubbing. Frequently, when several of these balls have been -given at the same time, they have all been seen in the antrum after the -stomach was otherwise empty. Here they remain to be softened in time -by the juices, or to be forced through the pylorus later, for solids -do pass into the intestine. Thus when the teeth neglect their work the -stomach attempts to perform their function; the relative inefficiency -of the gastric method of grinding and its interference with the normal -gastric activities point an obvious hygienic moral. - -During the process of digestion the food in the cardiac portion gives -no sign of currents. Balls which lie in the fundus immediately after -the food is ingested keep their relative positions until the cardiac -portion begins to contract, and then move very slowly towards the -antrum. Moreover, the food in the fundus of a cat has the same mushy -appearance when examined after gastric peristalsis had been active -for an hour and a half that it had when ingested. The contents of -the antrum, on the other hand, look quite different and have the -consistency of thick soup. The inactivity of the food in the fundus -can also be proved by feeding first five grams of bread and bismuth, -then five grams without bismuth, and finally five grams again with -bismuth in it. The stomach contents are thus arranged in two dark -layers along the curvatures, with a light layer between. Tracings made -on tissue paper show that ten minutes after peristalsis commenced the -stratification had entirely disappeared in the pyloric part, but that -an hour and twenty minutes thereafter the layers were still clearly -visible in the cardiac region. - -The value of the circulation of the food, as described by Beaumont -and Brinton, lay in the supposition that the contents of the stomach -were thus brought near to the secreting gastric wall, and that the -gastric juice could thus more readily exert its action. Although my -observations do not support their theories of mixing currents running -throughout the stomach, they still show that the pyloric portion is -an admirable device for bringing all of the food under the influence -of the glandular secretions of that region. For, when a constriction -occurs, the secreting surface enclosed by the ring is brought close -around the food lying within the ring in the axis of the stomach. -As this constriction passes on, fresh areas of glandular tissue are -continuously pressed in around the narrow orifice. And also, as -the constriction passes on, a thin stream of gastric contents is -continuously forced back through the orifice, and thus past the mouths -of the glands. The result of this ingenious mechanism is that every -part of the secreting surface of the pyloric portion is brought near to -every bit of food, before the latter leaves the stomach, a half hundred -times or more, as evidence by the moving ball. - - - SALIVARY DIGESTION IN THE STOMACH - -The absence of movement in the fundus would seem to give the food -during its stay there little opportunity to become mixed with the -gastric juices, and thus to undergo peptic digestion. The truth of -this supposition can easily be proved experimentally by feeding a -slightly alkaline meal, and later testing the chemical reaction of the -contents of various parts of the stomach. A cat which had been without -food for fifteen hours was given eighteen grams of mushy bread made -slightly alkaline with sodium carbonate. One hour and a half after -the cat had finished eating she was killed, and the stomach laid bare -by opening the abdomen. A very small hole was then made through the -wall in the fundus region, and another similar hole was made into -the antrum. By means of a glass pipette food was extracted first -from the periphery of the fundus; this food was slightly acid. The -cleaned pipette was then introduced two and a half centimetres into -the fundus contents, and the food thus extracted gave the original -alkaline reaction. Specimens of the liquid contents of the antral and -middle regions, taken from various depths, were all strongly acid. -A dog killed an hour and three-quarters after eating showed similar -differences between the reactions of the food in the fundus and the -food in the pyloric portion. So, as a matter of fact, the food does not -become acid at a uniform rate in all parts of the stomach, as would -be the case if Beaumont’s and Brinton’s theories of mixing currents -were true. Moreover, if the facts accorded with their notions, the -saliva, which ceases to act in the presence of more than 0.003 per -cent free hydrochloric acid, and is destroyed when the percentage -of acid proteids is large, would manifestly have its service as a -ferment limited to the relatively short time during which the stomach -contents, in the process of thorough mixing, were reaching that degree -of acidity. There is, however, no movement of food in the fundus, and -the alkaline food received from the œsophagus remains alkaline in this -region for a considerable period. The nutriment, therefore, if well -chewed and thus mixed with saliva, can undergo salivary digestion in -the fundus for a considerable period without interference by the acid -gastric juice.[32] - -From all these observations the conclusion must be that the fundus -acts as a reservoir for the food, in which the digestion of sugars and -starches may take place; and that the pyloric portion with its simple -but marvellous peristaltic mechanism, by a single process, triturates -the food, brings it near to the active glands, stirs it thoroughly with -their secretions, and expels the products into the intestines. - - - THE INHIBITION OF STOMACH MOVEMENTS DURING EMOTION - -Early in the research a marked unlikeness was noticed in the action -of the stomachs of male and female cats. The peristalsis seen with -only a few exceptions in female cats failed to appear in most of the -males, although both had received exactly the same treatment. Along -with this difference was a very striking difference in behaviour when -bound to the holder; the females would lie quiet, mewing occasionally, -but purring as soon as they were gently stroked. The males, on the -contrary, would fly into a violent rage, struggle to be loose from -their fastenings, bite at everything near their heads, cry loudly, and -resist all attempts to quiet them. On account of this difference only -female cats were used for some time, and the significance at first -attributed to the action of the males was almost forgotten when the -following incident recalled it and suggested that the excitement caused -the suspension of the stomach movements. On October 23, 1897, a male -cat was fed at 12.00, but was not placed on the holder till ninety -minutes later. The waves were passing at the rate of six a minute. The -cat fell into a rage and the waves suddenly stopped. - -A few days later an observation on a female with kittens explained -the absence of gastric movements in the males. While the peristaltic -undulations were coursing regularly over the cat’s stomach, she -suddenly changed from her peaceful sleepiness, began to breathe -quickly, and struggled to get loose. As soon as the change took place, -the movements in the stomach entirely disappeared; the pyloric portion -relaxed and presented a smooth, rounded outline. I continued observing, -and stroked the cat reassuringly. In a moment she became quiet and -began to purr. As soon as this happened the movements commenced again -in the stomach; first a few constrictions were visible near the end of -the antrum, then a few near the sharp bend in the lesser curvature, -and finally the waves were running normally from their habitual -starting-place. By holding the cat’s mouth closed between the thumb and -last three fingers, and covering her nostrils with the index finger, -she could be kept from breathing. At the first sign of discomfort -the fingers were removed. This experiment was repeated a great many -times on different cats, and invariably the evidence of distress was -accompanied by a total suspension of the motor activities of the -stomach and a relaxation of the antral fibres. - -No amount of kneading or compression of the abdomen with the fingers, -short of making the cat angry, would cause the waves to stop; so -that the cat’s movements, in themselves, were not the source of the -inhibition. And since expressions of strong feeling on the part of the -animal always accompanied cessation of the constriction-waves, the -inhibition was probably due to nervous influence. It has long been -common knowledge that violent emotions interfere with the digestive -process, but that the gastric motor activities should manifest such -extreme sensitiveness to nervous conditions is surprising. - - - SUMMARY - -1. By mixing a harmless powder, subnitrate of bismuth, with the food, -the movements of the stomach can be seen by means of the Röntgen rays. - -2. The stomach consists of two physiologically distinct parts: the -pyloric part and the fundus. Over the pyloric part, while food is -present, constriction-waves are seen continually coursing towards the -pylorus; the fundus is an active reservoir for the food and squeezes -out its contents gradually into the pyloric part. - -3. The stomach is emptied by the formation, between the fundus and the -antrum, of a tube along which constrictions pass. The contents of the -fundus are pressed into the tube and the tube and antrum slowly cleared -of food by the waves of constriction. - -4. The food in the pyloric portion is first pushed forward by the -running wave, and then by pressure of the stomach-wall is returned -through the ring of constriction; thus the food is thoroughly mixed -with gastric juice, and is forced by an oscillating progress to the -pylorus. - -5. The food in the fundus is not moved by peristalsis, and consequently -it is not mixed with the gastric juice; salivary digestion can -therefore be carried on in this region for a considerable period -without being stopped by the acid gastric juice. - -6. The pylorus does not open at the approach of every wave, but only at -irregular intervals. The arrival of a hard morsel causes the sphincter -to open less frequently than normally, thus materially interfering with -the passage of the already liquefied food. - -7. Solid food remains in the antrum to be rubbed by the constrictions -until triturated, or to be softened by the gastric juice, or later it -may be forced into the intestine in the solid state. - -8. The constriction-waves have, therefore, three functions: the mixing, -trituration, and expulsion of the food. - -9. At the beginning of vomiting, the gastric cavity is separated into -two parts by a constriction at the entrance to the antrum; the cardiac -portion is relaxed, and the spasmodic contractions of the abdominal -muscles force the food through the opened cardia into the œsophagus. - -10. The stomach movements are inhibited whenever the cat shows signs of -anxiety, rage, or distress. - - - - - THE MOVEMENTS OF THE INTESTINES STUDIED BY MEANS OF THE RÖNTGEN - RAYS[33] - - BY W. B. CANNON - - - _From the Laboratory of Physiology in the Harvard Medical School_ - - Extracts from _American Journal of Physiology_, 1902 - - - INTRODUCTION - -The investigation of intestinal movements has been beset by the same -difficulties that characterised the investigation of the gastric -mechanism. Pathological subjects or animals subjected to the disturbing -action of drugs and anæsthetics and of serious operations have been the -only sources of our knowledge. A considerable difference of opinion as -to the nature of the normal movements in the intestines has resulted -from observations made under these necessary abnormal conditions. The -slowly advancing peristaltic wave and the _Pendelbewegung_, or swaying -movement, described by Ludwig, have been regarded as true physiological -processes. Concerning antiperistalsis and the swiftly running -vermicular contraction, observers are not so nearly in agreement. -The activity of the large intestine has been described as simply -peristalsis of a slower rate than that seen in the small intestine. - -The best known of the intestinal movements is the normal peristaltic -wave. This wave is slow, having a rate of about two centimetres per -minute, is regular, and by most observers is said to move always in one -direction. The progress of the contraction, as suggested by Nothnagel’s -experiments, and as clearly stated by Mall and by Bayliss and Starling, -is dependent upon a local reflex. According to Mall, when an object -stimulates the mucosa there occurs above the point of stimulation a -constriction which forces the object downward; and as it moves downward -new regions immediately above the mass are by this reflex brought into -constriction, and thus the wave and its stimulus advance together. “At -the same time,” Mall states, “a sucking force, due to active dilatation -below the body, may have a tendency to drag it down.” In what manner -an active dilatation of the intestinal wall may occur so as to produce -a “sucking force” he does not make wholly clear. Bayliss and Starling, -in describing normal peristalsis in the intestine, state that the -contractions above the bolus increase until there is a strong tonic -constriction. This passes the bolus onward, and as it advances the ring -of constriction follows it. While the bolus is passing down, the gut -above it is traversed by waves running as far as the constricted ring. -These observers state the law of intestinal peristalsis thus: “Local -stimulation of the gut produces excitation above and inhibition below -the excited spot.” - -The pendulum movements are characterised by a gentle swaying motion -of the coils, and are accompanied by rhythmical contractions of the -intestinal wall. They continue with undiminished force after paralysis -of the local nervous mechanism by nicotine or cocaine; they have been -called, therefore, myogenic or myodromic contractions. Observers have -described them variously as shortenings and narrowings of the gut, -rhythmically repeated at nearly the same intestinal circumference; as -alternating to-and-fro movements of the long axis without changes in -the lumen; as local or extensive periodic contractions and relaxations -mainly of the circular musculature; and as waves involving both -muscular coats of the intestine, and travelling normally from above -downward at a rapid rate (2 to 5 cm. per second). They have been -seen in the dog, and in the rabbit and cat. In the cat Bayliss and -Starling noticed that when the lumen of the gut was distended by a -rubber balloon, there appeared rhythmical contractions, which nearly -always were most marked at about the middle of the balloon; _i. e._, -the region of greatest tension. This form of constriction, which, -as my observation shows, is an indication of the manner in which -the rhythmical contraction acts in the cat’s intestine, Bayliss and -Starling seem to have regarded with slight attention, since it did not -accord with the law of peristalsis. - -The swift vermicular wave may pass the whole length of the intestine -in about a minute. It is often seen just after death, as well as in -pathological states such as intestinal anæmia or hyperæmia, and when -the bowel contains gases and organic acids from decomposing food. -Starling is inclined to regard this type of intestinal activity as an -exaggeration of the rhythmic type; Mall, on the other hand, places -it in a class by itself, and declares that its service is to rid the -intestine rapidly of irritating substances. Nothnagel, who designates -this form of movement with the term _Rollbewegung_, thinks it is -transitional between a physiological and a pathological activity. - -The existence of antiperistalsis has been so much questioned that -it will be considered in a special section of this paper, where my -observations may be conveniently introduced. - -The common understanding of the manner in which food passes through the -intestinal canal is that the chyme ejected from the stomach is pressed -downward by a peristalsis, which passes slowly over a part or all of -the small intestine. The peristaltic waves of the colon are supposed -to constitute an independent group, similar to those of the small -intestine, but weaker and slower. Movements of the food other than the -uninterrupted advance have been mentioned by some observers. Starling -states that the effect of the pendulum movement is to mix the contents -of the intestine and bring them into intimate contact with the mucous -membrane. Grützner writes that he has been brought “by strange and -peculiar observations” to believe that the fluid contents of the small -intestine move irregularly forward, then forward and back, then perhaps -remain quiet for some time, only to pass backward for a long distance, -and finally to move forward steadily to the end. In this manner the -food is mixed and brought into contact with the absorbing walls. The -to-and-fro shiftings of the food Grützner ascribed to advancing and -retrograde contractions of the intestinal musculature, and he argued -that even circular constrictions must force the liquid contents away -in both directions. To support his contention, Grützner introduced -mercury into the intestine and observed it with the Röntgen rays. After -noting a backward and forward movement of the mercury he dismissed the -method, saying, “Many a flash must come from the Röntgen tube before -the _normal_ movement of the intestinal contents is made entirely clear -by this method.” - -The following account is a summary of many repeated observations on -different animals, and is a contribution to a clear understanding of -the normal movements of the intestines and their contents. - - - THE MOVEMENTS OF THE SMALL INTESTINE - -When the food has been distributed through the intestine so as to -present the appearance shown in Figure 1, a noticeable feature in most -or all of the loops is the total absence of movement. If the animal -remains quiet, however, only a few moments elapse before peculiar -motions appear in one or another of the loops, or perhaps in several, -and last for some time. These motions consist in a sudden division -of one of the long, narrow masses of food into many little segments -of nearly equal size; then these segments are again suddenly divided -and the neighbouring halves unite to make new segments, and so on, in -a manner to be more fully described. I have called this process the -rhythmic segmentation of the intestinal contents. Further observation -reveals peristalsis here and there, and under certain circumstances the -typical swaying movements may be seen. All these phenomena are now to -be considered in detail. - -[Illustration: - FIGURE 1.