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number of spines. Later the scales grow still smaller, becoming like shagreen; bony plates appear, while the spinous dorsal, ventral fins and the gill openings undergo reductions. Later the spinous dorsal and the ventrals disappear altogether, the teeth coalesce into two in each jaw and finally into one in each jaw; this series finding its extreme in the head-fish (Mola), in which the body is deeper than long and seems to be simply a great head with a fin behind it.
Turning in another direction, the spinous fins disappearing, the body is covered with bony plates, and these finally interlock with each other, forming a complete bony box absolutely immovable. Species thus provided are known as trunk-fishes (Ostracion), and in these the bony plates sometimes extend themselves into spines, especially on the head, which thus acquires a fantastic appearance.
Similar changes are found in other groups, the general rule being extreme specialization of a particular organ, producing its expansion and high development, ultimately followed by its reduction and final disappearance. In each group the species most normally formed are the earliest to appear in geological history, while primitive forms often linger with the others to the present time, most of these groups having their origin in the Eocene. Thus many of these early types, even the earliest, remain to the present day, showing apparently that non-specialization, ultra-specialization and loss of structure are all of secondary importance in the struggle for existence, and that they are conditioned on something else, a law not yet understood.
DAVID STARR JORDAN
EINSTEIN'S THEORY AND SHIFT OF
ACCORDING to Einstein's theory, as I understand it, any time piece, as e. g., a vibrating atom, automatically goes slow if placed in a strong field of gravitation; also the effect of a gravitational field is not to be distinguished from inertia effects in any accelerated motion. A particular illustration is that of a clock
moving in a circle. It would seem that there should not be much difference between the effects of an acceleration produced thus and that produced by magnetic or electric fields.
In the Stark effect, where the radiation from atoms in a strong electrical field is studied, it is probable that some of the radiating atoms are in a charged state. If one computes the acceleration of a hydrogen molecule with one unit of charge in a field of 20,000 volts per cm., without considering the dragging effect of other molecular fields, one finds it to be of the order of 1018 cm. per sec. per sec., much greater than the value of g at the sun, so that if the atom could radiate in this state very large displacements in the spectrum lines should be expected, amounting to the appearence of new lines. Even if the atom as a whole is neutral, yet because of the nonhomogeneity of the field and the distance between the positive and negative constituents of the atom, considerable accelerations are to be expected which will be larger according as an electron is farther removed from the central nucleus. It is interesting then to recall that Stark found in several instances a displacement of his central image towards the red end of the spectrum, and found the components unsymmetrically placed, also that in a number of cases entirely new lines have been found.
If the preceding point of view is correct, then in any case of luminosity in a gas, since during "collisions" the atoms are evidently in strong fields of force, a slight displacement of the center of gravity of a line towards the red would appear, and this would increase with the pressure as in the common pressure effect. The explanation of the pressure shift as due to the action of adjacent molecular fields has been given, and according to Einstein's theory that would bring it into accord with the general relativity views of time. The difficulty of distinguishing between the pressure effect and the one predicted by Einstein in the sun has been noted. Is it not possible that this lies in the nature of things, the difference being that while all matter is subject in the same degree to gravitation, the
forces between colliding atoms depends on the nature of the atoms and hence the pressure shift is different for different substances?1 ELIZABETH R. LAIRD
MOUNT HOLYOKE COLLEGE,
ANOPHELES LARVE IN SALT WATER
DR. F. E. CHIDESTER in SCIENCE, Vol. LI., No. 1314, presented some interesting data on the occurrence of certain North American Anopheles in brackish water, and referred to Professor Smith's account, which was published in 1904, and which "has been either ignored or discredited."
It may be of interest to call attention to some other Anopheles which live in brackish water and which are not included in Dr. Chidester's account. In my paper on the behavior of certain of our Canal Zone Anopheles (Annals Ento. Soc. of America, 1915, page 235) I gave the chlorine content of samples of water from which larvæ of Anopheles albimanus Wiede, A. tarsimaculata Goeldi and Edes taeniorhynchus Wiede, were taken. These samples had from 11,250 to 23,500 parts of Cl per million. Considering sea-water as having 22,000 parts of Cl per million, these samples represented from 51.1 per cent. to 107 per cent. of sea-water. There were 38 samples all told, the average Cl content being 15,817 parts per million, or equaling 72.0 per cent. of sea-water.
We get most of our A. tarsimaculata from the lowlands at both ends of the Panama Canal.
ANCON, C. Z.
