in the Johns Hopkins Hospital at Baltimore, has been appointed rector of the University of Liége for the period 1927-1930.

PROFESSOR H. VILLAT, of the University of Strasbourg, has been appointed to the newly established chair of the mechanics of fluids at the Sorbonne.

DISCUSSION AND CORRESPONDENCE THE TILDEN METEOR, AN ILLINOIS DAYLIGHT FALL

ON the afternoon of July 13, 1927, at about 1:00 P. M. central standard time, a stony meteor, hereafter referred to as the Tilden meteor, fell near Tilden, Illinois, about forty-five miles southeast of St. Louis, Missouri. The meteor fell in an area roughly two by seven miles, and four stones have been recovered, three of which weigh, respectively, one hundred and ten, forty-six, and nine pounds. The fourth is a small piece weighing a fraction of a pound.

The meteor came from the southeast, its path being inclined at an angle of perhaps fifty degrees to the horizontal, and with a velocity equal to, or slightly in excess of, the parabolic. Its brilliancy was such that at a distance of more than a hundred miles it appeared as "a piece falling off the sun." At a height of fifteen or twenty miles it burst, showing green and then purple, and after a second bursting was invisible to persons at a distance. A cloud of smoke was visible near the point of fall, but the falling pieces quickly had their velocity reduced so that they were no longer luminous by daylight, and only one piece was actually seen while falling. It was seen as "a dark streak, like smoke, for an instant."

The sky was partly cloudy in the vicinity of the fall, so few there saw anything, although nearly every one was looking, after the house-shaking blasts of the detonations. Following the detonations a roar like a tornado, or an earthquake, rolled to the southeast and died away in the distance. The meteor travelled with a velocity greater than that of sound, so the roar from the more distant portions of the path was heard after the detonations of the bursting in the nearer portion. This helped in evaluating the stories of the few who saw anything, for every one heard the sound rolling toward the southeast and assumed the meteor was travelling in that direction. The stones were actually seen to fall, and the smoke to roll, in the opposite direction.

The falling stones made a hum like an airplane flying high. The two larger stones could both be heard over considerable territory and at one place five men were out in a group straining their eyes to see an aviator who "flew over and passed out of hearing in the northwest, then came back flying much lower and landed a little to the north of the group."

The three larger pieces were heard to strike, the largest a few seconds after the blasts, the forty-sixpound piece "perhaps three minutes after," and for the nine-pound piece we have two careful estimates, "three to five minutes" and "five to eight minutes." The fact that for even the largest stone the thud of striking the earth was heard after the detonations of the bursting meteor shows that the average velocity of the fall from the point of bursting to the earth must have been less than the velocity of sound. Since the velocity of this meteor was twenty-five to thirty miles per second in the upper atmosphere, and sound travels at the comparatively leisurely rate of a mile in some five seconds, we have a striking illustration of the tremendous resistance of the lower atmosphere to bodies travelling at high velocities.

The soil of the territory is rather a stiff clay, and it was very hard because of no rain for weeks. The largest piece struck on the edge of a field of cow-peas, and went down three feet ten inches. The forty-sixpound piece went down fifteen inches in a clover pasture. The nine-pound piece went down five inches in grass in a back yard, and the small piece was found lying on a lawn. The fall was nearly vertical at the last, the largest stone departing about six inches from the vertical in penetrating three feet ten inches. The impact in no case noticeably scattered the soil; the holes were simply driven into the ground. The ninepound stone was easily lifted out of the hole. For the forty-six-pound piece a little digging with a pocket knife was necessary; and the removal of the one hundred and ten-pound stone required two hours' hard work for two men with spade, pick and crowbar. It was wedged "as if it were set in concrete."

The meteorites are composed of a light gray stone, and show small silvery globular aggregates, presumably of nickel-iron. The surfaces show typical pittings and a typical black crust, being blackened and pitted in fairly uniform fashion. From a preliminary study of the literature available, this fall appears to be the first recorded from the state of Illinois, and the one hundred and ten-pound stone ranks among the largest seen to fall and preserved reasonably intact. Plaster casts will be made of the larger stones of this fall.

