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*** START OF THE PROJECT GUTENBERG EBOOK 75392 ***
Transcriber’s Note: Italics are enclosed in paired _underscores_;
subscripts are indicated by a single underscore: H_2O. Superscripts are
indicated by a caret symbol: 10^9. When a superscript is longer than
one character, it is enclosed in curly braces: 10^{-11}. Additional
notes will be found near the end of this ebook.
LITTLE BLUE BOOK NO. 1000
Edited by E. Haldeman-Julius
The Wonders
of Radium
Maynard Shipley
HALDEMAN-JULIUS COMPANY
GIRARD, KANSAS
Copyright, 1926,
Haldeman-Julius Company
PRINTED IN THE UNITED STATES OF AMERICA
THE WONDERS OF RADIUM
CONTENTS
Page
I. Introductory 5
All Matter Radioactive 9
II. Everyday Uses of Radium 16
Radium Makes Gems Blush 18
A Radium Clock 19
III. Radium and the Age of the Earth 21
IV. An Epoch-Making Discovery 30
How Radium is Converted to Lead 34
V. Radium in the Treatment of Cancer 45
VI. Efficiency of Radium in Treatment of Various Diseases 51
VII. Where We Get Radium 55
New Sources of Radium 58
The Radioactive Disintegration Series 60
Uranium I Series 63
Uranium Y Series 63
Thorium Series 64
THE WONDERS OF RADIUM
CHAPTER I
INTRODUCTORY
It has been well said that a general idea of what radioactivity
signifies is a necessary part of the education of every intelligent
person, since “it is the one thing of paramount importance in the
chemical and physical science of the day.” But its importance extends
much farther, since radioactivity is now employed in many departments
of industry, as well as in biology and medicine.
It is known that the rays from radium have the power to stimulate
all forms of life, even to the extent of speeding up the growth of
plants and of making dormant plants burst into bud. Some authorities,
as we shall see later, are fully convinced that the radiations can
be employed successfully in the prolongation of human life. It is
well known that radiotherapy has, for some years now, been employed
advantageously in the treatment of many forms of illness, and is, in
some institutions, the sole medium for the cure or alleviation of
cancer and other malignant growths.
Not long ago the discovery was made that the curative agent in certain
famous baths in Europe is the radium which the waters of their springs
contain.
If one could really buy bottled water which has been properly treated
with radium rays or the “emanation,” beneficial results would no doubt
be obtained. The trouble is that such waters are difficult to secure.
“None of the foreign or domestic commercial bottled water sold
to consumers on the claim of radioactive content really contains
sufficient radioactivity to warrant its purchase,” according to the
report of investigation completed by the water and beverage laboratory
of the United States Department of Agriculture, Washington, D. C.
“In the examination of 46 samples from 15 states and eight foreign
countries, the bureau found the highest quantity of radioactivity of a
temporary nature in a bottled water from Massachusetts.
“The largest amount of permanent radioactivity was in a sample from a
deep well in Ohio. It was found, however, that it would be necessary to
consume 2,810 gallons of the Massachusetts water, or 1,957 gallons of
the Ohio water daily to obtain an efficient dose of radioactive salts.
“During the tests radioactivity of samples was determined by means of
electroscopes.”
When radium is taken in soluble form, 25 or 50 percent of it remains
in the body for four or five days. The rate of excretion after that is
only about one percent a day. “Wherever it is located, it carries on a
constant bombardment in releasing its energy, giving strength to the
tissues, cells and protoplasm of the body. And when once these begin
to function actively, they begin to rebuild themselves.”
Radium does not combine chemically with any known substance in the
body. The therapeutic effects are indirect. When the electrons are
ejected with great speed from the atoms of the radioactive salts, they
pass through millions of other atoms, knocking out new electrons as
they go, leaving the atoms with a positive charge, in which condition
they are called “ions.” These positively charged particles at once
enter into new combinations, new chemical unions, which produce new
substances. But these may be injurious to the normal tissues as well
as to the cells of the disease which it is desired to destroy. In some
cases, the diseased cells are more susceptible to the rays than are the
normal cells, in which instances the growth of the abnormal or diseased
cells may be retarded, or they may even be totally destroyed. It is
thus seen that application of the rays may result in alleviation of the
disease, or, possibly, effect a complete cure, as the case may be.
The action of radium on various (colloidal) substances is now well
understood from the point of view of the biophysicist; but this phase
of the subject is too highly technical for exposition in a book
intended for popular circulation.
While it is fully recognized that there are quite definite limitations
to the efficacy of radioactivity in its application to disease, as a
matter of fact the use of radium as a therapeutic agent would be much
more extensive were it not for its high cost and scarcity. No one
questions its exceptional value in the treatment of certain diseases,
and a method will probably be discovered, in the near future, by which
it may veritably be used to postpone the age of senility.
A young man who had read somewhere that radium is a sure cure for any
and all of the ills to which flesh is heir, entered a drug store and
asked: “How much is radium an ounce?” The druggist smiled, and named
a figure which made the young man blink. “Not really?” observed the
prospective customer. “Then you may give me an ounce of cough lozenges.”
Until quite recently, an ounce of radium cost almost as much as 3¾ tons
of gold! That is to say, an ounce of radium, if this much could be
purchased “off hand”--which it couldn’t--would cost about $2,500,000.
The price was at one time $3,000,000 an ounce.
When we speak of “radium,” we really mean--or ought to mean--_radium
salts_. Pure radium soon abandons its metallic form by entering into
chemical combinations. It is the purified radium salts that cost, as
late as 1923, $2,500,000 an ounce--the price of ¾ of a ton of platinum,
the most “precious” of all the metals excepting radium. In 1920, radium
was 200 times more valuable than an equal weight of pure blue diamonds,
and 180,600 times as valuable as gold. A cubic foot of the salts--had
this amount been obtainable--would have been worth $7,000,000,000.
The reason for the high cost of radium is not far to seek. First, the
demand for the pure salts far exceeded the supply--and this is still
the case, though relief is now in sight. Secondly, the scarcity of
radium was due to the enormous amount of time and labor involved in its
production.
Although radium was discovered and isolated by Mme. Curie in 1898,
22 years later--at the close of 1920--scarcely 140 grams (or about
five ounces) of pure radium salts had been extracted and put on the
world market. Of this amount, about 70 grams had been produced in the
United States (during the preceding seven years). The market value of
the standard salts was at this time about $100,000 a gram (about 1/28
ounce). Eighteen grams were produced in this country in 1920, and the
value of the purified salts was quoted in some journals as $2,160,000.
At this price, about $100,000 worth of radium could be put into a glass
tube about the diameter of a very coarse pencil lead and not more than
an inch in length.
To produce the gram of radium salts presented to Mme. Curie by the
women of America (in May, 1921), 500 tons of carnotite ore--containing
two percent or less of uranium oxide--were treated, consuming in the
process 1,500 tons of coal, more than a ton of chemicals, and over 30
tons of water.
ALL MATTER RADIOACTIVE
While certain substances have been designated as “radioactive,” it is
not to be understood that these bodies alone emit charged particles, or
radiant energy.
“All bodies whatever are a constant source of visible or invisible
radiations, which, whether of one kind or the other, are always
radiations of light” (Le Bon, “The Evolution of Forces,” p. 318, 1908).
Compounds of potassium, and also of rubidium, caesium and lanthanum, as
shown by Campbell, Wood, McLennan, Kennedy, and other investigators,
possess very high radioactive properties. While the atomic weight of
potassium is only about 39, and of rubidium about 84, the typical
radioactive elements have atomic weights ranging from 200 to 238. Of
the 12 to 15 elements essential to life, potassium is the only one
possessing distinct if minute radioactivity. “The activity of potassium
may readily be demonstrated by means of the goldleaf electroscope. It
is shown that Beta rays are emitted” (Burns). But potassium is 1000
times weaker than uranium, and 1,000,000,000 times weaker than radium,
in the emission of Beta (negative) rays. Caesium and lanthanum emit
Alpha (positive) rays.
Professor Dufour, the distinguished French scientist, has shown that
even air that has been breathed emits radioactive particles. The
presence of radioactive matter in the atmosphere has been shown to
account for its electric conductivity. Thomson found (1906) that many
specimens of water from deep wells contain a radioactive gas, and
Elster and Gertel have found that a similar gas is contained in the
soil.
It is probably safe to assert, with Le Bon, that all matter, “down to
the absolute zero of temperature,” radiates electrified and more or
less luminous particles, albeit they are invisible to the human eye.
It is because of its property of emitting negative electrons (Beta
rays) that potassium is a necessary constituent of all living matter.
It may, however, be replaced, under certain conditions, by other
radioactive substances.
