Page images
PDF
EPUB

Paris, entitled "Etudes de Photochimie" par Victor Henri. The front page of the book bears this further legend: Professor Henri, formerly assistant director of the "Ecole des Hautes Etudes " (Sorbonne), and much to my amazement at present "Directeur de laboratoire à l'Institut scientifique de Moscou."

I open the book with curiosity and read in the preface that this great work on photochemistry was begun by the author in Paris but since the war "la photochimie fut oubliée." In 1915 it was Henri's good fortune to be dispatched to Russia on an official war mission. Then the revolution broke out and -but here I make room and let Professor Henri tell his own story:

La révolution russe arriva avec toutes ses phases. Un souffle de vie nouvelle se leva. Un espoir d'organization scientifique générale amenant le progrès, c'est-à-dire augmentant la somme de bonheur de l'humanité, se réveilla et une période de vie active commença en Russie, à laquelle je fus mêlé à Mos

[blocks in formation]

CONCERNING OUR RELATIONS WITH TEUTONIC SCIENTISTS

TO THE EDITOR OF SCIENCE: I fear that Professor Henry Fairfield Osborn's letter in SCIENCE, June 4, 1920, quoting from and commenting upon letters from my esteemed friend Arrhenius and another colleague, will convey to many readers an erroneous impression in one very important particular, namely that there are scientists in the entente countries who would restrict the interchange of publications with scientists in the Teutonic countries. If there are any such entente scientists, I have not heard of them. I can safely parallel Professor Osborn's statement, "We paleontologists welcome the works of Othenio Abel," by saying that "We astronomers welcome the works of Struve

(Berlin) and von Hepperger (Vienna); we shall read these works as carefully as we have read those issued by them in 1913 and earlier; and as soon as peace is declared we shall unreservedly do our part in arranging that Struve and von Hepperger and their colleagues receive the published writings of American astronomers.

In the relief of present-day distress and suffering in enemy nations, to which the quoted Stockholm and Vienna letters refer, I feel sure that all American scientists are glad to contribute in accordance with their abilities, and without question as to what occurred in 1914-18. I doubt if any appeal for assistance from this country has been made in vain.

[ocr errors]
[ocr errors]

There still remains the question of personal relationships in the future. Professor Osborn has quoted from one of the European letters as follows: every German believed [in 1914] a war would be much cheaper than the steadily increasing military expenses." This undoubtedly assumed, on the part of " every German," that the war would be short, that Germany would win it, and that Serbia, France, and Russia would pay the bills! In this precise connection should the world be permitted to forget that Germany would not consent to a reduction of armaments when the other nations at the Second Hague Conference in 1907, made and urged this proposal?

Professor Foerster, of the University of Munich, was quoted throughout the world early in 1919 about as follows: "We Germans have only ourselves to blame for the moral blockade which hems us in, and the raising of this blockade depends upon ourselves alone." Whether the quotation is correct or not, it faithfully represents widely prevailing opinion in entente scientific circles.

MOUNT HAMILTON, June 11, 1920

W. W. CAMPBELL

QUOTATIONS

MEDICAL EDUCATION

DURING the last thirty years the feeling has become increasingly insistent, both in this

country and in America, that certain radical reforms were needed in the methods of education in medicine. But our American colleagues have been fortunate in having the opportunity and the means for building new schools of medicine to meet the new circumstances and for making drastic changes in their methods of teaching which a variety of circumstances has hitherto prevented us from attempting in Britain. Now that the Rockefeller Foundation, by its magnificent generosity, has made it possible for us to embark upon the difficult sea of reform, it is particularly interesting and instructive to study the policy adopted in the more advanced schools of America during the twenty-seven years since the Johns Hopkins Medical School gave the study of medicine in America a new aim and a higher ideal. Though we are a quarter of a century behind our American colleagues in making a start, our delay has given us the advantage that we can profit by the experiments made on the other side of the Atlantic.

It is not generally recognized here how thoroughly the leaders of medical education in America explored every possible method of education throughout the world, and how much devotion and thought they have expended on experiments to discover, by truly scientific methods, how best to employ the few years that the medical student can devote to the training for his profession. Those who want to understand something of the spirit and the high deals that have inspired the American leaders in this great reform movement should read the account of their work and aims in the volume "Medical Research and Education," issued by the Science Press in New York in 1913. Briefly expressed, the matters upon which chief insistence is placed are as follows: The absolute necessity of (a) an adequate preliminary education and a serious university training in the basal sciences, physics, chemistry, and biology, without which foundation it is impossible for the student really to profit from his training in medical science; and (b) a method of practical teaching in all branches of professional work, whereby the student can, so far as

[blocks in formation]

