Kant asserted that the processes of combination of surrounding cold materials would generate heat, and, therefore, that the resulting planetary masses would assume the liquid form; that Jupiter and Saturn are now in the liquid state; and that all the planets will ultimately become cold and solid. This is in fair agreement with present-day opinion as to the planets, save that modern astronomers go further in holding that the outer strata of Jupiter and Saturn, likewise of Uranus and Neptune, down to a great depth, must still be gaseous. In 1785, after the principle of heat liberation attending the compression of a gas had been announced, Kant supplemented his statement of 1755 as to the origin of the Sun's heat. He attributed this to gravitational action of the Sun upon its own matter, causing it to contract in size: he said the quantity of heat generated in a given time would be a function of the Sun's volumes at the beginning and at the ending of that period of time. This is substantially the principle which Helmholtz rediscovered and announced in 1854, and which is now universally accepted—with the reservation of the past ten years, that radioactive substances in the Sun may be an additional factor in the problem.

Kant's paper of 1754 enunciated the theory that the Moon always turns the same face to the Earth because of tidal retardation of the Moon's rotation by the Earth's gravitational attraction; and that our Earth tides produced by the Moon will slow down the Earth's rotation until the Earth will finally turn one hemisphere constantly to the Moon. This principle was in part reannounced by Laplace a half century later, and likewise investigated by Helmholtz in 1854, before Kant's work was recognized.

Kant's speculations on a possible destruction and re-birth of the solar system, on the nature of Saturn's ring, and on the nature of the zodiacal light are similar in several regards to present-day beliefs.

Kant wrote:

'I seek to evolve the present state of the universe from the simplest condition of nature by means of mechanical laws alone.'

In 1869 Sir William Thomson, afterwards Lord Kelvin, commented that Kant's

'attempt to account for the constitution and mechanical origin of the universe on Newtonian principles only wanted the knowledge of thermodynamics, which the subsequent experiments of Davy, Rumford and Joule supplied, to lead to thoroughly definite explanation of all that is known regarding the present actions and temperatures of the Earth and of the Sun and all other heavenly bodies.'

These are, apparently, the enthusiastic comments resulting from the re-discovery of Kant's papers. A present-day writer would not speak so decisively of them, but we must all bow in acknowledgment of Kant's remarkable contributions to our subject, published when he was but 31 years old.

LAPLACE'S HYPOTHESIS

In 1796, 41 years following Kant's principal contributions, Laplace published an extensive untechnical volume on general astronomy. At the end of the volume he appended seven short notes. The final note, to which he gave the curious title "Note VII and last," proposed a theory of the origin and evolution of the solar system which soon came to be known as Laplace's Nebular Hypothesis. There are several circumstances which indicate pretty clearly that Laplace was not deeply serious in proposing this hypothesis:

1. Its method of publication as the final short appendix to a large volume on general astronomy.

2. He himself said in his note that the hypothesis must be received "with the distrust with which everything should be regarded that is not the result of observation or calculation."

3. So far as we know he did not submit the theory to the test of well-known mathematical principles involved, although this was his habit in essentially every other branch of astronomy.

4. Laplace, in common with Kant, laid great stress upon the fact that the satellites all revolve around their planets from west to east, nearly in the common plane of the solar system; yet 6 or 7 years before Laplace's publication, Herschel had shown and published that the two recently discovered satellites of Uranus were revolving about Uranus in a plane making an angle of 98 degrees with the common plane of the solar system. While Laplace might not have known of Uranus's satellites in 1796, on account of existing political conditions, there is no evidence that he considered or took note of the fact when making minor changes in his published papers up to the time of his death in 1827. It is a further interesting comment on international scientific literature that Laplace died without learning that Kant had worked in the same field.

Laplace and his contemporary, Sir William Herschel, had been the most fruitful contributors to astronomical knowledge since the days of Sir Isaac Newton. Herschel's observations had led him to speculate as to the evolution of the stars from nebulae, and as a result interest in the subject was widespread. This fact, coupled with Laplace's commanding position, caused the nebular hypothesis to be received with great favor. During an entire century it was the central idea about which astronomical thought revolved.

Laplace conceived that the solar system has been evolved from a gaseous and hot nebula; that the nebulosity extended out farther than the known planets; and that the entire nebulous mass was endowed with a slow rotation that was UNIFORM IN ANGULAR RATE, as in the case of a rotating solid. This gaseous mass was in equilibrium under the expanding forces of heat and rotation and the contracting force of gravitation. Loss of heat by radiation permitted corresponding contraction in size, and increased speed of rotation. A time came, according to Laplace, when the nebula was rotating so rapidly that an outer ring of nebulosity was in equilibrium under centrifugal and gravitational forces and refused to be drawn closer in toward the center. This ring, ROTATING AS A SOLID, maintained its position, while the inner mass contracted farther. Later another ring was abandoned in the same manner; and so on, ring after ring, until only the central nucleus was left. Inasmuch as the nebulosity in the rings was not uniformly distributed, each ring broke into pieces, and the pieces of each ring, in the progress of time, condensed into a gaseous mass. The several large masses formed from the abandoned rings, respectively, became the planets and satellites of the solar system. These gaseous masses rotated faster and faster as their heat radiated into space, they abandoned rings of gaseous matter just as the original mass had done, and these secondary rings condensed to form the satellites; save that, in one case, the ring of gas nearest to Saturn for some reason formed a solid (!) ring about that planet, instead of condensing into one or more satellites. Thus, in outline, according to Laplace, the solar system was formed.

The first half of the nineteenth century found the nebular hypothesis accepted almost without question, but a tearing-down process began in the second half of the century, and at present not much of the original structure remains standing. This is due in small part to discoveries since Laplace's time, but chiefly to a more careful consideration of the fundamental principles involved. We have space to present only a few of the more salient objections.

1. If the materials of the solar system existed as a gas, uniformly distributed throughout what we may call the volume of the system, the density of the gas would be exceedingly low: at the most, several hundred million times less dense than the air we breath. Conditions of equilibrium in so rare a medium would require that the abandonment of the outer parts by the contracting and more rapidly rotating inner mass should be a continuous process. Each abandoned element would be abandoned individually; it would not be vitally affected by the elements slightly farther out in the structure, nor by the elements slightly nearer to the center. Successive abandonment of nine gaseous rings of matter, EACH RING ROTATING AS IF IT WERE A SOLID STRUCTURE, is unthinkable. The real product of the cooling process in such a nebula would undoubtedly be something in the nature of a spiral nebula, in which the matter would revolve around the nucleus the more rapidly the nearer it was to the nucleus. If the matter were originally distributed uniformly throughout the rotating structure, the spiral lines might not be visible. If it were distributed irregularly, the spiral form here and there could scarcely fail to be in evidence to a distant observer.

2. Laplace held that the condensation of each ring would result in one planet, rotating on its axis from west to east; this apparently by virtue of the fact that in a ring rotating AS A SOLID the outer edge travels more rapidly than the inner edge does, and therefore, the west to east direction of rotation must prevail in the planetary product. If now, as we firmly believe, each constituent of such an attenuated ring must rotate substantially independently of other constituents, those nearer the inner edge of the ring will possess the higher speeds of rotation, and the preponderance of kinetic energy in the inner parts of the ring should give the resulting planetary condensation a retrograde direction of rotation.

3. According to Laplace the satellites should all revolve around their primaries from west to east. Eight of the satellites do not follow this rule.

4. If the materials composing the inner ring of Saturn were abandoned by the parent planet, as this planet contracted in size and rotated ever more and more rapidly, then the ring should revolve about the planet in a period considerably longer than the planet period. The reverse is the fact. The rotation period of the equatorial region of the planet itself is 10 h. 14 m., whereas the inner edge of the ring system revolves about the planet once in about five hours.

5. The inner satellite of Mars revolves once in 7 h. 39 m., whereas Mars requires 24 h. 37 m. for one rotation. According to the Nebular Hypothesis, the period of the satellite should be the longer.

6. Laplace's hypothesis would seem to require that the orbits of the planets be circular or very nearly so. The orbits of all except Venus and Neptune are quite eccentric, and Mercury's orbit, which should have the nearest approach to circularity, is by far the most eccentric.

7. If the planetary rings were abandoned by centrifugal action, we should expect the Sun to be rotating in the principal plane of the planet system. The major planets, from Venus out to Neptune, are revolving in nearly a common plane. The Sun, containing 99 6/7 per cent. of all the material in the system, has its equator inclined 7 degrees to the planet plane. This discrepancy is a very serious and I think fatal objection to Laplace's hypothesis, as Chamberlin has emphasized.

