May, 1924
INDUSTRIAL A N D ENGINEERING CHEMISTRY
The Expansion
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By Edwin E. Slosson SCIENCE SBRVICE, WASEINGTON,
HEN last I had the privilege of addressing the AMERIICAN CHEMICAL SOCIETY, which was at the Pittsburgh meeting of 1922, I took as my theme the modesty of chemists, that extreme diffidence which keeps the chemists from claiming credit for what they do in the world. Now I am going to continue the same inexhaustible theme and talk again about the self.effacingness of the chemist. I can say this with more propriety than any of you since I am a semidetached chemist, for my present vocation requires me t o wander, like a loose electron, within the spheres of influence of other sciences. I have, in fact, nothing but my A. C. S. badge t o prove that I belong to the chemical fraternity, and I will take that off while I talk in order to relieve the SOCIETY of any responsibility for what I am going t o say. For I am going to touch upon the role of chemistry in the past and future, fields that the professional chemist has hitherto thought i t prudent to ignore. Civilization first became possible through the discovery by some prehistoric chemist of an exothermic reaction consisting of the rapid oxidation of carbohydrates, initiated by a manual rotary movement of a cylindrical section of cellulose in a socket of the same, and resulting in radiation of various wave lengths ranging from about 6000 to 600,000 Angstrom units. (I should explain t o the guests that what I mean is merely “making a fire,” but one has to talk to chemists in their own language.) Our modern civilization has been speeded up by the introduction of liquid rind gaseous forms of fuel. Gasoline has given man the automobile, the airplane, and the motor boat by which he can traverse earth, air, and water at will. Petroleum heats our homes and propels our liners and warships. But our supply of petroleum will sometime run short, in a dozen or fifteen years at the present,rate of consumption, according to the estimates of the oil in the ground by the U. S. Geological Survey. Sooner or later a t any rate we must grow our fuel, as we grow our food, from year to year. It is interesting now t o recall the prophecy of Dr. Diesel, shortly before his mysterious disappearance from the night boat that was carrying him from Germany to England just before the war. He foresaw the time when mineral oil would be exhausted, and then, he said, the supremacy of the sea would go to that power which possessed the most tropical territory for growing vegetable oil. Dr. Diesel has been dead but ten years, yet already in Africa boats are run with palm, cottonseed, and peanut oils. Diesel engines are reported’ to run on less than ten ounces of cottonseed oil per British horsepower-hour a t a thermal efficiency of 24.5 per cent. Peanut oil can be easily changed by catalytic agents to the gaseous and liquid hydrocarbons of petroleum, including benzene. If we come to depend upon such home-grown oils, instead of petroleum, then cotton will again be king and peanut politics will prevail. The reason why the chemists’ influence over the world is not property appreciated is because he works so silently, so unobtrusively. Sometimes, indeed, he sets off an explosion t h a t is heard around the world. That makes people aware of his power, but does not add to his popularity. Scents, savors, and colors are silent and subtle in their sway over emotions, and emotions move the world. When the mother advises her daughter that “The way to a man’s heart is through his stomach;” when the florist advertises, “Say it with flowers;” when the confectioner suggests, “Take a box of candy with you wheri you call on her,” they are recommending chemical courtship-the oldest way in the world, the method that prevails all 1
C A . , 17, 1878 (1923).
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through the animal kingdom frsm the insects up to man When the poet wishes to play most powerfully upon ou: emotions, he resorts to chemical allusions. Let me read you what seems to me the most tasty stanza in all poetry, t h e courtship scene from Keat’s, “Eve of St. Agnes.” And still she slept in azure-lidded sleep, I n blanched linen, smooth and Iavendered: While he from forth the closet brought a heap Of candied apple, quince. and plum, and gourd: With jellies soother than the creamy curd, And lucent sirups, tinct with cinnamon; Manna and dates, in argosy transferred From Fez; and spiced dainties, every one, From silken Samarcand to cedared Lebanon.
You will see that he said it with polysaccharides and coal-tar compounds, and you know how well i t worked. They eloped that very night. We will not properly understand the world‘s great literature until the teaching of English is transferred t3 t k e department of chemistry, or at least until the professors of English study chemistry. The same is true of history. The history of the world will remain a riddle, an inexplicable succession of chance happenings, until we recognize the chemical factors in the course of events. It is like looking at a tapestry from the wrong side; but when we turn it over the design becomes plain.