--Appearance of food in the intestines 5¾ hours after eating. - This and other radiographs reduced two-thirds.] - -[Illustration: - FIGURE 2.--Diagram representing the process of rhythmic segmentation. - Lines 1, 2, 3, 4 indicate the sequence of appearances in the loop. - The dotted lines mark the regions of division. The arrows show the - relation of the particles to the segments they subsequently form.] - -_Rhythmic segmentation of the intestinal contents._--This is by far the -most common and the most interesting mechanical process to be seen in -the small intestine. The nature of the process may best be understood -by referring to the diagram in Figure 2. A string-like mass of food -is seen lying quietly in one of the intestinal loops (line 1, Fig. -2). Suddenly an undefined activity appears in the mass, and a moment -later constrictions at regular intervals along its length cut it into -little ovoid pieces. The solid string is thus quickly transformed, -by a simultaneous sectioning, into a series of uniform segments. A -moment later each of these segments is divided into two particles, -and immediately after the division neighbouring particles (as _a_ -and _b_, line 2, Fig. 2) rush together, often with the rapidity of -flying shuttles, and merge to form new segments (as _c_, line 3, Fig. -2). The next moment these new segments are divided, and neighbouring -particles unite to make a third series, and so on. At the time of the -second segmentation (line 3, Fig. 2) the end particles are left small. -Observation shows that these small pieces are not redivided. The end -piece at A simply varies in size with each division; at one moment it -is left small, at the next moment it is full size from the addition -of a part of the nearest segment, and a moment later is the small bit -left after another division. The end piece at B (probably the rear -of the mass) shoots away when the end mass is divided, and is swept -back at each reunion to make the large end mass again, only to be -shot away and swept onward with each recurrence of the constrictions. -Thus the process of repeated segmentation continues, with the little -particles flitting towards each other and the larger segments shifting -to and fro, commonly for more than half an hour without cessation. -From the beginning to the end of a period of segmentation the food -is seen to have changed its position in the abdomen to only a slight -extent; whether this change is a passing of the food along the loop, -or a movement of the loop itself, it is impossible to tell from the -shadows on the screen. The change of position, however, is much less -conspicuous than the lively division and redivision which the mass -suffers so many times from the busy, shifting constrictions. - -From this typical form of rhythmic segmentation there are several -variations. Sometimes, and especially when the mass of food is thick, -the constrictions do not make complete divisions and are so far apart -that the intermediate portions are relatively large. Moreover, the -constrictions do not take place in the middle of each portion, but -near one end; thus each portion is constricted, not into halves, -but into thirds. If a little pointer is placed at the middle of a -segment, when the segments are completely divided into halves, in a few -seconds the pointer will be in the middle of the clear space between -two segments; but in a few seconds more the first phase will return -and the pointer will again be indicating a segment,--two operations -intervene between similar phases. When, however, the portions are -constricted into thirds, the indicator shows it, since three operations -intervene between similar phases. The manner of these changes is made -clearer by reference to the diagram in Figure 3. That each portion is -constricted into three pieces is proved also by watching the gradual -reduction of the portion at the left end of line 1 through lines 2 -and 3, and also in the gradual formation of a full-sized portion at -the right end of lines 2, 3, and 4. When food undergoing this process -is watched, it appears to be affected by a series of constrictions, -each of which starts at one end of the mass and marches through to the -other end, leaving its impress at short intervals along the length. The -progression of the dotted lines from right to left in _a_, _b_, _c_, -and _d_, etc., Fig. 3, gives a notion of these advancing constrictions. - -Another variation of the segmentation is shown in Figure 4. In this -type there are evidently divisions and subdivisions, _i.e._, one more -operation between the appearance and the reappearance of the same phase -than is present in the simple division of the small segments in a long -string of food (Fig. 2). This form of segmentation is fairly typical -for the constrictions seen in food advancing through the intestine. -Sometimes the divisions occur in the middle of a long string of food -and leave the ends wholly unaffected. - -[Illustration: - FIGURE 3.--Diagram showing the relations of the portions when they are - constricted into three pieces. The dotted lines indicate regions of - constriction; the arrows indicate the relationship of the pieces to - the portions they subsequently form.] - -A remarkable feature in the segmentation of the food is the rapidity -with which the changes take place. The simplest way of estimating the -rate of division is to count, not the number of times the partition of -the food recurs in the same place, but the number of different sets of -segments observed in a given period. Thus in Figure 4 the appearances -of lines 1, 2, 3, 4, etc., would be counted, and not merely lines 1, -4, etc. Repeated observations on different animals have shown that -the most common rate of division in long, thin chains of food varies -between twenty-eight and thirty times in a minute; _i. e._, there is -a change from one set of segments to another set every two seconds, -and a return of the same phase every four seconds. In some cases the -rate is as low as twenty-three times per minute. The larger masses seem -to be associated with a slower segmentation; the operations indicated -in Figure 3, for example, occurred from eighteen to twenty-one times -in a minute, so that the same phase reappeared only once in eight or -nine seconds. The segmentation frequently continues for more than half -an hour; in one instance it was seen to persist with only three short -periods of inactivity for two hours and twenty-two minutes. At the rate -of thirty segmentations per minute it is clear that a slender string -of food may commonly undergo division into small particles more than a -thousand times while scarcely changing its position in the intestine. - -I have seen once, in a cat only lightly etherised, the exterior of an -intestine which was dividing the food as above described. An hour and -a half after a meal of salmon the anæsthetic was given, the abdomen -opened, and the flaps raised so as to form walls. Warm salt solution -was then poured into the abdominal cavity, and the floating coils left -covered with the transparent omentum. The gastric peristaltic waves -were running regularly; on the intestine there were visible at various -places during the period of observation regions of constriction which -had the appearance shown in Figure 3, except that the rings were -relatively nearer together. New rings of constriction took place on the -same side of all the bulging parts at the margin of the constricted -portion (_cf._ dotted lines, Fig. 3). As new rings occurred the old -relaxed, but apparently with tardiness, for the contents gurgled as -if forced through the narrowed lumen. The constrictions recurred -irregularly and at much longer intervals than in the normal animal. The -contracted rings were pale and bloodless. - -The effect of the process of rhythmic segmentation proves it an -admirable mechanism. The food over and over again is brought into -closest contact with the intestinal walls by the swift kneading -movement of the muscles. Thereby not only is the undigested food -intimately mixed with the digestive juices, but the digested food is -thoroughly exposed to the organs of absorption. Mall has shown that -contraction of the intestinal wall has the effect of pumping the blood -from the submucous venous plexus into the radicles of the superior -mesenteric vein, and thus materially aids the intestinal circulation. -Moreover, lacteals loaded with fat will in a few moments become empty -unless the intestine is slit lengthwise, so that the muscles cannot -exert compression. The rhythmic constrictions, therefore, both -propel the blood in the portal circulation and act like a heart in -promoting the flow of lymph in the lacteals. This single movement with -its several results is an excellent example of bodily economy; the -repeated constrictions, as already shown, thoroughly churn the food and -digestive fluids together, and also plunge the absorbing mucosa into -the very midst of the food masses: but not only are the processes of -digestion and absorption favoured by these movements; they also, by -compression of the veins and lacteals of the intestinal wall, serve -to deport through blood and lymph channels the digested and absorbed -material. - -_Peristalsis._[34]--The phenomena of peristalsis and segmentation are -usually combined in some manner while the food passes through the small -intestine. Peristalsis is observed normally in two forms: as a slow -advancing of the food for a short distance in a coil, and as a rapid -movement sweeping the food without pause through several turns of the -gut. The latter form is frequently seen when the food is carried on -from the duodenum; and it may readily be produced in other parts of the -small intestine by giving an enema of soapsuds. - -When a mass of food has been subjected for some time to the segmenting -activity of the intestine, the separate segments, instead of being -again divided, may suddenly begin to move slowly along the loop in -which they lie. That this movement is not a swinging of the coil as -a whole, but a peristaltic advance of separate rings of its circular -musculature, is made probable by the fact that the succeeding segments -follow along the same path their predecessors have taken. The advance -of the little pieces may continue for seven or eight centimetres, -when finally the front piece stops or meets other food. Then all the -succeeding pieces are swept one by one into the accumulating mass, -which at last lies stretched along the intestine, a solid string -manifesting no sign of commotion. - -[Illustration: - FIGURE 4.--Diagram showing combined peristalsis and segmentation.] - -Another form of slow peristalsis is frequently observed when the food -is pushed forward, not in small divisions, but as a large lump. The -relatively long string of food is first crowded into an ovoid form as -the forward movement begins, and as it is collecting thus, it seems -at the last to be suddenly formed into a more rounded ball, as if the -mass were pulled or pushed together at the two ends. The next moment -it is indented in the middle by a circular constriction (as shown in -Fig. 4, line 2), which spreads it in both directions along the loop. -The trailing portion (_a_) is next cut in two, and the severed part -sometimes flies back over its course about a centimetre. Now the whole -mass is swept together again and slightly forward as shown in line 4, -Fig. 4, and the segmenting process is repeated. At stage 3, Fig. 4, -a constriction sometimes appears around the middle of the advanced -portion (_b_). Thus, with many halts and interruptions, the food slowly -advances. - -A slight variation of the movement just described is observed when the -amount of food is greater and extends farther along the intestine. -Under such circumstances, as the mass moves forward, constrictions -appear just in front of the rear end, which separate it from the main -body, and cause it to shoot backward sometimes through the distance of -a centimetre. The main body meanwhile is not disturbed. No sooner has -the rear section been shot away than it is swept forward again into -union with the rest of the food, and the whole mass then advances until -another interfering constriction repeats the process. - -_Rhythmic segmentation and the pendulum movement._--There is little -doubt that the segmentation of the food which I have seen is due -to an activity of the intestinal musculature similar to that which -causes the so-called pendulum movement. This activity, as already -noted, is rhythmic, and, although accounts differ, analytical methods -prove that it involves both the longitudinal and the circular layers -of muscle. Observations of the effect of the rhythmic contractions -upon the food show that the action of the circular fibres is most -prominent. It is probable, however, that the longitudinal fibres also -play an important part in the process of segmentation. Examination -of Figure 2 makes clear that in line 2 the regions of constriction -appear between the regions of constriction in line 3; before _c_ can -be formed, therefore, the constriction between _a_ and _b_ must relax. -Contraction of the longitudinal fibres between two segments would help -to enlarge the constricted lumen of the gut. It seems probable that, as -the constrictions on either side of _c_ occur, the longitudinal fibres -between them contract; almost simultaneously the constriction between -_a_ and _b_ relaxes, and the two particles are thus brought swiftly -together. A similar process naturally would take place for each of -the shifting segments. Thus the function of the longitudinal muscles -would be to contract between new rings of constriction and thereby aid -in relaxing the former ring between them. During my one observation -of the segmenting process, as seen on the surface of the intestine, -I could not be sure that the distance between neighbouring segments -was shortened as the constriction relaxed; that activity of the -longitudinal fibres is present, however, is indicated by observations -of Raiser on the intestines of the rabbit and the cat. Raiser observed -the outer surface of the coils, and describes the normal movement -as an alternate contraction and relaxation of single divisions of -the longitudinal fibres; he notes that these short divisions shift. -But whether they shift in alternation with the shifting circular -constrictions, as seems probable, is an interesting point not yet -determined. - -[Illustration: FIGURE 5.