8. Laplace assumed a nebula whose form was a function of its rotational speed, its gravitation, its internal heat, and, although he does not so state, of its internal friction. He did not distribute the matter within the nebula to conform in any way to the distribution as we observe it to-day, but he let the entire structure contract, following the loss of heat, until the maintenance of equilibrium required the successive abandoning of seven or eight rings. He mentions a central condensation, but gives no further particulars. Thirty years ago Fouche established clearly that the condensing of Laplace's assumed nebula into the present solar system would involve the violent breaking of the law known as the conservation of moment of momentum. Fouche proved that a distribution of matter beyond any conception of the subject by Laplace must be assumed. Fully 96 per cent. must be condensed in the central nucleus AT THE OUTSET, and not more than 4 per cent. of the total mass must lie outside of the nucleus and be widely distributed throughout the volume of the solar system. Chamberlin puts the case very strongly in another way. If the planet Mercury was abandoned as a ring of nebulosity, the equatorial velocity of the remaining central mass must at that time have been in the neighborhood of 45 km. per second, as this is the orbital speed of Mercury. If the central mass condensed to the present size of the Sun, the Sun's equatorial velocity of rotation should now be fully 400 km. per second, in accordance with the requirement of the rigid law of constancy of moment of momentum. The Sun's actual equatorial velocity is only 2 km. per second!

In several other respects the hypothesis of Laplace, as he proposed it, fails to account for the facts as they are observed to exist.

Poincare devoted his unique talents to the evolution problem shortly before his death. He recognized that the Laplace hypothesis is not tenable except upon such an assumed distribution of matter as was defined by Fouche. Accepting this modification, and extending the hypothesis to involve the application of tidal interactions at many points throughout the solar system, Poincare expresses the opinion that the Laplacian hypothesis, of all those proposed, is still the one which best accounts for the facts.[3] However, he does not utilize the hypothesis of rings rotating as solids, for he finds it necessary to conclude that the planetary masses in the beginning must have had retrograde rotations. In the large planetary masses of Jupiter and Saturn, for example, the materials which form the outer retrograde satellites were abandoned while the rotations were still retrograde, and when the diameters of the planetary masses were several scores of times their present diameters. In these extended masses the Sun would create tidal waves, and here, as always, such waves would exert a retarding effect upon the rotations. A time would come, Poincare thought, when these planets would rotate once in a revolution; that is, present the same face to the Sun; and this is in fact a west to east rotation. Further contraction of the planetary masses would give rise to increasing rotational speeds in the west to east direction. The materials which form the inner satellites of Jupiter and Saturn were abandoned successively after the west to east direction of rotation had become established. According to modifications of the same theory, tidal retardation has slowed down Saturn's speed since the abandonment of the materials which later condensed to form the inner ring of that planet; or, possibly, the ring materials encountered resistance after the planet abandoned them, with the consequence that the ring drew in toward the planet and increased its speed; and similarly in the case of Mars and its inner satellite.

[3] Poincare has made the following interesting comments on Laplace's hypothesis: "The oldest hypothesis is that of Laplace; but its old age is vigorous and for its age it has not too many wrinkles. In spite of the objections which have been urged against it, in spite of the discoveries which astronomers have made and which would indeed astonish Laplace himself, it is always standing the strain, and it is the hypothesis which best explains the facts; it is the hypothesis which responds best to the question which Laplace endeavored to answer, Why does order rule throughout the solar system, provided this order is not due to chance? From time to time a breach opened in the old edifice (the Laplace hypothesis); but the breach was promptly repaired and the edifice has not fallen."



To me this modification of the Laplacian hypothesis is unsatisfactory, for several reasons. To mention only one: if Jupiter was a large gaseous mass extending out as far as the 8th and 9th satellites, the gaseous body was very highly attenuated; friction in the outer strata would be essentially a negligible quantity, and tidal retardation would not be very effective; and it would be under just these conditions that loss of heat from the planet should be most rapid and the rate of increase of retrograde rotation resulting therefrom be comparatively high. It would seem that the rotation of the planet in the retrograde direction must have accelerated under the contractional cause, rather than have decreased and reversed in direction under an excessively feeble tidal cause.

The recognized weaknesses of Laplace's hypothesis have caused many other hypotheses to be proposed in the past half century. The hypotheses of Faye, Lockyer, du Ligondes, See, Arrhenius, and Chamberlin and Moulton include many of the features of Kant's or Laplace's hypotheses, but all of them advance and develop other ideas. It is unfortunate that space limits do not permit us to discuss the new features of each hypothesis.

(To be continued.)



PROGRESS AND PEACE

BY PROFESSOR ROBERT M. YERKES

HARVARD UNIVERSITY

LASTING peace among the nations of the earth we must regard as of supreme moment, the discovery of the conditions thereof, as most worthy of human effort. Physical struggle is no longer accepted as either a necessary or a desirable means of settling differences between individuals. Why, then, should it be tolerated to-day in connection with national disagreements? To admit the impossibility or the impracticability of universal peace is to stigmatize our vaunted civilization as a failure. Surely we will not, can not, humble ourselves by such an admission until we have exhausted our energies in searching for the conditions of national amity.

With my whole life I believe in the possibility and value of worldwide friendliness and cooperation. I am writing to discuss not the attainability or the merits of peace, but ways of achieving it; not to criticize present activities on its behalf, but to indicate the promise of a neglected approach and to present a program which should, I believe, find its place in the great "peace movement."

Must peace be achieved and maintained by brute strength, regardless of sense and sentiment, or may it be gained through intelligence, humanely used? Must the pathway thereto be paved with human skulls, builded with infinite suffering and sacrifice, or may it he charted by scientific inquiry and builded by the joyous labor of mutual service and helpfulness? Is it possible, in the light of the history of the races of man, to doubt that we must place our dependence on intelligence sympathetically employed, not on physical prowess? To me it seems that peace must be achieved peacefully, not by the clash of arms and bloodshed.

But even if we grant that science is our main hope, there remains a choice of methods. On the one hand, there is the way of material progress, physical discovery and feverish haste to apply every new fact to armament; on the other, that of biological research, social enlightenment, and ever-increasing human understanding and sympathy.

Firm believers in each of these possible approaches, through science, to international peace, are at hand. The one group argues that nations, like individuals, must be controlled in all supreme crises by fear; the other contends that civilization has developed in enlightened human sympathy a higher, a more worthy, and a safer control of behavior.

As a biologist and a believer in the brotherhood of man, I wish to present the merits of sympathy, as contrasted with fear, and to plead for larger attention to the biological approach to the control of international relations. For I am convinced that the greatest lesson of the present stupendous world-conflict is the need of thorough knowledge of the laws of individual and social human behavior. Surely this war clearly indicates that the study of instinct, and the use of our knowledge for the control of human relations, is incalculably more important for the welfare of mankind than is the discovery of new and ever more powerful explosives or the building of increasingly terrible engines of destruction.

During the last half-century the physical sciences, technologies, arts and industries, have made marvelous advances. At enormous cost of labor and material resources there have been discovered and perfected means of destroying life and property at once so effective and so terrible to contemplate that preparedness for war seemed a safe guarantee of peace. But who is there now to insist, against the evidence of blood-drenched Europe, that material progress, physical discovery, and armament based thereupon, assure international friendship?

Only if one of the nations should discover, and guard as its secret, some diabolically horrible means of destroying human life and property by wholesale and over materially unbridged distances, can armaments even temporarily put an end to war. In such event—and it is by no means an improbability—the whole world might suddenly be made to bow in terror before the will of the all-powerful nation. Before this approaching crisis, can we do less than earnestly pray that the translation of physical progress into armament may be halted until the brotherhood of man has been further advanced? Dare we stop to contemplate what would happen to-morrow if Germany, with half the civilized world arrayed against her, should come into possession of some imponderable, and to the untutored mind mysterious, means of directing her torpedoes, exploding magazines, mines, shells from distant bases? Undoubtedly we are close upon the employment of certain vibrations for this deadly purpose. Shall we veer in time and take a safer course, or are we doomed to the inevitable?

For the certain result of pushing forward relentlessly on the path of preparation for war—in the name of peace—is the dominance of a single nation and the destruction or subjugation of all others. This is as inevitable as is death. If we would preserve and foster racial and national diversity of traits, promote social individuality as we so eagerly foster the diversity of selves, we must speedily focus attention upon human nature and seek that knowledge of it which shall enable us to control it wisely rather than to destroy it ruthlessly.