HISTORICAL Wherein is modern civilization superior to ancient civilization and primitive barbarism? In what respects is the man of today ahead of his primitive forebears? Probably not in physique or mentality. If the winners of the Olympic games could be matched against our own athletic champions we would not know which side t o bet on. If a Binet-Simon-Stanford intelligence test were put to a Roman consul, a Phoenician merchant, or an Egyptian priest, I presume he would score high. But a man in modern times, even though he may be comparatively weak in body and dull in mind, knotvs more and can do more than the strongest and the brightest of men in former times. He knows more because he has a t his command the accumulated knowledge of the ages, selected, tested, and arranged for his benefit. He can do more because he can supplement his feeble muscles with engine power. He can travel fifty times as fast, accomplish a hundred times as much work in a day, lift a weight a thousand times as heavy, and make his voice heard ten thousand times as far. Both these advantages, the physical and the intellectual, he owes t o chemistry. It is chemistry that has given him the power that runs his engines and the metals that make his machines. It is chemistry that has given him books-the paper, the ink, the type, and the alphabet. It is a strange thing-and when you think of it a very lucky thing-that substantially the same alphabet is used nearly all over the world, in Europe, the Americas, Australasia, and a large part of Asia and Africa. How did i t happen? Why should we not get along without an alphabet as the ancient Egyptians did and as the Chinese do? Ask any schoolboy to whom we owe the alphabet and he will reply, if he be of the Macaulay kind that answers rhetorical questions off-hand, that the Phoenicians invented it. But if you ask him the natural next question-why the Phoenicians, who left us no literature, should have yet supplied the means by which our literature is expressed and preserved-you will probably stump him. That is because history has not been interpreted from a chemical standpoint.
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The Phoenicians invented the alphabet because they needed it in their business. And what was their business? Chemical industries and commerce in chemical commodities. With a trade extending From the foggy and barbarous islands of northwestern Europe where tin was mined to the sunny islands of southeastern Asia where spice was grown, with dealings in dozens of different languages and accounts to keep in varying rates of exchange, the Phoenicians had to cut down the cumbrous hieroglyphics to simplified forms and to reduce their number from a thousand.to twenty-two. The basis of almost all the alphabets of the world is the commercial code of the Phoenician traders. After the fall of the Phoenicians the next great commercial power was Venice, and this also was founded on chemical industries. When Attila the Hun swooped down on Italy the cities on the northern shore of the Adriatic were sacked and the people driven to take refuge on the barren islands of the lagoons. Here they had neither fields nor forests, no food but fish, no minerals but salt and sand. Venice was wedded to the sea, not by the annual ceremony when the doge threw a ring into the water, but by economic necessity. From the sea the Venetians drew the fish. With sea salt they preserved them. From the sand they made glass. Their fishing smacks grew into argosies and navies. Cassiodorus, minister t o the Emperor Theodoric, wrote to the Venetians about 500 A. D. : “All your energy is expended on your salt works. In place of plows and sickles you turn your pans. You own many a ship and your vessels fear not the stormy winds.” For a thousand years after that Venetian vessels dominated the seas, and to this day Venetian glass is valued throughout the world. In northern Europe we see another illustration of how momentous changes in world history may be traced to obscure chemical causes. The powerful confederation of commercial cities about the Baltic, known as the Hanseatic League, owed its rise largely to the herring which then shoaled abundantly in the Baltic. But in 1424 the herring made a sudden shift from the Baltic to the North Sea. This brought about the fall of the Hanseatic League and the rise of the sea power of the Netherlands and the British Isles. Now what caused the migration of the herring? Dr. Edwin B. Powers, of the Puget Sound Biological Station, finds that the alkaline reserve of fish is very sensitive to changes in the carbon dioxide content of the water, and suggests that “the desertion of the shores by the herring after storms is perhaps due to the carbon dioxide of the air being mixed with the sea water and thus driving the herring away.” This momentous shift in the sea power was doubtless not due to a preference on the part of the herring to being caught by Dutch and English instead of Germans and Russians, but was more likely due to a change in the composition of the water, perhaps an alteration in the pH, which made the fish or their food feel more comfortable in the North Sea than the Baltic. Benchels, a Dutchman, discovered a new method of curing herring, which enabled them to be preserved and sent all over Europe for Lent and Fridays. The Dutch boats extended their cruises close to the British coast. The British navy was started by Charles I to keep the Dutch from fishing in what was claimed as British waters. This led to war between the Dutch and English, and to a conflict of international law that continues to this day. Grotius, the Dutch jurist, wrote his famous treatise, “Mare Liberum,’’ advocating the doctrine of the freedom of the seas, and Seldon, the English jurist, replied with his “Mare Clausum,” defending the British claim to closed seas. America took the Dutch side of the controversy and so the freedom of the seas became a fundamental principle of our national policy. It was waived in favor of the British during the late war, but reaffirmed in principle. So the present talk about the three-mile or the twelve-mile limit can be traced back t o two chemical factors, a change in the composition of sea water and a new preservative.