Prof. Barton Scammel, of the British Radium Society, gave it as his
opinion (in 1922) that further experience in the proper uses of
potassium salts and radium in solution would lead to the realization of
a new golden age. He predicted, among other “good tidings,” life for
120 years in the bloom of youth, the “pep” of 25 years at 75, a third
set of teeth, new hirsute coverings for erstwhile bald heads, muscles
like Jack Dempsey’s.
Dr. C. Everett Field, of the New York Radium Institute, stated
publicly, in backing up Scammel’s hopes and theories, that he thinks
another ten years will see human life vastly prolonged as a matter of
course by the use of radium. He said:
“We have ascertained beyond question that potassium salts are necessary
to heart action, that they are slightly radioactive, and that radium
can be substituted for them with a degree of success.
“It was Dr. Zwaardemaker, physiologist of the University of Utrecht,
who first discovered, a number of years ago, that radium could do in
the blood stream what potassium salts do in the normal person. He took
an animal’s heart, which was kept beating outside the animal, and
removed the potassium element. It was not longer possible then to keep
it in action. Then he substituted a radium solution and it was possible
to restore action.”
Dr. Field stated that it had been discovered that the systems of
victims of cancer and other wasting diseases were deficient in
potassium salts, and that as their systems were made to assimilate
potassium a tonic effect was noticeable at once. The greatest trouble
was to make the body assimilate the potassium.
“The fact is,” said Dr. Field, one of the more conservative radium
therapists, “that radium does not do the healing. But, for that matter,
neither does any other form of healing. The healing exists within
the organism. And radium, I am convinced, in some cases, is the most
efficient medicine to give needed stimulus to the healing apparatus of
diseased organisms.”
Even now, he believes, radioactive treatment may prolong life at least
15 years. For internal treatment, either doses of radioactive water,
or extremely minute quantities of radium itself, are administered.
Radioactive water is taken from springs found to contain traces of
radium, or radium is used to make ordinary water radioactive. The
difficulty with spring waters is that they lose their radioactive power
when bottled and transported, and must be consumed at their source.
“Because of this fact,” says a writer for _The Popular Science Monthly_
(June, 1923), “a group of physicians interested in the use of radium as
a curative stimulant have invented an ingenious device for imparting
radioactive properties to ordinary water. As designed for use in the
home, this instrument consists of a case containing an arrangement
of glass tubes and vessels in which emanations from radium salts in
solution are imparted to air, which is then mixed with the water.
“A much simpler apparatus, available for office use, somewhat resembles
a hypodermic syringe, containing special capsules of radium salts.
Pushing a plunger forces air through the radium capsules and into a
glass of water and is said to make the water radioactive. The doses of
radium in each case are constant, because radium emanates at a constant
rate, and only a certain amount can be dissolved in water, no matter
how many times a day the apparatus is brought into use.
“Whether radium treatment will prove able to restore youth to old age,
grow new sets of teeth and perform other marvels that its more ardent
supporters predict for it, only time will tell.
“If radium treatment proves to facilitate the process of cell
elimination, it will have gone a long way toward delivering the world
from its enemies of disease.”
The philosopher-scientist, Le Bon, makes bold to suggest that
light-waves which are invisible to human eyes may be perceptible to
nocturnal animals, which would include most of the lemurs and the
felines, and some other beasts which seem to be capable of finding
their way and carrying on their predatory or other activities in the
dark. “To them,” says Le Bon, “the body of a living being, whose
temperature is about 37° C., or about 98° F., ought to be surrounded
by a luminous halo, which the want of sensitiveness of our eyes alone
prevents our discovering. There do not exist in nature, in reality, any
dark bodies, but only imperfect eyes.”
Le Bon has also said that the human body is sufficiently radioactive
to photograph itself by its own rays, if we could find a substance
sensitive to these radiations, as the photographic plate is to the
actinic rays. Nothing would then be easier, he declares, than to
photograph a living body in the dark without any other source of light
than the invisible light which it is continually emitting.
Some recent (1924) experiments of the French scientist, Dr. Albert
Nodon, seem to afford the actual proof of Le Bon’s _a priori_
conclusions. In the presence of a number of noted scientists, Dr. Nodon
exhibited three photographic plates on which were unmistakable light
impressions, which, he claimed, were caused by the rays emitted by a
radioactive mineral, an insect, and a green leaf, which had been placed
on the emulsion side of the plates in a dark-room.
A similar experiment, in which a dead insect and a dead leaf were used,
resulted in no ray impressions on the plates. Dr. Nodon offered as his
conclusion that radioactivity is an inevitable accompaniment of living
processes, and stated that the strength of photographic impressions
produced in experiments such as his are an accurate measure of vitality
(see _Popular Science Monthly_, October, 1924).
Radium is probably present in all the planets and stars. Some time ago
the Astronomer Royal of England, Dr. F. W. Dyson, demonstrated the
existence of radium and of radium emanation in the sun’s chromosphere
(the ocean of incandescent hydrogen gas surrounding the photosphere, or
actual surface of the sun).
CHAPTER II
EVERYDAY USES OF RADIUM
During the World War large quantities of radium were employed by the
Allies for night compasses, luminous dials on airplanes, gun-sights,
etc. In times of peace it is used on pendants for locating electric
lights and switches in the dark, key-holes, fire-extinguishers, poison
bottles, emergency call-bells, and in many other ways. For example,
some mining corporations use signs in their mines made luminous in the
dark by phosphorescent paint made from radioactive substances. These
luminous signs are not affected by atmospheric conditions.
Yet for all these uses, including “radium watches” and clocks, not more
than half an ounce of radium has been used since its discovery in 1898.
A few millionth parts of a gram of radium, in the form of radioactive
barium sulphate, a large portion of phosphorescent zinc sulphide
(crystallized zinc), mixed with varnish and some adhesive substance,
give enough material to illuminate 40 or 50 watches. One gram of
radium (= 16 grains) combined with 20,000 grams of secret process
phosphorescent zinc sulphide is sufficient to make 667,000 watches
luminous for many years. The factories of this country are now turning
out about four million radium watches annually.
Unless a special preparation--known only to the manufacturer--is
used, the luminosity of the material gradually disappears, owing to
the destruction of the zinc sulphide crystals by the powerful rays
constantly bombarding them, producing flashes at the rate of 200,000
a second. The radium itself does not glow, nor does it deteriorate in
power.
If we examine a luminous dial through a magnifying glass, after the
eyes have been in total darkness for a few minutes, tiny flashes of
light may be seen. These are caused by the explosion of hundreds of
millions of radium atoms. The more radium there is in the paint, the
greater the number of flashes per second, and the more durable the
luminosity. Since every flash means a blow upon a crystal of zinc
sulphide, the crystals gradually break under the strain. In this
process helium is released from the disintegrating radium atoms.
Mr. M. A. Henry (_Scientific American_, April 2, 1921) points out that
the problem of the chemist “is to produce a phophorescent substance
which will stand up longest under the terrific bombardment of the
radium rays and which, at the same time, will give off the most light.
Such progress is being made in this direction that today [1921] only
about one-twentieth the amount of radium used four years ago [1917] is
needed in the making of luminous material. And the chemist insists that
he has only scratched the surface of possibilities in this direction
and that even better results can be attained. At present the life of
the zinc crystals is from 15 to 20 years, although the radium lasts for
centuries.
“This life will be much longer if the instrument to which it is applied
is kept away from the light most of the time. The crystals, already
stressed by the radium rays, have an additional strain imposed by the
light and this hastens the process of disintegration. Strong sunlight,
especially at the seashore where the presence of much ozone in the air
intensifies the ultra-violet rays, has a very destructive effect on
luminous material. For this reason the manufacturers of this delicate
substance usually guarantee it for about half its normal life, or ten
years.”
A radium-lighted fish-bait is now on the market, and fishermen say that
this bait is very successful in attracting fish which haunt deep water.
RADIUM MAKES GEMS BLUSH
D. Berthelot, F. Bordes, C. Doelter, and others observed that the rays
from radium induced important changes in the colors of minerals.
Dr. T. Squance, of Sunderland, England, succeeded in transforming a
sapphire of faint pink hue into a gorgeous ruby color, and a faint
green sapphire into an oriental emerald hue. It was already known that
a diamond exposed to the rays of radium glows with a beautiful green
light.
In experiments carried out at the United States Bureau of Mines (1921),
in Reno, Nevada, a colorless Colorado topaz was tinted yellow by
exposure to penetrating radiation. If a method can be devised to make
the color permanent, the discovery will greatly increase the value of
the gem-stone material found in the west.
If we submit yellow phosphorous to the action of radioactive
substances, it becomes changed into the red “alotropic” variety.
Certain of the rays decompose ammonia, and water under their influence
is subjected to electrolysis, yielding oxygen and hydrogen.