It should be said that the information in this note was obtained by personal interview, the writer visiting people, not only in the vicinity of the fall, but more than a hundred miles from that point. CHARLES CLAYTON WYLIE

UNIVERSITY OF IOWA

ETIOLOGY OF EUROPEAN FOUL-BROOD OF BEES

SINCE Cheshire and Cheyne investigated the cause of foul-brood of bees in England and attributed the

etiology of the disease to B. alvei, which is almost invariably found in large numbers in infected larvae, much work has been done to corroborate their results. In no case, however, has an isolated culture of B. alvei been known to produce the disease. On the other hand, G. F. White and others have refuted the claim of Cheshire and Cheyne and ascribed infection in this disease to B. pluton. Owing to their inability to cultivate and isolate the organism, however, their claim has remained hypothetical; for it could not be determined whether this organism was itself merely a secondary invader-as they said was B. alvei-or whether the infection was mixed, or whether, indeed, these organisms played any pathological rôle in the disease.

It has been the writer's fortune, however, to develop a medium admirably suitable for the growth of B. pluton (White). An 0.15 per cent. concentration of agar, together with certain nutrients, is employed as an enrichment medium; and a concentration of 1.5 per cent. agar for the isolation of the organism at 37° C. By this method pure cultures of B. pluton can be readily obtained, provided the larvae used contain a preponderance of this organism.

The writer has obtained infection in a healthy colony of black bees in four days, using as inoculum cultures of the organism derived from isolated colonies. The symptoms of the diseased larvae accorded with those observed in naturally infected larvae, and the microscopical picture was typical-B. alvei forms being also present, though only in small numbers. The organism has been reisolated successfully.

Morphological studies thus far suggest the identity of the two organisms. While the results in this are not yet complete, cultures of B. pluton have been observed to change to B. alvei form, resembling biologically the B. alvei isolated from infected larvae. This further corresponds very closely with the changes observed in brood naturally infected, where the ratio of B. alvei to B. pluton generally increases as the putre faction of the larvae progresses, so that B. pluton is almost eliminated. The more conclusive substantiation of this is anticipated, and its accomplishment should lead to the demonstration of important relations between the pathogenicity of microorganisms

and their life stages.

OTTAWA, CANADA

DENIS R. A. WHARTON

NOTE ON A SECOND OCCURRENCE OF THE MOSASAURIAN REPTILE, GLOBIDENS

IN 1912 (Proc. U. S. Nat. Mus., vol. 41, p. 479) the new genus and species, Globidens alabamaensis Gilmore, was established on a rather meager specimen from the Upper Cretaceous of Alabama. The unusual

globular form of the teeth as contrasted with the pointed, sharp-cutting teeth of other Mosasaurians made this an outstanding genus on which Dollo has subsequently founded a distinct family, the Globidensidae.

Recently I have received for examination the crowns of two teeth collected from the Selma Chalk, in the vicinity of Saltillo, Lee County, Mississippi, by a student of Prof. J. M. Sullivan, of Millsaps College, Jackson, Mississippi.

The crowns of these teeth show no evidence of wear and this fact, in conjunction with their relatively small size, would indicate that they were probably germ teeth which had not yet come into use. The globular form of their crowns, with wrinkled enameled surfaces, however, are in perfect accord with the teeth of the type specimen.

The fragmentary character of the specimen contributes nothing new to our knowledge of this little known Mosasaurian, but it is of interest as recording a new occurrence, and especially in definitely locating its geological occurrence as being in the Selma Chalk. CHARLES W. GILMORE

U. S. NATIONAL MUSEUM

MORE AND BETTER ETHICS FOR SCIENTIFIC MEN

THAT the code of ethics1 adopted at the Santa Fé meeting of the Southwestern Division, American Association for the Advancement of Science, has been found by Dr. Kempton2 a subject for genial mirth, seems to call for comment from some other quarter than that immediately involved, the members of the Southwestern Division having, one might say, cramped their style in controversy by the adoption of Rule 4. Thus, as so often, a new law works hardship first upon the law-abiding.