The great development in the science of anatomy during the last thirty years has been due mainly to the use of the microscope for the investigation of the structure of the body and for the study of embryology. British anatomy has been hampered by the lack of the facilities for teaching these vital parts of the subject, and has suffered enormously from the lack of stimulating daily contacts with them. In other countries, and especially in America, the cultivation of histology and embryology has not only made anatomy one of the most active branches of medical study and research, but also brought the work of the department into close touch with physiology, biochemistry and pathology, to the mutual benefit of all these subjects, and especially to the student who has to integrate the information acquired in the different departments. It was the radical reforms effected in the teaching of anatomy by the late Professor Franklin Mall at the Johns Hopkins Medical School in 1893 that played the chief part in starting the great revolution in medical education in America. The stimulating influence of the abolition of the methods of medieval scholasticism in anatomy and the return to the study of Nature and to the use of experiment brought about a closer cooperation with other departments and a general quickening of the

[blocks in formation]

19, No. 10, pp. 317-334, one plate, two textfigures. February 13, 1920.

Professor Kofoid, the leading student of the Flagellata, in a brief but important paper, discusses convincingly the morphology and relationship of Noctiluca. The data and their bearing are well indicated in the author's summary, as follows:

1. Notiluca is a tentacle-bearing dinoflagellate with a sulcus, girdle, and longitudinal and transverse flagella.

2. The sulcus is longitudinal and midventral. It includes the apical trough and the recessed oral pouch and cytostome.

3. The tentacle arises from its posterior end. 4. The girdle has hitherto been overlooked. It is a shallow trough at the left of the sulcus and at right angles to it. It is seen best in small individuals.

5. The longitudinal flagellum is reduced and lies within the oral pouch. The transverse flagellum is represented by the prehensile tooth at the proximal end of the girdle at the left of the base of the longitudinal flagellum. This organ exhibits structural undulations and spasmodic or rhythmical contractions.

6. Distention by hydrostatic vacuoles, with flotation replacing active locomotion, has led to degen. eration of the flagella and their reduction in size, and to the almost complete disappearance of the girdle.

7. Noctiluca belongs in the Noctilucidæ, a family of the tribe Gymnodenioida, with Pavillardia, another tentaculate, naked, non-ocellate dinoflagellate.

8. There is no morphological justification of a separate order of flagellates to hold Noctiluca, such as the Cystoflagellata Haeckel.

9. The Cystoflagellata may be retained as thus emended to receive Leptodiscus and Craspedotella pending discovery of their affinities.

MAYNARD M. METCALF

THE ORCHARD LABORATORY, OBERLIN, OHIO

SPECIAL ARTICLES

THE EFFERENT PATH OF THE NERVOUS SYSTEM REGARDED AS A STEP-UP TRANSFORMER OF ENERGY

THE properties of nervous tissue which fit it for its peculiar rôle in the animal economy

are given by Sherrington as (1) excitability (2) spatial transmission of impulses and (3) control of the liberation of energy in contiguous tissues. Pawloff and others have emphasized the rôle of the peripheral sense organs as energy transformers, since the energy of light or heat or sound is transformed, by appropriate mechanisms, to the energy of a nerve impulse. Lucas and Adrian's all or none hypothesis of nerve conduction calls attention to another aspect of the work of the nervous system as a transformer of energy. According to this hypothesis, the nerve impulse conducted by any single nerve fiber is at all times the maximum impulse which it is capable of conducting. The evidence in favor of this view appears to be steadily accumulating, although there are still conditions under which the energy relationships are not clear. The efferent paths of the nervous system appear to me to furnish additional confirmation of the general truth of the hypothesis.

Neurologists have frequently commented on the relatively few nerve fibers in the main motor tracts of higher animals, i. e., the pyramidal tracts, as compared to the number of fibers in the ventral roots of the spinal nerves and the great mass of muscles to be activated. According to von Monakow, Redlich, Schäfer and others, fibers of the pyramidal tract do not end directly about the cells of origin of the motor nerves, but about some intermediate or intercalated cells in the spinal cord. Von Monakow has supposed that each of these intermediate cells comes into relation, through the branching of its processes, with more than one motor cell in the spinal cord. Furthermore, the axone of each peripheral motor nerve may branch on its way to its effector. There is a possibility, therefore, that each descending fiber in the pyramidal tract of the spinal cord may ultimately be able to actuate several terminal axones in the peripheral motor system. Suppose that one pyramidal fiber may, through the intercalated neurone, come into relation with three cells of origin of peripheral fibers,

[blocks in formation]

at the periphery by six branches of axones, each of which is in its turn capable of acting upon an effector. The energy, a, coming down the first fiber in the series, Py, is, according to the all or none hypothesis, the maximum which the fiber is capable of conducting. Similarly, the energy passing over the intercalated (Int.) fiber before its branching is also the maximum which it is capable of conducting. Suppose that it is equal to a. At the point of branching, the energy conducted along each branch must either be brought up to some quantity closely approximating a, or else it must fall to a/3. In the latter case, the energy passing over the proximal unbranched portion of the fiber M must either be brought up to the value a, or else in its turn be close to the value a/3. Going on out to the bifurcation of this fiber, there must again be a raising of the energy in each of the branches to some value closely approximating a, or else it must fall to a value a/6. There is little or no evidence that the energy of the nerve impulse falls off in any such degree in its passage from central system to periphery. The presumption is, therefore, that the efferent distribution path acts as a step-up transformer of energy, although the manner of its action is as yet unknown. It should be stated here that the nerve fiber itself furnishes the energy, derived in some manner as yet unknown from its own metabolic processes, and that there is, in all probability, no change in voltage at the expense of the amperage, as in the electrical transformers with which the physicist is familiar.