A RADIUM CLOCK
A very interesting instrument was devised by Sir William Strutt (now
Lord Rayleigh) which has been called a “radium clock.” It consists of
a glass vessel containing a tube of radium salts in the center, from
which two gold leaves are hung. The inner surface of the containing
vessel is coated with tinfoil, and this foil is grounded. The radium
salts cause the leaves to become electrically charged. They then
diverge, and, coming in contact with the grounded tinfoil coating, they
are discharged, only to fall back again and repeat the process. This
clock will operate as long as the supply of radioactive material will
act, which in the case of pure radium would be nearly 2000 years.
G. Lentner has recently succeeded in utilizing atmospheric potential by
the aid of radioactive substances, which, in some way not yet clearly
understood, exert an influence upon the transformer. The method is
as follows: A post about 12 m. in height, forming a sort of antenna,
is erected; the post ends in a collector consisting of an aluminum
sphere provided with points covered with radioactive substances.
This collector communicates by a conducting wire with a special
transformer. Under these conditions the earth and atmospheric currents
attract each other through reciprocal induction.
Dr. S. A. Sochocky, the well known radium expert, has made radium
oil paints, and made paintings with them. “Pictures painted with
radium look like any other pictures in the daytime, but at night they
illuminate themselves and create an interesting and weirdly artistic
effect. This paint would be particularly adaptable for pictures of
moonlight or winter scenes, and I have no doubt that some day a fine
artist will make a name for himself and greatly interest us by painting
pictures which will be unique, and particularly beautiful at night in a
dark or semi-darkened room.”
Dr. Sochocky also predicts that “the time will doubtless come when
you will have in your own home (or someone you know will have) a room
lighted entirely by radium. It would be possible today to illuminate
a room, so that at night, without the aid of electricity or other
artificial illumination, you could read fine newspaper print without
difficulty. The light in such a room, thrown off by radium paint on
walls and ceiling, would in color and tone be like soft moonlight,
blue with a tint of yellow. Today, a room ten by nine feet could be
illuminated in this way at a cost of $400, and the illumination would
last ten years.
“However, such illumination will soon be much cheaper, because of new
discoveries as to the best materials to combine with radium to produce
light.”
CHAPTER III
RADIUM AND THE AGE OF THE EARTH
One of the important consequences of the discovery of radioactivity was
to afford the scientist a means for solving the problem of the earth’s
age. By “age of the earth” we mean here the time which has elapsed
since the earth’s surface became fitted for the habitation of living
beings. By means of radioactivity we can form an approximate estimate
of the time which has passed since the formation of any given series of
geological strata. Radium is our geological time clock.
It is now known that all the common rocks and soils of which the
earth’s crust is built up contain measurable amounts of radium.
According to the computation made by Prof. John Joly, the total
quantity of radioactive matter may be as much as one 500 billionth part
of the whole volume of the globe, or something over half a cubic mile.
All of the 36 known radio-elements are disintegration products of the
primary radio-elements uranium and thorium--_i.e._, they are produced
from one or the other of these in their long sequence of changes. And
the rate at which the radioactive products change--their average life
period,--from the first transmutation to the final product, radium
lead, an isotrope of common lead, is accurately known. (Helium atoms
are “the debris shed at the various stages of the transformation.”)
It is now well established that a gram of uranium as found along with
its products in rocks and minerals is changing at a rate represented by
the production of 1.88 x 10^{-11} grams of helium and 1.22 x 10^{-10}
grams of lead (isotrope) _per annum_. We do not know for a certainty,
of course, that this rate of production has been maintained throughout
geological time. In the opinion of Lord Rayleigh, we may safely assume
that the rate of transformation has not changed, so that “it would seem
that in the disintegration of a gram of uranium we have a process the
rate of which can be relied upon to have been the same in the past as
we now observe it to be” (_Nature_, October 27, 1921).
Acting on Rutherford’s suggestion, the Hon. R. J. Strutt (later
Lord Rayleigh) made a determination of the amount of radium in the
superficial parts of the earth--which are alone accessible; and he
also determined the ratio of the lead (isotope) to the uranium, which
was found to be 1.3 (specifically, in the broggerite found in the
Pre-Cambrian rocks at Moss, Norway). Now, if we assume--as the evidence
seems to warrant--that the lead of this atomic weight (206.06) was
all produced by uranium at the rate given above, we get an age of 925
million years for these rocks. Some minerals from other Archaean rocks
in Norway give a rather larger figure.
“In other cases,” says Lord Rayleigh, “there is some complication,
owing to the fact that thorium is associated with uranium in the
mineral and that it, too, produces helium and an isotrope of lead of
atomic weight probably 208 exactly, about one unit higher than common
lead.”
Sir Ernest Rutherford estimated the time required for the accumulation
of the radium content of a uranium mineral in the Glastonbury granitic
gneiss of the early Cambrian as no less than 500,000,000 years. Later
investigations give some of the Pre-Cambrian rocks an antiquity of
1,640 millions of years! The zoologist may now have all the time he
wants for the slowly evolving organisms revealed by the sedimentary
strata.
Prof. John W. Gruner, of the geology department of the University
of Minnesota, discovered (in 1925) microscopic forms of plant life
(algae) embedded in iron formations of the Vermillion Range near Lake
Armstrong, Minnesota. Most of Minnesota’s iron deposits are due to the
algae, Dr. Gruner thinks. The growth has the property of extracting
iron from sea water and making of it a solid shell with which to
surround itself. Accumulations of these iron shells through millions of
years have been embedded in rock formations forming the iron ore.
Slices of rock a thousandth of an inch thick were examined under
microscopes in the search for the algae. Algae began to flourish
immediately after the earth, in cooling (according to one cosmological
theory), got below the boiling point. Their form is much like seaweed,
and they thrive at a temperature of 95° C. Dr. Gruner estimates the
age of these algae-bearing deposits at 200,000,000 years, ten million
years earlier than previous evidence showed.
If we employ the radioactivity test as a measure of geological
time, the age of these fossil algae would have to be placed much
higher--older by hundreds of millions of years. And the same must be
said of the amphibian footprints recently (1925) discovered in the
sandstone slabs of the Grand Canyon, by the caretaker on Hermit’s
Trail, a thousand feet below the rim of the canyon. On the older
geological time scale, these deposits date back some 50,000,000 years
(lower Carboniferous period--the so-called “Mississippian” system). On
the radium time schedule, these figures would need to be multiplied
considerably (according to Boltwood and Holmes, by a multiple of six or
more). It should be said, however, that on the time deposits of Walcott
and Schuchert, based on the rate of deposition of sediments, the
lower Carboniferous (Mississippian) deposits are not older than some
18,000,000 years.
But amphibian footprints are known from the far older Devonian period,
whose strata are, on the radium basis, some 370 million years old.
Prof. Charles Schuchert, of Yale, regards the estimates of geological
time based upon the rate of disintegration of radioactive minerals as,
on the whole, far more reliable than estimates based upon the rate of
deposition of sediments. No scientist pretends to be able to state
exactly the age of strata by the amount of radium lead contained in
them.
“In a third class of cases,” Lord Rayleigh points out, “the uranium
mineral, pitchblende, occurs in a metalliferous vein, and the lead
isotope produced in the mineral is diluted with common lead which
entered into its original composition, ... but the complications
cannot, I think, be considered to modify the broad result.
“A determination of the amount of helium in minerals gives an
alternative method of estimating geological age; but helium, unlike
lead, is liable to leak away, hence the estimate gives a minimum only.
I have found in this way ages which, speaking generally, are about
one-third of the values which estimates of lead have given, and are,
therefore, generally confirmatory, having regard to leakage of helium.”
Dr. Homer P. Little, of the National Research Council, Washington,
D. C., tells us (_Scientific American Monthly_, August, 1921, p. 173)
that “from both calculation and experiment it is found that one gram
of uranium will produce helium at the rate of one cubic centimeter in
9,600,000 years. The ratio between the amount of radium in a mineral
and the amount of helium present therefore allows us to calculate the
age of the mineral. The amount of uranium originally present compared
to that left does not enter into the problem unless extreme lengths of
time are under consideration, because of the fact that it is calculated
to take 5,000 million years for one-half a given volume of uranium to
disintegrate.
“It is perfectly true that much of the helium generated may escape. The
assumption is, however, that in some minerals comparatively little
escapes: zircon, particularly, seems to be an effective retainer.
This mineral shows very effectively the increasing ratio of helium
to uranium as consecutively older rocks are examined. Recent or
Pleistocene specimens from Vesuvius show an apparent age of 1 million
years; Miocene specimens from the Auvergne, France, of 6.3 million. The
Devonian of Norway furnishes specimens 54 million years in age, and the
Upper Cambrian of Colorado specimens of 141 million years; the Archaean
of Ceylon, of the diamond-bearing rocks of South Africa, and of certain
rocks of Ontario furnish specimens aged 286, 321 and 715 million years,
respectively.”