Even were I able to do so, I should in no degree belittle the achievements of the physical sciences and their technologies, for I believe whole-heartedly in their value, and long for the steady increase of our power to control our environment. But when these achievements are offered as means of creating or maintaining certain desired conditions of individual and social life, I must insist that other knowledge is essential—nay, more essential—than that of the physicist or chemist. Knowledge, namely, of life itself.

Most briefly, the situation may thus be described. In peace and in war there are two large, complex and intricate groups of facts to be dealt with by those who seek the welfare of man. The one group comprises the phenomena of physical nature as the condition of life—environment; the other is constituted by the phenomena of life and the relations of lives. Those who sincerely believe in preparedness for war as a preventive measure, misconceive and attempt to misuse the emotion of fear and its modes of expression. It is as though we should strive tirelessly to develop machinery and methods for educating our children, the while ignorant of the laws of child development and branding as of no practical importance the fundamentals of human nature.

To nations no more than to individuals is it given to live by fear alone. By it a nation may become dominant, and diversity of body, mind, and ideals be eradicated. To base our civilization upon fear entails uniformity, monotony of life; the sacrifice of peoples for the unduly exalted traits and national ideals of a single homogeneous social group—a single all-powerful nation. Knowledge of life, and the sympathy for one's fellow men which springs from it, must control the world if nations are to live in peaceful and mutually helpful relations. If life, whether of the individual or of the social group, is to be controlled, it must be through intimate knowledge of life, not through knowledge of something else. The world must be ruled by sympathy, based upon understanding, insight, appreciation. This is my prophecy, this my faith and my present thesis.

Material as contrasted with purely intellectual or spiritual progress is the pride of our time. We worship technology as reared upon physics and chemistry. But what is our gain, in this progress, so long as we continue to use one another as targets? Would it not be wiser, more far-sighted, more humane, more favorable to the development of universal peace and brotherhood, to give a large share of our time and substance to the search for the secrets of life? As compared with the physical sciences, the biological departments of inquiry are, in general, backward and ill-supported. Why? Because their tremendous importance is not generally recognized, and, still more, because the control of inanimate nature as promised by physical discovery and its applications appeals irresistibly both to our imagination and to our greed. We long for peace—because we are afraid of war—we long for the perfecting of individual and social life, but much more intensely and effectively we long for wealth, power and pleasure.

What I have already said and now repeat in other words is that if we really desired above anything attainable on earth the lasting peace of nations, we should diligently foster and tirelessly pursue the sciences of life and seek to perfect and exalt the varied arts and technologies which should be based upon them. Experimental zoology and genetics; physiology and hygiene; genetic psychology and education; anthropology and ethnology; sociology and economics, would be held in as high esteem and as ardently furthered as are the various physical sciences and their technologies.

Does it not seem reasonable to claim that human behavior may be intelligently controlled or directed only in the light of intimate and exhaustive knowledge of the organism, its processes, and its relations to its environment? If this be true, how pitiably, how shamefully, inadequate is our knowledge even of ourselves! How few are those who have a sound, although meager, knowledge of the laws of heredity, of the primary facts of human physiology, of the principles of hygiene, of the chief facts and laws of mental life, including the fundamental emotions and their corresponding instinctive modes of action, the modifiability or educability of the individual and the important relations of varied sorts of experience and conduct, the laws of habit, the nature and role of the sentiments, the unnumbered varieties of memory and ideation, the chief facts of social life and their relations to individual experience and behavior. Not one person in a thousand has a knowledge of life and its conditions equal in adequacy for practical demands to his knowledge of those aspects of physical nature with which he is concerned in earning a livelihood. Even those of us who have dedicated our lives to the study of life are humble before our ignorance. But with a faith which can not be shaken, because we have seen visions and dreamed dreams, we insist that the knowledge which we seek and daily find is absolutely essential for the perfecting of educational methods; for the development of effective systems of bodily and mental hygiene; for the discovery, fostering and maintenance of increasingly profitable social relations and organizations. In a word, we believe that biology, of all sciences, can and must lead us in the path of social as contrasted with merely material progress; can and ultimately will so alter the relations of nations that war shall be as impossible as is peace to-day.

Fortunately the biologist may depend, in his efforts to further the study of all aspects of life, not upon faith and hope alone, but also upon works, for already physiology and psychology have transformed our educational practices; and the medical sciences given us a great and steadily increasing measure of control over disease.

At least two men, as different in intellectual equipment, habits of mind, and methods of inquiry as well could be, the one an American, the other an Englishman, have heralded the broadly comparative and genetic study of mind and behavior—let us call it Genetic Psychology—as the promise of a new era for civilization, because the essential condition of the intelligent and effective regulation of life.

The one of these prophets among biologists, President G. Stanley Hall, has lived to see his faith in the practical importance of the intensive study of childhood and adolescence justified by radical reforms in school and home. Hall should be revered by all lovers of youth as the apostle to adolescents. The other, Professor William McDougall, has done much to convince the thinking world that all of the social sciences and technologies must be grounded upon an adequate genetic psychology—a genetic psychology which shall take as full and intelligent account of behavior as of experience; of the life of the ant, monkey, ape as of that of man; of the savage as of civilized man; of the infant, child, adolescent as of the adult; of the moron, imbecile, idiot, insane, as of the normal individual; of social groups as of isolated selves. It is to McDougall we owe a most effective sketch—in his introduction to Social Psychology of the primary human emotions in their relations to instinctive modes of behavior.

Hall, McDougall and such sociologists—lamentably few, I fear—as Graham Wallas would agree that for the attainment of peace we must depend upon some primary human instinct. I venture the prediction that no one of them would select fear as the safe basis. Instead, they surely would unite upon sympathy.

Among animals preparedness for struggles is a conspicuous cause of strife. The monkey who stalks about among his fellows with muscles tense, tail erect, teeth bared, bespeaking expectancy of and longing for a fight, usually provokes it. We may not safely argue that lower animals prove the value of preparedness for war as a preventive measure! Among them, as among human groups, the only justification of militarism is protection and aggression. Preparedness for strife is provocative rather than preventive thereof.

As individual differences, and resulting struggles, are due to ignorance, misunderstanding, lack of the basis for intelligent appreciation of ideals, motives and sympathy, so among nations knowledge of bodily and mental traits, of aims, aspirations, and national ideals fosters the feeling of kinship and favors the instinctive attitude of sympathetic cooperation.

Every student of living things knows that to understand the structure, habits, instincts, of any creature is to feel for and with it. Even the lowliest type of organism acquires dignity and worth when one becomes familiar with its life. Children in their ignorance and lack of understanding are incredibly cruel. So, likewise, are nations. The treatment of inferior by superior races throughout the ages has been childishly cruel, unjust, stupid, inimical to the best interests not only of the victims, but also of mankind. This has been so, not so much by reason of bad intentions, although selfishness has been at the root of immeasurable injustice, but primarily because of the utter lack of understanding and sympathy. To see a savage is to despise or fear him, to know him intimately is to love him. The same law holds of social groups, be they families, tribes, nations or races. They can cooperate on terms of friendly helpfulness just in the measure in which they know one another's physical, mental and social traits and appreciate their values, for in precisely this measure are they capable of understanding and sympathizing with one another's ideals.

Selfishness, the essential condition of individualism and nationalism, must be supplanted by the sympathy of an all inclusive social consciousness and conscience if lasting peace is to be attained.

To further the end of this transformation of man we should become familiar with the inborn springs to action, those fundamental tendencies which we call instincts, for we live more largely than is generally supposed by instinct and less by reason. All of the organic cravings, hungers, needs, should be thoroughly understood so that they may be effectively used. And, finally, the laws of intellect must be at our command if we are to meet the endlessly varying and puzzling situations of life profitably and with the measure of adequacy our reason would seem to justify.

Clearly, then, the least, and the most, we can do in the interest of peace is to provide for the study of life, but especially for the shamefully neglected or imperfectly described phenomena of behavior and mind, in the measure which our national wealth, our intelligence and our technical skill make possible. For one thing, it is open to us to establish institutes for the thorough study of every aspect of behavior and mind in relation to structure and environment, comparable with such institutions for social progress as the Rockefeller Institute for Medical Research. The primary function of such centers for the solution of vital problems should be the comparative study, from the genetic, developmental, historical, point of view of every aspect of the functional life of living things, to the end that human life may be better understood and more successfully controlled. Facts of heredity, of behavior, of mind, of social relations, should alike be gathered and related, and thus by the observation of the most varied types, developmental stages, and conditions of living creatures there should be developed a science of behavior and consciousness which should ultimately constitute a safe basis for the social sciences, for all forms of social endeavor, and for universal and permanent peace.