--Tracing showing segmentation of chyme in the -duodenum. This and other tracings reduced two-thirds.] - -Bayliss and Starling state that the swaying pendulum movements are -essentially due to peristaltic waves recurring in the same place and -running rapidly downward. This form of the movements I have seen only -once. At this time about 90 c.c. of soapy water had been injected. -This procedure has the effect of exaggerating in every particular the -movements of the small intestine. In this instance a broad constriction -appeared about the middle of a long string of food and persisted there -while it spread down the gut. As the contraction spread, the gut swayed -slowly to and fro before it. Then there was a relaxation, followed by -a recurrence of the constriction in the same place, a spreading of the -contraction, and a swinging of the loop just as before. This phenomenon -was repeated again and again, till finally the string was divided and -the forward piece pushed through a tortuous course to the colon. - -_The course of the food in the small intestine._--Chyme is not forced -from the stomach by every wave that passes over the antrum, but only -at intervals. When the pylorus relaxes, the food, moved towards the -pylorus under considerable pressure, is squirted along the duodenum -for two centimetres or more. Careful watching of this food shows that -usually it lies for some time in the curve of the duodenum until -additions have been made to it from the stomach, and a long, thin -string of food is formed. While it is resting in this place it is -exposed to the outpouring of the bile and pancreatic juices. All at -once the string becomes segmented (see Fig. 5) and the process of -rhythmic segmentation continues several minutes, thoroughly mixing -the intestinal digestive juices with the chyme. In this region the -alternate positions of the segments are sometimes far apart, and the -to-and-fro movements of the particles may be a relatively extensive -and very energetic swinging. Finally the little segments unite into -a single mass, or form in groups, and begin to move forward. The -peristalsis here, as already mentioned, is much more rapid than the -normal peristalsis elsewhere in the small intestine. The masses, once -started, go flying along, turning curves, whisking hither and thither -in the loops, moving swiftly and continuously forward. After passing on -in this rapid manner for some distance the food is collected in thicker -and longer strings, resembling the strings seen characteristically in -the other loops. Towards the end of digestion the small masses shot -out from the stomach, after a few segmentations, may move on in the -rapid course without being accumulated in a larger mass until the swift -movement ceases. - -During the first stages of digestion in the cat’s small intestine the -food usually lies chiefly on the right side of the abdomen; during the -last stages the loops on the left side contain the greater amount of -food. In these loops the food remains sometimes for an hour or more -with no sign of movement. All at once a mass begins to show irregular -depressions and elevations along its length, and then suddenly it is -divided, at first partially, later completely, into many little equal -parts, and these repeatedly undergo division and reunion, division -and reunion, over and over again, in the manner described above as -rhythmic segmentation. After a varying length of time the activity -wanes and the little segments are carried forward individually and -later brought together, or join and move on as a single body, or they -may reunite and lie quietly for some time without further change. Thus -by a combined process of kneading and peristaltic advance the food is -brought to the ileocæcal valve to enter the large intestine. Records -from ten different animals show that salmon does not appear in the -small intestine until an hour or an hour and a half after the food is -eaten. Inasmuch as five or six hours elapse after eating before this -food begins to be seen in the colon, it is evident that the chyme takes -four to five hours to pass the length of the small intestine. It is -interesting to note that the operations are considerably shortened if -the meal has consisted of bread and milk. - - - THE COMPETENCE OF THE ILEOCÆCAL VALVE - -The ileocæcal valve in the cat is situated three or four centimetres -from the blind end of the cæcum. Its position is usually marked in -shadows of the food in the colon by a slight indentation, towards which -masses about to enter the colon are ordinarily directed from a point -somewhat distant in the small intestine (see Fig. 6). - -Regarding the competence of the ileocæcal valve many observations -have been made. Grützner has reviewed the evidence bearing on the -question and concludes that the valve is not competent, least of all -for liquids. He declares that as soon as liquids or thin fluid masses -appear in the upper part of the colon they pass in many instances into -the small intestine the moment that the pressure on the colon side -rises slightly. If the colon contains a solid or a thick, mushy mass, -the passage towards the small intestine is scarcely possible, because -every increase of pressure in the large intestine must force the two -lips of the valve together and close it. - -The importance of the competence of the ileocæcal valve under normal -conditions cannot be appreciated until the function of the first part -of the colon is considered. In order that this part of the intestinal -mechanism may perform its service, the competence of the valve for the -food which enters the colon from the ileum should be perfect. As a -matter of fact, such is the case. Not only does the activity of the -colon prove this statement, but the failure of every attempt to drive -the food in the colon back through the valve into the ileum confirms -the proof. Again and again I have tried, by manipulation through the -abdominal wall, to press the normal contents of the colon downward with -sufficient force to cause them to return to the small intestine, but -without success. The valve held perfectly. - - - THE MOVEMENTS OF THE LARGE INTESTINE - -When the large intestine is full, palpation through the abdominal wall -demonstrates that the material in the lower descending colon and in -the sigmoid flexure is usually composed of hard, incompressible lumps, -while that in the ascending and transverse colon and the cæcum is -soft, permitting the walls of the gut to be easily pushed together. -The condition of the contents in these two regions seems to indicate -a rough division of the large intestine into two parts, and the -mechanical activities of these two parts verify the differentiation. In -the descending colon the material is very slowly advanced by rings of -tonic constrictions (see Fig. 7); in the ascending and transverse colon -and in the cæcum by far the most common movement is an antiperistalsis. - -_Antiperistalsis in the colon._--The colon of cats which have been -without food for a day usually contains enough gas to make the position -of the gut distinguishable with the fluorescent screen (see Fig. 1). -The first food to enter the colon from the small intestine is carried -by antiperistaltic waves into the cæcum (Fig. 1), and all new food as -it enters is also affected by these waves. Thus the contents of the -colon, instead of being driven immediately toward the rectum by slow -peristalsis, as is the general opinion, are first repeatedly pushed -toward the cæcum by an antiperistaltic action. - -These antiperistaltic waves follow one after another like the -peristaltic waves of the stomach (see Figs. 5, 6, and 10). They begin -either on the more advanced portion of the food in the colon (when only -a small amount is present), or at the nearest tonic constriction, which -is usually at the turn between the transverse and descending colon -(Figs. 7 and 8.) The waves rarely run continuously for a long time. -When the colon is full, it is usually quiet. The first sign of activity -is an irregular undulation of the walls, then very faint constrictions -passing along the gut towards the cæcum. These constrictions may -first appear only on the ascending colon. As they continue coursing -over the intestine they become deeper and deeper, until there is a -marked bulging between successive constrictions. When the waves have -thus become more prominent, they are seen to start near the end of -the transverse colon and pass without interruption to the end of the -cæcum. After these deepest waves have been running for a few minutes -the indentations grow gradually less marked, until at last they are so -faint as to be hardly discernible. The final waves are sometimes to be -observed only at the end of the transverse colon. - -Such a period of antiperistalsis lasts from two to eight minutes, -with an average duration of four or five minutes. The periods recur -at varying lengths of time; in one instance a period began at 1.38 -P.M. and was repeated at 2.06, 2.34, 2.55, 3.15, and at 3.36, when -the observation ceased; in another instance a period began at 2.43 -P.M., and was repeated at 2.57 and at intervals of from ten to fifteen -minutes thereafter while the animal was being watched. The waves have -nearly the same rate of recurrence as those in the stomach; about five -and a half waves pass a given point in a minute, _i. e._, eleven waves -in two minutes. This rate has proved fairly constant in different cats -and at different stages in the process of digestion; in one case, -however, the waves passed at the rate of nine in two minutes. - -The stimulating effect of rectal injections on the movements of the -small intestine has already been noted. Enemata have also pronounced -stimulating action on the antiperistalsis of the colon. Usually the -almost immediate result of a rectal injection of warm water is the -appearance of deep antiperistaltic waves, which often continue running -for a long period. In one case, after an injection of 50 c.c. of warm -water, the waves followed one another with monotonous regularity during -an observation lasting an hour and twenty minutes. The manner in which -this antiperistaltic mechanism affects nutrient enemata introduced into -the bowel will be discussed in the section devoted to the question of -antiperistalsis. - -These constrictions passing backward over the colon do not force -the normal contents back through the valve into the small intestine -again. I have seen hundreds of such constrictions, and only twice have -there been exceptions to this rule,--once under normal conditions, -when a small mass slipped back into the ileum, and at another time -when a large amount of water had been introduced into the colon. The -importance of the competence of the ileocæcal valve is now apparent; -indeed, antiperistalsis in the colon gives new meaning and value to -the location of a valve at the opening of the ileum. For, inasmuch -as the valve is normally competent, the constrictions repeatedly -coursing towards it force the food before them into a blind sac. The -effect on the food must be the same as the effect seen in the stomach -when the pylorus remains closed before the advancing waves. The food -is pressed forward by the approach of each constriction; but since -it cannot go onward in the blind sac, and is, moreover, subjected to -increasing pressure as the constriction comes nearer, it is forced -into the only way of escape, _i. e._, away from the cæcum through -the advancing constricted ring. About twenty-five waves affect every -particle of food in the colon in this manner during each normal period -of antiperistalsis. The result must be again a thorough mixing of the -contents and a bringing of these contents into close contact with the -absorbing wall--a process which has already been variously repeated -many times in the stomach and in the small intestine. - -Two other movements have been observed in the ascending colon, but -they are rare appearances. The first of these was a serial sectioning -of the contents noticed in an animal given castor oil with the food. -A constriction separated a small segment in the cæcum; another -constriction then cut off a segment just above the first, and with the -disappearance of the first constriction the two separated segments -united. A third segmentation took place above the second, and the -changes occurred again. Thus the whole mass was sectioned from one -end to the other; and no sooner was that finished than the process -began again and was repeated several times. A slight modification of -this movement was observed in a colon containing very little food. The -mass was pressed and partially segmented in the manner characteristic -of the small intestine, and was thus again and again spread along -the ascending colon, and each time swept back into a rounded form -by antiperistalsis. The second of the two movements mentioned above -consisted in a gentle kneading of the contents. This was caused by -broad constrictions appearing, relaxing, appearing, relaxing, over -and over again, in the same place. When several of these regions were -active at the same time, they gave the food in the colon the appearance -of a restless undulatory mass. Once a constriction occurred and -remained permanently in one place, while the bulging parts on either -side of it pulsated alternately, at the rate of about eighteen times -in a minute, with the regularity of the heart-beat. Although these -phenomena are somewhat striking, they are not usual, and are in no way -so important as the antiperistalsis. - -_The changes when food enters the colon._--The passage of food through -the ileocæcal valve seems to stimulate the colon to activity. As food -is nearing the ileocæcal valve the large intestine is usually quiet and -relaxed (Fig. 6, 4.00), though occasionally indefinite movements are -to be observed; and sometimes just before the food reaches the end of -the ileum the circular fibres of the colon in the region of the valve -contract strongly, so that a deep indentation is present there. The -indentation may persist several minutes; it disappears as the muscles -relax just previous to the entrance of the food. The food is moved -slowly along the ileum and is pushed through the valve into the colon. -The moment it has entered a strong contraction takes place all along -the cæcum and the beginning of the ascending colon, pressing some of -the food onward, and a moment later deep antiperistaltic waves (Fig. 6, -4.03) sweep down from the transverse colon and continue running until -the cæcum is again normally full, _i. e._, for two or three minutes. - -[Illustration: - FIGURE 6.--Tracings showing changes when food enters the colon and - also the first tonic constriction. 4.00, the colon relaxed as food - approaches in the ileum. 4.03, the colon contracted and traversed by - antiperistaltic waves after the food has entered.] - -_The appearance of tonic constrictions._--It has already been noted -that as the food accumulates in the ascending colon it is at first -confined to this region by antiperistaltic waves. With further -accessions, however, the contents naturally must be pressed more and -more into the transverse and descending colon. In the early stages of -this accumulation, while the food lies chiefly in the ascending colon, -the only activity of the muscular walls is the antiperistalsis. As the -contents extend along the intestine a deep constriction appears near -the advancing end and nearly separates a globular mass from the main -body of the food (Fig. 6). The contents of the large intestine progress -farther and farther from the cæcum; meanwhile new tonic constrictions -appear which separate the contents into a series of globular masses. -And as the number of these divisions increases they take a position -farther from the cæcum, so that they are present chiefly in the -descending colon (Fig. 7). Raiser has recorded a similar appearance -in the terminal portion of the rabbit’s colon, in which deep circular -constrictions separate the scybalous masses. He maintains that these -masses are pushed onward by the constrictions. Comparing tracings -made at rather long intervals (forty-five minutes), I found that the -rings disappear from the transverse colon, and then are present with -the waste material in the descending colon. Thus in the cat also -these rings, which seem with short observation to be remaining in one -position, are in reality moving slowly away from the cæcum, pushing -the hardening contents before them. The contents at this stage are no -longer fluid, and consequently they must offer considerable resistance -to a force pushing them through the colon. It is an advantage to have -this pultaceous substance propelled in divisions rather than in a -uniformly cylindrical mass, since the fibres along the length of the -mass are thereby rendered effective. Such are the functions of the -persistent rings; they form the waste matter into globular masses at -the end of the transverse colon and slowly push these masses onward. - -[Illustration: - FIGURE 7.--Radiograph showing the region of tonic constrictions - (descending colon) and the region of antiperistalsis (transverse and - ascending colon).] - -In the transverse colon, which is free from the slowly moving rings, -the antiperistaltic waves have full sway. In the region of the -tonic rings an infrequent or even a slowly periodic relaxation and -contraction are often to be observed. These changes seem to take place -in all the rings at about the same time. Once I saw antiperistaltic -waves running over the uppermost of four segments, but since the rings -on either side of the segment held tightly, the waves had merely the -effect of churning the material of the segment and did not move it -onward. Inasmuch as the material in these segments at first is soft, so -that the segments are easily compressible, while the fæcal masses which -are the final result are relatively hard and dry, it follows that even -within the confines of these persistent rings some absorption is taking -place. - - - DEFECATION - -The process of clearing the colon is a process of repeated reduction -of the amount of material present. Figure 8 (3.11) is a radiograph -showing the food in the colon at 3.11 P.M. About 3.25, with a slow, -sweeping movement, the gut swung around so that the ascending colon was -lying in the position of the last half of the transverse colon, and the -transverse colon had taken the position of the descending part (Fig. -8, 3.25). At the same time the tonic constrictions disappeared and -were replaced by a strong, broad contraction of the circular muscle, -tapering the contents off on either side in two cones. The region of -strongest contraction was apparently drawn downward with the rest of -the gut by a shortening of the descending colon. As the intestine -swung around, more material was forced into the rectum, and when the -swinging of the intestine stopped, the constriction which divided -the lumen passed slowly downward, and with the aid of the muscles -surrounding the abdominal cavity, pushed the separated mass out of -the canal.