The following table gives the mean of the results of Professors
Boltwood and Holmes’ careful studies, based upon the accumulation of
lead as a final product of the uranium series:
MILLIONS OF
YEARS
Carboniferous 340
Devonian 370
Pre-Carboniferous 410
Silurian or Ordovician 430
Pre-Cambrian:
Sweden 1,025
United States of America 1,310–1,435
Ceylon 1,640
These results, a total of 1,400,000,000 years, greatly transcend Lord
Rayleigh’s (Strutt’s) earlier calculations regarding the antiquity they
assign to Paleozoic and Pre-Cambrian times.
In 1918, Prof. Joseph Barrell reviewed the various methods employed
and the results obtained in the attempt to determine from geological,
chemical and physical evidences the time that has elapsed since the
beginning of the Cambrian Period (when abundant fossil invertebrates
are first met with), and reached the following time estimates for
the principal divisions of the geologic record (exclusive of the
Pre-Cambrian rocks):
Cenozoic time, 55,000,000 to 65,000,000 years long
Mesozoic time, 135,000,000 to 180,000,000 years long
Paleozoic time, 360,000,000 to 540,000,000 years long
The time thus established covers a period of from 550,000,000 to
700,000,000 years, or from ten to 15 times longer than has usually been
accepted by geologists. Pre-Cambrian time was found to have a similar
order of magnitude; but here the evidence rests largely upon the
radioactivity of the crystalline rocks formed during this vast period.
It is now universally accepted that the time required for the formation
of the Pre-Cambrian rocks was fully as long as, if not longer than,
that for the succeeding geological divisions. The Archaean deposits
have a vertical thickness, in the regions north of the Great Lakes,
estimated at about 65,000 feet, or 12 miles. Their base, as a matter
of fact, has never been reached. It is interesting to note that the
granites of Norway, Canada, Texas and East Africa have an indicated age
of 1,120,000,000 years, measured in terms of radium products. Prof.
Henry Norris Russell, of Princeton University, concludes, from his
careful investigations in radioactivity, that the age of the earth is
“a moderate multiple of 1000 million years.”
Professor Joly has computed that if there are two parts of radioactive
material for every million million parts of other matter throughout the
whole volume of the earth, and this is considerably less than he has
found on the average in the earth’s crust, then this earth, instead of
cooling off, is actually now heating up, so that in a hundred million
years the temperature of the core will have risen through 1,800 degrees
centigrade.
Dr. Millikan observes (_Science_, July 9, 1921) that this is a
temperature “which will melt almost all of our ordinary substances....
It means that a planet that seems to be dead, as this our earth seems
to be, may, a few eons hence, be a luminous body, and that it may go
through periods of expansion when it radiates enormously, and then of
contraction when it becomes like our present earth, a body which is
a heat insulator and holds in its interior the energy given off by
radioactive processes, until another period of luminosity ensues.”
Lord Rayleigh’s series of researches for the purpose of determining
the quantity of radium present in a number of representative rocks,
both igneous and sedimentary, seems to prove that the average amount of
radium in the earth’s crust is about 20 times larger than the amount
calculated by Rutherford to be necessary to retain its temperature
unaltered. Joly’s investigations revealed values in general agreement
with these, but in many cases he obtained a value several times greater
than the amount found by Lord Rayleigh. Further investigations showed
that thorium is as widely distributed as radium in the earth’s crust,
which is true also of uranium.
“Incredible as it may appear,” remarks Rutherford, “the radioactive
bodies must have been steadily radiating energy since the time of their
formation in the earth’s crust. While the activity of uranium itself
must decrease with the lapse of time, the variation is so slow that an
interval measured by millions of years would be required to show any
detectible change.”
In his 1921 address to the British Association for the Advancement of
Science, Lord Rayleigh said: “It appears certain that the radioactive
materials present in the earth are generating at least as much heat as
is now leaking out from the earth into space. If they are generating
more than this (and there is evidence to suggest that they are), the
temperature must, according to all received views, be rising.”
CHAPTER IV
AN EPOCH-MAKING DISCOVERY
When radium was discovered by Mme. Curie in 1898, the effect upon
the scientific world was startling, not to say “catastrophic”--as
one author wrote at the time--since its activities ran counter to
every known principle of physical science. “Some of the most solid
foundations of science were destroyed, some of its noblest edifices
wrecked, and scientists had to nerve themselves to face and investigate
a new form of energy.”
So soon as radium compounds (salts) became available, however, the
amount of energy given out in radioactive processes--the emission of
powerful radiations which can be transformed into light and heat--was
measured; and it was found that radium, weight for weight, gives out
as much heat as any known fuel every three days, and in the course of
fifteen years releases a quantity of energy nearly 2,000 times as much
as is obtained from the best fuel, with no signs of exhaustion (Soddy).
In the combustion of coal, the heat evolved is sufficient to raise a
weight of water some 80 to 100 times the weight of the fuel from the
freezing-point to the boiling-point. The spontaneous heat from radium
is sufficient to heat a quantity of water equal to the weight of radium
from the freezing-point to the boiling-point every three-quarters of an
hour. In other words, a pound of radium contains and evolves in its
changes the same amount of energy as 100 tons or more of coal evolve in
their combustion.
In ordinary chemical changes it is the _molecules_ (groups of
atoms) which are altered or rearranged; in radioactive change
the atoms themselves suffer disintegration and rearrangements.
The energy of radioactivity, then, is--according to the accepted
view--intra-atomic--stored-up energy within the atom itself. It was
calculated by Prof. Curie that the energy of one gram of radium would
suffice to lift a weight of 500 tons to a height of one mile. If it
were possible to obtain one cubic centimeter (a thimbleful) of the
“emanation” from radium in the form of a gas, we should find that it
possessed the power, altogether, of emitting more than seven million
calories of heat! A thimbleful of this invisible gas would be more
than sufficient to raise 15,000 pounds of water 1°. But in every mass
of radium, small or large, not more than 13 trillionths of it is
undergoing change per second.
“The processes occurring in the radio-elements,” says Rutherford again,
“are of a character quite distinct from any previously observed in
chemistry. Although it has been shown that the radioactivity is due
to the spontaneous and continuous production of new types of active
matter, the laws which control this production are different from the
laws of ordinary chemical reactions. It has not been found possible in
any way to alter either the rate at which the matter is produced or its
rate of change when produced. Temperature, which is such an important
factor in altering the rate of chemical reactions, is, in these cases,
entirely without influence. In addition, no ordinary chemical change is
known which is accompanied by the expulsion of charged atoms with great
velocity.... Besides their high atomic weights, [they] do not possess
in common any special chemical characteristics which differentiate them
from the other elements.”
It was early observed by Curie and Laborde that the temperature of a
radium salt is always a degree or two above that of the atmosphere,
and they estimated that a gram of pure radium would emit about 100
gram-calories per hour. Giesel later showed that radium was always at a
temperature 5° higher than the surrounding air, regardless of what the
temperature of the air might be. This continues unchanged whether the
temperature of the surroundings be 250° below zero Centigrade, or in
the intense heat of an electric furnace.
“Perhaps,” remarks a writer in _The Scientific American_ (February,
1922), “there will come a time when we shall use the energy in the
atoms to drive our machines, cook our food and heat our rooms. Besides,
already today we are actually using--even if only a very tiny part--the
atomic energy. Thus, for instance, the rays emanating from radium
are used for therapeutic purposes and the electrons emanating from a
glowing filament can be directed so easily that they can be used in a
large number of apparatus for wireless telegraphy and telephony. Most
probably plants also make use of this energy in their growth because
it has been demonstrated that the rays of the sun liberate electrons
from the green leaves, and lastly it may also be mentioned that we
humans use a little of this intra-atomic energy when seeing with
our eyes, which we are enabled to do by the photoelectric action of
light.”[A]
During the course of the process of disintegration, atoms of uranium
and thorium and their products give rise to no fewer than 36 different
substances (A. S. Russell), and of these at least a dozen are “new
elements.”
All of the 36 radioactive elements are disintegration products of one
or the other of the two parent elements, uranium and thorium. They are
arranged by the chemist in three series: namely, Uranium 1, Uranium 2
(the Actinium Series), and Thorium. In the first series there are known
to be 15 transmutations of matter; in the second, 11; and in the third,
10. The periods of “half change”--the period required for one-half of a
given quantity of a radioactive element to decompose--of the different
radioactive elements vary all the way from thousands of millions of
years for the longest lived primary elements--2.6x10^{10} years for
thorium, 8x10^9 for uranium 1--to .002 second for actinium A. In the
case of radium itself, 1,670 years are demanded for the disintegration
of half of any portion, according to the exact measurements of Profs.
B. O. Boltwood and Ellen Gleditsch. The stable end product appears to
be in each case an _isotope_ of lead--leads having similar chemical
properties but of different _atomic weights_ (_i.e._, different atomic
composition).
[A] See Shipley, Maynard, “Electricity and Life,” ch. vi.,
Little Blue Book No. 722.