I submit that such centers of research as the psycho-biological institute I have so imperfectly described are sorely needed. For it is obvious that the future of our species depends in large measure upon how we develop the biological sciences and what use we make of our knowledge. I further submit, and therewith I rest my case, that familiarity with living things breeds sympathy not contempt, and that sympathy in turn conditions justice.

May it be granted us to work intelligently, effectively, tirelessly for world-wide peace and service. not by the suppression of racial and national diversities, the leveling of the mass to a deadly sameness, but through steadily increasing appreciation of racial and national traits. May the world, even sooner than we dare to hope, be ruled by sympathy instead of by fear.



THE PROGRESS OF SCIENCE

THE MISSOURI AND THE NEW YORK BOTANICAL GARDENS

THE Missouri Botanical Garden has recently celebrated the twenty-fifth anniversary of its foundation and the New York Botanical Garden its twentieth anniversary. Within these short periods these gardens have taken rank among the leading scientific institutions of the world. Botanical gardens were among the first institutions to be established for scientific research; indeed Parkinson, the "botanist royal" of England, on the title page of his book of 1629, which we here reproduce, depicts the Garden of Eden as the first botanical garden and one which apparently engaged in scientific expeditions, for it includes plants which must have been collected in America. However this may be, publicly supported gardens for the cultivation of plants of economic and esthetic value existed in Egypt, Assyria, China and Mexico and beginning in the medieval period had a large development in Europe there being at the beginning of the seventeenth century botanical gardens devoted to research in Bologna, Montpellier, Leyden, Paris, Upsala and elsewhere. An interesting survey of the history of botanical gardens is given in a paper by Dr. A W. Hill assistant director of the Kew Gardens, prepared for the celebration of the Missouri Garden, from which we have taken the illustration from Parkinson and the pictures of Padua and Kew.

The papers presented at the celebration have been published in a handsome volume. It includes addresses by a number of distinguished botanists, though owing to the war several of the foreign botanists were unable to be present. Dr. George T. Moore, director of the garden, made in his address of welcome a brief statement in regard to its origin in the private garden and by the later endowment of Mr. Henry Shaw. Mr. Shaw came to this country from England in 1818, and with a small stock of hardware began business in one room which also served as bedroom and kitchen. Within twenty years he had acquired a fortune and retired from active business to devote the remaining forty-nine years of his life to travel and to the management of a garden surrounding his country-home on the outskirts of St. Louis. In 1859 he erected a small museum and library, and in 1866 Mr. James Gurney was brought to this country as head gardener. Mr. Shaw died in 1889, leaving his estate largely for the establishment of the Missouri Botanical Garden, but providing also for the Henry Shaw School of Botany of Washington University and a park for the city. With this liberal endowment constantly increasing as the real estate becomes more productive, Dr. William Trelease, the first director, and Dr. George T. Moore, the present director, have conducted an institution not only of value to the city of St. Louis but largely contributing to the advance of botanical science.

The New York Botanical Garden, largely through the efforts of Dr. N. L. Britton, the present director was authorized by the New York legislature in 1891. The act of incorporation provided that when the corporation created should have secured by subscription a sum not less than $250,000 the city was authorized to set aside for the garden as much as 250 acres from one of the public parks and to expend one half million dollars for the construction and equipment of the necessary buildings. The conditions were met in 1895, and the institution has since grown in its land, and its buildings, in its collections and in its herbaria, so that, in association with the department of botany of Columbia University, it now rivals in its material equipment and in the research work accomplished any botanical institution in the world.



THE SECOND PAN-AMERICAN SCIENTIFIC CONGRESS

THERE will be held at Washington from Monday, December 27, to Saturday, January 9, the second Pan-American Scientific Congress, authorized by the first congress held in Santiago, Chili, six years previously. This was one of the series of congresses previously conducted by the republics of Latin America. The Washington congress, which is under the auspices of the government of the United States, with Mr. William Phillips, third assistant secretary of state, as chairman of the executive committee, will meet in nine sections, which, with the chairmen, are as follows:

I. Anthropology, Wm. H. Holmes.

II. Astronomy, Meteorology, and Seismology, Robert S. Woodward.

III. Conservation of Natural Resources, Agriculture, Irrigation and Forestry, George M. Rommel.

IV. Education, P. P. Claxton.

V. Engineering, W. H. Bixby.

VI. International Law, Public Law, and Jurisprudence, James Brown Scott.

VII. Mining and Metallurgy, Economic Geology, and Applied Chemistry, Hennen Jennings.

VIII. Public Health and Medical Science, Wm. C. Gorgas.

IX. Transportation, Commerce, Finance, and Taxation, L. S. Rowe.

Each section is divided further into subsections, of which there are forty-five, each with a special committee and program. Several of the leading national associations of the United States, concerned with the investigation of subjects of pertinent interest to some of the sections of the congress, have received and accepted invitations from the executive committee of congress to meet in Washington at the same time and hold one or more joint sessions with a section or subsection of corresponding interest. Thus the nineteenth International Congress of Americanists will meet in Washington during the same week with the Pan-American Scientific Congress, and joint conferences will be held for the discussion of subjects of common interest to members of the two organizations

As an example of the wide scope of the congress we may quote the ten subsections into which the section of education is divided. Each of these subsections is under a committee of men distinguished in educational work and men of eminence have been invited to take part in the proceedings. The subjects proposed for discussion by each of these sections are:

Elementary Education: To what extent should elementary education be supported by local taxation, and to what extent by state taxation? What should be the determining factors in the distribution of support? Secondary Education: What should be the primary and what the secondary purpose of high school education? To what extent should courses of study in the high school be determined by the requirements for admission to college, and to what extent by the demands of industrial and civic life? University Education: Should universities and colleges supported by public funds be controlled by independent and autonomous powers, or should they be controlled directly by central state authority? Education of Women: To what extent is coeducation desirable in elementary schools, high schools, colleges and universities? Exchange of Professors and Students between Countries: To what extent is an exchange of students and professors between American republics desirable? What is the most effective basis for a system of exchange? What plans should be adopted in order to secure mutual recognition of technical and professional degrees by American Republics? Engineering Education: To what extent may college courses in engineering be profitably supplemented by practical work in the shop? To what extent may laboratory work in engineering be replaced through cooperation with industrial plants? Medical Education: What preparation should be required for admission to medical schools? What should he the minimum requirements for graduation? What portion of the faculty of a medical school should be required to give all their time to teaching and investigation? What instruction may best be given by physicians engaged in medical practice? Agricultural Education: What preparation should be required for admission to state and national colleges of agriculture? To what extent should the courses of study in the agricultural college be theoretical and general, and to what extent practical and specific? To what extent should the curriculum of any such college be determined by local conditions? Industrial Education: What should be the place of industrial education in the school system of the American republics? Should it be supported by public taxation? Should it be considered as a function of the public school system? Should it be given in a separate system under separate control? How and to what extent may industrial schools cooperate with employers of labor, Commercial Education: How can a nation prepare in the most effective manner its young men for a business career that is to be pursued at home or in a foreign country.



SCIENTIFIC ITEMS

WE record with regret the death at the age of ninety-two of Henri Fabre, the distinguished French entomologist and author; of William Henry Hoar Hudson, late professor of mathematics at King's College, London; of Dr. Ugo Schiff, professor of chemistry at Florence; of Susanna Phelps Gage, known for her work on comparative anatomy; of Charles Frederick Holder, the California naturalist, and of Dr. Austin Flint, a distinguished physician and alienist of New York City.

DR. RAY LYMAN WILBUR, professor of medicine, has been elected president of Leland Stanford Junior University. He will on January 1 succeed Dr John Caspar Branner, who undertook to accept the presidency for a limited period on the retirement of Dr. David Starr Jordan, now chancellor of the university. Dr. Wilbur graduated from the academic department of Stanford University in 1896.

AT the Manchester meeting of the British Association for the Advancement of Science, Sir Arthur J. Evans, F.R S., the archeologist, honorary keeper of the Ashmolean Museum, Oxford, was elected president for next year's meeting, to be held at Newcastle-on-Tyne. The meeting of 1917 will be held at Bournemouth.

DR. MAX PLANCK, professor of physics at Berlin, and Professor Hugo von Seeliger, director of the Munich Observatory, have been made knights of the Prussian order pour le merite. Dr. Ramon y Cajal, professor of histology at Madrid, and Dr. C. J. Kapteyn, professor of astronomy at Groningen, have been appointed foreign knights of this order.