[35] After the terminal mass had thus been pushed out, the -colon with the remainder of its contents returned to nearly its former -position (Fig. 8, 3.46). About two hours afterward this remnant had -been spread throughout the length of the large intestine by means of -the slowly moving rings. Figure 7 is a radiograph of the same colon -pictured in Figure 8; the radiograph was taken at 11.50 A.M., and at -12.15 P.M. the material in the lower descending colon was forced out in -the manner above described. Within three hours the remaining portion -had been spread into the evacuated region, as shown in Figure 8, 3.11. -The manner in which the material is spread from the region of the -antiperistaltic waves into the region of the slowly advancing rings -presents a problem. During normal living new food constantly arriving -in the colon must force the old contents forward just as the later -parts of a meal force forward the earlier parts; there is no doubt, -however, that most of the contents of the cæcum and the ascending colon -may be passed onward even during starvation. The emptying of these -regions, according to my observations, is never complete; for after -considerable time has elapsed and the large intestine is cleared and -dilated with gas, some substance is still to be detected in the cæcum -and clinging to the walls of the ascending colon. The only activities -manifested here are the antiperistaltic waves and the strong tonic -contraction of the whole circular musculature shown in Figure 6. It is -clear that the latter activity would serve to press into the transverse -colon a considerable portion of the contents of the ascending colon, -and the remnant seen clinging to the walls would be the part not thus -pressed forward. - -[Illustration: - 3.11 3.25 3.46 - - FIGURE 8.--Two radiographs and a tracing showing the changes taking - place in defecation. 3.11, material in the colon. 3.25, colon carried - downward and terminal mass separated. 3.46, after defecation, when the - colon returns to former position. Defecation occurred at 3.27.] - -Twice I have seen appearances which might account for the emptying of -the first portion of the large intestine in a more thorough manner -than that above described. At one time, without apparent stimulation, -strong tonic contraction occurred along the entire length of the -ascending colon, which forced the contents almost wholly into the -transverse portion. This action seemed merely an exaggerated form of -that observable after food passes the ileocæcal valve (see Fig. 6). At -another time, after a mass of food had passed through the ileocæcal -valve, after the ascending colon had contracted generally and the -antiperistaltic waves had coursed over it in the usual manner, a deep -constriction appeared at the valve and ran upward without relaxation -nearly the length of the ascending colon, pushing the contents before -it. For an instant the wave paused; then the constriction relaxed and -the food returned towards the cæcum. These observations indicate that -either a general contraction of the wall of the large intestine or a -true peristalsis may be effective in pressing waste matter from the -region where antiperistalsis is the usual activity into the region -where the slowly advancing rings may carry it on to evacuation (see -Fig. 7). - - - THE QUESTION OF ANTIPERISTALSIS - -In 1894 Grützner published an observation and made an assumption about -which there has since been much controversy. He maintained that when -normal salt solution, holding in suspension hair, powdered charcoal, or -starch grains, is injected into the rectum, it is carried upward into -the small intestine and may even enter the stomach. These experiments -have been repeated by several observers. Some have confirmed Grützner’s -results; others have failed, after using most careful methods, to -find any evidence of the passage of the injected material back to the -stomach, and they have declared that the apparent success was due to -carelessly allowing the food of the animal to become contaminated with -the test materials, so that these were introduced into the stomach by -way of the mouth. That antiperistalsis does not occur in the small -intestine seems to be proved by Mall’s experiment of reversing a -portion, sewing it in place, and then finding that the food does not -pass the reversed region, but collects at the upper end. Sabbatani -and Fasola reversed stretches of small intestine of varying length, -and found that the reversed portions allowed fluids to pass, but that -the persistence of the physiological direction of movement caused an -accumulation of undigested food in the region of the upper suture. -However a portion of the intestine lay in relation to the rest, it -always manifested the normal peristalsis. Many other observers working -directly on the intestine confirm this testimony and state that the -progress of the constriction-rings is always downward, and that -antiperistalsis is not physiological. In 1898, however, Grützner took -his stand again in favour of a backward movement in the intestines, -and in a somewhat metaphysical manner argued that peristalsis and -antiperistalsis belong to each other just as relaxation of muscle is -related to contraction. He assumed that as the contents are advanced -by slow peristalsis, so are they returned by a similar movement in -the opposite direction, and he mentions several pathological cases -(fistula of intestine) to substantiate the assumption. - -By means of the X-rays it is possible to see just what takes place when -a fluid is injected into the rectum. For the purpose of determining -how nutrient enemata are received and acted upon in the intestines, -I have introduced thin, fluid masses in large and small amounts, and -thick, mushy masses in large and small amounts, in different animals. -The enemata consisted of 100 c.c. of milk, one egg, ten to fifteen -grams of bismuth subnitrate, and two grams of starch to hold the -bismuth powder in suspension. To make the thick enema all these were -stirred together and boiled to a soft mush; to make the thin enema -all the parts were boiled together except the egg, which was added -after the boiled portion was cooled. The small amount injected was 25 -c.c.; the large amount almost 90 c.c., about the capacity of the large -intestine when removed from the body. The animals were given first a -cleansing injection, and after this was effective the nutrient material -was introduced. In order to make sure of the observation, a control -radiograph was first taken to show no bismuth food present, and other -radiographs taken at varying intervals after the injection to record -the course the food was following. - -[Illustration: - 1.50 2.15 3.00 - - FIGURE 9.—- Radiographs showing that after a large nutrient enema - (about 90 c.c.) has been given the food is forced more and more from - the large into the small intestine. The enema was introduced at about - 1.40 P.M. At 3.00 segmentation was occurring in many loops.] - -These experiments show that when small amounts of nutrient fluid are -introduced they lie first in the descending colon. In every instance -antiperistaltic waves are set going by the injection, and the material -is thereby carried to the cæcum. When large amounts are injected they -stop for a moment in the region between the transverse and descending -colon, as if a constriction existed there. Then a considerable amount -of the fluid passes the point, and antiperistaltic waves carry it -to the cæcum. In any case the repeated passing of the waves seems -to have the effect of promoting absorption, for in the region where -these waves continue running, the shadows become gradually more dim, -and finally the bismuth appears to be only on the intestinal walls; -in other regions, _e. g._ in the descending colon, the shadows retain -their original intensity. Small injections have never in my experience -been forced even in part into the small intestine; but with the larger -amounts, whether fluid or mushy, the radiographs show many coils of the -small intestine containing the bismuth food. - -The passage of the injected material beyond the ileocæcal valve is -probably due entirely to antiperistalsis in the colon,--a factor -unknown to both Grützner and his opponents. The valve, which is -thoroughly competent for food coming normally from the small intestine -into the large, is curiously incompetent for a substance, even of the -consistency of thick cream, introduced in large amount by rectum. When -the valve first permits the food to enter the ileum, the fluid pours -through and appears suddenly as a winding mass occupying several loops -of the intestine (Fig. 9, 1.50, about ten minutes after the injection). -The mass is continuous from the valve to the other end; antiperistalsis -is therefore not visible in the small intestine under the circumstances -of this experiment. The antiperistaltic waves of the colon, however, -continue running; the transverse and ascending colon are thus almost -emptied, and the small intestine more and more filled with food (Fig. -9, 2.15 and 3.00). After a short time the typical segmenting movements -can be seen in the loops, busily separating the food into small masses, -and over and over again dividing and redividing them. - -I have never seen food material pass back from the colon so far as the -stomach; but once, about ten minutes after an injection of 100 c.c. of -warm water, the cat retched and vomited a clear fluid resembling mixed -water and mucus. In the fluid were two intestinal worms still alive. - -The importance of the mechanism by which nutrient enemata are passed -backward in the intestine is evident. In the colon the nutrient -material is worked over by the antiperistaltic waves, intimately -mixed with whatever digestive juices may be present, and exposed to -the organs of absorption in that region. If the enemata are large, -the digestive and absorptive processes are by no means confined to -the colon, but may take place along extensive surfaces of the small -intestine. I have repeatedly seen rhythmic segmentation active -throughout many loops of the small intestine, thus exposing the -injected food to the same mixing and absorbing processes as affect the -nutriment which has come through the stomach in a normal manner. - - - THE EFFECT OF EMOTIONS AND SLEEP - -Observations on the stomach of the cat showed that the peristalsis -is inhibited whenever the animal manifests signs of anxiety, rage, -or distress. Since the extrinsic innervation of a large part of -the intestinal tract is the same as that of the stomach, it is of -interest to note the effect of emotional states on the movements of -the intestines. Esselmont, in a study of the dog’s intestine, noted -constantly after signs of emotion a marked increase of activity lasting -for only a few moments. Fubini also observed that fear occasioned more -rapid peristalsis. There is no doubt that many emotional states are -a strong stimulus to peristalsis, but it is equally true that other -emotional states inhibit peristalsis. In the cat the same conditions -which stop the movements of the stomach stop also the movements of the -intestines. - -[Illustration: - FIGURE 10.--Tracings showing the effect of excitement on - antiperistalsis in the colon.] - -The female cats used in these observations ordinarily lie quietly on -the holder and make no demonstration. Sometimes, however, with only a -little premonitory restlessness, the cat suddenly flies into a rage, -lashing her tail from side to side, pulling and jerking with every -limb, and biting at everything near her head. During such excitement, -and for some moments after the animal becomes pacified again, the -movements, both of the large and small intestine, entirely cease. Such -violence of excitement is not necessary to cause the movements to stop; -a cat which was restless and continually whining while confined to the -holder showed no signs of intestinal movements during any period of -observation (one period lasted more than an hour), although the changes -in the distribution of the food observable from one period to the next -proved that movements were going on during the quiet intermissions. -In another cat, uneasy and fretful for fifty minutes, no activity was -seen; then she became quiet for several minutes, and peristalsis of the -small intestine appeared. - -When the segmentation process in the small intestine is stopped by -excitement the segments unite and the series of parts returns to the -form of a solid string. The change occurring in the large intestine -when the antiperistalsis is inhibited by excitement is shown in Figure -10. The tonic constrictions in the descending colon are apparently not -affected by emotional states, for they do not seem to relax in the -excitement which causes the movements to cease. - -By holding the mouth and nostrils closed, or by pressing between the -rami of the jaw, the breathing may be stopped. As soon as the cat shows -distress from lack of breath every form of intestinal movement stops. - -The statement is sometimes made in text-books of physiology that the -gastric and intestinal mechanisms cease to act during sleep. It is -worthy of note that nearly all the animals curled up and slept during -the time between observations; nevertheless, the progress of the food -through the intestines continued. The statement is also made that at -night, even without sleep, the intestines are almost entirely at rest; -that this is their normal time for repose. I have seen both large and -small intestines actively at work, however, from half past nine until -half past ten o’clock at night. - - - SUMMARY - -1. Bismuth subnitrate, 10 to 33 per cent, mixed with the food renders -the movement of the intestinal contents, and thereby the movements of -the intestinal walls, visible on the fluorescent screen. - -2. The activity most commonly seen in the small intestine is the -simultaneous division of the food in a coil into small segments, and -a rhythmic repetition of the segmentation each time applied to the -new segments formed from parts of those just divided. In the cat this -rhythmic segmentation may proceed at the rate of thirty divisions per -minute. The effects of the constrictions causing the segmentation are -the mixing of the food and the digestive juices, the bringing of the -digested food into contact with the absorbing mechanisms, and the -emptying of the venous and lymphatic radicles of their contents by -compression of the intestinal wall. - -3. Peristalsis is usually combined with segmentation. As the food is -advancing, interfering constrictions often separate the rear end of the -mass from the main body. The separation is momentary, however; the -rear end is swept into union with the main body again, and the whole -mass is pushed onward until another constriction repeats the changes. - -4. The ileocæcal valve is thoroughly competent for food entering the -colon from the ileum. - -5. The usual movement of the transverse and ascending colon and the -cæcum is an antiperistalsis. This recurs in periods about every fifteen -minutes, and each period lasts commonly about five minutes; the waves -recur during a period at the rate usually of eleven waves in two -minutes. This antiperistalsis gives new significance to the ileocæcal -valve; for the food, now in a closed sac, is thoroughly churned and -mixed by the constrictions running towards the cæcum, and again exposed -to absorbing walls without any interference with the processes in the -small intestine. - -6. As soon as new food enters the large intestine a strong general -contraction takes place along the cæcum and ascending colon, forcing -some of the food onward; a moment later antiperistaltic waves begin to -pass. - -7. With the accumulation of material in the transverse colon, deep -tonic constrictions appear one after another and carry the material -into the descending colon, leaving the transverse and ascending -portions free for the antiperistaltic waves. - -8. In emptying the large intestine the material in the lower descending -colon is first carried out by combined peristalsis and pressure of -abdominal muscles; the remainder of the material is then spread into -the evacuated region, and this region is again cleared; the second -remainder may be similarly affected. In normal life the new food -arriving in the colon must force forward the old contents of the -ascending and transverse colon. - -9. The observations have revealed no evidence of antiperistalsis in -the small intestine, but since the ileocæcal valve will allow nutrient -material under pressure to pass backward, the antiperistalsis of the -large intestine may force into the small intestine a considerable -portion of a large nutrient enema. Segmentation in the small intestine -affects such an enema precisely as it affects food which has passed -normally through the stomach. - -10. Signs of emotion, such as fear, distress, or rage, are accompanied -by a total cessation of the movements of both large and small -intestines. The movements continue in the cat both during sleep and at -night. - - - - - THE BATTLE CREEK LABORATORIES - -THE MAMMOTH SANITARIUM AND THE LARGE ADOPTED FAMILY OF DR. AND MRS. J. - H. KELLOGG - - - [A report of one experiment has been selected from _Modern Medicine_ - relative to the work of the laboratories connected with the Battle - Creek Sanitarium because it relates to the effect of cooking and - mastication upon food in illustration of the statement of Dr. Campbell - pertaining to these aids to digestion. Much more evidence could be had - from the Sanitarium reports, but sufficient has already been given - herewith from various authoritative sources to justify our claims of - the great importance of mouth-treatment in human nutrition. - - It may be said here, however, that the trial of thorough mouth-work as - an aid to digestion, which has been in progress at the Sanitarium for - more than a year, and which has finally been accepted and prescribed - as the first requirement of the treatment of patients, is of the - utmost significance. This is, by far, the largest sanitarium in the - world, having some hundreds of physicians, nurses, and other attachés, - and treating many thousands of patients annually. The “cure” is based - upon natural methods of recuperation, and while all of the staff, both - medical and surgical, are fully equipped diplomatists, and whereas the - organisation has a legally and professionally