Isotopes are groups of elements which cannot be distinguished (or
separated from) one another by any known chemical methods, and which
differ only in the atomic weights of the members of the group. In the
radioactive groups, the various elements differ also in degree of
stability of their atoms.
Chemists cannot actually weigh the mass of an atom of an element on a
pair of scales, or by any other method. But if we put down 16 as the
“atomic weight” of oxygen, and ascertain the “combining weight” (ratio)
of hydrogen to oxygen, we can determine the “atomic weight” of hydrogen
(1.008). (See Shipley, “The A B C of the Electron Theory of Matter,”
p. 14, Little Blue Book, No. 603.) The ratio of the masses of _any_
two elements in a chemical compound can be very accurately determined.
Without going into the details here, it may be said that the _relative_
weights of the atoms of any element can be determined to 0.01% in many
cases (by chemical analysis and synthesis); while the _actual_ weight
of any atom has not yet been determined to better than 0.1%.
HOW RADIUM IS CONVERTED TO LEAD
Lead is produced from uranium by a successive series of losses of Alpha
particles--or helium atoms. Omitting the less essential outcomes, or
transition stages, we find that each atom of uranium spontaneously
ejects three atoms of another element, helium, and thereby is
converted into still another element, radium. By losing one atom of
helium, radium, in turn, is converted into the so-called emanation,
or _niton_. The latter quickly loses four more atoms of helium and
is converted into lead, “uranium lead,” having an atomic weight of
206.08. Ordinary (common) lead, constituting the vast bulk of the lead
of the world, has a much higher atomic weight, namely, 207 (Prof.
Theodore Richards). Lead from thorium has an atomic weight of 208; from
actinium, 206. So we have, in fact, four kinds of lead.
Omitting the less stable transition products, we may say, then, that
an atom of uranium is converted into lead by the loss of eight atoms
of helium--losing three to become radium, then one to become the
emanation, and finally four to become lead. No known human agency can
either retard or hasten this breaking down of the uranium atom into
radium, or of the radium into emanation, with the final production of
lead.
This statement has been universally accepted as true. Nevertheless,
Dr. A. Glaschler stated (_Nature_ [London], September 12, 1925) that
he had succeeded in accelerating the change of uranium to uranium X
(the first product of uranium 1) by submitting uranium oxide to “strong
rushes of momentary high-tension currents.” As early as 1923, A. Nodon
(_Comp. rend., 176_, 1705 [1923]) brought forward strong evidence of
an increase of the activity of radioactive substances when outdoors
and enclosed by envelopes of small absorbing power for Gamma rays as
contrasted to the smaller radioactivity of the same substances in
cellars and when heavily enveloped by lead. For a tentative explanation
of this phenomenon, see _Science_, January 8, 1926 (Vol. LXIII, No.
1619), pp. 44–45.
Both uranium and thorium, as we have just stated, break down and become
radium, then change to helium and lead.
Says Rutherford: “Although thorium is nearly always present in old
uranium minerals and uranium in thorium minerals, there does not appear
to be any radioactive connection between these two elements. Uranium
and thorium are to be regarded as two distinct radioactive elements.
“With regard to actinium, there is still no definite information of its
place in the scheme of transformations. Boltwood has shown that the
amount of actinium in uranium minerals is proportional to the amount
of uranium. This indicates that actinium, like radium, is in genetic
connection with uranium....”
The recently discovered product, _protoactinium_,--isolated by Hahn and
Soddy,--is the hitherto missing link between uranium Y and actinium.
“This substance emits Alpha rays and has an estimated period of 10,000
years. The actinium series is believed to have its origin in a dual
transformation of uranium X. The first branch product, representing
about 4% of the total, is believed to be uranium Y, a Beta-ray product
of period one day. This is directly transformed into protoactinium.”
This element has not yet been obtained in a pure state.
Many of the radioactive elements are isotropic with known chemical
elements--_i.e._, alike in their chemical properties, but dissimilar
in radioactive properties. Since they cannot be distinguished--or
separated--from the ordinary elements with which they are isotropic, by
any chemical methods, they must occupy the same place in the periodic
classification of the elements. Radium and mesothorium, for example
(as Soddy was first to show) do not have the same atomic weight, but
they cannot be distinguished from each other by any chemical methods.
Therefore they both have the atomic _number_ 88, though the atomic
_weight_ of radium is 226 and of mesothorium 228. (See Shipley, “Origin
and Development of the Atomic Theory,” p. 64, Little Blue Book, No.
608.) Radium D and lead, and thorium and ionium, are examples of
radioactive isotropes.
The nature of the end-product was first suggested by Boltwood, who
pointed out the invariable presence of lead in old radium minerals,
and in amount to be expected from their uranium content and geologic
age. “Thus,” says Prof. T. W. Richards, of Harvard University, “we
must adopt a kind of limited transmutation of the elements,” although
not of the immediately profitable type [gold] sought by the ancient
alchemists.”
Sir Ernest Rutherford, who succeeded Sir J. J. Thomson as Cavendish
Professor of Physics at Cambridge University, was first to recognize
that the rays from uranium and radium were not all alike, but consisted
of three distinct kinds. In order to distinguish them clearly, without
committing himself in advance as to their exact nature, he christened
them Alpha, Beta, and Gamma rays--the first three letters of the Greek
alphabet. We know now that the Alpha rays are positively charged helium
atoms, with two negative electrons missing; that the Beta rays are
negatively charged electrons (disembodied “particles” of electricity,
exactly like cathode rays); and that the Gamma rays are a type of
X-rays, not material particles but merely extremely short magnetic
waves or oscillations, akin to ordinary light waves or rays.
Dr. R. A. Millikan calls them “the wireless waves of the denizens of
the sub-atomic world. They are ether waves, just like light or just
like wireless waves, except that the vibration frequency ... amounts to
30 billion billions per second. These are the Gamma rays.” This means
that this number of light waves would pass a given point in space each
second. Since these rays do not consist of charged particles they are
not deflected by electromagnetic or electrostatic fields, as are the
Alpha and Beta rays. It has been found that one gram of radium ejects
136,000,000,000 particles a second!
The Gamma rays of radium have such penetrating power that a half-inch
sheet of lead will reduce their original intensity by only one-half,
and they are not absolutely stopped by 20 inches. These invisible
light waves, thousands of times shorter than those of visible light,
are produced whenever a cathode ray (negative electron) hits matter.
Of the atoms forming the substance penetrated, perhaps only one in a
billion is struck. It has been said that the Gamma rays (and X-rays)
are the result of the back-kick of ejected electrons. Prof. Comstock
says that the connection between the Beta rays and the Gamma rays “is
probably similar to that between the bullet and the sound in the case
of a gun.” However this may be, we know that the Gamma rays are, after
all, in essence only excessively minute light waves. While the longest
visible light waves are 0.00008 centimeter, the longest Gamma rays are
0.000000013 centimeter; and whereas the shortest visible light waves
are 0.00004 centimeter, the shortest Gamma rays are but 0.0000000007
centimeter.
The Beta particles are ejected with a velocity of from 90,000 to
160,000 miles a second.
Prof. Gustave Le Bon calculated that it would require 340,000 barrels
of powder to discharge one bullet at this inconceivable speed! These
negatively charged electrons normally revolve around the positively
charged nucleus. Under certain conditions, an electron will make 2200
billion revolutions within an atom in one second.
Radium is not only continually losing matter and energy as electricity,
but it is also losing energy as heat. Professor and Mme. Curie
discovered that any substance placed near radium becomes itself
a _false_ radium. This applies to all substances. The acquired
radioactivity persists for many hours, or even days, after the removal
of the radium. In the case of zinc, these secondary radiations were
found to be four times as intense as ordinary uranium. It vanishes
sooner or later upon the removal from the neighborhood of the potent
radium.
The radioactive something which passes out of radium was not the
already known group of Alpha, Beta and Gamma rays, but an _emanation_
akin to gas. Rutherford, its original discoverer, was not sure that
it was a gas, so he cautiously gave it the name _emanation_. When the
radium was heated, or dissolved in water, the quantity of emanation
was greatly increased, which seemed to show that it was a gas of
some kind occluded (bound up) in the radium. The quantity obtained
was insufficient to bring the emanation within the testing power of
spectroscope or balance.
Nevertheless, the emanation has been detected, and investigated by the
electroscope, which measures the radium rays by the power to discharge
its electrified gold leaves. “The electroscope is about a million
times more sensitive than the most sensitive spectroscope and yet the
spectroscope is capable of detecting easily the millionth part of a
milligram of matter” (Duncan).
Calculations made by Rutherford show that if a thimbleful of this
active gas could be collected, the bombardment of its powerful rays
would heat to a red heat, or even might melt down, the walls of the
glass containing it. The emanation emits only Alpha rays (or particles)
forming helium.