MR. JACOB H. SCHIFF, a member of the board of trustees of Barnard College and its first treasurer, has given $500,000 to the college for a woman's building. It will include a library and additional lecture halls as well as a gymnasium, a lunch room and rooms for students' organizations.

BY the will of the late Dr. Dudley P. Allen, formerly professor of surgery in the Western Reserve University, $200,000 has been set aside as a permanent endowment fund for the Cleveland Medical Library.



THE SCIENTIFIC MONTHLY

DECEMBER, 1915

THE INSIDE HISTORY OF A GREAT MEDICAL DISCOVERY

BY ARISTIDES AGRAMONTE, M.D., Sc.D. (HON.)

UNIVERSITY OF HAVANA.

THE construction of the Panama Canal was made possible because it was shown that yellow fever, like malaria, could be spread only by the bites of infected mosquitoes.

The same discovery, which has been repeatedly referred to as the greatest medical achievement of the twentieth century, was the means of stamping out the dreaded scourge in Cuba, as well as in New Orleans, Rio de Janeiro, Vera Cruz, Colon, Panama and other Cities in America.

This article is intended to narrate the motives that led up to the investigation and also the manner in which the work was planned, executed and terminated. No names are withheld and the date of every important event is given, so that an interested reader may be enabled to follow closely upon the order of things as they occurred and thus form a correct idea of the importance of the undertaking, the risk entailed in its accomplishment and how evenly divided was the work among those who, in the faithful performance of their military duties, contributed so much for the benefit of mankind; the magnitude of their achievement is of such proportions, that it loses nothing of its greatness when we tear away the halo of apparent heroism that well-meaning but ignorant historians have thrown about some of the investigators.

The whole series of events, tragic, pathetic, comical and otherwise, took place upon a stage made particularly fit by nature and the surrounding circumstances.

Columbia Barracks, a military reservation, garrisoned by some fourteen hundred troops, distant about eight miles from the city of Havana, the latter, suffering at the time from an epidemic of yellow fever, which the application of all sanitary measures had failed to check or ameliorate and finally, our experimental camp (Camp Lazear), a few army tents, securely hidden from the road leading to Marianao, and safeguarded against intercourse with the outside world; the whole setting portentously silent and gloriously bright in the glow of tropical sunlight and the green of luxuriant vegetation.

Two members of a detachment of four medical officers of the United States Army, on the morning of August 31, 1900, were busily examining under microscopes several glass slides containing blood from a fellow officer who, since the day before, had shown symptoms of yellow fever; these men were Drs. Jesse W. Lazear and myself; our sick colleague was Dr. James Carroll, who presumably had been infected by one of our "experiment mosquitoes."

It is very difficult to describe the feelings which assailed us at that moment; a sense of exultation at our apparent success no doubt animated us; regret, because the results had evidently brought a dangerous illness upon our coworker and with it all associated a thrill of uncertainty for the reason of the yet insufficient testimony tending to prove the far-reaching truth which we then hardly dared to realize.

As the idea that Carroll's fever must have been caused by the mosquito that was applied to him four days before became fixed upon our minds, we decided to test it upon the first non-immune person who should offer himself to be bitten; this was of common occurrence and taken much as a joke among the soldiers about the military hospital. Barely fifteen minutes may have elapsed since we had come to this decision when, as Lazear stood at the door of the laboratory trying to "coax" a mosquito to pass from one test-tube into another, a soldier came walking by towards the hospital buildings; he saluted, as it is customary in the army upon meeting an officer, but, as Lazear had both hands engaged, he answered with a rather pleasant "Good morning." The man stopped upon coming abreast, curious no doubt to see the performance with the tubes, and after gazing for a minute or two at the insects he said: "You still fooling with mosquitoes, Doctor?" "Yes," returned Lazear, "will you take a bite?" "Sure I ain't scared of 'em," responded the man. When I heard this, I left the microscope and stepped to the door, where the short conversation had taken place; Lazear looked at me as though in consultation; I nodded assent, then turned to the soldier and asked him to come inside and bare his forearm. Upon a slip of paper I wrote his name while several mosquitoes took their fill; William E. Dean, American by birth, belonging to Troop B, Seventh Cavalry; he said that he had never been in the tropics before and had not left the military reservation for nearly two months. The conditions for a test case were quite ideal.

I must say we were in great trepidation at the time; and well might we have been, for Dean's was the first indubitable case of yellow fever about to be produced experimentally by the bite of purposely infected mosquitoes. Five days afterwards, when he came down with yellow fever and the diagnosis of his case was corroborated by Dr. Roger P. Ames, U. S. Army, then on duty at the hospital, we sent a cablegram to Major Walter Reed, chairman of the board, who a month before had been called to Washington upon another duty, apprising him of the fact that the theory of the transmission of yellow fever by mosquitoes, which at first was doubted so much and the transcendental importance of which we could then barely appreciate, had indeed been confirmed.

STATE OF THINGS BEFORE THE DISCOVERY OF MOSQUITO TRANSMISSION

Other infectious diseases, tuberculosis, for instance, may cause a greater death-rate and bring about more misery and distress, even to-day, than yellow fever has produced at any one time; but no disease, except possibly cholera or the plague, is so tragic in its development, so appalling in its action, so devastating in its results, nor does any other make greater havoc than yellow fever when it invades non-immune or susceptible communities.

For two centuries, at least, the disease has been known to exist endemically, that is, more or less continuously, in most of the Mexican Gulf ports, extending its ravages along the West India Islands and the cities of the Central and the South American coast.

In the United States it has made its appearance in epidemic form as far north as Portsmouth, N. H. At Philadelphia in 1793, more than ten per cent. of the entire population died of yellow fever. Other cities, like Charleston, S. C., suffered more than twenty epidemics in as many summers, during the eighteenth century. In the city of New Orleans, the epidemic which developed in the summer of 1853 caused more than 7,000 deaths. Later, in 1878, yellow fever invaded 132 towns in the United States, producing a loss of 15,932 lives out of a total number of cases which reached to more than 74,000: New Orleans alone suffered a mortality of 4,600 at that time. Recently (1905), this city withstood what is to be hoped shall prove its last invasion, which, thanks to the modern methods employed in its suppression, based upon the new mosquito doctrine, only destroyed about 3,000 lives.

It is by contemplating this awful record, and much more there is which for the sake of brevity I leave unstated, that one realizes the boon to mankind which the successful researches of the Army Board have proved. The work of prevention, the only one that may be considered effective when dealing with the epidemic diseases, was entirely misguided with regard to yellow fever until 1901: the sick were surrounded by precautions which were believed most useful in other infectious diseases, the attendants were often looked upon as pestilential, and so treated, in spite of the fact that evidence from the early history of the disease clearly pointed to the apparent harmlessness even of the patients themselves. All this notwithstanding, cases continued to develop, in the face of shotgun quarantine even, until the last non-immune inhabitant of the locality had been either cured or buried.

The mystery which accompanied the usual course of an epidemic, the poison creeping from house to house, along one side of a street, seldom, crossing the road, spreading sometimes around the whole block of houses before appearing in another neighborhood, unless distinctly carried there by a visitor to the infected zone who himself became stricken, all this series of peculiar circumstances was a never-ending source of discussion and investigation.

In the year 1900, Surgeon H. R. Carter, of the then Marine Hospital Service, published a very interesting paper calling attention to the interval of time which regularly occurred between the first case of yellow fever in a given community and those that subsequently followed; this was never less than two weeks, a period of incubation extending beyond that usually accorded to other acute infectious diseases. The accuracy of these observations has later been confirmed by the mosquito experiments hereinafter outlined.

FACTORS WHICH LED TO THE APPOINTMENT OF THE BOARD

One may well believe that such a scourge as yellow fever could not have been long neglected by medical investigators, and so we find that from the earliest days, when the germ-theory of disease took its proper place in modern science, a search for the causative agent of this infection was more or less actively instituted.

Men of the highest attainments in bacteriology engaged in numerous attempts to isolate the yellow fever microbe: unfortunately not a few charlatans took advantage of the dread and terror which the disease inspires, to proclaim their discoveries and their specific CURES; one of these obtained wealth and honor in one of the South American republics for presumably having discovered the "germ" and prepared a so-called vaccination which was expected to eradicate the disease from that country, but for many years after the foreign population continued to suffer as before and the intensity and the spread of yellow fever remained unabated, although thousands of "preventive inoculations" were made every month.