accepted medical school - of its own, so-called medicines are rarely used, and never except as - antidotes to specific poisons. Nature is assisted by scientific means - to do the curing, and now that an economic nutrition to relieve the - exhausted system of the patient from all possible strain through ample - mouth-treatment of food, as intended by the anatomical, dental, and - chemical plan on which man is constructed, has been tried and accepted - as a fundamental principle of the institution, it gives a practical - indorsement of the claims set forth in “Glutton or Epicure,” and in - this present book, and declares that they are of greatest importance - in securing health and efficiency. - - The Battle Creek Sanitarium is a philanthropic and humanitarian - institution operating under a perpetual charter which compels the use - of all the profits gained to foster the spread of the humanitarian - work. More than sixty branches of the parent institution have been - established in or near large cities in different parts of the world, - under the title of The American Medical Missionary Association, - and each of these branches conducts a life-saving business on Good - Samaritan principles. The organisation started its medical missionary - work some thirty-seven years ago, with almost no capital and only - one patient, in a small two-storey frame house, in the then small - village of Battle Creek, Michigan. The incorporators were religious - enthusiasts who believed that Christianity should be expressed in - works as much as in faith, in curing the sick and healing the wounded, - and thus preparing the unfortunate for the reception of moral and - spiritual inspiration. - - The best evidence that this scheme of procedure to attain the ultimate - end was a good one is shown by the success of the institution in - its growth from such small beginning to the immense proportions of - the present time, with one of its buildings nearly a thousand feet - in length and five storeys in height and numerous other buildings - radiating from the main one and scattered about it in a finely wooded - park. Fire came and destroyed the old building and all its contents, - but yet it was soon rebuilt, and the concern goes on growing and - growing, because the foundation principle of the institution is the - beautiful Golden Rule, and the method of treatment employed is taken - from the open book of Nature. - - While the organisation was primarily based upon a special religious - creedal enthusiasm, it has become so broadly altruistic as to suggest - a return to original Christianity as defined in the Sermon on the - Mount. In such Christian expression honest agnostics, born Buddhists, - and the tolerant of all the different Christian creeds may join and - say amen! - - One of the splendid results of an economic nutrition, attained by - following the natural requirements and impulses, is the curing of - many diseases, among them several forms of constipation. The writer - has a genuine admiration for the spirit that is the motive power - of the Battle Creek Sanitarium and firm belief in the Christianity - demonstrated in the work, especially in the private experiment of Dr. - and Mrs. Kellogg, with their family of adopted waifs. Twenty-four - children of unfortunate parents, waifs so unfortunate in their - attractability as to be hopelessly neglected, have been gathered - under this sheltering roof and are showing their mettle and gratitude - by splendid behaviour and brilliant accomplishment in a manner that - any proud parent might approve. To miss any opportunity to express - gratitude to Dr. and Mrs. Kellogg for giving us such a splendid - example of the true meaning of practical Christianity would be showing - symptoms of the worst form of constipation; viz., constipation of - appreciation and affection.—HORACE FLETCHER.] - - - - -EXPERIMENTAL INVESTIGATION OF THE INFLUENCE OF MASTICATION AND COOKING - OF FOOD, ETC., IN THE LABORATORIES OF THE BATTLE CREEK, MICHIGAN, - SANITARIUM, UNDER THE DIRECTION OF DR. J. H. KELLOGG - - From _Modern Medicine_ - - -The table clearly shows the effect of cooking and the effect of -mastication upon the salivary digestion of food. Column 1 shows the -results obtained after an ordinary test meal consisting of 1½ ounces -of water biscuit to 8 ounces of water; column 2, 1½ ounces of water -biscuit ground fine, mixed with water and swallowed without chewing; -column 3, test meal consisting of 1½ ounces of raw wheat flour and -8 ounces of water; column 4, test meal consisting of 1½ ounces of -unground pearled wheat with 8 ounces of water. - - ═════════════════════════════════╤════════╤════════╤══════╤══════ - │ Water │ Water │ │ - │biscuit,│biscuit,│ Raw │ Raw - │ well │ not │flour.│wheat. - │chewed. │chewed. │ │ - │ 1 │ 2 │ 3 │ 4 - —————————————————————————————————┼————————┼————————┼——————┼—————— - Total acidity (A) │ 0.142 │ 0.140 │0.204 │0.136 - Calculated acidity (A´) │ 0.156 │ 0.132 │0.186 │0.128 - Total chlorine (T) │ 0.296 │ 0.284 │0.332 │0.272 - Free HCl (H) │ 0.050 │ 0.028 │0.056 │0.052 - Combined chlorine (C) │ 0.106 │ 0.104 │0.130 │0.076 - Fixed chlorides (F) │ 0.114 │ 0.152 │0.146 │0.144 - Maltose (M) │ 1.088 │ 0.272 │0.000 │0.000 - Dextrine and soluble starch (D) │ 0.812 │ 0.548 │0.300 │0.448 - │ │ │ │ - COEFFICIENTS │ │ │ │ - │ │ │ │ - Digestion of albumin (_a_) │ 0.82 │ 0.97 │1.00 │1.00 - Digestion of starch (_b_) │ 0.71 │ 0.42 │0.00 │0.00 - Salivary activity (_c_) │ 1.17 │ 1.11 │1.14 │1.37 - Fermentation (_x_) │ 5.00 │ 11.00 │6.00 │6.00 - Chlorine liberation (_m_) │ 0.80 │ 0.70 │0.85 │0.71 - —————————————————————————————————┴————————┴————————┴——————┴—————— - -Several points of interest are to be noted in the above table, the -first and most conspicuous of which is the fact that the saliva did -not act at all upon the raw flour and raw wheat, as shown by the total -absence of maltose in the cases represented in columns 3 and 4. The -small amount of dextrine and soluble starch shown was, perhaps, already -present in the raw grain, but this point I have not investigated. -It is clear, however, that no sugar was produced when raw starch was -taken, whereas the amount of sugar produced after the ordinary test -meal was more than 1 gram in each 100 c.c. of stomach fluid; in other -words, the stomach fluid contained more than one per cent of sugar -without taking into account the amount which had been absorbed. - -The figures for maltose in column 2 represent a test meal in which -little or no saliva was mixed with the test meal, the food being -swallowed without chewing, indicating very slight action of the saliva, -the amount of maltose found in the stomach fluid being but a trifle -more than one-fourth the amount obtained after an ordinary test meal. -The amount of soluble starch and dextrine was less than half the normal -amount in the case of the raw flour, and but little more in the case of -the raw wheat. - -Another point of interest is the increased amount of lactic acid found -in the test meal taken without chewing, represented in column 2. The -coefficient of fermentation which represents the number of milligrams -of lactic acid (as expressed in terms of HCl) found in 100 c.c. of -stomach fluid was more than double that found after the same kind -of test breakfast properly masticated, represented in column 1. The -results of this experiment distinctly associate acid fermentation with -imperfect mastication and imperfect salivary digestion. - -Another fact noted in a comparative study of the results of the -analysis of over 5000 stomach fluids, which very strongly confirms -this idea, is that starch conversion is usually complete in cases of -apepsia, while lactic acid is conspicuous by its absence. In nearly all -cases of apepsia which I have encountered, numbering about forty cases -in all, the most delicate tests for lactic acid have failed to show its -presence except in the most minute quantities; in most cases it was -entirely absent. - -There are a number of other points of interest in the above table in -addition to those which relate particularly to starch digestion. One of -the most noteworthy of these is the fact that the digestion of albumen -was not unfavourably influenced by the neglect to masticate the food, -the coefficient of digestion, in fact, being raised from .82 to .97. -This coefficient is a qualitative and not a quantitative index. The -higher coefficient indicates a more perfect elaboration of proteids and -a close approach to an absolutely perfect proteid digestion. - -Another fact of perhaps even greater interest has relation to the -digestion of albumen when the wheat was eaten raw, in the form of -either flour or wheat. The coefficient of proteid digestion in both -cases, as shown in columns 3 and 4, was 1.00, indicating perfect -elaboration of the albuminoids. From this it appears that raw gluten, -or the proteids of wheat, is digested more perfectly when taken in a -raw state than when cooked, the very opposite of which we have seen -to be true of starch. The digestion of raw starch may take place in -the intestines, by the action of the pancreatic juice, but cannot take -place in the stomach, for the reason that the saliva has not the power -to penetrate the cellulose envelope of the starch granule, and hence -cannot digest raw starch. - -This fact coincides in a most interesting manner with the biological -fact that man is by nature a frugivorous animal. In the process of -ripening, the starch of fruits undergoes a hydration similar to that -which takes place in cooking and in pancreatic digestion, whereby -the insoluble starch is converted into soluble starch, dextrine, and -sugar. This explains, also, why well-ripened fruit may be eaten raw -with impunity, while unripe fruit and farinaceous food of all sorts -require cooking. In his diet, man, like his nearest relative, the -monkey, being naturally a frugivorous animal, may eat fruits in the -state in which Nature has provided them; but when he introduces other -natural products into his bill of fare, he must adopt artificial means -for securing the preparation for digestion which Nature makes in the -ripening process of fruits. - -The coefficient of chlorine liberation (_m_) is very nearly uniform, -indicating that the mastication of food and the cooking of food have -little influence upon this digestive function. - -The coefficient of salivary activity (_c_) was determined independently -for each test breakfast. Its practical uniformity indicates that there -was no essential change in the character or quality of the saliva to -account for the differences shown by the totals in relation to the -stomach digestion of starch. - - - - - DR. EDWARD HOOKER DEWEY AND THE “NO BREAKFAST PLAN” - - - The “No Breakfast Plan,” evolved from the long experimental experience - of Dr. Dewey, to secure much needed rest for the stomach and - intestines, is described in a book bearing that title which can be - had direct from the author by addressing him at his home, Meadville, - Penn., U. S. A. - - “No Breakfast” is, evidently, a misnomer, but means, in the present - application, an appetite _earned_ after arising from sleep. The - writer, for instance, often begins work so early in the morning that - by the time the ordinary breakfast is ready he has already done a fair - day’s work. - - The writer has no reported details of the work of Dr. Dewey to add - to this volume. In “Glutton or Epicure” full appreciation of this - Esculapian Luther is expressed and extracts of his writings are - reprinted. In fighting for more than forty years for the principle of - less abuse of the tired body of man, Dr. Dewey has rendered a service - that some time will be reckoned very great; and while there is no - scientific report of the good doctor’s work to call for introductory - comment, it would be equally unhealthy to miss an opportunity to - express gratitude for what he has done for us all. - - - - - PROFESSOR JAFFA AND THE FRUITARIANS - - - Professor Jaffa, too, of the University of California, has been doing - most valuable service in testing the usefulness of fruits and nuts as - human foods. He generously furnished the author with elaborate tables - of his results, covering several years of observation, showing low - nitrogen possibilities similar to those demonstrated by the writer and - his colleagues at Cambridge and Yale. These have since been published, - and relating to special kinds of foods, as they do, suggest a wide - range of choice among the fruits of earth; but the collected evidence - of this book shows that human nutrition is best served when the - appetite, being kept at normal, is allowed to make selection from the - whole range of nutritious products furnished by good Mother Nature. - - - - - DR. H. P. ARMSBY - - - In the Oct. 16th, 1903, number of _Science_, also, is an interesting - article by Dr. H. P. Armsby on the heat values and muscular energy - values of different food elements and their isodynamic replacement of - each other under various conditions.—HORACE FLETCHER.] - - - - - Explanation of The A. B. C. Life Series - - THE ESSENTIALS AND SEQUENCE IN LIFE - - -It would seem a considerable departure from the study of menticulture -as advised in the author’s book, “Menticulture,” to jump at once to an -investigation of the physiology and psychology of nutrition of the body -and then over to the department of infant and child care and education -as pursued in the _crêche_ and in the kindergarden; but as a matter of -fact, if study of the causation of human disabilities and misfortunes -is attempted at all, the quest leads naturally into all the departments -of human interest, and first into these primary departments. - -The object of this statement is to link up the different publications -of the writer into a chain of consistent suggestions intended to -make life a more simple and agreeable problem than many of us too -indifferent or otherwise inefficient and bad fellow-citizens make of it. - -It is not an altogether unselfish effort on the part of the author of -the A. B. C. Life Series to publish his findings. In the consideration -of his own mental and physical happiness it is impossible to leave out -environment, and all the units of humanity who inhabit the world are -part of his and of each other’s environment. - -It would be rank presumption for any person, even though gifted with -the means to circulate his suggestions as widely as possible, and -armed with the power to compel the reading of his publications, to -think that any suggestions of his could influence any considerable -number of his fellow-citizens of the world, or even of his own -immediate neighbourhood, to accept or follow his advice relative to the -management of their lives and of their communal and national affairs; -but while the general and complete good of humanity should be aimed -at in all publications, one’s immediate neighbours and friends come -first, and the wave of influence spreads according to the effectiveness -of the ideas suggested in doing good; that is, in altering the point -of view and conduct of people so as to make them a better sympathetic -environment. - -For instance, the children of your neighbours are likely to be the -playmates of your own children, and the children of degenerate parents -in the slum district of your city will possibly be the fellow-citizen -partners of your own family. Again, when it is known that right or -wrong nutrition of the body is the most important agent in forming -character, in establishing predisposition to temperance or intemperance -of living, including the desire for intoxicating stimulants, it is -revealed to one that right nutrition of the community as a whole is an -important factor in his own environment, as is self-care in the case of -his own nourishment. - -The moment a student of every-day philosophy starts the study of -problems from the A. B. C. beginning of things, and to shape his study -according to an A. B. C. sequence, each cause of inharmony is at once -traced back to its first expression in himself and then to causes -influenced by his environments. - -If we find that the largest influences for good or bad originate with -the right or wrong instruction of children during the home training or -kindergarden period of their development, and that a dollar expended -for education at that time is worth more for good than whole bancs of -courts and whole armies of police to correct the effect of bad training -and bad character later in life, it is quite logical to help promote -the spread of the kindergarden or the kindergarden idea to include -all of the children born into the world, and to furnish mothers and -kindergarden teachers with knowledge relative to the right nutrition -of their wards which they can themselves understand and can teach -effectively to children. - -If we also find that the influence of the kindergarden upon the parents -of the infants is more potent than any other which can be brought to -bear upon them, we see clearly that the way to secure the widest -reform in the most thorough manner is to concentrate attention upon the -kindergarden phase of education, advocate its extension to include even -the last one of the children, beginning with the most needy first, and -extending the care outward from the centre of worst neglect to finally -reach the whole. - -Experience in child saving so-called, and in child education on the -kindergarden principle, has taught the cheapest and the most profitable -way to insure an environment of good neighbours and profit-earning -citizens; and investigation into the problem of human alimentation -shows that a knowledge of the elements of an economic nutrition is the -first essential of a family or school training; and also that this is -most impressive when taught during the first ten years of life. - -One cannot completely succeed in the study of menticulture from its A. -B. C. beginning and in A. B. C. sequence without appreciation of the -interrelation of the physical and the mental, the personal and the -social, in attaining a complete mastery of the subject. - -The author of the A. B. C. Life Series has pursued his study of the -philosophy of life in experiences which have covered a great variety -of occupations in many different parts of the world and among peoples -of many different nations and races. His first book, “Menticulture,” -dealt with purging the mind and habits of sundry weaknesses and -deterrents which have possession of people in general in some degree. -He recognised the depressing effect of anger and worry and other -phases of _fearthought_. In the book “Happiness,” which followed next -in order, _fearthought_ was shown to be the unprofitable element of -forethought. The influence of environment on each individual was -revealed as an important factor of happiness, or the reverse, by means -of an accidental encounter with a neglected waif in the busy streets of -Chicago during a period of intense national excitement incident to the -war with Spain, and this led to the publication of “That Last Waif; -or, Social Quarantine.” During the time that this last book was being -written, attention to the importance of right nutrition was invited by -personal disabilities, and the experiments described in “Glutton or -Epicure; or, Economic Nutrition” were begun and have continued until -now. - -In the study of the latter, but most important factor in profitable -living, circumstances have greatly favoured the author, as related in -his latest book, “The A. B.