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What was i t that drew Columbus across the Atlantic? What was it that enticed Vasco da Gama to India around the Cape of Good Hope? What was i t that sent Magellan around t h e world? It was “the spicy breezes that blow soft o’er Ceylon’s Isle.” The great explorers followed that spoor as the bee scents out the flower or the vulture his game. Sometime I am going to write a book on “The Influence of the Pepper Power upon History,” in three large volumes. In order to get time for that I may have to commit a crime and get sent to the penitentiary for ten years. What deters me from the project is that the way the courts are run nowadays the chances are about ten to one against my conviction, and I might lose my soul without getting the necessary leisure for historical research. The search for a rare polymer of isoprene, called by Indians “caoutchouc,” set the Belgians to cutting off the hands of little children in the Congo and to similar atrocities in Putamayo. All this cruelty occurred because the chemist is behind time in his manufacture of synthetic rubber. Secretary Hoover has called for measures that will free us from dependence upon the British plantations for our rubber supply and Congress has appropriated half a million dollars to promote rubber growing on our own tropical possessions. But the chemist might solve the problem and secure the economic independence of his country if he could work out a way of making rubber cheaper than the tree can do it.
PHYSIOLOGICAL In the past the chemist has controlled the course of civilization through such gross means as the introduction of a new food or fuel, or inventions like glass or paper. But he is now beginning to get his hands upon minuter means of control, which are more direct and vastly more powerful in their influence upon the human race. Chemical changes of almost inconceivable minuteness are found to affect the balance of the body. The growth of young rats is perceptibly promoted by the addition to their daily diet of much less than a hundredth of a milligram of vitamin A from codliver oil. An infinitesimal amount of pollen protein may not only start a new plant to growing but may start a big man to sneezing. This is Nature’s sternutatory gas, the chemical warfare service of the ragweed. Adrenalin produces a perceptible effect upon the tissues in a dilution of one part in 330,000,000. The hormone that Professor Abel has extracted from the pituitary body has still higher potency, for it can be detected in a dilution of more than 80,000,000,000. “A deviation in the acid-alkaline balance of the blood no greater than that between tap water and distilled water is fatal” to human beings.2 The new chemistry is invading the province of psychology as well as of biology. A psychoanalyst may interpret your dreams as he likes best, but a chemist can give you any kind of d r e a q you like by a dose of hashish, strychnine, or opium, or you may get dreams of a kind you don’t like from an untimely mince pie or an unruly Welsh rarebit. The late Jacques Loeb found that he could not be a biologist without becoming a chemist, and he came to believe that all physiological and psychological processes were essentially chemical. He showed us frogs who had no father but a fatty acid, and he held that the artificial production of living beings from lifeless matter might sometime be achieved in the laboratory. He even went so far as to say that “Experimental abiogenesis is the goal of b i ~ l o g y . ” ~ F. Lohnis, soil bacteriologist of the U. S. Department of Agriculture, finds that a single species of bacteria grown in substrates of different chemical composition will assume the various forms hitherto ascribed t o different species. The azotobacter, for instance, may a t will be made to grow large or small, round or rodlike or any shape between, and to adopt different modes of 2
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Hoskins, Scienfkfic Monthly, March, 1924. “Dynamics of Living Matter.”