Dr. Kempton, as a resident of the Atlantic coastal plain, can hardly be expected to understand the distressing conditions prevailing in scientific and educational circles in outlying provinces west of the Appalachian Highland. It is a source of deep gratification to us in the West to learn that the conditions

deprecated in the resolutions mentioned are nonexistent in the East, which we have so long been taught to look to as the home of culture, truth and grace. The writer is glad to be corrected in his evidently erroneous assumption that Rule 10, for example, might, in the awkward gambols of its play

1A Code of Ethics for Scientific Men,'' SCIENCE, Vol. LXVI, No. 1700, pp. 103–104, July 29, 1927.

2 Kempton, J. H., "Scientors appear in the Southwest." Ibid., Vol. LXVI, No. 1711, pp. 354-355, Oct. 14, 1927.

ful youth, tread upon as many corns east as west of the Mississippi River. Be that as it may, if the wild scientists of the woolly west desire to pass resolutions to protect themselves from outside aggression and internecine strife, we should expect such ambition for self-improvement to be lauded rather than condemned by the cultured exponents of an older civilization east of the Alleghany Mountains.

In defense of the southwest code, we note first that it is specifically stated to be "tentative." We take this to mean that any of the rules may be altered or stricken out to which there is sufficient objection at home or abroad. Furthermore, it appears that the code is intended by members of the Southwestern Division to apply only to themselves; as we understand it, they have no intention-and probably no hope of applying their reforms to scientists at large. There is, therefore, no occasion for immediate alarm, unless it be on the part of individual eastern scientists who intend, for climatic or other reasons, to migrate to the Southwest.

Now it would be invidious to intimate that Dr. Kempton would personally violate, or condone the violation of, any of the rules in question. We interpret his attitude rather as a kind of Menckenese objection to the appearance of anything savoring of a Rotarian philosophy among scientific men. this point of view there is much to be said. But as between the two extremes of super-sanctity and subMenckenism we plead for a carefully weighted mean.

For

We should like to believe that scientific men as a class are above the need of a code of ethics. But the enthusiasm with which we commonly refer to an admired colleague as a gentleman and a scholar seems to involve a tacit admission that the virtues connoted by these two terms may exist separately as well as in combination.

It may be urged that, if a scholar be not already a gentleman, he can not be made one by any array of rules or resolutions. Alas, too true! But it would appear advantageous at any rate to have a definite code, by which one might decide for himself whether or not he is a gentleman, instead of depending on his colleagues to tell him, which sometimes causes lasting embarrassment on both sides. Then, too, even if it be antecedently improbable that anything can be done about the ethics of the present generation, there is the coming generation to consider the nascent Ph.D.'s and innocents yet unborn. Is it not our duty to provide that they may learn by precept what it is not wholly certain we can teach them by example?

If, in view of these weighty arguments, it should seem desirable to follow the lead of the physicians, southwestern scientists and other groups of professional men in semi-public service, and to adopt a

code of ethics to apply to scientists at large, we propose that, somewhere near the bottom of the list of needed reforms, the following be included:

Rule 160z. Scientific men shall be restrained from flailing each other through the medium of the press. The following penalties shall be provided:

(a) For gentle sarcasm the offender shall be given n black marks, in a large book to be kept by the Secretary of the National Research Council.

(b) For open satire he shall be given black marks to the number of 2n +1.

(c) For burlesquing or lampooning colleagues, he shall receive a number of black marks to be represented by the expression

SCIENTIFIC BOOKS

Les Physiciens Hollandais et la Methode Experimental en France au XVIIIème Siècle. Par PIERRE BRUNET, Paris, 1926.

An Introduction to the Study of Experimental Medicine. BY CLAUDE BERNARD, translated by HENRY COPLEY GREENE and LAURENCE J. HENDERSON. New York, Macmillan Co. 1927.