Geo. M. Sternberg in 1880, then an army surgeon, was directly instrumental in exposing the swindle that was being perpetrated, putting an end, after the most painstaking investigation, to all the claims to discovery of the "germ" of yellow fever that had been made by several medical men in Spanish America. The experience which he obtained during a scientific excursion through Mexico, Cuba and South America gave him a wonderful insight as to the difficulties one has to contend with in such work and made him realize the importance of special laboratory training for such undertaking. It is interesting to note that, as surgeon general of the U. S. Army, twenty years after, General Sternberg chose and appointed the men who constituted the yellow fever board, in Cuba.

The year before the Spanish-American war, an Italian savant, who had obtained a well-deserved reputation as bacteriologist while working in the Institute Pasteur of Paris, came out with the announcement from Montevideo, Uruguay, that he had actually discovered the much-sought-for cause of yellow fever; his descriptions of the methods employed, though not materially different from those followed by Sternberg many years before, bore the imprint of truth and his experimental inoculations had apparently been successful. Sanarelli—that is his name—for about two years was the "hero of the hour," yet his claims have been proved absolutely false.

The question of the identity of his "germ" was first taken up by the writer under instructions from General Sternberg: during the Santiago campaign I had opportunity to autopsy a considerable number of yellow fever cases and, following closely upon Sanarelli's directions, only three times out of ten could his bacillus be demonstrated; at almost the same time, Drs. Reed and Carroll, in Washington, were carrying out experiments which showed that Sanarelli's bacillus belonged to the hog-cholera group of bacteria and thus when found in yellow fever cadavers could play there only a secondary role as far as the infection is concerned.

Unfortunately, two investigators belonging to the U. S. Marine Hospital Service, Drs. Wasdin and Gleddings, were, according to their claims, corroborating Sanarelli's findings: there was nothing to do but that the investigation should continue, and so I was sent by General Sternberg to Havana in December, 1898, with instructions and power to do all that might be necessary to clear up the matter. Wasdin and Geddings had preceded me; the work carried us through the summer of 1899; we frequently investigated the same cases; I often autopsied bodies from which we took the same specimens and made the same cultures, in generally the same kind of media, and finally we rendered our reports to our respective departments, Wasdin and Geddings affirming that Sanarelli's bacillus was present in almost all the cases, while I denied that it had such specific character and showed its occurrence in cases not yellow fever. A virulent epidemic which raged in the city of Santiago and vicinity during 1899 afforded me abundant material for research.

In the meantime the city of Havana was being rendered sanitary in a way which experience had taught would have overcome any bacterial infection, and, in fact, the diseases of filth, such as dysentery, tuberculosis, children's complaints and others, decreased in a surprising manner, while yellow fever seemed to have been little affected if at all.

Evidently, a more thorough overhauling of the matter was necessary to arrive at the truth, and while the question of Sanarelli and his claims was practically put aside, Surgeon-General Sternberg, recognizing the importance of the work before us and that its proportions were such as to render the outcome more satisfactory by the cooperation of several investigators in the same direction, wisely decided to create a board for the purpose and so caused the following to be issued:

Special Orders No. 122 HEADQUARTERS OF THE ARMY, ADJUTANT GENERAL'S OFFICE, WASHINGTON, May 24, 1900

Extract

34. By direction of the Secretary of War, a board of medical officers is appointed to meet at Camp Columbia, Quemados, Cuba, for the purpose of pursuing scientific investigations with reference to the infectious diseases prevalent on the Island of Cuba. Detail for the board:

Major Walter Reed, surgeon, U. S. Army; Acting Assistant Surgeon James Carroll, U. S. Army; Acting Assistant Surgeon Aristides Agramonte, U. S. Army; Acting Assistant Surgeon Jesse W. Lazear, U. S. Army.

The board will act under general instructions to be communicated to Major Reed by the Surgeon General of the Army. By command of MAJOR GENERAL MILES, H. C. CORBIN, Adjutant General

It may be of interest to the reader to learn who these men were and the reasons why they were probably selected for the work.

Major Reed, the first member in the order of appointment, was the ranking officer and therefore the chairman of the board. He was a regular army officer, at the time curator of the Army Medical Museum in Washington and a bacteriologist of some repute. He deservedly enjoyed the full confidence of the surgeon general, besides his personal friendship and regard. Reed was a man of charming personality, honest and above board. Every one who knew him loved him and confided in him. A polished gentleman and a scientist of the highest order, he was peculiarly fitted for the work before him.

Dr. James Carroll, the second member of the board, was a self-made man, having risen from the ranks through his own efforts: while a member of the Army Hospital Corps he studied medicine and subsequently took several courses at Johns Hopkins University in the laboratory branches. At the time of his appointment to the board he had been for several years an able assistant to Major Reed. Personally, Carroll was industrious and of a retiring disposition.

Dr. Jesse W. Lazear was the fourth member of the board. He had graduated from the College of Physicians and Surgeons (Columbia University) in the same class as the writer, in 1892, and had afterwards studied abroad and at Johns Hopkins. Lazear had received special training in the investigation of mosquitoes with reference to malaria and other diseases. Stationed at Columbia Barracks, he had been in Cuba several months before the board was convened, in charge of the hospital laboratory at the camp. A thorough university man, he was the type of the old southern gentleman, kind, affectionate, dignified, with a high sense of honor, a staunch friend and a faithful soldier.

The writer was the third member of the Army Board. Born in Cuba during the ten years' war, while still a child, my father having been killed in battle against the Spanish, I was taken to the United States and educated in the public schools and in the College of the City of New York, graduating from the College of Physicians and Surgeons in 1892. At the breaking out of the war I was assistant bacteriologist in the New York Health Department. The subject of yellow fever research was my chief object from the outset, and, at the time the board was appointed, I was in charge of the laboratory of the Division of Cuba, in Havana.

It may be readily seen from the brief sketch regarding the several members that the components of the yellow-fever board really constituted a perfectly consistent body, for the reason, mainly, that they were all men trained in the special field wherein their labors were to be so fruitful and that before their appointment to the board they had been more or less associated in scientific work.

FIRST PART OF THE WORK OF THE BOARD

My first knowledge of the existence of the board was had through the following letter from my friend Major Reed:

WAR DEPARTMENT, SURGEON GENERAL'S OFFICE, WASHINGTON, May 25, 1900

DR. A. AGRAMONTE, Act'g Asst. Surgeon U. S. A., Military Hospital No. 1, Havana, Cuba

My dear Doctor: An order issued yesterday from the War Department calls for a board of medical officers for the investigation of acute infectious diseases occurring on the Island of Cuba. The board consists of Carroll, yourself, Lazear and the writer. It will be our duty, under verbal instructions from the Surgeon General, to continue the investigation of the causation of yellow fever. The Surgeon General expects us to make use of your laboratory at Military Hospital No. 1 and Lazear's laboratory at Camp Columbia.

According to the present plan, Carroll and I will be quartered at Camp Columbia. We propose to bring with us our microscopes and such other apparatus as may be necessary for the bacteriological and pathological work. If, therefore, you will promptly send me a list of the apparatus on hand in your laboratory, it will serve as a very great help in enabling us to decide as to what we should include in our equipment. Any suggestions that you may have to make will be much appreciated.

Carroll and I expect to leave New York, on transport, between the 15th and 20th of June and are looking forward, with much pleasure, to our association with you and Lazear in this interesting work. As far as I can see we have a year or two of work before us.

Trusting you will let me hear from you promptly, and with best wishes, Sincerely yours, (Signed) WALTER REED

On the afternoon of June 25, 1900, the four officers met for the first time in their new capacity, on the veranda of the officers' quarters at Columbia Barracks Hospital. We were fully appreciative of the trust and aware of the responsibility placed upon us and with a feeling akin to reverence heard the instructions which Major Reed had brought from the surgeon general; they comprised the investigation also of malaria, leprosy and unclassified febrile conditions, and were given with such detail and precision as only a man of General Sternberg's experience and knowledge in such matters could have prepared. After deciding upon the first steps to be taken, it was unanimously agreed that whatever the result of our investigation should turn out to be, it was to be considered as the work of the board as a body, and never as the outcome of any individual effort; that each one of us was to work in harmony with a general plan, though at liberty to carry out his individual methods of research. We were to meet whenever necessary, Drs. Reed, Carroll and Lazear to remain at the Barracks Hospital and I to stay in charge of the laboratory in Havana, at the Military Hospital, where I also had a ward into which yellow-fever cases from the city were often admitted.