The radium from which the emanation has been abstracted, after the
lapse of an hour or so, loses 75% of its activity. During the course
of a single month, radium will be found to have restored all its lost
emanation. In thirty days it will have regained all its original
activity. It was soon discovered that the emanation abstracted from the
radium loses its radioactivity at the same rate and according to the
same laws as the de-emanated radium regains it. The radium is therefore
said to be “in equilibrium with its products.”
Since these processes are wholly outside the sphere of known
controllable forces, and cannot be created, altered or destroyed--“since
the process is independent of the chemical form of the radium, whether
bromide, chloride, sulphate, etc., we are absolutely shut up to the
conviction that it is a function of the atom. We are in the presence of
an actual decay of the atom. The atom of radium breaks down into atoms
of emanation and the atoms of emanation in their turn break down into
something else. The activity of emanation decays and falls to half value
in about 3.7 days.”
Although the amount of emanation produced from a gram of radium
does not amount to more than a needle-point of the gas (= 1.3 cubic
millimeter), this is sufficient to raise the temperature of 75 grams
of water 1° per hour, which is enough heat to melt _more than its own
weight of ice_ in an hour, and to raise it to the boiling-point in the
next hour, which is equivalent to 60,000 horse-power days! In other
words, the heat evolved by the radium emanation is more than 3,500,000
times greater than that produced in any known chemical reaction: such
as, for example, the union of oxygen and hydrogen to form water.
It was soon discovered that if the spectrum of this mysterious gas--or
radium emanation--be examined again after an interval of about four
weeks, it has changed into a familiar spectrum easily recognized as
that of the gaseous element known as helium. Here the chemist comes
face to face with the astounding fact that the element radium is
decomposed and produces another element, helium--a discovery made by
Ramsay and Soddy in the summer of 1903.
In the successive radioactive changes, one Alpha particle (sometimes
called “ray”) is ejected from each atom disintegrated by the change--in
some cases, at least, accompanied by Beta particles (negative
electrons). The Alpha particle, as already stated, is really an atom of
helium carrying two atomic charges of positive electricity--twice that
of an atom of hydrogen. Strictly speaking, the Alpha particle is only
the _nucleus_ of a helium atom, since it has lost two of its negatively
charged electrons, which are combined in the ordinary helium atom. The
exact velocity of the expelled Alpha particle “varies in the different
radioactive elements” (Joly)--say from 10,000 to 18,000 miles each
second--a velocity sufficient to carry the particle around the earth in
less than two seconds, if unchecked.
But these relatively heavy particles (of atomic size) are actually soon
checked, even by seven centimeters (about a third of a foot) of air.
The Beta particle (1,845 the mass of a hydrogen atom) “shoots a hundred
times as far [as the Alpha particle] and the Gamma rays are a hundred
times more penetrating still” (Millikan). But the Alpha particle is
sometimes ejected with a velocity nearly 40,000 times that of a rifle
bullet,--the velocity of the latter being about half a mile a second.
Even the super-guns which bombarded Paris could not eject a projectile
with a speed of more than about a mile a second. Rutherford observes
that if it were possible to give an equal velocity to an iron cannon
ball, the heat generated on a target would be many thousand times more
than sufficient to melt the cannon ball and dissipate it into vapor.
The flashes of light seen when the Alpha rays bombard a screen of zinc
sulphide, as in Crookes’ spinthariscope, are due to cleavages produced
in the zinc sulphide crystals by the impact of the Alpha rays (positive
ions). Each impact on a crystal produces a splash of light big enough
to be seen by a microscope.
In the phosphorescence caused by the approach of an emanation of radium
to zinc sulphate, the atoms throw off the Alpha (helium) particles to
the number of five billion each second, with velocities of 10,000 miles
or more a second. If the helium projectile should chance to “crash”
into an atom of nitrogen or of oxygen, an atom of hydrogen can be
knocked out of it, as was discovered by Sir Ernest Rutherford, perhaps
the most distinguished of Mme. Curie’s pupils. (Strictly speaking, the
disintegration particles are isotropes of helium, of atomic weight
3, the atomic weight of helium being 4.) Despite its large size as
compared with an electron (or Beta particle), the Alpha particle passes
through a glass wall without leaving a hole behind, and without in any
way interfering with the molecules of the glass. It shoots through
hundreds of thousands of atoms without ever going near enough to them
to be deflected from its course.
CHAPTER V
RADIUM IN THE TREATMENT OF CANCER
The action of radium on human tissues was unknown until 1896, when
Prof. Henri Becquerel of Paris, having incautiously carried a lump of
pitchblende in his pocket, discovered on his skin, within two weeks, a
severe inflammation, or ulcer, which was known as the famous “Becquerel
burn.” As physicians of the nineteenth century were accustomed to
burn out cancers with caustics, the idea occurred to them that the
application of radium might prove to be an improvement on the older
method.
It has proved to be so, affording in many cases not only relief,
but in some instances, even a cure, not only for cancer, but for
many other ailments--as we shall see presently. Since that time
active investigation into the action of radium on diseased tissues
has been carried on, resulting in the establishment in Paris of
the “_Laboratoire biologique du Radium_,” and also of the Radium
Institute of Vienna, followed by the establishment of somewhat similar
institutions in various other countries, notably in England and the
United States.
One of the most famous institutions for radiotherapy is the recently
established Radium Institute of Paris, under the management of Mme.
Curie and Professor Debierne. This is composed of two distinct
compartments. In one the scientific properties of radium are studied,
while the other is devoted to its therapeutic applications. Dr. Regaud,
who is in charge of the latter department (a branch of the widely known
Pasteur Institute), endeavors to cure cancer and tumors by application
of radium and X-rays.
New York City boasts a magnificently equipped Radium Institute, under
the directorship of Dr. C. Everett Field. And an even more famous
institution is that founded by the Mayo brothers, in Rochester,
Minnesota, where these eminent surgeons had accumulated an entire
gram of radium as early, at least, as 1920--the largest amount owned
by private individuals. This great institution--now known as the Mayo
Foundation--is no longer privately owned, but it is still under the
direction of the Mayos.
Radiotherapy (or, in France, _curietherapy_, in honor of the discoverer
of radium) or the treatment of various diseases by radioactive
substances, has not been applied so extensively as has treatment by
X-rays (Roentgen rays), produced in vacuum tubes. On the other hand,
the X-rays are not so effective (as usually applied) in the treatment
of certain morbid conditions as are the more penetrating Gamma rays
from radioactive substances; though the latter are essentially
identical with X-rays--swift Beta particles, or negative electrons--of
very short wave-length. To produce X-rays as penetrating as the Gamma
rays, about two million volts would have to be “cut” on the discharge
tube.
The Alpha rays are not often used in medical practice, and have little
penetrating power. They are stopped by 3½ cm. of air, or by a thin
sheet of paper. They are employed only in the way of radium “emanation”
(a gas) dissolved in saline solution, or by the use of needles upon
which active deposit from radium emanation has been collected. “In
either case the emanation water or the active deposit needles must be
introduced into the system--whether intravenously or into the solid
tissues,--otherwise the Alpha rays would have no power to act. In
either case, too, they act along with the Beta and Gamma rays produced
by the active deposit” (Lozarus-Barlow).
Beta radiation is used only for superficial conditions and always in
conjunction with Gamma radiation. “Instead of a radium salt, one of
its products, viz., radium emanation, is often employed chemically.
No essential difference is introduced by the use of this emanation
excepting that its intensity undergoes a progressive diminution with
time, since it falls to half value in 3.85 days. Early rodent cancer,
certain conditions of the eyelids, some cutaneous non-malignant tumors
and birth-marks, are treated successfully in this way.”
Physicians of the Memorial Hospital, New York City, announced in
October, 1925, that by filtering out 90% of the caustic Beta rays
emanating from radium and the high voltage X-ray tube, and using
principally the healing and stimulating Gamma rays, radiation treatment
of cancer of the tongue, lips, nose, ears or other part of the head has
been greatly improved.
In the first six months after the new method was begun, more than 100
cases had been treated with what were considered very satisfactory
results. Owing to the elimination of the caustic rays, much stronger
applications of the beneficial rays can be used, and painful effects
are largely obviated.
If experience and special research lead eventually to successful
treatment of cancer, it will be a great boon to the human race. The
United States leads the world in deaths from this dread disease, with
its average of 90 per 100,000 of the population. The mean average of
cancer deaths in Europe is 76, in Asia 54, in Africa 33, in Oceania
73. Several races, including the American Indians, are stated to
be entirely free from cancer, and others are partially immune. The
Japanese, for example, are subject to all forms except cancer of the
breast. Eighty-five percent of Americans afflicted with this malady are
persons over 40 years of age.
Science Service states that a careful analysis of cancer statistics
gathered by the United States Census Bureau over a period of about 20
years in ten Eastern states reveals definitely that cancer mortality
is from 25 to 30% higher than it was about 20 years ago. This is the
claim of Dr. J. W. Schereschewsky, of the United States Public Health
Service, who made the statistical analysis and reported it to the
American Medical Association. “There has been a pronounced increase in
the observed death rate from cancer in persons 40 years old and over in
the ten states comprising the original death registration area,” Dr.