THE LISTER INSTITUTE
THE Lister Institute of Preventive Medicine was founded in 1891, in honor of Lord Lister, to conduct scientific inquiries tending to prevent disease. The attachment of a hospital to the institute was specifically excluded by the articles of association, possibly to secure support from the many leaders of medicine who were on the staffs of existing hos
pitals, and possibly, also, because the intimacy of the union between clinical work and research was not sufficiently realized. By 1914 it had become plain that research could not be conducted with full advantage unless it went hand in hand with clinical opportunity. The experiences of the war drove home the lesson. Members of the staff of the Lister Institute and many other physicians and surgeons engaged on the battle-fronts, at base hospitals, or at military hospitals in this country, found that the immediate task of healing the sick not only advanced abstract knowledge, but set new problems for research. The governors of the institute have resolved unanimously to make the requisite changes in the articles of association. A convenient site for the proposed hospital lies adjacent to the institute. The council of medical research is the channel through which funds provided by the state are allotted to universities and research institutes, and it is to that body that the appeal is addressed. The proposed hospital need not be large. Its beds would be filled with selected cases, varying from time to time according to the specific inquiries that were being made. There would be relief to the general hospitals rather than rivalry with them. The experience of the Pasteur Institute in Paris and of the Rockefeller Research Hospital in New York shows that patients selected for a special purpose take an interest in their involuntary contribution to the advancement of knowledge, and rejoice that their own misfortunes may be the source of relief to others. They are certain of getting treatment even more considerate than that of a general hospital, and they have the advantage of not being the object-lessons of clinical teaching.-The London Times.
Pasteur, The History of a Mind. By EMILE DUCLAUX. Translation by Erwin F. Smith and Florence Hedges.1
Both the French publication and this trans
1 A translation with annotations and additions of the original work, "Pasteur: Histoire d'un esprit," which appeared in 1896.
lation are unusual books. The conception is not that of a mere biography of Pasteur. It is, indeed, that in part, but Duclaux undertook the greater and subtler thing, an interpretation of the master mind, the dominant soul, the "histoire d' un esprit." His success in this is the thing which gave remarkable power to the French edition. While perhaps, as the translators state, something of the verbal force and charm of the original is inevitably lost in its transfer to English, yet there are in this translation some noteworthy gains which to the reviewer are fully compensatory.
In the first place, this English edition contains probably the finest and certainly the most complete series of portraits of Pasteur that has ever been published. There are fourteen of these, picturing him from early manhood to his later maturity. Pasteur's face and especially his eyes were unusually expressive and one traces in these portraits almost more surely, and certainly more quickly, than in the text the traits or moods belonging to the different periods of his lifethe student, the crusader, the laureled victor.
Pasteur's life was dramatic. This was recently brought out with remarkable vividness by the French playwright Sacha Guitry.2
Duclaux in his "histoire d'un esprit " with a dramatist's skill selected successively the epochal events which crowded in succession through Pasteur's career from his apprenticeship days in l'école normale at Paris. These author's pictures serve also to portray vividly the direct bearing of Pasteur's early training in physics and especially in chemistry upon his later work on fermentation and other aspects of bacteriology. The reader is shown with almost kaleidoscopic abruptness first one picture then another, yet always with a dramatic unity since Pasteur is always the central figure. It is first Pasteur's works in crystallography, then in lactic and alcoholic fermentation, spontaneous generation, wines and vinegars, diseases of the silkworm, yeasts and brewing, etiology of microbial diseases,
2 Sacha Guitry, Pasteur. Pièce en 5 actes. La Petite Illustration Theatrale. March, 1919.
and finally the evolution of his work on viruses and vaccines including his studies on chicken cholera, rabies and the problems of immunity.
In this way the reader is given a synoptical survey of the period which marked the transition from the dominance of Liebig's chemical theories of fermentation to the full acceptance of the modern organic conception, i. e., from the dominance of philosophical empiricism in biology and medicine to the full acceptance of the modern leadership of the laboratory investigator, trusting only the experimental method.
Duclaux's fitness for the task of portraying this with such remarkable vividness in so compact a volume is clearly shown in the senior translator's introduction of some thirty pages, which is a valuable contribution to the literature of biological history. It is prefaced by a portrait of Duclaux showing his alertly intellectual face at about the period 1897, when, upon the death of the master, he succeeded him as director of the Pasteur Institute, and is followed by another showing the careworn man in the last year of his life.
In this preface one traces Duclaux's intimate relationship with Pasteur from his enrollment as a student in the normal school at Paris in 1858 where "the master 99 was in charge of chemistry and the related scientific studies to the death of Pasteur in 1895-37 years. Here he and the other young laboratory assistants played their part as armor bearers in the heroic times of the early Pasteurian struggle. "The master was in the forefront of the conflict over molecular dissymmetry in crystals, the campaign on fermentations and the great battle over spontaneous generation." Duclaux, who was himself trained early as a chemist, analyzes Pasteur's mental attitude on these questions with keen facility. Nor can we overlook the fact that this English edition has been enriched throughout because of the like fitness of the translators for their task. Smith has always been chemically minded in his approach to his bacteriological problems. Moreover, while Duclaux is a remarkably well in
formed chronicler and a sympathetic interpreter of Pasteur, it is doubtless true that Smith represents a type of mind and workmanship much more like that of Pasteur himself. He, like Pasteur, has fought the pioneer's battles and keenly relished the fray. One who knows this is prepared to find everywhere, in the introduction, in the translator's notes which are scattered through the book and especially in the annotations at the close a certain flavor quite other than Duclaux himself could impart.