May, 1924
INDUSTRIAL AND ENGINEERING CHE;MIXTRY
locomotion and to employ all the various methods of reproduction. They will dissolve into an incoherent, transparent, slimy mass that does not take a stain, and again may reform into visible individuals of characteristic form. Lohnis holds4 that pathogenic bacterra, such as cause bubonic plague, anthrax, cholera and diphtheria, take different forms as do the soil bacteria, and that the whole system of classifying bacteria into different species and genera according to their shape and habit of life needs to be revised in the light of our new knowledge of their variability. The conventional classification of animals and plants from the time of Aristotle and Linnaeus has been chiefly based on morphology, just as mineralogy was in its early days mostly a matter of crystalline form. But nowadays we know that minerals can better be classified according to chemical composition than by their shape, color, hardness, and other visible characteristics A similar change must take place in thefield of biology, for it is already apparent that the forms of all creatures from the microbe to man are determined by certain chemical compounds in extremely minute amount. This may put it in the power of the chemist to control the size and shape of plants or animals, to fix the number and location of their branches and leaves, or legs and eyes, to modify color or complexion, and to determine or alter sex. The factors of heredity and the origin of species, when you get down to bedrock, are chemical problems. But this is not all. The chemist will soon have power, not only to control the course of life in the future, but he will be able to reinterpret the past. We already hear endocrine explanations of the character and career of Napoleon and Roosevelt, and may look forward to a new school of historical writers, the chemical interpretation of history, based upon the composition of the blood of the leaders of thought and action in the past. But chemical analysis may extend much farther than man into the past. We already know something of the chemical causes of the development of organs and excrescences in animals, and we may in time be able t o tell the true story of “How the Camel Got His Hump” and how the dinosaur got his horns. The chemist of the future may be able to measure the p H concentration of the blood of prehistoric monsters of millions of years ago as he can now follow the gyrations of the electrons in stars billions of miles afar. Neither time nor space can curtail the scope of chemistry. Hitherto the chemist has confined himself to the humble task of providing the conveniences of life. In the future he may gain control of life itself. He may mold stature and character as the sculptor his clay. The world knows too well the evil influences on the race of certain chemicals such as alcohol, opium, and cocain, but some day the chemist will turn his attention to the preparation of compounds that will contribute to human welfare instead of woe and will stimulate virtues instead of vices. The way is open. We know now that what we value as individuality-the familiar features, the fascinating temperament, the charms of vivacity, wit and sympathy, all the peculiar qualities that attract or repel us in a personality-are due to definite hormones, some of which are already known as chemical compounds. The new theory of hormones reminds one of the old theory of humors which were supposed to regulate health and determine temperament. The hyperthyroid type corresponds closely to the choleric and the hypothyroid to the melancholic temperament. Diabetic patients taking insulin tell me the first effect of an overdose is a feeling of formless fear, a vague apprehension, a sense of futility and failure, a shiver of anxiety. Their courage can be a t once restored by sucking a lollipop. A variation of a few hundredths of one per cent in the glucose of the blood may make the difference between cowardice and courage, may determine whether a man shall be shot as a slacker or medaled as a hero. Courage is not a matter of “sand,” but of sugar. In the 4
J . Agr. Research, 28, 427 (19231.
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excitement of combat the secretion of adrenalin is stimulated and this causes more sugar to be released to the blood and so strengthens a man’s valor and endows him with greater strength. Sugar fed to plant lice will so sweeten their dispositions that they will grow wings, while the administration of alcohol has, as we should expect, the opposite effect, and prevents any approach to the angelic state. The effect of ethyl hydroxide on the cerebral functions, causing temporary anesthesia and inactivity, was discovered by Noah in the year 2349 B. C., shortly after the world had gone wet. Like a true scientist he experimented upon himself and the results were conspicuously successful and decisive. Nevertheless, many of his descendants have thought it desirable to repeat the Noachian reaction even to this day. “In vino veritas” is an old adage. The new version is “In scopolamine veritas.” But neither is to be relied upon. What alcohol or scopolamine does is to dislodge the censor and loosen the tongue. But whether the released and uncensored tongue tells what is true or merely what the speaker wishes were true nobody can know. The drug only pulls out the cork, what pours out depends on what the bottle contains, whether truths or falsities, sincerities or make-believes. But the loose-lipped individual reveals the truth about himself even when he utters lies. The chemist can so sensitize a man with an injection of hematoporphyrin that he will be light-struck and die if he ventures out of doors, even on a cloudy day, and yet would feel well so long as he remained in the house. According to Professor Child, of the University of Chicago, the way a body grows, how many eyes or legs or heads it has, depends upon the differential quantitative gradient in metabolism. The end of the embryo that lives most rapidly gets to the head. I don’t understand exactly what changing the physiological gradient is, but I imagine it is something like shifting to another gear in automobiling. Anyway it can often be