Schereschewsky said. “Part of this increase is due to greater precision
and accuracy in the filling out of death returns, but the remainder is
an actual increase in the mortality of the disease.”
The only way to stop the ravages of cancer, says the Paris Academy of
Medicine, is to diagnose it early--in time for operation. For this
to be practicable, physicians must be specially instructed. Family
doctors are often ignorant of all but a few forms of cancer and do
not recognize it in its first manifestations. Women of 40 to 50 are
apt to consider little irregularities of bleeding to be associated
with the menopause and therefore harmless. Often this is right, but
unfortunately the bleeding from an early cancer may not differ in the
slightest degree from such harmless irregularities and by the time
other symptoms have developed, the cancer has perhaps grown through
the wall of the uterus and has spread to regions where no treatment
can hope to reach it. The only safe rule to go by is to seek expert
investigation for any unusual or irregular bleeding or discharge,
however slight, especially if these occur at or near the “change of
life.”
One phase of this subject of special interest is that of the use of
radium in the treatment of cancer, especially of the neck or lower
end of the uterus. There is already sufficient evidence to warrant
the statement that some cancers of this region have been permanently
cured by radium alone. And as a relief measure in the late and hopeless
stages of the disease, radium prolongs life, relieves pain and adds
much to the comfort of the victim.
It has been amply demonstrated that radium treatment increases the
permanency of the results obtained by surgery, and often converts
inoperable into operable cases.
CHAPTER VI
EFFICIENCY OF RADIUM IN TREATMENT OF VARIOUS DISEASES
In 1923, Dr. R. E. Loucks, president of the American Radium Society,
announced that toxic goiter had been cured by radium. Exophthalmic
goiter has been, in most cases, successfully treated by irradiation.
Just how the cure is effected is still unknown; for the thyroid body
from animals exposed for many hours to the Gamma irradiations of
radium bromide shows no perceptible histological changes. Yet far
less radiation produces marked changes in the tadpoles derived from
normal ova fertilized by spermatazoa which have been radiated in the
frog, though no testicular changes can be detected with certainty
(Encyclopaedia Britannica, Vol. 32, p. 224, 12th Ed.).
Among other diseases which have been more or less successfully
treated by radium may be mentioned lupus vulgarus, epithelial tumors,
syphilitic ulcers, chronic itching of the skin, papillomata (an
epithelial tumor formed by hypertrophy of the papillae of the skin
or mucuous membrane, as a corn or a wart), angiomata (tumor composed
chiefly of dilated blood or lymph vessels), pigmentary naevi (blemish
of the skin due to pigment, as a birth-mark), and pruritus (itching).
Radium has been particularly effective in treating serious affections
of the eyes, as was first fully demonstrated by Dr. Walter S. Franklin
and Frederick C. Cordes, of San Francisco.
The most brilliant successes of radium have been in those cases “where
some serious complicating ailment, such as heart disease, tuberculosis,
Bright’s disease, or an extreme anemia, contra-indicates anesthesia
or any procedure which will tax the patient’s vital resources; radium
steps in and does its work quietly, imperceptibly and, indeed, without
the slightest risk to life.”
Dr. Howard A. Kelly, of Johns Hopkins University, has been very
successful in curing swollen masses of glands on the sides of the neck,
cancer of the thyroid and of the cervix, and sarcoma of the chest.
Dr. E. S. Molyneaux of London, has cured obdurate cases of tubercular
glands in the neck, a disease rather frequent among children. Thanks
to the patient researches of Dr. John A. Marshall, associate professor
of biochemistry and dental pathology at the University of California,
it is now known that a radioactive liquid may be used for sterilizing
infected tissue. Experiments employing the radioactive liquid in the
treatment of root canals have been conducted at the George Williams
Hooper Foundation for Medical Research and at the College of Dentistry
of the University of California.
Within the time that the new antiseptic has been in use at these
colleges, 85% of all the cases treated have been successful; and,
with one exception, no soreness or pain has followed its use. This
radioactive preparation is a solution of radium salts, “Radium D plus
E,” which results from the decomposition of radium emanation, which,
readily soluble in water, possesses definite radioactive properties. In
making the solution the tiny capillary tubes containing the decomposed
radium are crushed under water in a mortar and the liquid is then ready
for use in the treatment of an ulcerated root of a tooth.
Dr. Marshall had been working with radium for months before
admitting the success of his investigations, which were conducted
in a long series of experiments on the lower animals. “Microscopic
examinations of abscessed tissue,” he said, “which have been treated
with radioactive solutions, indicate that the bacteria producing the
affection were killed. And in no cases observed has the treatment
produced radium burns; the amounts used have been too small and the
effects of too transitory a nature. That sterilization of tissue can be
produced, however, seems apparent.
“The discovery is purely of academic interest because of the fact
that radium is too expensive, and it is possible to obtain it only in
limited quantities; so that the chief value of the discovery will rest
in the fact that it will stimulate further work for the identification
of more accessible material.”
In external treatment by radium itself, emanations from a certain
quantity of radium are allowed to focus on parts of the body over the
diseased organs. Thus the curative functions of the diseased portion
are stimulated to activity. The atrophying of diseased tonsils has
been the most successful use of this form of treatment.
In the destruction of disease germs the radium emanation has been
found more useful than the direct rays. The emanations kill or check
the growth of anthrax, typhoid, and diphtheric germs. The direct
rays are efficient in the relief of severe cases of enurites and
facial neuralgia, cancer, tumors, affections of the skin and abnormal
growths. Dr. Guyenot has proved that radium effects a complete cure for
rheumatism, which he accounts for in these words: “Uric acid circulates
in the blood in the form of urate of soda, of which there are two
isomeric forms differing from each other by their respective solubility
in the blood plasms. The soluble salt is converted into an insoluble
form.” Radium breaks up this compound. The “rheumatism” disappears.
CHAPTER VII
WHERE WE GET RADIUM
The extraction process consists in eliminating the various substances
in the ore until only the radium salts are left. But, in the case of
carnotite, more than 900 different operations, requiring six months of
labor, are required between the digging of the ore and the production
of a gram of pure radium salt. A solution containing barium and radium
salts in the ratio of ten parts of radium to a billion is treated with
sulphate to precipitate an insoluble “raw sulphate of barium.”
Radium ores are generally found in connection with granitic
masses--_i.e._, in places where granite forms at least part of the
rock of the country. The carnotite ore usually consists of a thin
layer of sandstone which crops out on the side of a canyon wall and is
recognized by the characteristic sulphur-yellow color. The narrow seams
are usually in the form of pockets, so that the value of a claim is
dubious until it has been thoroughly explored and worked.
Most of the original radium minerals, such as uraninite, samarskite,
and brannerite, are black and have a shiny fracture and a high specific
gravity. These minerals are, however, rarely found in commercially
valuable quantities.
Pitchblende, the richest source of radium, has the same composition
as uraninite and the same general appearance, except that it shows
no crystal form. It occurs in veins. There are extensive deposits of
pitchblende or uraninite at Joachimstahl, Bohemia (Czecho-Slovakia),
containing from 30 to 70 per cent uranium oxide, from which the radium
is extracted. But here the uranium ore occurs in small pockets in
widely separated localities, so that it is merely a by-product of other
mining operations. However, after separation of the uranium from the
ore, the residues are three to five times as radioactive, weight for
weight, as the uranium. The amount of radium in old unaltered mineral
is always proportional to its content of uranium in the ratio of 3.3
parts of radium by weight to ten million parts of uranium.
New radium ore fields were discovered in Czecho-Slovakia in 1922. The
production of radium in that country increased from .7746 gram in 1911,
to 1.7118 grams in 1915, and 2.2310 grams in 1920. In 1922, steps were
taken to modernize the plants in the Jachcymov district (Bohemia),
where the known supply will last 20 years at the present rate of
production--a little more than two grams a year.
The famous Joachimstahl pitchblende deposits were a monopoly of the
Austrian Government before the World War, but they are now being
worked by the Imperial and Foreign Corporation of London, under an
agreement with the Czecho-Slovak Government. In 1922 a loan of two
grams of radium (valued at more than $300,000) was made to Oxford
University, for a period of fifteen years. This material is being used
for experimental purposes by Prof. Frederick Soddy, of Oxford, and his
associates. It has been stated that one of the chief objectives is
the discovery of a method for the release and control of intra-atomic
energy.
Pitchblende has been found in only a few places--in Bohemia
(Czecho-Slovakia), southern Saxony, Cornwall, and Gilpin County,
Colorado. So far, this ore has not been the source of any radium
produced in this country.