-Z. of Our Own Nutrition.” - -The almost phenomenal circulation of “Menticulture” for a book of its -kind, and a somewhat smaller interest in the books on nutrition and -the appeal for better care of the waifs of society, showed that most -persons wished, like the author, to find a short cut to happiness by -means of indifference to environment, both internal and external, while -habitually sinning against the physiological dietetic requirements of -Nature. In smothering worry and guarding against anger the psychic -assistance of digestion was stimulated and some better results were -thereby obtained, but not the best attainable results. - -Living is easy and life may be made constantly happy by beginning -right; and the right beginning is none other than the careful feeding -of the body. This done there is an enormous reserve of energy, a -naturally optimistic train of thought, a charitable attitude towards -everybody, and a loving appreciation of everything that God has made. -Morbidity of temperament will disappear from an organism that is -economically and rightly nourished, and death will cease to have any -terrors for such; and as _fear_ of death is the worst depressant known, -many of the _worries_ of existence take their everlasting flight from -the atmosphere of the rightly nourished. - -The wide interest now prevalent in the subjects treated in The A. B. C. -Life Series is evidenced by the scientific, military, and lay activity -in connection with the experiments at the Sheffield Scientific School -of Yale University and elsewhere, as related in the “A. B.-Z. of Our -Own Nutrition” and in “The New Glutton or Epicure” of the series. - -The general application is more fully shown, however, by the -indorsement of the great Battle Creek Sanitarium, which practically -studies all phases of the subject, from health conservation and child -saving to general missionary work in social reform. - - HORACE FLETCHER. - - - - - Index - - - A - - A. B. C. Life Series, the, xxiv, 15, 47; - explanation of, 399-407 - - Abdominal glands, the, 189, 190 - - —— muscles, the, 326, 388 - - —— wall, the, 364 - - Abernethy biscuit, 131 - - Acid reaction, of food, 269 - - Acids, stimulating properties of, 270; - supplement weak action in the stomach, 270; - special relation to the pancreas of, 270 - - Addison, Joseph, upon the work of Luigi Cornaro, 28 - - Adenoids, largely dietetic in origin, 148-152, 156 - - Afferent nerves, special duty of the peripheral terminations of, 184-185 - - Agriculture, U. S. Department of, 37 - - Albumen, digestion of, 394 - - Albuminoids, the, 395 - - Albuminous foods, minimum amount of, 74, 78 - - Alcoholic beverages, explanation of the use of, 252 - - Algarroba bean, the, 124 - - Alimentary canal, the, 13, 14, 15, 40; - pabulum derived from, 40, 92, 117; - Professor Pawlow’s conclusions concerning, 186; - experimental investigation of the pathology and therapeutics of, - 248, 260, 273, 275, 276, 277 - - Alimentation, human, study of, 13; - theory of, 180 - - Alkalies, the, 278, 279, 280, 281, 282 - - Alkaline reduction, 33, 34, 35, 36, 44 - - —— saliva, 33; - its quantity increased by mastication, 96, 102, 146 - - Alkalinisation, 92 - - Altruism, placed upon a business basis, xxiv - - American Medical Missionary Association, the, 390 - - —— Medical Missionary Cause, the, xxiii - - —— Physiological Society, the, 68 - - Anderson, Dr. William G., 54, 87, 88 - - Anger, causes indigestion, 7 - - Animal economy, 40 - - —— food, necessitates less thorough mastication than vegetable, 67, - 99-100, 173; - influenced less than vegetable by cooking, 118 - - —— organism, the efficiency of, 58 - - Anthropoid apes, 115, 116 - - Antiperistalsis, 326, 333, 342, 345, 364; - in the colon, 365-370; - the question of, 377-383, 384, 385, 387, 388 - - Antiperistaltic waves, 365, 367, 373, 374, 376, 381, 383, 387, 388 - - Antrum, the, 307, 308, 311, 315, 322, 323, 326, 327, 333, 334, 336, - 340, 341, 360 - - Apepsia, 394 - - Appendicitis, relationship between diet and, 141 - - Appendix, the, cause of catarrh of, 141 - - Appetite, demands proteid when wanted, xxxii; - knows what to do and when to do it, xxxiii; - most important factor in digestion, 6; - a perfect indicator, 6; - a creature of the mind, 7; - the caprices of, 7; - easily comprehended, how to read, 8, 9, 12; - an indicator of what the body requires, 20; - will close the valve when enough is eaten, 20; - striking effect of insalivation upon, 50; - fully understood, prevents intemperance in eating or drinking, 95; - sooner satisfied with thorough mastication, 137; - the first and mightiest exciter of the secretory nerves of the - stomach, 210; - is juice, 213; - Dr. Pawlow’s experiment showing value of, 226; - its initial impulse may originate in the stomach, 244; - in the rich and in the poor, 252-253; - care should be taken of, 254; - physicians most often called on to restore, 254; - remarkable how little attention is paid to, 255; - bitters increase, 263, 265; - the strongest of all stimuli to the digestive glands, 263; - connection between gastric juice and, 265. - - —— earned, a preliminary necessity of easy digestion, 180 - - ——, false, 6, 9, 29, 75 - - ——, normal, 6 - - “Appetite juice,” the, 213, 228, 258, 259, 260 - - Apples, 169 - - Appreciation, attention necessary to create, 7; - necessary to stimulate flow of digestive juices, 7, 12 - - Armsby, Dr. H. P., on the heat values and muscular energy values of - different food elements, 397 - - Asiatics, the, consume smaller proportion of proteids, 82 - - Asparagus, 93 - - Astrup, E., 126 - - Athletes, reason for training, 22 - - Attention, necessary to create appreciation, 7; - how to command, 8, 9, 12 - - Atwater, Prof. W. O., 54; - on the daily proteid requirement, 76 - - —— Respiration Apparatus, the, 57 - - Australians, the, 118, 129, 163 - - - B - - Bache Fund, the, 69 - - Bacteria, the action in the intestines of, 39, 117 - - Bacterial digestion, 40 - - —— flora, the, examination of, 26 - - Bacteriology, advances of, 248, 249 - - Bailey, 128 - - Balthazard, experiments of, 314, 315, 327, 328 - - Baltimore, Md., 68 - - Barling, Gilbert, 141 - - Barrett, Robert, 47 - - Bayliss, experiments of, 343, 344, 345, 359 - - Batter pudding, 98 - - Battle Creek, Michigan, 390 - - —— Laboratories, the, 389-391; - experimental investigation of the influence of mastication and - cooking of food, etc., in, 391-396 - - —— Sanitarium, the, xvii, xxiii, xxvii; - described, 389-391 - - Bayert, 123 - - Beans, 95, 132 - - Beaumont, experiments of, 305, 309, 310, 313, 326, 327, 329, 330, 334, - 336 - - Beef, 100 - - Benedict, Prof. Francis G., 54 - - Berlin, 56, 65 - - Berne, Switzerland, 284 - - Betel, chewing, 103, 128 - - Beverages, mastication in the preparation of, 123 - - Bidder and Schmidt, experiments of, 202, 204, 231; - conditions for success, 204-206 - - Bile, the, 360 - - Bitters, therapeutic influence of, 262, 265; - increase the appetite, 263, 264, 265 - - Blondlot, experiments of, 181, 182, 277 - - Blood, the, toxins absorbed into, 40; - influence of the contraction of the masticatory muscles on local - circulation of, 107, 148, 149, 278, 355 - - —— elements, the, 41 - - Blumfield, Dr. Joseph, 26 - - Body, the, considered as an engine, 4, 23; - derives its necessary energy from food, 72; - burdened by excess of food, 73 - - Boer War, the, 11 - - Bolting food, 35, 36, 134, 135, 138, 140 - - Bolus, the, 329, 343, 344 - - Boston Society of Medical Sciences, the, 342 - - Bouillon, 266 - - Bowditch, Dr. Prof. Henry Pickering, xxiv, xxv, 67, 68, 70, 284, 285, - 287, 306 - - Bowel, the, liable to suffer, 140, 345 - - “Bracer,” a, why required, 20 - - Braun and Grützner, experiments of, 278 - - Bread, 78, 98, 99, 132, 137, 143, 171, 270, 271, 274, 275 - - Brinton, experiments of, 329, 330, 334, 336 - - British Guiana, 124 - - —— Medical Association, the, 27, 48, 91, 92 - - “British Medical Journal,” the, 141 - - Bronchitis, 144, 146 - - Broth, strong, 268 - - Brown bread, 43 - - Brussels, 68 - - Buccal digestion, 8 - - —— nerves, the, 194 - - Bushmen, the, 118, 123 - - Butter, 43, 100 - - - C - - Cabbage, why indigestible, 99 - - Cæcum, the, 140, 141, 363, 364, 365, 366, 368, 370, 371, 372, 375, - 376, 377, 381, 387 - - Cake, 132 - - California, University of, 90, 397 - - Calm, easy to cultivate, 7 - - Cambridge, England, xxxi, 26, 47, 49 - - —— tests, the, 47, 69 - - —— University, England, xxv, 26, 53, 68, 91 - - Campbell, Dr. Harry, 8, 12; - on the importance of mastication, 92-179, 389 - - Cancer, produced by inefficient mastication, 138 - - Cane-sugar, changed to grape-sugar, 21, 169 - - Cannon, Dr. W. B., 7, 12; - on “Swallowing and Movements of the Stomach and Intestines,” - 284-300; - on the “Movements of the Stomach Studied by means of - the Röntgen Rays,” 301-341; - on the “Movements of the Intestines Studied by Means of the - Röntgen Rays,” 342-388 - - Carbohydrate foods, 78, 79, 80, 85, 86, 89 - - Cardia, the, ideas of early writers concerning, 303, 304, 325, - 326, 328, 329 - - Cardiac sphincter, the, 307 - - Carelessness, the sin of, xvii - - Carnegie, Andrew, xxxv - - —— Institution, the, 53 - - Carnivora, the, do not masticate, 97, 161 - - Cassava root, 124 - - Cat, the, experiments upon, 289-293, 299, 303, 307, 311, 312, 315, - 320, 322, 325, 333, 335, 337-339, 341, 344, 353, 359, 361, 365, - 366, 372, 382, 383-386, 388 - - Catarrh of the appendix, caused by inefficient mastication, 141 - - Cauliflower, 99 - - “Cause and Prevention of Decay in Teeth, the,” Wallace’s, 161 - - Cavendish lecture, Sir Frederick Treves’s, 140 - - Cell, a, determination of the metabolism of, 40 - - Cellulose, 117, 170 - - Cereals, 78, 84, 146 - - Ceylon, 128 - - Cheese, 43, 95; - when indigestible, 100, 137 - - Chemical excitants, the, 268 - - —— secretion, 259 - - Chemistry, organic, 62 - - ——, physical, 62 - - Chewing, length of time necessary for, xxxii - - Chicken bone, 166 - - Chigin, Dr., experiments by, 214, 216, 282 - - - Children, early feeding of, 130-132, 143; - defective mastication in, 148; - feeding of, 262 - - Children’s Aid Society, the, xxv, 68 - - Chimpanzee, the, 115 - - China, 82 - - Chittenden, Prof. R. H., conducting the experiments at Yale, xvii, 5; - emphasises the want of exact knowledge of nutrition, 53, 67, 68; - the Yale test, 69-91. - - Chop bone, 166 - - Chyme, the, 346, 360, 362 - - Circulation, the, stimulated by mastication, 96, 103, 157 - - Cocoa-nut, 137 - - Coffee, 132 - - Cole, Sidney W., 47; - his paper upon the isolation of the tryptophane element of the - proteid molecule, 47 - - Colon, the, 363, 364; - antiperistalsis in, 365-370; - changes when food enters, 370, 371, 372; - process of clearing, 373-377, 381, 382, 384, 387, 388 - - Comminution, 98, 100, 101 - - _Commonwealth_, the S. S., 69 - - Condiments, influence of, 261, 265 - - Constipation, cannot exist, 43 - - Constriction, waves of, 323, 340, 341 - - Cooked flesh, requires mastication, 97, 174 - - Cooking, influences vegetable more than mineral food, 118; - effect of, 389, 391-396 - - Cornaro, Luigi, reformed manner of living of, ix; - his autobiography, x, xvi, xvii; - Dr. Van Someren’s paper upon his theory of living, 26-46; - his treatise on the “Sure and - - Certain Method of Attaining a Long and Healthful Life,” 28; - Addison’s comments upon his work, 28, 92 - - Craving for food, 256 - - Cream, experiments with, 38-39, 43 - - Cuba, xiv, 70 - - Curr, E. M., 125, 129 - - - D - - Dastre, Dr. Prof. A., 67, 68 - - Day, experiments of, 337 - - Defecation, 373-377 - - Deglutition, Magendie’s theory of, 284, 285; - movements of, 285; - divided into three parts, 285; - Falk’s and Kronecker’s theory of, 286; - the X-ray method in the study of, 287-295; - phenomena of œsophageal, 298-300 - - —— reflex, the, 287 - - Dental caries, causation of, 161 - - Dewey, Dr. Edward Hooker, and the “No Breakfast Plan,” 396, 397 - - De Witt, Assistant Surgeon, Lieut. Wallace, in command of soldiers - in the Yale investigation, xiii, 70 - - Dextrine, 170, 171, 392, 393, 395 - - Diaphragm, the, 324, 326 - - Diet, best manner and system of, xiii; - the optimum, xxxi; - minimum, 74; - the anthropoid stage, 116; - the pre-cooking human stage, 117; - the pre-agricultural cooking period, 118; - the early agricultural age, 119; - the late agricultural period, 120; - for children, 130-132; - relationship between appendicitis and, 141 - - Dietary Ten Commandments, 5 - - Dietetics, precepts of, 272 - - Digestion, appetite the most important factor in, 6; - the true chemical end-point of, 10-11; - effect of the mental state upon, 74, 145; - psychic influence in, 180; - the phenomena in, 251; - thorough mouth-work as an aid to, 389 - - Digestion-ash, the, what it should be like, 10-11, 14; - should not be unclean, 24; - in experiments, 38-39, 42, 43, 47, 51, 79, 83, 84, 85, 94 - - Digestive activity, stopped by anger and worry, 7 - - —— canal, the. _See_ Alimentary canal, the - - —— glands, the, analogy between the innervation mechanism of the - salivary glands and, 188-190; - appetite the strongest of all stimuli to, 263, 280, 282 - - —— juices, the, 7; - appreciation necessary to stimulate flow of, 7, 12, 96; - mastication brings the food into intimate contact with, 98; - quantity of, 267; - relation of milk to the secretion of, 274, 383, 386 - - Digitalis, 281 - - Diphtheria, 149 - - Disease, caused by indiscretions in eating, x, xxxi; - follows disobedience, 29 - - Disobedience, disease follows, 29 - - Distention, 144 - - Distress, effect of, 388 - - Dog, the experiments upon, 181, 194-211, 212-246, 249, 254, 258, - 263, 279, 280, 285, 292, 293, 297, 298, 299, 303, 310, 311, - 313, 314, 315, 336, 344 - - Dolomites, the, 26 - - Drinking, too much, xix, 95 - - Dry food, 97 - - Dunn, Miss Eva, 122 - - Duodenum, the, 303, 315, 356, 360 - - Dyspepsia, dangers of, xv; - might cease to exist, 35 - - - E - - Eat, how to, 19 - - Eating, too much, ix; - indiscretions of, x, xix, xxix, 29, 95, 135; - too fast, 20; - systematic inattention to, 259, 260; - English have made a cult of, 261 - - Economic nutrition. _See_ Nutrition, economic - - Efferent nerves, 184, 185 - - Efficiency, human, the measure of, xxx; - research into causes for, 54 - - Eggs, experiments with, 38, 43, 78, 95, 100, 137, 277 - - “Encyclopædia Britannica,” the, 27 - - Enemata, the, 367, 379, 380, 388 - - Energy, the minimum transformation of, 59 - - ——, potential, 59 - - Engine, an, the body considered as, 4, 23 - - English, the, have made a cult of the art of eating, 261 - - Emetic, an, 325 - - Emotion, inhibition of stomach movements during, 337; - effect of, 383-384, 388 - - Empiricism, medical practice largely based upon, 52 - - Esquimaux, the, 118, 123, 125, 126 - - Esselmont, experiments of, 383 - - Evolution, Nature’s plan of, xi - - Ewald, experiments of, 313, 314 - - Excess, habitual, confirmed by experiments, ix - - Excrements. _See_ Digestion-ash, the - - Excretia. _See_ Digestion-ash, the - - Exercise, necessity of, xxix - - - F - - Fæces, the, 374. _See also_ Digestion-ash - - Falk, Dr., 284; - theory of deglutition of, 286 - - Fallopius, on the functions of the stomach, 302 - - Farinaceous food, 395 - - Fasola, experiments of, 378 - - Fat, potatoes need not produce, 21, 78, 79, 80, 85, 86, 95, 98, 100; - experiments upon, 271, 272, 274 - - Faucial tonsils, the, influence of mastication upon, 148 - - Fear, effect of, 388 - - Fearthought, 404 - - Featherman, 123 - - Fibrin, 276 - - Flesh food, reduction of craving for, 50 - - Fletcher, Horace, Dr. Van Someren’s comments upon the case of, - 30-31; - his experiments confirmed by Marckwald, 46; - Sir Michael Foster’s comments, 48; - the Cambridge tests, 49-52; - the Middletown test, 54-55, 60; - the Yale test, 75-91 - - Flour, 132, 392, 393, 395 - - Food, mal-assimilation of, x; - length of time for chewing, xxxii; - Dr. Kellogg’s estimate of amount habitually used, xxxiv; - mouth-treatment of, 5; - how to masticate and swallow, 8, 9, 31, 32; - actual