accomplished by light, electricity, or minute amounts of certain chemicals. So the experimental physiologist has the power to produce mythological creatures such as famous fictionists of former times, Homer and Sir John Mandeville, have described-giants, dwarfs, the cyclops, and “they whose heads do grow beneath their shoulders.” A little magnesium chloride in the water will cause a fish to grow one eye in the middle of his forehead instead of two on the sides. One of the dreams of the alchemists, the transmutation of the elements, has recently been realized, and another is already in sight of fulfilment, the love philter that has frequently figured in romance and opera, such as “Midsummer Night’s Dream” and “Tristram and Isolde.” Hormones have been found by Allen and Doisy6that will make female animals assume the prerogatives of leap year, regardless of the calendar. A few injections of the magic fluid make baby rats take the initiative in courtship. This hormone is “probably common to all female animals.” According to Goldschmidt6 sex in birds and mammals depends upon a balance of opposing hormones both present in both sexes. “In the female the production of female hormones is more rapid than that of male hormones, the opposite is the case in the male.” Wilhelmine E. Key, of Battle Creek, says: Among the initiated it is no longer permitted t o speak of men and women, youths and maidens, but only of sexual majorities. Sex is nowadays defined in terms of internal secretions. The sissy and the tomboy are to be expressed quantitatively as a predominance of female or male characteristics. Sex differences thus become quantitative and conditions on the effect of two diverse chemical systems on the life cycle.’
It seems, then, that we must regard sex, with all it means throughout the range of animate nature, with all its influence on C A , , 17, 3,532 (1923). “Mechanism and Physiology of Sex Determination,” 1928. 7 “Endocrine Factors in H u m a n Development and Behavior,” Jouvnal of the M$chigan Schoolmasters Club, 1924. 6
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the development of art, literature, morals, and social life, as essentially a chemical affair, regulated, repressed, stimulated, or reversed by minute amounts of certain definite compounds in the blood or food. Experimentation is already active in this field and none can foretell how far it will lead. The experiments of Evans and Bishop in the University of California, of Sure in the University of Arkansas, and of Stone in Stanford University8 indicate that a specific vitamin in food is necessary for reproduction, in addition to those essential for growth and health. This, too, may involve a reinterpretation of history, for it may be that what has been called “race suicide” in a class or nation may be sometimes due to a change in diet to a new one, which, though quite as nutritious and more tasty, is deficient in vitamin X or E. That sex itself can be reversed at adult age by chemical means, at least as high up in the scale of life as birds, is proved by Dr. Crew, of Edinburgh, who observed the transformation of a hen into a cock, and by Dr. Oscar Riddle, of the Carnegie Station for Experimental Evolution, who reports the change of a female pigeon to P male. What this means for the future should be left for one who can speak with authority to say, so I quote Dr. Riddle’s own words. This demonstration of an actual occurrence of complete sex transformation in an adult animal is of course a n item of unusual interest to the general public. The scientific interest and importance of the demonstration can, however, scarcely be exaggerated, since the result clearly indicates that the hereditary basis of no bodily or mental characteristic may be considered as irrevocably fixed and uncontrollable. One of these characteristics known to be hereditary, and also known to be normally controlled through the so-called “chromosomes” of the germ cell, has been shown t o be capable of a reversal t o the alternative form. It therefore becomes wholly probable that all hereditary characteristics of every human being and of every organism are capable of reversal and modification; and that the accomplishment of such modification and control is a matter which merely awaits the definitely directed efforts of investigators in this branch of science. This striking statement may tend to relieve the minds of those who have become alarmed a t what has seemed to them the depressing doctrine of the inexorableness of heredity. It is apparent that we have i t in our power to modify the characteristics of plants and animals in two ways, biologically by eugenics, and chemically by such agencies as vitamins and hormones. It is evident tbat we are entering upon a new epoch in medicine, for when the physician injects into the blood a hormone, such as insulin thyroxin or adrenalin, he is not introducing a foreign compound, such as strychnine, quinine or arsenic, but merely restoring a natural compound unnaturally deficient. It is more like a food than a medicine. Several of the hormones and vitamins have now been isolated; some even have been synthesized. We may reasonably expect that in the course of time many, if not all, of them will be made in the laboratory. But the chemist does not stop with the imitation of nature. He produces metals, building materials, dyes, scents, and foods not found in nature, and having for human purposes certain superiorities over natural products. Why should not the chemist be able to create hormones and vitamins not found in nature but capable of producing greater or different effects? And why should not these effects be desirable as well as undesirable? Why should it not be possible by chemical means to improve the stature, looks, longevity, or capabilities of human beings? Two biologists have allowed their imagination to stray in this direction-H. G. Wells in “The Food o€the Gods,” and J. B. S. Haldane in “Daeda1us”-and their vision of the future is most amazing. But chemists are, as I say, more modest and conservative, and keep their imaginations tethered closely to their test tubes. They even feel offended if one suggests to 8
J . B i d . C h c n . , 58, 709 (1024).