When the original radium minerals (uraninite, samarskite, brannerite,
etc.) break down through weathering, other radium minerals are formed
from them, such as autunite, trobernite, carnotite, and tyuyamunite.
The two latter ores are the most widespread and abundant. Autunite, a
phosphate of calcium and uranium, is as active as uranium. Carnotite
and tyuyamunite cannot be distinguished visually from each other.
Both are a bright canary-yellow in color, and are powdery, finely
crystalline, or, rarely, clay-like in texture. Both these minerals are
found in the same section of Utah and of Colorado, usually associated
with fossil wood and other vegetation, in friable, porous, fine-grained
sandstone.
The only other deposits that yield tyuyamunite in marked quantity are
those of Tyua-Muyun, in the Andiyan district, Ferghana Government,
central Asiatic Russia (Russian Turkestan), where it occurs with rich
copper ores in a pipe in limestone.
The radium salts--hydrous sulphate, chloride, or bromide--are all white
or nearly white substances, no more remarkable in appearance than
common salt. Neither radium nor the radium minerals are in themselves
luminescent. Tubes containing radium salts glow because they include
impurities which the invisible radiations from the radium cause to give
light. The pure radium metal has been isolated only two or three times,
and few persons have seen it.
NEW SOURCES OF RADIUM
In 1921, a rich deposit of pitchblende was discovered in the province
of Ontario, Canada. Since 1921 there has been a rather considerable
exportation of radioactive minerals from Madagascar; and in 1922
deposits of uranium oxide (U_3O_8) were discovered in Switzerland.
During the same year an unknown Belgian traveler sold to a curio dealer
a strange stone picked up in the Congo. The dealer sold it to the
British Museum. Upon examination the stone was found to be radioactive.
Belgian geologists were immediately informed, and a Belgian mission
was sent to the Katanga district, where the stone was found. Two veins
of chalcolite (torbernite) containing substances rich in radium were
soon located by the geologists, one near the Portuguese frontier.
Chalcolite, the crystallized phosphate of copper and uranium, is twice
as active as uranium.
The newly discovered mineral has been given the name “curite,”
in honor of Mme. Curie, the discoverer of radium. These deposits
are now known to be the richest in the world. And, what is hardly
less important, the radium may be isolated by simple dissolution in
nitric acid, even in the cold. It is also readily dissolved in warm
hydrochloric acid. Only 15 tons of the ore need to be treated to
produce a gram of radium.
Curite is found in three forms, as translucent reddish brown
needle-like crystals; as compact saccharoid crystalline aggregates,
orange in color; and as orange-colored earthy masses surrounding the
preceding variety. The chemical composition is expressed by the formula
2(PbO)5(UO_3)4(H_2O).
In 1924 a pitchblende deposit, very rich in radium, was discovered in
Ferghana, in Russian Turkestan. Soviet Russia is now mining the ore and
extracting the radium, which is kept at the Radium Institute of the
Academy of Science.
Curiously enough, more than $500,000 worth of radium has been added to
the world’s store of this valuable element by “boiling down” British
cannons used in the World War. No fewer than five grams--less than a
tablespoonful--have been secured by British scientists by this process.
The radium is stored in a lead safe weighing almost two tons--a
container which was invented by a Dr. Kuss, and the composition of
which is known only to himself. One of the greatest difficulties of
scientists has been to find some material which would prevent the
constant bombardment of the radium rays.
One important result of these recent discoveries--especially that of
the Congo deposits--is that the price of radium dropped $30,000 a gram,
and sells now at the rate of $70,000 a gram instead of some $100,000.
The Standard Chemical Company of Denver, Colorado, has been obliged to
close down its three-story laboratory, which until the close of the
year 1922 had, for several years previously, been producing a million
dollars’ worth of radium annually. The Paradox Valley carnotite ore
cannot be worked in competition with the rich deposits of the Belgian
Congo. It has been stated that five pounds annually could be produced
from these Congo deposits. The Colorado company had been selling at the
rate of $58,500,000 a pound. The Congo company can profitably sell the
precious element at $29,250,000 less a pound.
So, unless war breaks out again to prevent shipments from abroad, the
United States of America will produce no more radium for a long while
to come.
THE RADIOACTIVE DISINTEGRATION SERIES
In order to show the decomposition products of the two parent
radioactive elements--Uranium and Thorium--and their chief
characteristics, together with their relations to one another, and the
time required for the product (element) to be half transformed, it is
customary to arrange them in a _disintegration series_. There are
three series, Uranium I, Uranium Y, and Thorium.
In the first table given below is shown how the series known as
Uranium I is transformed into the end-product, uranium lead. This is
followed by the Uranium Y (or Actinium) series, and by the Thorium
series; the end-product of all three being a characteristic type of
lead. In the tables T is the “time-period” of a product, or the time
required for the product to be _half transformed_. In the column
“Rays” is shown what type of ray, or rays, is, or are, emitted during
the disintegration process--A=Alpha rays (or particles), B=Beta
rays (negative electrons), and G=Gamma rays (or X-rays of very high
“frequency”).
“In the great majority of cases,” says Sir Ernest Rutherford, “each
of the radioactive elements breaks up in a definite way, giving rise
to one Alpha or Beta particle and to one atom of the new product.
Undoubted evidence, however, has been obtained that in a few cases the
atoms break up in two or more distinct ways, giving rise to two or more
products characterized by different radioactive properties. A branching
of the uranium series was early demanded in order to account for the
origin of Actinium.”
In the first column is given the “atomic weight” of each radioactive
element, the weight decreasing with (almost) every “disintegration
period.” The figures followed by an interrogation point are
Rutherford’s, and indicate that slightly different figures are given by
other authorities.
URANIUM I SERIES
T (average Rays (given out in
Element Atomic time-period--half each
Weight transformed) decomposition)
---------------------------------------------------------------------
Uranium I 238 4.5 × 10^9 yrs. Alpha
Uranium X1 234 23.8 days Beta, Gamma
Uranium X2 234 1.15 min. Beta, Gamma
Uranium II 234 About 2 × 10^6 yrs. Alpha
Ionium 230 About 9 × 10^4 yrs. Alpha
Radium 226 (+) 1700 yrs. Alpha
Niton (Emanation) 222 3.85 days Alpha
Radium A 218 3.05 min. (?) Alpha
Radium B 214 26.8 min. (?) Beta, Gamma
Radium C 214 19.5 min. (?) Alpha, Beta, Gamma
Radium C′ 214 10^{-6} sec. (?) Alpha
Radium D 210 (+) 16 yrs. Beta, Gamma
Radium E 210 (+) 4.85 days Beta, Gamma
Radium F (Polonium) 210 (+) 136.5 days Alpha
Radium G (End-product 206 ............... ...............
uranium-lead)
---------------------------------------------------------------------
URANIUM Y (ACTINIUM) SERIES
T (average Rays (given out in
Element Atomic time-period--half each
Weight transformed) decomposition)
---------------------------------------------------------------------
Uranium Y (branching 234 (+) 24.6 hrs. Beta
from Uranium II) (2.2 days?)
Protoactinium 230 About 10^4 yrs. (?) Alpha
Actinium 226 20 yrs. Beta
Radio-actinium 226 19 days Alpha
Actinium X 222 (+) 11.2 days Alpha
Actinium (Emanation) 218 3.92 sec. Alpha
Actinium A 214 .002 sec. Alpha
Actinium B 210 36 min. (?) Beta, Gamma
Actinium C 210 2.16 min. (?) Alpha
Actinium D 206 4.76 min. Beta, Gamma
Actinium E (End-product 206 ............... ...............
actinium-lead)
---------------------------------------------------------------------
THORIUM SERIES
T (average Rays (given out in
Element Atomic time-period--half each
Weight transformed) decomposition)
---------------------------------------------------------------------
Thorium 232.1 2.2 × 10^{10} yrs. Alpha
Mesothorium I 228 6.7 yrs. Beta, Gamma
Mesothorium II 228 6.2 hrs. (?) Beta, Gamma
Radio-thorium 228 1.90 yrs. (?) Alpha
Thorium X 224 3.64 days Alpha
Thorium (Emanation) 220 54 sec. (?) Alpha
Thorium A 216 .14 sec. (?) Alpha
Thorium B 216 10.6 hrs. (?) Beta, Gamma
Thorium C 212 60 min. (?) Alpha
Thorium D 208 3.2 min. (?) Beta, Gamma
Thorium E (End-product 208 ............... ...............
thorium-lead)
---------------------------------------------------------------------
Transcriber’s Notes
Punctuation, hyphenation, and spelling were made consistent when a
predominant preference was found in the original book; otherwise they
were not changed.
Simple typographical errors were corrected; unbalanced quotation
marks were remedied when the change was obvious, and otherwise left
unbalanced.
This book uses terminology that was current at the time of publication,
and reflects the state of science as it was understood by the author at
that time.
*** END OF THE PROJECT GUTENBERG EBOOK 75392 ***
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