The translation is avowedly addressed to the younger generations of American scientists who are liable to forget the dramatic conflicts through which were won the ways to the higher and freer conceptions which they have inherited. For this reason the book (and the translation better than the original) should serve admirably as a reading book about which a seminary may be conducted with students desiring to trace the history of biological thought during the last century. The reviewer proposes so to use it. For such purposes there is much gained through the addition by the translators at the close of the book of an annotated list of all persons to whom reference has been made in the text. Here as elsewhere there is evidence of those intimate, highly individualistic, personal touches through which Duclaux and Smith in combination have served to reflect so much of the dominant individualism of Pasteur.
UNIVERSITY OF WISCONSIN
L. R. JONES
NOTES ON METEOROLOGY
In an interesting paper read before the American Meteorological Society at its New York meeting, January 3, 1920, Professor A. J. Henry analyzed the flood records of many of the streams of America and Europe with a view to determining their time and space distribution, and, if possible, any systematic or cyclic recurrence.
"The Distribution of Maximum Floods," ibid., pp. 861-866.
For the purpose of his discussion, Professor Henry has used the " average annual flood," which is defined as the arithmetical mean of the annual floods for a number of years"; also the "maximum flood" which is that caused by excessive run-off when the rainfall is sufficient to raise the ground storage to a high level and thus saturate the soil, or when a warm rain falls on a snow cover; and finally, the "absolute maximum flood" which is the greatest reported for a given station. It is important to know what the absolute maximum flood magnitude is for a given place, and to know whether that maximum has been reached. Says Professor Henry:
It can not be too strongly emphasized that the occurrence of the absolute maximum flood is usually conditioned upon the synchronism of certain climatic events which in themselves have no fixed law of occurrence. Very intense rainstorms are seldom long continued and of great extent. The heavy summer showers that occur in the United States being limited in area may cause an extraordinary flood in a small watershed, and doubtless many such floods occur in some part of the country annually. These extreme floods in small streams are completely absorbed as soon as they reach the trunk stream.
To the end of determining any relation between the absolute maximum and the average, the ratios of these two values have been tabulated for 45 of the principal rivers of the United States. The agreement of the various ratios is, as the author remarks, "better than was expected," amounting in general from 1.3 to 1.5; that is, the absolute maximum flood was 1.3 to 1.5 times the annual average. There are a number of ratios of greater magnitude, but, in most cases, this is accounted for either in the nature of the watershed, or the local conditions surrounding the gaging. Small ratios are found at places where overflow takes place easily and the river may greatly increase its cross-section.
There appears to be no cyclic distribution of floods but "that the dominating control is rainfall, and since there may be one, two or even three years of excessive rainfall, it follows that great floods may likewise occur
Of the European rivers, the Danube, the Seine, the Neckar, the Rhine and the Main are investigated. The records of floods in these rivers extend back many centuries and would provide ample data for any periodic recurrence, but these also are found to be dependent upon the nature of the watershed and the rainfall distribution. The conclusions derived from the paper are:
1. The records of both American and European rivers show an average of 7 to 10 great floods per century.
2. Great floods are primarily due to precipitation, and that precipitation, in the form of rain, which produces floods may be of two distinct types, (a) so intense and widely distributed as to produce flooding regardless of antecedent conditions; (b) moderate rains continued intermittently for eight to ten days or more with antecedent conditions favorable to high run-off.
3. There does not appear to be an orderly progression in the magnitude of floods with the lapse of years; that is to say, the absolute maximum flood of any 100-year period is not necessarily greater than the absolute maximum flood for the preceding 100 years.
4. The magnitude of great floods with respect to the average annual flood, seems to increase in geometrical progression but apparently wholly regardless of the flow of time.
5. Great floods like great rainfalls are essentially a local phenomenon even for the same stream.
This paper was discussed by Mr. Robert E. Horton, the hydrologic engineer, who is of the opinion that the occurrence of maximum floods is fortuitous and that the combinations
Warren Smith, of the United States Weather Bureau. This is the first text-book exclusively devoted to this subject and is certain to find a large demand, not only from agricultural colleges and universities, but also from the farmer and general reader, to whom it will be of practical value.
IN the October, 1919, Monthly Weather Review, there are several short articles and abstracts on forecasting from local signs, such wind direction, clouds, pressure change, clouds, sky colors, and the scintillation of the stars. It is interesting to note the difference in character of the forecasting problems in Europe, where data is incomplete from the west, and in America, where more data is available but a greater diversity of local problems is encountered. C. LEROY MEISINGER WASHINGTON, D. C.
A SIMPLE METHOD FOR TITRATING ELECTROMETRICALLY TO A DESIRED END POINT IN ACID-ALKALINE REACTIONS
SÖRENSEN1 and Clark and Lubs have published detailed directions for the preparation
1 Sörensen, "Über die Messung und Bedeutung der Wasserstoffionenkonzentration bei biologischen Prozessen," Ergebnisse d. Physiologie, 12, 393,
2 Clark and Lubs, "The colorimetric determination of hydrogen ion concentration and its application in bacteriology," Jour. Bacteriology, 2, pp. 1, 109, 191, 1917.
Ibid., pp. 866-867.