Reference to Ranson's1 diagram of the sympathetic system will show that the same considerations apply there. In fact, the diagram given in this paper was suggested by Ranson's diagrams.

One more link in the scheme of the step-up transformer may be what Langley has called the receptive substance, interposed, chemically if not histologically, between the motor end plates and the contractile substance in muscle. It is certain that there is a great increase in the energy of a muscle contraction as compared with the energy of the nerve impulse, which, starting in the central system, finally evokes the muscle contraction at the periphery. It seems reasonable to suppose, in the light of our present knowledge, that the efferent nerve path is a part of this transformer system.

Such general relationships of the energy of the response to the energy changes in the processes preceding the response have long been recognized. Balfour Stewart (p. 163) remarks: "We have seen that life is associated with delicately-constructed machines, so that whenever a transmutation of energy is brought about by a living being, could we trace the event back, we should find that the physical antecedent was probably a much less transmutation, while again the antecedent of this would probably be found still less, and so on, as far as we could trace it." We should recognize, however, that such relationships have a limit in the living organism. Otherwise, we would arrive at perpetual motion. F. H. PIKE

DEPARTMENT OF PHYSIOLOGY,
COLUMBIA UNIVERSITY

ON SPIRAL NEBULE

ONE of the privileges of the vacation is the opportunity of making one's own tea in one's own vessels. I did so recently, aided by a deep precipitation glass, g, with a lip, l, running far down the sides. On stirring the 1 Ranson, S. W., 1918, Journal of Comparative Neurology, Vol. 29, p. 306.

2 Stewart, Balfour, 1874, "The Conservation of Energy," New York, p. 163.

liquid with a spoon, energetically, and removing the latter, I noticed that a sharply outlined spiral was persistently present on the surface, until the deep paraboloid returned to the plane. My explanation would be, that at 7, part of the tangential velocity is converted into local vortical motion, whereby the particles at 1, because of the reduced centrifugal force, slide down the inclined plane of the rotating paraboloid. From another point of view, a stationary wave is produced on the surface by the interference at l.

g

д

FIG. 1.

Now though I will not venture to repeat the superscript of this note, I will nevertheless ask whether something analogous to the above simple experiment may not be taking place in astronomical space. Suppose we replace the glass vessel of the figure by a gravitational mechanism; and suppose we "lip" it at 1, by making that locality a region of effectively greater density and relatively at rest. If Kepler's law be written in the form so convenient in its present relations to the modern atom (M, being the virtual mass at the center and A the angular momentum per gram, whereby rv2= A2/r=M, for the tangential velocity v at r), then any local diminution of A in accordance with the above model, would be followed by a diminution of r in the part affected.

At all events the hydrodynamic experiment (rotational surface figures, as related to shape of boundary) is very beautiful and certainly more approachable. I shall allow myself to

[blocks in formation]

THE PACIFIC DIVISION OF THE AMERICAN AS-
SOCIATION FOR THE ADVANCEMENT
OF SCIENCE

THE Seattle meeting of the Pacific Division of the American Association for the Advancement of Science held June 17 to 19 at the University of Washington, Seattle, was perhaps the most successful so far held by the Pacific Division. Sixteen affiliated societies were scheduled in the final program and delegates were in attendance from every part of the Pacific Coast area. The representation from the University of California and Stanford University was particularly large.

The special sessions of the convention in which the various affiliated societies participated were well attended and the beneficial results of this cooperation were apparent. The conference of Research Committees from the educational institutions of the Pacific Coast held two sessions which were attended by all the delegates. The problems connected with the maintenance and encouragement of active research in the college and university were presented and discussed and some practical suggestions were made. It was felt that distinct progress in the solution of these problems had resulted from this meeting and that the research conference should be a permanent feature of the annual meetings of the Pacific Division.

A symposium on the "Einstein Theory of Relativity" was of general interest and was also well attended. In the symposium on "The Animal and Plant Resources of the North Pacific Ocean" given under the auspices of the Pacific Fisheries Society and the Western Society of Naturalists, each speaker emphasized the great need for more knowledge of the ocean and its life to save the fisheries industry. It is hoped that the means will be found to publish the papers in this symposium as a contribution to a better understanding of the importance of the projected exploration of the North Pacific Ocean through international co

« PreviousContinue »