THERE never was a time when man did not use the experimental method of investigating his environment. There never has been a time when man did not form hypotheses on observations made thus and in other ways. An editor of Bacon's Novum Organum more than a hundred years ago remarked that Sir Isaac Newton had a very extraordinary method of making discoveries. When he was engaged in his famed inquiries about light he seemed first to have imagined in his mind how things were and afterwards contrived his experiments. Newton boasted he made no hypotheses, but no mind will work without hypotheses. There can be no doubt Newton made hypotheses both before and after he contrived his experiments on light or gravitation either. It is remarkable there was once a majority of scientific men who, less than a hundred years ago, talked about the experimental

method in such a manner the inference was justified that obtaining knowledge by the experimental method is the only way of obtaining knowledge. Claude Bernard was born in the year 1813; in that year Dr. Shaw wrote the above in the appendix he added to his translation of the Novum Organum. Magendie was Bernard's teacher and the inheritor of what the Dutch had been so instrumental in introducing to the French a hundred years before. Paul Bert, who succeeded to the chair of his master, says this book of Bernard's, published first in 1865, struck cultivated minds with admiration and astonishment, and it may be added threw many of the admirers off their base and into a foolish exaggeration which is not apt to be repeated now, sixty years later that it appears in the admirable form given to it in this translation.

It is seldom it is thought worth while to republish any work of medicine or general science after sixty years, but this work is in the same class with the Novum Organum. I fancy it is the lingering tradition of the mental obsession to which Bert refers we may look for the interest the publishers expect. It is opportune that we have Brunet's book to enlighten us as to how the experimental methods entered France so long before Bernard made it unreasonably dominant, an exaggeration against which he repeatedly protests. Such exaggerations are always to be expected to attend the advent of every manifest step forward in the progress of thought and the achievements of men, but we must realize that Bernard has no claim and made none to having first introduced modern experimental methods in France.

When the House of Hanover crossed the channel to govern England there was a large following from the Netherlands, though perhaps not so large as Holland had sent over with her Prince of Orange and long before that the English Puritans had fled to the Low Countries from the British Isles, so there had been large and frequent interchange between the two nations for many generations before. Even the war between the Dutch and the English on the water had done something. It was not broadsides alone of shot they had fired into one another. It was ideas too they had exchanged after Lord Bacon's death. The new learning and the models by which Bacon and Newton shaped it made a deep impression on the Dutch, but they had no thought of not making hypotheses. Much which Newton called mathematics, others called reasoning, they insisted. Although the mathematician, left to his own processes, "never deviates into sense," he must have a beginning that is to him rational if not sensible, while the result to the layman is neither; but sensible is a word that long since has begun to be slippery in usage. Physics formed the basis of

Newton's mathematics and reckoning from it was more exactly done than by hypotheses, but in mathematics hypotheses also have to be used. The Dutch followers of Newton saw more clearly than some of his later English, but s'Gravesande declared that in order to arrive at the admirable wisdom of Newton every physicist should see to it that his reasoning was not founded on simple hypotheses alone. At Utrecht they instituted a large laboratory supplied with instruments of every kind then procurable for the study of physical phenomena, yet s'Gravesande laid down the maxim that the student should try to imagine in his own mind how the phenomena he was about to investigate could arise. Despite his warning that some method more reliable should form the basis of his projected work, six rules for the use of hypotheses were given by the Dutch savant and Brunet says he was apparently not far from thinking that "truths" themselves of physics are only high probabilities. Consequently the results of the experimental method are naught but hypotheses, however close to the truth they may come. We can not deny the experimental method is more often the origin of theories than of facts. Thus early in the Baconian and Newtonian creed did heresy arise when transported to the continent by their disciples. Nevertheless it was they who transmitted to France long before Claude Bernard a rational experimental method. It was not Bernard who was responsible for an irrational experimental method which caused much of the falling away of students in science in France in the latter part of the last century rather than the FrancoPrussian war.