process of mastication described, 32-34; - important bearing upon the economy of the body of its treatment - in the mouth, 48-49; - its function to supply material from which the body derives - necessary energy, 72; - any excess an incubus, 72-73; - classified under three heads, 78; - in excess, produces a large amount of unnecessary work, 80; - its nutritive value determined by the thoroughness of its - digestion, 79; - softness of, 129; - mastication tends to reduce amount of, 136; - should be eaten with interest and enjoyment, 252; - passionate craving for, 256; - its nutritive value should be considered rather than taste, 261; - the acid reaction of, 269; - relative nutritive values of different, 275, 276; - experiments upon the utilisation of, 275; - effect of the movements of the stomach upon, 328; - circulation of, 329; - experimental investigation of the influence of mastication and - cooking of, 389-396 - - Foster, Sir Michael, xxiv, xxv, 26; - his note upon Dr. Van Someren’s paper, 48-52; - emphasises the want of exact knowledge of nutrition, 52, 53, 67, - 68, 91 - - Fowls, experiments upon, 299 - - Fruitarians, the, 90, 397 - - Fruit sugar, 169 - - Fruits, 43; - under-ripe and over-ripe, 141, 395, 396; - usefulness of, 397 - - Fubini, experiments of, 383 - - Fundus, the, 317, 322, 323, 324, 325, 330, 333, 334, 335, 336, 337, - 340 - - - G - - Galen, on the functions of the stomach, 302 - - Gastric catarrh, 249 - - —— digestion, 309, 316 - - —— glands, the, 182; - the vagus and the sympathetic nerves exciters of, 183, 198; - mechanical and chemical stimulation of the cavity of the mouth - has no effect on, 201; - psychic excitation of, 205; - sleep exercises no restraining influence upon, 206; - the simultaneous excitation of the different sense organs the - first and strongest impulse toward activity of, 210; - psychic secretion the normal commencement of secretory activity - on the part of, 214; - conditions upon which depends the secretory work of, 227; - mechanical stimulation of, 237, 245, 249, 271, 272, 274, 280 - - Gastric juice, the, appreciation necessary to stimulate flow of, 7; - destroys micro-organisms, 41; - its flow increased by mastication, 102, 146; - secretion of, 181, 206, 208, 211, 213, 262; - connection between the appetite and, 265, 266; - experiments for, 267; - too little, 270, 272, 273; - salts of sodium promote a flow of, 277, 279, 280, 329, 334, 335, - 337, 340, 341 - - —— mechanism, the, 385 - - —— movements, the, 301; - early writings on subject of, 302; - later experiments upon, 303, 327, 329, 338 - - —— mucous membrane, the, excitability of, 181, 231, 241, 249, 258, - 259, 264 - - —— muscular fibres, the, 307 - - “Gastric tonics,” 255 - - Gastritis, inefficient mastication may produce, 138 - - Gastro-intestinal catarrh, 144 - - Gastronomic enjoyment, increased by proper mastication and - insalivation, 22 - - Germany, food in, 267 - - Ginger, preserved, 141 - - Gladstone, William E., his theory of mastication, 92 - - Gland metabolism, 277 - - Glinski, Dr., 190, 194, 196, 197 - - Gluten, raw, 395 - - “Glutton or Epicure,” 26, 31, 92, 389, 396. - _See also_ “New Glutton or Epicure, The” - - Goose, the, experiments upon, 288 - - Goose-fat, 100 - - Gorilla, the, 115 - - Gran Chaco Indians, the, 123 - - Grape-sugar, chemically made from cane-sugar, 21, 169 - - Greens, 132 - - Grey, Sir George, 128 - - Griddle-cakes, need not be hurtful, 21 - - Griffin, Charles & Company, 180, 181 - - Grützner, experiments of, 278, 346, 363, 377, 378, 381 - - Gscheidlen, 235 - - Guinea-pigs, experiments upon, 39 - - Gum arabic, chewing, 103 - - Gustatory indifference, 263 - - —— nerves, the, 263, 269 - - Gut, the, 344, 345, 355, 360, 364, 365, 374 - - - H - - Hæmorrhoids, cannot exist, 43 - - Haller, experiments of, 304; - his summary of the motor functions of the stomach, 304-305, 309 - - Harvard Medical School, 68 - - —— Physiological Laboratory, the, 284 - - Haste, danger of, 134-135 - - Headache, produced by inefficient mastication, 138 - - Health, the optimum, xxxi - - Hearing, the sense of, 210 - - Heart, the, stimulated by mastication, 96, 103, 281 - - Heartburn, 144 - - Heat values, 397 - - Heger, Dr. Prof. Paul, 67, 68 - - Heidenhain, 181, 182, 183, 235 - - Herbivora, the, practice thorough mastication, 97 - - Higgins, Dr. Hubert, letter from, xxvii-xxxiii, 47 - - Hirsch, experiments of, 305, 315 - - Hofmeister, experiments of, 305, 308, 309, 310, 311, 313, 314, 326, - 327, 332 - - Hopkins, Dr. F. Gowland, 26; - his paper upon the isolation of the tryptophane element of the - proteid molecule, 47 - - _Hors d’œuvre_, 266 - - Horse, the, experiments upon, 293, 294, 300 - - Hospital Corps, the, at New Haven, xiii, 70 - - Hunger, 241; - “the best sauce,” 254 - - Hyperacidity, 145 - - Hyperæmia, 345 - - Hyperchlorhydria, 144, 147 - - - I - - “Igniting juice,” 260 - - Ignorance, dietic, sin of, xvii - - Ileocæcal valve, the, 355, 362; - the competence of, 362-364, 367, 370, 376, 381, 387, 388 - - Ileum, the, 363, 364, 367, 370, 382, 387 - - India, 82, 128 - - Indians of Honduras, the, 124 - - —— of Nicaragua, the, 124 - - —— of North California, the, 122, 126 - - Indigestion, x; - dangers of, xv; - caused by anger and worry, 7; - “bunching hits” to oppose, 13-16 - - Indol, the odourous, 47 - - Industries, the, mastication in, 124 - - Infant life, action of saliva in, 36 - - Innervation mechanism, an, constituent parts of, 184 - - Insalivation, defined, 8, 22; - increases gastronomic enjoyment, 22, 46, 48; - its striking effect upon appetite, 50, 60; - effects of, 74, 89, 92, 93, 96; - mastication promotes, 101 - - Insane, the, forced feeding of, 268 - - Instinct, human, the outcome of every-day experience, 251; - physiology merely confirms the precepts of, 251; - provisions for digestion made by, 267; - demands of, 272 - - Intemperance, 95 - - International Congress of Physiologists, the, 26, 48, 56, 68, 91 - - —— Laboratory of Research, the, proposal to found, 55-69; - suggestions as to staff and personnel, 62; - estimate of initial outlay, 63; - suggestions as to location, 63; - suggestions as to management, 66 - - Intestinal anæmia, 345 - - —— canal, the, 39, 346 - - —— contents, the, rhythmic segmentation of, 347-355, 386 - - —— digestive juices, the, 361 - - —— mechanism, the, 385 - - —— movements, difficulties of investigating, 342; - the best known of, 343 - - —— secretion, 61 - - —— wall, the, 344, 381, 386 - - Intestine, the large, activity of, 343; - movements of, 364-377, 379, 386, 387, 388 - - ——, the small, 343, 346; - the movements of, 347-362, 366; - course of food in, 360-362, 365, 367, 369, 378, 381, 383, 385, - 386, 387, 388 - - ——, the, action of the bacteria in, 39; - micro-organic action in, 40, 80, 92; - much more sensitive than the stomach, 139, 301, 317, 328, 337, - 341; - studied by means of the Röntgen rays, 342-388, 395 - - - J - - Jaffa, Professor, 90; - and the fruitarians, 397 - - Japan, 82 - - Jaws, the, mastication stimulates the nutrition of, 96, 103, 155; - influence of mastication upon, 109, 148; - changes during man’s evolution in, 115-121; - instances of vigorous use, 122 - - Johns Hopkins University, 68 - - “Journal of Physiology, The” (American), 284, 301, 342 - - —— (English), 47 - - - K - - Kais Root, 123 - - Kane, Dr., 125 - - Kara, 124 - - Katabolic action, 41 - - Katabolism, 95 - - Kellogg, Dr. J. H., xxvii; - letter from, xxxiii-xxxv; - his estimate of amount of food habitually used, xxxiv; - tribute to, 391; - his experimental investigation of the influence of mastication - and cooking of food, 391-396 - - —— Mrs. J. H., 389; - tribute to, 391 - - Kelp, 122 - - Kotljar, experiment by, 217 - - Kreuznach, 46 - - Kronecker, Dr. Prof. Hugo, 67, 68, 284, 285; - theory of deglutition of, 286 - - Kumagawa, experiments of, 81 - - _Kwas_, 267, 269, 270 - - - L - - Lactic acid, prepared in the stomach, 269, 393, 394 - - - “Lancet, The,” 8, 26, 31; - Dr. Campbell’s articles from, 92-179, 145 - - Lard, 272 - - Laws of Nature, health, strength, and moral tone dependent upon - proper fulfilment of, 73 - - Leonardi, Dr. Professor, 26 - - Life, right conduct of, xiii; - the essentials and sequence in, 399 - - Lippincott, J. B. & Company, 180, 181 - - Liqueurs, 266 - - Liquids, how to treat, 9, 34, 93, 94, 95 - - Lobassoff, Dr., experiments by, 217, 218, 220, 222, 226 - - Lobster, 137, 141 - - London, 65 - - Lower Californians, the, 123 - - Ludwig, experiments of, 342 - - Lumen, the, 374 - - Lymph, influence of the contraction of the masticatory muscles on - local circulation of, 107, 148, 149, 355 - - - M - - Macaroni, 132 - - —— cheese, 100 - - Mackerel, 141 - - Madrid, 69 - - Magendie, theory of deglutition of, 284 - - Maize, chewed, 124 - - Mal-assimilation, of nutriment, x, xxi; - “bunching bits” to oppose, 13-16; - dangers of, 24, 35 - - Malay, 128 - - Mall, experiments of, 343, 345, 354, 378 - - Mal-nutrition, causes of, xxi, 35 - - “Malt extracts,” 102 - - Maltose, starch turned into, 101, 170, 392, 393 - - Man, the First Assistant of Nature, xi; - his disparity due to ignorance, xii; - absurdity of his ignorance, 4, 23; - experiments upon, 300; - by nature a frugivorous animal, 395 - - Maple sugar, 84 - - Marckwald, Max, paper “On Digestion of Milk in the Stomach of - Full-grown Dogs,” 46 - - Masticate, how to, 19 - - Mastication, inefficient, causation of, 129; - must lead to many evils, 129; - evils resulting from, 135; - conduces to excessive eating, 135; - may cause suffocation, 137; - may produce gastritis, 138; - excess of starch may pass into stomach because of, 141; - prevents a sufficient amount of alkali to pass into the stomach, - 146; - causes evils with the jaws and their appendages and the adjacent - structures, 148; - responsible for adenoids, 148-152; - a potent cause of Rigg’s disease, 159; - secondary evils of, 164, 394 - - ——, proper, increases gastronomic enjoyment, 22, 46, 48, 60; - effects of, 74, 89; - Dr. Campbell’s observations upon, 96-173; - the effects of, 96; - primary object of, 96; - promotes flow of saliva, 96, 101; - stimulates the heart and circulation, 96, 103; - influences the nutrition of the jaws, 96, 103; - facilitates swallowing, 97; - brings the food into intimate contact with the digestive juices, - 98; - increases amount of alkaline saliva passing into the stomach, 96, - 102; - acts reflexly upon the stomach, 102; - the muscles of, 104; - its influence upon the jaw-bones, 109; - its influence upon the teeth, 110; - in the preparation of beverages, 123; - in the industries, 124; - the instinct of, 126; - the causation of inefficient, 129; - less opportunity than formerly for, 130-133; - defective apparatus for, 133; - affected by individual differences, 134; - tends to diminish amount of food consumed, 136; - most effective way to secure starch digestion, 145; - effect upon the nasal passages, naso-pharynx, and faucial tonsils, - 148; - fast becoming a lost art, 157; - means of insuring adequate, 164, 389; - experimental investigation of the influence of, 391 - - Masticatory instinct, the, 126-129 - - —— muscles, the, 104; - influence of their contraction on local circulation of blood and - lymph, 107, 148 - - Matri, 128 - - Meadville, Penn., 396 - - Measles, 149 - - Meat, 78 - - —— broth, 266; - an important chemical excitant of gastric secretion, 266, 267 - - —— extract, 268 - - —— juice, 268 - - Mechanical stimulus, great importance assigned to, 257 - - Medical practice, largely based upon empiricism, 52 - - —— science, not possessed of final information concerning questions - of nutrition, 52 - - Medicine, ideal only when it can take its proper position, 249; - physiology can make no pretence to guide the field of, 251; - to what it will at length grow, 251; - treats too lightly the loss of appetite, 256 - - Melanesia, 128 - - Melanesians, the, 120 - - - Meltzer, Dr., 284; - experiments of, 294, 296, 297, 298 - - Mendel, Dr. Lafayette B., 69 - - Mendel Pass, _bei_ Bozen, Süd Tirol, Austria, experiments at, 26 - - Mental energy, 41 - - —— state, 12; - its effect upon digestion and nutrition, 74 - - Menticulture, physical and mental equipments necessary to promote, - 7 - - “Menticulture,” xxi, xxiv - - Metabolism, 37; - determination of, 40; - calorimetric trial-balance measurement of, 54 - - Micro-organisms, 40; - destroyed by acid gastric juices, 41 - - Middletown, Conn., experiments at, 54 - - Milk, how to drink, 9; - experiments in drinking, 36, 38-39, 78, 84, 93, 94, 268; - takes a special position among foods, 272; - the three properties of, 273; - its relation to the secretion of the digestive juices, 274, 275, - 276, 277 - - —— pudding, 97, 143, 172 - - “Modern Medicine,” 389, 391 - - Modoc Indians, the, 123 - - Moist foods, 97 - - Moritz, experiments of, 324, 328, 332 - - Mosso, Dr. Prof. Angelo, 67, 68, 284, 285 - - Mouth, the, should do all it can, 93, 180; - examination of, 174-179; - rinsing, 179; - mechanical and chemical stimulation of the cavity of, 201, 285, - 286 - - —— breathing, evils of, 151-153 - - —— discrimination, 94 - - —— thoroughness, 8 - - —— treatment, of food, 5, 12, 92; - a preliminary necessity of easy digestion, 180, 389 - - - Mucosa, the, 343, 355 - - Mucous membrane, the, 346 - - Munich, 56, 76, 81 - - Muster, 128 - - Mutton, 100 - - - N - - Nansen, J. F., 123 - [36] - Napoleon, died from fast eating, 138 - - Nasal passages, the, effect of mastication upon, 148 - - Naso-pharyngitis, 144, 148, 149 - - Naso-pharynx, the, influence of mastication upon, 148 - - National Academy of Sciences, the, contribute to fund for research, - 69 - - Natural Automatic Processes, 3, 180 - - Nature, plan of evolution of, xi; - Man the First Assistant of, xi; - her reward for conformity with her requirements, xii; - her generous assumption of forty-seven forty-eighths of labour, 5, - 12; - given an opportunity by economic nutrition, 22; - her plans perfect if her laws are obeyed, 29; - never intended a special diet or bottle of medicine, 30; - endeavours to prepare lactic acid in the stomach, 269 - - Negritos, the, 118 - - Negroes, the African, 120 - - Nerve cells, the, specific qualities of, 187 - - —— fibres, 184 - - Nervous system, the, influence upon the glands of, 183 - - Neutralisation, 92 - - “New Glutton or Epicure,” the, xxviii, 47. - _See_ also “Glutton or Epicure” - - New Guinea, 124 - - New Haven (Conn.), scientific experiments at, xiii, 54, 71. - _See_ Yale investigation, the, and Yale test, the - - Nitrogen, 85, 86 - - Nitrogenous equilibrium, 86 - - —— measurements, tests of, 26 - - “No Breakfast Plan,” the, 396 - - Nothnagel, experiments of, 343, 345 - - Northwest London Hospital, the, 8, 92 - - Nutarians, 90 - - Nutrient enemata, 367, 379, 380, 382, 388 - - —— fluid, 381 - - Nutriment, selection of, 7 - - Nutrition, economic, experiments upon problem of, ix, x, 48-52; - active interest now taken in, x; - the financial saving the least of the profits in, xi; - the key to England’s welfare, xxv; - attitude of the scientific mind towards, xxvii; - little accurate knowledge concerning, xxx; - psychology of, 6-7; - appetite the most important factor in, 6; - mechanical and chemical physiology of, 8; - its entire principle simple and practical, 19; - does not advise avoiding starchy foods for stout people, 21; - assures that the same food will add or decrease weight, 21; - keeps one in perfect condition, 22; - its requirements not hardships but pleasures, 22; - not a joke or fad, 24; - an appeal to self-examination and self-instruction, 24, 25; - first scientific recognition of principles of, 26; - medical science not possessed of final information concerning - questions of, 52; - plan for institution of an international inquiry into the subject - of, 53-55; - proposed to found an international laboratory of research for the - study of, 55-68; - no question of greater importance, 72; - poverty and vice traced to perversion of, 73; - great need of thorough physiological study of, 74; - effect of the mental state upon, 74 - - Nutrition, animal, 56, 57, 58 - - Nutritive equilibrium, 37; - experiments in, 37-39 - - Nuts, 141, 173; - usefulness of, 397 - - Nuttall, Dr. George H. F., 26, 39, 47 - - - O - - Œsophagus, the, may protect the stomach, 139, 192, 285, 286, 289, - 291, 292, 297, 299, 300, 303, 304, 307, 316, 325, 326, 336, 341 - - Openchowski, experiments of, 305, 325 - - Orang, the, 115 - - Oranges, 169 - - O’Reilly, Surgeon-General, xvii, 69, 70 - - Ozawa, Professor, 55 - - - P - - Pabulum, the, derivation of, 40, 41 - - Pacific Islands, the, 124 - - Padua, Italy, 28 - - Palate, the, “the dietetic conscience,” 75 - - Pancreas, the, excited by the vagus and the sympathetic nerves, 183, - 270; - special relations of acids to, 270, 271, 273, 274, 279 - - Pancreatic digestion, 395 - - —— gland, the, 269, 270, 271, 280 - - —— juice, the, experiments for, 267, 270, 273, 279, 360, 395 - - Paris, 56, 65 - - Pastry, 132, 172 - - Patagonians, the, 128 - - Pathology, 249 - - Pavia, University of, 26 - - Pawlow, Dr. Prof. J. P., 6, 7, 12; - researches of, 61, 67, 68; - his demonstrations of psychic influence in digestion, 180-283 - - Peas, 132 - - _Pendelbewegung_, the, 342 - - Pendulum movement, the, 358-360 - - Penegal, xxxiii - - Peptic digestion, 318, 335 - - Peristalsis, 327, 330, 333, 337, 340, 343, 344, 346, 348, 355-357, - 361, 365, 377, 378, 383, 384, 386, 388 - - Peristaltic wave, the, 343, 353, 365 - - Pflüger’s Archives, 182 - - Pharynx, the, 285, 286, 290, 298 - - Philippines, the, 69 - - Physicians, most of them called on to restore appetite, 254; - their indifference to appetite, 257; - in Russia, 260; - should bear in mind the question of psychic secretion, 261 - - Physiology, applied, 251 - - Pine-apple, 141 - - Pitcherie, chewing, 129 - - Polynesia, 128 - - Poorer