Work was begun at once. Fortunately for our purpose, an epidemic of yellow fever existed in the town of Quemados, in close proximity to the military reservation of Camp Columbia. Even before the arrival of Reed and Carroll, Lazear and I had been studying its spread, following the cases very closely; subsequently a few autopsies were made by me, Carroll making cultures from the various tissues and Lazear securing fragments for microscopical examination; a careful record was kept and the results noted; cases gradually became less in number as the epidemic slowly died out, about the middle of August.

In the meantime a rather severe outbreak of yellow fever had occurred in Santa Clara, a city in the interior of the island, having invaded the garrison and caused the death of several soldiers; as the origin of the infection was shrouded in mystery, and cases continued to appear among the troops even after they had moved out of the town, it was agreed that I should endeavor to trace the source of the epidemic and aid the medical authorities in establishing whatever preventive measures might seem proper. This service is here recorded because in the general discussion of the start and course of the epidemic with Dr. J. Hamilton Stone, the officer in charge of the military hospital, we incidentally spoke of the possible agency of insects in spreading the disease, pointing particularly in this direction the fact of the infection of a trooper who, suffering from another complaint, occupied a bed in a ward across the yard from where a yellow fever case had developed two weeks before.

The infection of the city of Santa Clara had evidently taken place from Havana, distant only one night's journey by train. Captain Stone, a particularly able officer, had already instituted effective quarantine measures before my arrival, so that I only remained there a few days.

But as to the actual cause of the disease we were still entirely at sea; it helped us little to know that a man could be infected in Havana, take the train for a town in the interior and start an outbreak there in the course of time.

Upon rejoining my colleagues (July 2) we resumed our routine investigations; not only in Quemados, where the disease was being stamped out, but also in Havana, at "Las Animas" Hospital and at Military Hospital No. 1, where my laboratory (the division laboratory) was located. There was no scarcity of material and the two members who until then had never seen a case of yellow fever (Reed and Carroll) had ample opportunity, and took advantage of it, to become acquainted with the many details of its clinical picture which escape the ordinary practitioner, the knowledge and the appreciation of which, in their relative value, give the right to the title of "expert."

Since the later part of June, reports had been coming to headquarters of an extraordinary increase of sickness among the soldiers stationed at Pinar del Rio, the capital of the extreme western province, and very soon the great mortality from so-called "pernicious malarial fever" attracted the attention of the chief surgeon, Captain A. N. Stark, who, after consulting with Major Reed, ordered me to go there and investigate. A man had died, supposedly from malaria, just before my arrival on the afternoon of July 19. The autopsy which I performed at once showed me that yellow fever had been the cause of his death, and a search through the military hospital wards revealed the existence of several unrecognized cases being treated as malaria; a consultation held with the medical officer in charge showed me his absolute incapacity, as he was under the influence of opium most of the time (he committed suicide several months afterwards), and so I telegraphed the condition of things to headquarters; in answer I received the following:

CHIEF SURGEON'S OFFICE, HDQRS. DEPT. HAVANA AND PINAR DEL RIO, QUEMADOS, CUBA, July 20, 1900

SURGEON AGRAMONTE, Pinar del Rio Barracks, Pinar del Rio, Cuba

Report received last night. My thanks are due for your prompt action and confirmation of my suspicions. STARK, Chief Surgeon

Conditions in the hospital were such as to demand immediate action; the commander of the post refused to believe he had yellow fever among his 900 men and was loath to abandon his comfortable quarters for the tent life in the woods that I earnestly recommended. In answer to my telegram asking for official support, I received the following:

CHIEF SURGEON'S OFFICE, HDQRS. DEPT. HAVANA AND PINAR DEL RIO, QUEMADOS, CUBA, July 21, 1900

SURGEON AGRAMONTE, Pillar del Rio Barracks, Pinar del Rio, Cuba

Take charge of cases. Reed goes on morning train. Wire for anything wanted. Nurses will be sent. Instructions wired commanding officer. Other doctors should not attend cases. Establish strict quarantine at hospital. You will be relieved as soon as an immune can be sent to replace you. Report daily by wire. STARK, Chief Surgeon

When Major Reed came to Pinar del Rio (July 21) I had, the day before, established a separate yellow-fever hospital, under tents, attended by some of the men who had already passed an attack and were thus immune. The Major and I went over the ground very carefully, we studied the sick report for two months back, fruitlessly trying to place the blame upon the first case. I well remember how, as we stood in the men's sleeping quarters, surrounded by a hundred beds, from several of which fatal cases had been removed, we were struck by the fact that the later occupants had not developed the disease. In connection with this, and particularly interesting, was the case of a soldier prisoner who had been confined to the guard-house since June 6; he showed the first symptoms of yellow fever on the twelfth and died on the eighteenth; none of the other eight prisoners in the same cell caught the infection, though one of them continued to sleep in the same bunk previously occupied by his dead comrade. More than this; the three men who handled the clothing and washed the linen of those who had died during the last month were still in perfect health. Here we seemed to be in the presence of the same phenomenon remarked by Captain Stone in reference to his case at Santa Clara, and before that by several investigators of yellow fever epidemics; the infection at a distance, the harmless condition of bedding and clothing of the sick; the possibility that some insect might be concerned in spreading the disease deeply impressed us and Major Reed mentions the circumstance in his later writings. This was really the first time that the mosquito transmission theory was seriously considered by members of the board, and it was decided that, although discredited by the repeated failure of its most ardent supporter, Dr. Carlos J. Finlay, of Havana, to demonstrate it, the matter should be taken up by the board and thoroughly sifted.

The removal of the troops out of Pinar del Rio was the means of at once checking the propagation of the disease.

On the first day of August the board met and after due deliberation determined to investigate mosquitoes in connection with the spread of yellow fever. As Dr. Lazear was the only one of us who had had any experience in mosquito work, Major Reed thought proper that he should take charge of this part of the investigation in the beginning, while we, Carroll and I, continued with the other work on hand, at the same time gradually becoming familiar with the manipulations necessary in dealing with the insects.

A visit was now made to Dr. Finlay, who, much elated at the news that the board was about to investigate his pet theory, the transmission of yellow fever from man to man by mosquitoes, very kindly explained to us many points regarding the life of the one kind he thought most guilty and ended by furnishing us with a number of eggs which, laid by a female mosquito nearly a month before, had remained unhatched on the inside of a half empty bowl of water in his library.

Much to our disappointment and regret, during the first week of August, Major Reed was recalled to Washington that he might, in collaboration with Drs. Vaughan and Shakespeare, complete the report upon "Typhoid Fever in the Army." Thus we were deprived of his able counsel during the first part of the mosquito research. Major Reed was detained longer than he expected and could not return to Cuba until early in October, several days after Lazear's death.

The mosquito eggs obtained from Dr. Finlay hatched out in due time; the insects sent to Washington for their exact classification were declared by Dr. L. O. Howard, entomologist to the Agricultural Department, to be Culex fasciatus. Later, they have been called Stegomyia fasciatus and now go under the name of Stegomyia calopus (Aedes cal.).

Lazear applied some of these mosquitoes to cases of yellow fever at "Las Animas" Hospital, keeping them in separate glass tubes properly labeled, and every thing connected with their bitings was carefully recorded; the original batch soon died and the work was carried on with subsequent generations from the same.

The lack of material at Quemados caused us to remove our field of action to Havana, where cases of yellow fever continued to appear. We met almost every day at "Las Animas" Hospital, where Lazear was trying to infect his mosquitoes, or now and then I performed autopsy upon a case, and Carroll secured sufficient cultures to last him for several days of bacteriological investigation.

Considering that, in case our surmise as to the insect's action should prove to be correct, it was dangerous to introduce infected mosquitoes amongst a population of 1,400 non-immunes at Camp Columbia, Dr. Lazear thought best to keep his presumably infected insects in my laboratory at the Military Hospital No. 1, from where he carried them back and forth to the patients who were periodically bitten.

Incidentally, after the mosquitoes fed upon the yellow fever patients, they were applied, at intervals of two or three days, to whoever would consent to run the risk of contracting yellow fever in this way; needless to say, current opinion was against this probability and as time passed and numerous individuals who had been bitten by insects which had previously fed upon yellow fever blood remained unaffected, I must confess that even the members of the board, who were rather sanguine in their expectations, became somewhat discouraged and their faith in success very much shaken.

No secret was made of our attempts to infect mosquitoes; in fact many local physicians became intensely interested, and Lazear and his tubes were the subject of much comment on the part of the Havana doctors, who nearly twenty years before had watched and laughed at Dr. Finlay, then bent apparently upon the same quest in which we were now engaged. Dr. Finlay himself was somewhat chagrined when he learned of our failure to infect any one with mosquitoes, but, like a true believer, was inclined to attribute this negative result more to some defect in our technique than to any flaw in his favorite theory.