Not only did primitive man experiment with the experimental method, but when science dawned in our civilization it was not entirely neglected by the old Nature Philosophers, though we have scant record of any. Hippocrates and Celsus, however, are recorded as having resorted to it in medicine and Galen was one of the greatest experimenters who ever lived. Neither Bacon nor Bernard were the earliest pioneers, nor the Italian School. Men believed Bernard had but followed in the path of Bacon, but he did far more than that. He was the most important of his critics. He was no bigot who believed that pure induction from observed facts can often lead directly to the truth. In this many, who have insistently quoted him for two generations of scientific men, have totally misapprehended him and English readers are put in the way by the present volume of avoiding this error. As to his inspiration by Bacon, nothing could be more erroneous. The chief criticism which Bernard aims against the methods of modern science is not against the neglect of experimental science which had

The chances were forty years ago that a student on entering a laboratory for the first time was adjured by the director to approach his problems with an open mind almost so insistently that the student had reason to believe he was to approach them with an empty mind. He must have no preconceived ideas as to the solution of them. This was mere drivel. It put a premium on infancy and idiocy. Claude Bernard was supposed to be the protagonist of such doctrine, for the history of medicine, especially of science, was not wide spread among laboratory workers in those days. Bernard insists "facts are necessary materials, but their working up by experimental reasoning, i.e., by theory, is what establishes and really builds up science." Bernard seems, by the frequency with which he sounds this note, to be protesting against certain pernicious tendencies in French methods of the pursuit of science. It was the revival of a new science in the Netherlands, which was the origin of its juvenescence in France. There were more solid cultivators of it than Voltaire, but when he returned from England he made the ideas of science he had imbibed there popular. Probably his friend, Mme. du Chatelet, understood them better, but he was the greatest propagandist of them all, so that through him a very much more extended stratum of the people became acquainted with the ideas, which several years before had arrived by the way of Holland and were thus given a wider circulation than otherwise would have been the case from the introduction Nollet was able to give them among learned men.

Descartes and his philosophy had had a great effect on the teachings in the universities of Holland, but most of the physicists there appreciated the inefficiency of his doctrine. Boerhaave in his doctor's thesis in 1693 had already published matter in which he dwelt on the importance of the experimental method in medical research. In less than ten years he had acquired a great reputation at the University of Leyden, which extended throughout Europe. Leeuwenhoek had already communicated his observations with the microscope to the Royal Society of London, but it was in 1715 that s'Gravesande was appointed secretary to the embassy sent to congratulate George I on his accession to the crown of England. By means of one of

the students he had had in the Low Countries he gained the acquaintance and the esteem of Newton and became a member of the Royal Society. When he returned to Holland Boerhaave had pronounced a discourse De Comparando in Physicis, which acted as a sort of primer of science for future work in Holland. After that the names we know of those who became indoctrinated with the ideas of the experimental method in science there are numerous. Thither Voltaire repaired to consult Boerhaave about not his health alone, but about the new things in science. In France already Nollet's influence had become marked among men of science. When the instruments then in use in the neighboring country became known in France they were constructed with more precision there, but Brunet does not forget the indebtedness not alone of France but of England and Holland also to the Italians, Galileo, Torricelli, Redi, Borelli. Milton drew on Italian culture for his great works in literature. Harvey, Willis, owed a deep debt to them. Later, however, the current of advance in methodology in science flowed through England, and with the impulse of Bacon's crude revolt from scholasticism behind them the new departure found its way to France very largely through Holland.

It was Boerhaave and s'Gravesande and Muschenbroek and doubtess many others who introduced and developed an admirable experimental method in the early part of the eighteenth century in Holland. They yield in no way to their great protagonists in England in that acuity of intellect, which manifests itself by talent and common sense rather than by genius. They escaped many of the errors of Bacon and Newton. They got their cue from them, but when the mantle fell on their shoulders science made vast strides in the Netherlands. In its earliest years in France there had already been some instruction given and some exposition of the experimental method by Polinière, but already the fame of Boerhaave was spreading there as well as elsewhere in the continent and in England and students were going to him from the latter country, whence at the beginning of the century he had drawn his first inspiration. Vaillant, who had been fired by the lectures of Boerhaave, left a posthumous book in the care of the latter, a confidence which Brunet thinks exceptional in a Frenchman for a Dutchman at that time, but its title has a significant interest for us. Boerhaave, five years after Vaillant's death in 1722, published it at Leyden and Amsterdam in 1727 as the Botanicon Parisiense. In France Castel had been provoked to attack Boerhaave for too much worship of Newton as the greatest of physicists and especially because he wished to banish every sort of hypothesis, which exclusion Castel was quite right in declaring often stops access to the truth, claiming that