classes, the, appetite stronger among, 253; - food of, 266, 267 - - “Popular Science Monthly, The,” xxxiii, 53; - Professor Chittenden’s article in, 69-91 - - Pork, 100, 141 - - Porridge, 97, 143, 172, 270 - - Potato, made digestible by saliva, 20; - if masticated, need not produce fat, 21; - experiments with, 38, 102; - yields abundant sugar by long-continued mastication, 142, 146 - - Potatoes, boiled, 143, 172 - - Poverty, traced to perversion of nutrition, 73 - - Proteid, demanded by the appetite, xxxii; - the putrid decomposition of, 47; - minimum amount of, 74, 78, 79; - Asiatics consume smaller proportion of, 82, 83, 85, 98, 100, 272, - 394 - - ——, the high, xxxii, xxxiii - - ——, the low, xxxi, xxxii, xxxiii - - —— digestion, perfect, 394, 395 - - —— molecule, the, isolation of the tryptophane element of, 47 - - Physiology, experimental, 249; - can make no pretence to guide the field of medicine, 251; - merely confirms the precepts of instinct, 251 - - Psychic environment, 12 - - —— excitation, 259 - - —— influence, in digestion, 180-283 - - —— juice, the, 213, 257, 267 - - —— secretion, 261 - - —— stimulation, 249 - - Pultaceous foods, 95, 97 - - Pyloric sphincter, the, movements of, 314 - - Pylorus, the, stands guard over the intestines, 139, 141; - observations of Fallopius upon, 302; - ideas of early writers concerning, 303; - later experiments, 304, 307, 308, 315, 316, 317, 325, 326, 328, - 330, 331, 332, 333, 340, 341, 360 - - - R - - Rabbit, the, experiments upon, 344, 359, 371 - - - Rage, effect of, 388 - - Raiser, experiments of, 359, 371 - - Rectal injections, stimulating effect on movements of small - intestine of, 367 - - Rectum, the, 374, 379, 382 - - Reed, Dr. Major Walter (martyr to science), 70 - - Regina Margherita Laboratory, the, summit Monte Rosa, 64, 68 - - Regurgitation, 35 - - Rhinitis, 144, 148, 149 - - Rhythmic segmentation, of the intestinal contents, 347-355, 358, - 360, 362, 383, 386 - - Rice, 82, 132 - - Rickets, 144 - - Rigg’s disease, 159, 163 - - Rjasanzew, Professor, experiments of, 275 - - Roberts, Sir William, 75, 147 - - Rockefeller, John D., xxxv - - —— Institute of Preventive Medicine, the, 68 - - _Rollbewegung_, 345 - - Röntgen rays, the, Dr. Cannon’s studies with, 180, 284, 287-300, - 301-341, 342-388 - - Roosevelt, President Theodore, 70 - - Root, Secretary of War, Elihu, 70 - - Rosa, Monte, 64, 68 - - Rossbach, experiments of, 305, 309, 311, 313, 314 - - Roux, experiments of, 314, 315, 327, 328 - - Royal Society, the, 68 - - Rumination, 35, 98 - - Russell, Dr. William, 145 - - Russia, physicians in, 260; - food in, 267, 272 - - Russian Imperial Military School of Medicine, the, 68 - - —— peasant, the, 270 - - - S - - Sabbatani, experiments of, 378 - - St. Martin, Alexis, investigations on, 305, 309 - - Saliva, its chemical effect upon potato, 20; - upon syrup, 21, 33, 34, 35; - its action in infant life, 36; - an important therapeutic agent, 45, 93, 94, 95; - mastication promotes flow of, 96, 101; - dry food produces greater flow than moist, 97, 147; - complicated physiological functions of, 191-192, 337, 392, 393, - 395, 396 - - Salivary digestion, in the stomach, 335, 341; - effect of mastication and cooking of food upon, 391; - imperfect, 394 - - —— glands, the, 155; - analogy between the innervation mechanism and the glands of - digestion, 188-190; - the exciting agencies of the nervous mechanism of, 191; - their particular properties, 191-194; - differences between the exciting agencies of the different, - 194-198; - Professor Pawlow’s sham-feeding experiment, 198-211, 280 - - —— secretion, excitants of, 191 - - Sapidity, 44 - - Sauces, 269 - - Schäfer, 40, 82 - - Schmidt, experiments of, 202, 204, 231; - conditions for success, 204-206 - - Schütz, experiments of, 305, 308, 309, 310, 311, 313, 314, 327, - 332 - - Schwartz, experiments of, 303, 304 - - Scientific Assessors, Board of, 67, 68, 181 - - Secretions, digestive, 180 - - Secretory fibres, 183 - - —— nerves, 266 - - Segmentation, 386, 388 - - Selection, of nutriment, 7 - - Self-nutrition, secret of, xii - - Sensory nerves, 187 - - Sham feeding, experiments in, 198-211, 214-246; - psychic effect may become an absolute and independent factor in, - 209, 279 - - Sheffield Scientific School, the, experiments at, 53, 68 - - Sight, the sense of, 210 - - Sivén, experiments of, 81 - - Skatol, the odourous, 47 - - Sleep, exercises no restraining influence upon the gastric glands, - 206; - effect of, 383-386 - - Smell, the sense of, 210 - - Snyder, Dr., experiment in nutritive equilibrium, 37-38 - - Société de Biologie, the, 46 - - Sodium, salts of, 277; - promote a flow of gastric juice, 277, 278, 279, 281, 282 - - Soft foods, 97, 129, 136, 142, 160, 162 - - Solid foods, 94, 268 - - Solray Sociological Institute, the, 68 - - Sorbonne, Universitie de la, 68 - - Soups, 266, 267 - - South Africa, 11 - - —— America, 124 - - “Spectator,” the, 28 - - Sphincter, the, 315, 316, 317, 331, 333, 341 - - Spinach, 99 - - Spirits, 93, 94 - - Ssanozki, Professor, experiments of, 203, 228 - - Starch, needed by body, 20, 21, 78, 98; - changed into maltose, 101, 102; - danger to the stomach in receiving an excess of, 141-146; - the last constituent to leave the stomach, 145, 170, 171, 172, - 270, 337, 393, 395, 396; - - Starling, experiments of, 343, 344, 345, 346, 359 - - Stews, 266 - - Stomach, the, struggles bravely to overcome abuse, 19; - man’s ignorance concerning requirements of, 23; - mastication acts reflexly upon, 102; - a long-suffering organ, 138; - its danger of receiving an excess of starch, 141; - starch the last constituent to leave, 145; - necessity of alkali in, 146; - secretory work of, 182, 183, 229; - secretory nerves of, 210, 227; - the seat of certain definite sensations, 241; - the initial impulse towards awakening an appetite may originate - in, 244, 246; - no material progress in the physiology of, 250; - Nature endeavours to prepare lactic acid in, 269; - acids supplement weak action in, 270, 279; - catarrhal affections of, 280; - gives no obvious external sign of its workings, 301; - studied by means of the Röntgen rays, 301-341; - Galen’s observations on the functions of, 302; - Fallopius’s views upon, 302; - the motor functions of, 304; - the anatomy of, 306; - its relations to the shadow, 306; - the musculature of, 308; - normal movements of, 309; - the peptonising function of, 314; - its appearance at various stages of digestion, 319; - composed of two physiologically distinct portions, 324, 340; - its movements in vomiting, 325; - effect of its movements upon the food, 328; - attempts to perform function of teeth, 333; - salivary digestion in, 335; - inhibition of its movements during emotion, 337 - - —— fluids, 393, 394 - - Suffocation, caused by inefficient mastication, 137 - - Sugar, 21, 78, 89, 95, 169, 337, 393, 395 - - Sugar-cane, 123, 124, 169 - - “Sure and Certain Method of Attaining a Long and Healthful Life,” - Luigi Cornaro’s treatise upon, 28 - - Swallowing, facilitated by mastication, 97; - mechanism of, 284. - _See also_ Swallowing Impulse, the - - —— Impulse, the, xxxii, 8, 9, 93, 94 - - —— reflex, Dr. Van Someren’s, 26, 44 - - Sweet potato, 124 - - Sweets, why pleasant, 268, 269 - - Sympathetic nerve, the, an undoubted exciter of the gastric glands - and of the pancreas, 183 - - Syrup, chemical effect of saliva upon, 21 - - - T - - Tapioca, 132 - - Taplin, 125 - - Tasmanians, the, 122 - - Taste, delicacy of the sense of, 22, 23; - should be dissipated in the mouth, 93, 210; - necessary to give an impulse to the organs of, 253; - the nutritive value of food should be considered rather than, - 261 - - —— gratification, 93 - - Tea, 132 - - Tea-taster, the professional, methods of, 23, 93 - - Teeth, the, influence of mastication upon, 110; - changes during man’s evolution, 115-121; - instances of vigorous use, 122-126; - irregularity in, 156; - evils of imperfect use of, 157; - examination of, 174-179; - the - - stomach attempts to perform function of, 333 - - “Text-Book of Physiology,” Schäfer’s, 40 - - “That Last Waif: or Social Quarantine,” xxv - - Therapeutic experiments, pathological, 249 - - Therapeutics, precepts of, 272 - - Thierfelder, 39 - - Thirst, 95 - - Thompson, Dr., 142 - - —— Prof. W. H., 180, 181 - - Thorax, the, 290 - - Tobacco-chewing, 103, 129 - - Tokio, University of, 55 - - Tongue, the, needs exercise, 154 - - Tonic constrictions, the, 344; - the appearance of, 370-373, 385, 387 - - —— rings, the, 373 - - Tonsillitis, 144, 148 - - Tooth-brush, the, 177 - - Tooth-powder, 178 - - Toxins, absorbed into the blood, 40, 41, 44, 143 - - Training, for athletes, why necessary, 22 - - “Traité Analytique de la Digestion,” Blondlot’s, 181 - - Treves, Sir Frederick, on bolting of food, 140, 141 - - Trinity College, Dublin, 180 - - Trophic fibres, 183 - - Tryptophane, 47 - - Tuberculosis, 144 - - Turin, Italy, Congress of Physiologists at, 26, 48, 56, 91 - - ——, University of, 68, 284 - - - U - - Urine, should be inoffensive, 42, 93, 274 - - - V - - Vagus nerve, the, an undoubted exciter of the gastric glands and - of the pancreas, 183; - its functions almost interminable, 183, 249 - - Van Someren, Dr. Ernest, xxv, 7, 12; - his paper “Was Luigi Cornaro Right?” 26-46; - his swallowing reflex, 26, 44; - his experiments confirmed by Marckwald, 46; - Sir Michael Foster’s Note upon his paper, 48-52; - the Cambridge tests, 49-52, 53, 60, 91, 92, 98 - - Van Valzah, 146 - - Veal, 100 - - Veddahs, the, 128 - - Vegetable food, experiments with, 40; - necessitates more thorough mastication than animal, 97, 98, 173; - influenced more by cooking than animal, 118, 132, 170 - - Vegetables, 43, 78 - - Venice, Italy, 30, 63, 64, 91 - - Vermicelli, 132 - - Vermicular contraction, 343 - - —— wave, the, 345 - - Vermiform appendix, the, 140 - - Vice, traced to perversion of nutrition, 73 - - Vienna, 65 - - —— bread, 131 - - Vinegar, 269 - - Vivisection, 303, 305 - - Voice, the, requires lusty exercise in youth, 149 - - Voit diet, the, 76, 81, 84, 86 - - Vomiting, the act of, 193, 303; - movements of the stomach in, 325, 341 - - - W - - Wallace, Dr. G. Sim, 110, 113, 130, 154, 158, 161, 169, 174, 177 - - - Walther, Dr., experiments of, 267, 276 - - Washington, D. C., 70 - - Water, how to drink, 9, 34, 95, 268, 391, 392 - - —— biscuit, 391 - - Weight, must become normal, 43 - - Welch, Dr. Prof. William H., 67, 68 - - Wepfer, experiments of, 303, 304 - - Wheat, unground pearl, 392, 393, 394 - - —— flour, 392 - - Wine, how to take, 9, 22, 23 - - Wine-tasters, the professional, methods of, 23, 93 - - Wolves, experiments upon, 303 - - Wood, Maj. Gen. Leonard, 69, 70 - - Worry, causes indigestion, 7 - - Wulfson, Dr., 197 - - - X - - X-ray. _See_ Röntgen ray - - - Y - - Yale investigation, the, x, xi, xiii-xv, xvii, xviii, xix, xxxiii - - —— Gymnasium, the, 87 - - —— test, the, 5, 69, 75-91 - - —— University, 68 - - - Z - - Z, in the nutrition alphabet, 10, 12; - - Zuntz, Dr. Prof. N., 67, 68 - - - - -FOOTNOTES: - -[1] Appetite alone can judge accurately of the former, and the true -Swallowing Impulse is the limitation of the latter. If we study the -natural instincts, the rest will take care of itself. - -[2] This is very strong evidence that appetite knows what to do and -when to do it, if you study and consult it and give it a chance to -prescribe. - -[3] The Yale test reported herein by Professor Chittenden showed the -possibility of full alimentation according to the requirements of -Economic Nutrition in from 24 to 26 minutes daily, which is less than -1∕48 of a day. Beginners of the practice of careful mouth-treatment -of their food _may_ require more time, but, whatever it may be, it -is worth it. A little care for a short period will establish a right -habit, and then no further tedious attention nor unusual time will be -necessary to accomplish a perfectly healthy nutrition. - -[4] Physiological Economy in Nutrition: The Frederick A. Stokes -Company, New York. - -[5] William Heinemann: London. - -[6] The author is not yet permitted to publish the particulars of these -reforms in process, but he has official information regarding them and -is in full sympathy with them. - -[7] Dental surgeons now speak of the upper jaw as the maxilla, and of -the lower jaw as the mandible. - -[8] This subject I am obliged to deal with very briefly, and am -compelled to omit the reasons for my conclusions. - -[9] Recent observations go to show that man possesses no power of -digesting cellulose, though this substance is to a limited extent -capable of solution by the agency of bacteria in the lower portions of -his alimentary canal. - -[10] I am under great obligation to Miss Eva Dunn, who has collected -valuable information for me on this and kindred subjects. - -[11] Social History of the Races of Mankind, 1881. - -[12] S. Powers: Tribes of California, 1877. - -[13] E. M. Curr: The Australian Races, 1886-7. Taplin: The Narrinyeri; -an account of Tribes of South Australian Aborigines, 1879. - -[14] J. F. Nansen: Eskimo Life, 1893. - -[15] Dr. Kane: Arctic Exploration, 1854. - -[16] E. Astrup: With Peary near the Pole, 1898. - -[17] Sir George Grey: Journal of Two Expeditions in North-West and -Western Australia, 1841. - -[18] Muster: With the Patagonians, 1869. - -[19] Bailey: Transactions of the Ethnological Society, 1862. - -[20] E. M. Curr: The Australian Race, 1886-87. - -[21] The Causes and Prevention of Decay in Teeth, pp. 88, 89. London, -1902. - -[22] Gilbert Barling also traces the relationship between appendicitis -and diet. “In a considerable number of cases,” he writes, “the attack -of appendicitis can be directly attributed to unsuitable food--pork, -mackerel, over-ripe or under-ripe fruit, uncooked vegetables” (Brit. -Med. Jour., vol. i., 1903, p. 61). - -[23] My friend, Dr. Thompson, undertook, at my suggestion, some -experiments to test the digestibility of raw starch within the mouth; -he found that raw potato yields abundant sugar when subjected to -long-continued mastication. - -[24] _The Lancet_, March 21st, 1903, p. 806. - -[25] Brit. Med. Jour., Epitome, vol. i., 1903, p. 45. - -[26] A further aid to the circulation in the naso-pharynx is afforded -by the lusty use of the voice. It a natural for the young human to cry -and to shout, and unless this instinct is allowed full play the child -is apt to suffer in health. I cannot but think that the modern child -is too much repressed in this respect, and that he is not afforded, -especially in towns, proper opportunity of venting his vocal energy -in out-door play. May we not have here a contributory factor in the -causation of adenoids? - -[27] Among the Australian skulls I have examined in museums caries -of the wisdom teeth--_i.e._, in those very teeth which, as shown by -their atrophy, are least used--is by no means uncommon (though it is -possible that some of the skulls belong to natives who have embraced -the dietetic customs of the white man). I submit that this fact may -fairly be used as an argument in favour of the view that inefficient -use of the teeth predisposes them to caries by interfering with their -resisting power, though it must be acknowledged that the position of -the wisdom teeth places them at a disadvantage, owing to the tendency -of food to accumulate about them, especially in undeveloped jaws in -which they have not adequate room. - -[28] This film can be felt by the tongue as a somewhat rough covering, -which gives place to a smooth surface after the use of the tooth-brush. - -[29] By the term “external stimulus” I mean here without distinction -every outward agency of nature, as well as every agency which has -its seat within the organism. The word “external” applies here to -everything with the single exception of the nervous system itself. - -[30] One may be permitted to use this expression for the sake of -brevity. - -[31] _Kwas_ is a favourite Russian drink, prepared from water, bread -or meal, with malt and yeast. It contains a considerable quantity of -lactic acid, some acetic acid, and other products of fermentation. - -[32] An investigation by Cannon and Day (_American Journal of -Physiology_, 1903) has confirmed this conclusion. An hour after starchy -food mixed with saliva was ingested a unit volume of the food in the -cardiac end of the stomach contained almost twice the amount of sugar -found in a unit volume of the food in the pyloric end. - -[33] The results of this investigation were reported to the Boston -Society of Medical Sciences, November 19, 1901. - -[34] Without the possibility of seeing the relations of a movement to -the ends of the intestine, it cannot be stated absolutely whether the -movement is peristaltic or antiperistaltic. Such relations can be seen -on the fluorescent screen only near the stomach and near the ileocæcal -valve. The evidence that advancing peristalsis is the normal movement -is so overwhelming that I have assumed that when food is moving in -loops not visibly related to fixed points it is moving forward. - -[35] In this case the fæces were soft. - -[36] While Napoleon was building his power and fame he was very -careful and abstemious, but in later life succumbed to luxury and -gluttony; Bismarck’s rise and decline were similarly related to dietary -influences.--H. F. - - -*** END OF THE PROJECT GUTENBERG EBOOK THE A.B.-Z. OF OUR OWN -NUTRITION *** - -Updated editions will replace the previous one--the old editions will -be renamed. - -Creating the works from print editions not protected by U.S. copyright -law means that no one owns a United States copyright in these works, -so the Foundation (and you!) can copy and distribute it in the -United States without permission and without paying copyright -royalties. 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