Although the board had thought proper to run the same risks, if any, as those who willingly and knowingly subjected themselves to the bites of the supposedly infected insects, opportunity did not offer itself readily, since Major Reed was away in Washington and Carroll, at Camp Columbia, engrossed in his bacteriological investigations came to Havana only when an autopsy was on hand or a particularly interesting case came up for study. I was considered an immune, a fact that I would not like to have tested, for though born in the island of Cuba, I had practically lived all my life away from a yellow fever zone; it was therefore presumed that I ran no risk in allowing mosquitoes to bite me, as I frequently did, just to feed them blood, whether they had previously sucked from yellow fever cases or not. And so, time passed and several Americans and Spaniards had subjected themselves in a sporting mood to be bitten by the infected (?) mosquitoes without causing any untoward results, when Lazear applied to himself (August 16, 1900) a mosquito which ten days before had fed upon a mild case of yellow fever in the fifth day of his disease; the fact that no infection resulted, for Lazear continued in excellent health for a space of time far beyond the usual period of incubation, served to discredit the mosquito theory in the opinion of the investigators to a degree almost beyond redemption, and the most enthusiastic, Dr. Lazear himself, was almost ready to "throw up the sponge."

I had as laboratory attendant a young American, a private belonging to the Hospital Corps of the Army, who more than once had bared his arm to allow a weak mosquito a fair meal with which to regain its apparently waning strength; Loud, for that was his name, derided the idea that such a little beast could do so much harm as we seemed ready to accuse it of, although he was familiar with the destruction caused by bacteria, but then, he used to say, "bacterial work in armies of more than a million bugs at the same time and no one would be d—— fool enough to let more than one or two gnats sting him at once."

This state of things, the gradual loss of faith in the danger which mosquitoes seemed to possess, led Dr. Lazear to relax a little and become less scrupulous in his care of the insects, and often, after applying them to patients, if pressed for time, he would take them away with him to his laboratory at Columbia Barracks, where, the season being then quite warm, they could be kept as comfortably as at the Military Hospital laboratory. Thus it happened that on the twenty-seventh of August he had spent the whole morning at "Las Animas" Hospital getting his mosquitoes to take yellow-fever blood: the procedure was very simple; each insect was contained in a glass tube covered by a wad of cotton, the same as is done with bacterial cultures. As the mouth of the tube is turned downwards, the insect usually flies towards the bottom of the tube (upwards), then the latter is uncovered rapidly and the open mouth placed upon the forearm or the abdomen of the patient; after a few moments the mosquito drops upon the skin and if hungry will immediately start operations; when full, by gently shaking the tube, the insect is made to fly upwards again and the cotton plug replaced without difficulty. It so happened that this rather tedious work, on the day above mentioned, lasted until nearly the noon hour, so that Lazear, instead of leaving the tubes at the Military Hospital, took them all with him to Camp Columbia: among them was one insect that for some reason or other had failed to take blood when offered to it at "Las Animas" Hospital.

This mosquito had been hatched in the laboratory and in due time fed upon yellow-fever blood from a severe case on August 15, that is, twelve days before, the patient then being in the second day of his illness; also at three other times, six days, four days and two days before. Of course, at the time, no particular attention had been drawn to this insect, except that it refused to suck blood when tempted that morning.

After luncheon that day, as Carroll and Lazear were in the laboratory attending to their respective work, the conversation turning upon the mosquitoes and their apparent harmlessness, Lazear remarked how one of them had failed to take blood, at which Carroll thought that he might try to feed it, as otherwise it was liable to die before next day (the insect seemed weak and tired); the tube was carefully held first by Lazear and then by Carroll himself, for a considerable length of time, upon his forearm, before the mosquito decided to introduce its proboscis.

This insect was again fed from a yellow fever case at "Las Animas" Hospital on the twenty-ninth, two days later, Dr. Carroll being present, though not feeling very well, as it was afterwards ascertained.

We three left the yellow-fever hospital together that afternoon; I got down from the doherty-wagon where the road forks, going on to the Military Hospital, while Carroll and Lazear continued on their way to Camp Columbia. On the following day, Lazear telephoned to me in the evening, to say that Carroll was down with a chill after a sea bath taken at the beach, a mile and a half from Camp, and that they suspected he had malaria; we therefore made an appointment to examine his blood together the following morning.

When I reached Camp Columbia I found that Carroll had been examining his own blood early that morning, not finding any malarial parasites; he told me he thought he had "caught cold" at the beach: his suffused face, blood-shot eyes and general appearance, in spite of his efforts at gaiety and unconcern, shocked me beyond words. The possibility of his having yellow fever did not occur to him just then; when it did, two days later, he declared he must have caught it at my autopsy room in the Military Hospital, or at "Las Animas" Hospital, where he had been two days before taking sick. Although we insisted that he should go to bed in his quarters, we could only get him to rest upon a lounge, until the afternoon, when he felt too sick and had to take to his bed.

Lazear and I were almost panic-stricken when we realized that Carroll had yellow fever. We searched for all possibilities that might throw the blame for his infection upon any other source than the mosquito which bit him four days before; Lazear, poor fellow, in his desire to exculpate himself, as he related to me the details of Carroll's mosquito experiment, repeatedly mentioned the fact that he himself had been bitten two weeks before without any effect therefrom and finally, what seemed to relieve his mind to some extent, was the thought that Carroll offered himself to feed the mosquito and that he held the tube upon his own arm until the work was consummated.

I have mentioned before that, as Lazear and I, vaguely hoping to find malarial parasites in Carroll's blood, sat looking into our microscopes that morning, the idea that the mosquito was what brought him down gradually took hold of our minds, but as our colleague had been exposed to infection in other ways, by visiting the yellow fever hospital "Las Animas," as well as the infected city of Havana, it was necessary to subject that same mosquito to another test and hence the inoculation of Private Dean, which is described in the opening chapter of this history.

TERMINATION OF THE FIRST SERIES OF MOSQUITO EXPERIMENTS.

DEATH OF LAZEAR.

The month of September, 1900, was fraught with worry and anxiety: what with Carroll's and Private Dean's attacks of yellow fever and Major Reed's inability to return, Lazear and I were well-nigh on the verge of distraction. Private Dean was not married, but Carroll's wife and children, a thousand miles away, awaited in the greatest anguish the daily cablegram which told them the condition of the husband and father, who was fighting for life, sometimes the victim of the wildest delirium caused by consuming fever, at others almost about to collapse, until one day, the worst of the disease being over, the wires must have thrilled at our announcement, "Carroll out of danger."

Fortunately both he and Dean made an uninterrupted recovery, but we were still to undergo the severest trial, a sorrow compared to which the fearful days of Carroll's sickness lose all importance and dwindle almost into insignificance.

On the morning of the eighteenth my friend and classmate Lazear, whom in spite of our short intercourse I had learned to respect and in every way appreciate most highly, complained that he was feeling "out of sorts." He remained all day about the officers' quarters and that night suffered a moderate chill. I saw him the next day with all the signs of a severe attack of yellow fever.

Carroll was already walking about, though enfeebled by his late sickness, and we both plied Lazear with questions as to the origin of his trouble; I believe we affectionately chided him for not having taken better care of himself. Lazear assured us that he had not experimented upon himself, that is, that he had not been bitten by any of the purposely infected mosquitoes.

After the case of Dean so plainly demonstrated the certainty of mosquito infection, we had agreed not to tempt fate by trying any more upon ourselves, and even I determined that no mosquito should bite me if I could prevent it, since the subject of my immunity was one that could not be sustained on scientific grounds; at the same time, we felt that we had been called upon to accomplish such work as did not justify our taking risks which then seemed really unnecessary. This we impressed upon Major Reed when he joined us in October and for this reason he was never bitten by infected mosquitoes.

Lazear told us, however, that while at "Las Animas" Hospital the previous Thursday (five days before), as he was holding a test-tube with a mosquito upon a man's abdomen, some other insect which was flying about the room rested upon his hand; at first, he said, he was tempted to frighten it away, but, as it had settled before he had time to notice it, he decided to let it fill and then capture it; besides, he did not want to move in fear of disturbing the insect contained in his tube, which was feeding voraciously. Before Lazear could prevent it, the mosquito that bit him on the hand had flown away. He told us in his lucid moments, that, although Carroll's and Dean's cases had convinced him of the mosquito's role in transmitting yellow fever, the fact that no infection had resulted from his own inoculation the month before had led him to believe himself, to a certain extent, immune.