Vol. 16, No. 5
them that they should raise their eyes occasionally from their work and take a long look out of the window into the future.
MATHEMATICAL AND METAPHYSICAL We see that chemistry plays an important part in the political and commercial world and in the physiological processes of our bodies. We may go farther and trace its influence on our most abstract mathematical and metaphysical conceptions. Our concept of space seems to be founded primarily upon the movement of our muscles. It requires more of an effort to reach a yard than to reach a foot. We get more tired in walking two miles than in walking one. Of course, it does not always require the same effort to cover a given distance with the arm or by the legs, but the relation is much more constant than the data given by the sense of sight, wiere objects change their shape and size quickly, as we or they move about, in a way that must be most perplexing to a baby. Even yet we may be deceived by our eyes and mistake a bush on the next hill for a tree on the horizon. Our sense for sound is still more unreliable. So we fall back for substantiation and verification of extent and distance on some sort of muscular exertion. We measure space by our feeling of fatigue. It is much the same with our sense of the lapse of time. Two hours’ work seems longer than one. Though time seems to go faster or slower, depending on whether our employment is enjoyable or ‘distasteful, yet we average it up in the long run, as we do our spatial estimates, and consider space and time objectively as constant. Now what is the cause of the feeling of fatigue on which we base our ideas of extension and duration? It is evidently dependent in some way upon the accumulation of the waste products of muscular exertion, such as lactic acid. “The fatigue maximum is associated with the lactic acid content in the m u s ~ l e . ” ~ “The rate at which lactic acid is produced almost certainly varies directly with the activity of the muscles.”10 A minute and a half of violent exercise has been found to increase the percentage of lactic acid in a sample of the blood, taken twelve minutes afterward nearly five times, not counting the much larger quantity that had been oxidized.“ A man weighing 150 pounds may by exercise produce 3.5 ounces of lactic acid. “The exhaustion following long continued moderate exercise is due to the diffusion of lactic acid out of the muscles where it is slowly oxidized and removed.”l2 Further support to my theory comes from recent studies in the chemistry of lactacidogen. Our only knowledge of space comes from our exploration of it by movements of limbs or body. A spherical and stationary amoeba cannot be considered as having any conception of spatial extent. When a little lactic acid accumulates on the surface of the amoeba the protoplasmic granules at that point absorb water by inhibition from other parts of the organism. This produces a pseudopodium, or extempore limb, with which the amoeba may reach out or propel itself along. When the lactic acid vanishes surface tension overcomes inhibition and the organism resumes its resting spherical form.18 According to this theory the origin of limbs and of movements comes from an accumulation of lactic acid. It seems to me that there is a chain of casual connection between lactic acid formation and our conceptions of space and time. If so, i t means that our metaphysics has a chemical foundation; that geometry is essentially a branch of chemistry; that astronomy likewise depends on chemistry; that Einstein’s theory of a four-dimensional time-space continuum has its origin in deficient oxygen; in short, we have a lactic acid theory of theruniverse. C . A , , 16, 2645 (1922); 17, 816 (1923). Brainbridge, “Physiology of Muscular Exercise.” 1’ C. A . , 17, 3532 (1923). 12 Zbid., 15, 2311 (1921). 18 Firth, Arch. Nberland. physiol., 7. 39 (1922); Physiot. Abslracf, April (1923). 0
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