and many others are projected. Among them is a formaldehyde factory at Vetluga, and a technical laboratory for the production of lanolin, naphthalene, etc., at Rostov. A large company has been formed at Moscow for the production of coke-benzol products and at Tomsk a chemical factory is projected for the making of medical chemicals. Several new works for making sulphuric acid have been. erected in the Volga region, in the Donets basin, in the Caucasus and in the Urals. Mirrors, lenses and other optical instruments, thermometer tubing and chemical glass, formerly imported, are now being made. There is a large demand for microscopes and other scientific apparatus, as well as for articles for medical and surgical use. Ar a meeting of the board of managers of the Cold Spring Harbor Biological Laboratory of the Brooklyn Institute of Arts and Sciences, the completion of an endowment of $25,000 for the laboratory was announced. The principal donors are: Mr. W. J. Matheson, estate of Colonel Robert B. Woodward, Mr. Walter Jennings, Mr. A. A. Healy, Mr. August Heckscher, Mr. Cleveland H. Dodge, Mr. Louis C. Tiffany, Mr. Howard C. Smith, Mrs. E. H. Harriman, Colonel T. S. Williams, Mr. Henry F. Noyes, Mr. Albert Strauss and Mr. Donald Scott. It is expected that the laboratory will now become one of the four fundamental departments of the institute, and will be under the special care of a governing committee of the trustees of the institute. ALTHOUGH New York was not included among the states where a serious fungous disease of poplars was reported by the federal authorities, the State College of Agriculture at Ithaca announces that the disease has been found on Long Island. This disease is similar in appearance to that which destroys the chestnut trees and may be found on any species of poplars or cottonwoods. Trees attacked by this fungus show cankers or depressed areas in the bark, which spread rapidly and often girdling the twig, limb or trunk of the tree and killing the part above the canker; the trees become ragged in appearance and finally die. This is especially true of the Lombardy poplars so often planted in rows along highways. The fungus which causes this disease, according to the authorities, was imported from Europe, and is especially severe on stored and transplanted nursery stock. The centers of infection appear to be, in every case, either certain nurseries known to contain diseased trees, or points where poplars from such nurseries have been planted. Residents of New York who think their trees are affected by the disease may receive exact information by sending samples to the department of plant pathology, New York State College of Agriculture, Ithaca, New York. THE Rizzoli Orthopedic Institute of Bologna has inaugurated an exposition of orthopedic appliances, to be held at Bologna in February under the auspices of the national federation of committees engaged in welfare work for blinded, mutilated and crippled soldiers. The institute has announced a prize of 5,000 lire for the best appliance, and is urging others to collect funds for additional prizes. PROFESSOR L. C. KARPINSKI writes that the first volume of the "Nouvelles Tables trigonométriques fondamentales" by Professor H. Andoyer, of Paris, mentioned in a recent review in SCIENCE as delayed by the war, appeared in 1915. This volume of 341 pages + lxviii pages includes the sines and cosines for each one hundredth of the quadrant to 20 decimal places, for each 9 minutes to 17 places, and for each 10 seconds to 15 decimals. UNIVERSITY AND EDUCATIONAL A GIFT of $20,000 from Mrs. George Putnam to Harvard University was announced at the last meeting of the president and fellows. The money will be used to establish a fund in memory of Mrs. Putnam's brother, James Jackson Lowell, and the income will be used for the purchase of books for the college library. THIRTY-FOUR thousand guineas have been subscribed to the South Wales University College for the extension of scientific and technical education. THE University of Stockholm has received from Mrs. Amanda Ruben the sum of 50,000 kroner to found a readership in experimental zoology. DR. B. C. CROWELL, professor of pathology and bacteriology, University of the Philippines, has been appointed director of the Graduate School of Tropical Medicine and Public Health of that university. This school gives courses which in one year lead to the degree of Doctor of Tropical Medicine and in two years to Doctor of Public Health. DR. H. B. FANTHAM, of Christ's College, Cambridge, has been appointed to the professorship of zoology at the South African School of Mines and Technology, Johannesburg, and Dr. C. E. Moss, of Emmanuel College, has been appointed professor of botany in the same institution. WE learn from Nature that Dr. Johanna Westerdijk has been appointed associate professor of phytopathology in the University of Utrecht. She is said to be the first woman to receive such an appointment in Holland. DISCUSSION AND CORRESPONDENCE THE LIMIT OF THE SPECTRUM IN THE ULTRAVIOLET IN the Astrophysical Journal for March, 1916, I gave an account of my work in the extreme ultra-violet. During the past year I have continued my investigations in the same field; the results have not been commensurate with the labor, but it is perhaps worth while to make a brief report of them. I have not changed the general design of my spectroscope but I have replaced the 100 cm. grating by one of 50 cm. radius, thus halving the light path and considerably reducing the volume to be exhausted. My source of light is still a quartz discharge tube, but I have so altered the design that the end of the capillary can be brought much nearer the slit of the spectroscope than before; I have considerably increased the potential of the transformer; as before, I employ helium at one or two millimeters pressure to fill my spectroscope and discharge tube. The net result of these changes is that I have certainly extended the spectrum from 600 to the neighborhood of 510 Ångströms; a trace of a line exists on my very best negative near 450 Ångströms, but it is far too faint to afford trustworthy evidence. From time to time during the past five or six years I have tried Wood's miniature arc in vacuum, and a variety of vacuum spark arrangements, recently I have repeated the more promising of these experiments. None of these sources appear to yield lines in the most refrangible region. Helium continues the most promising source. THEODORE LYMAN JEFFERSON PHYSICAL LABORATORY, THE FOUNDATIONS OF DYNAMICS AND DADOURIAN'S ANALYTICAL MECHANICS My attention was called recently to a review of the second edition of my 66 Analytical Mechanics" by Professor E. W. Rettger, which appeared in SCIENCE (No. 1130) last summer when I was in the mountains and did not see it. The review on the whole was favorable and would not have tempted the author of the book to make an answer at this late date were it not for the fact that the two questions raised by the reviewer bear upon the foundations of the science of mechanics. The first of these is directed against my direct application of the laws of vectors to the directed magnitudes of mechanics: Before we apply the law of vector addition to any kind of quantity, ought we not first assure ourselves that the parallelogram law holds for these quantities? Since force, for instance, is a directed quantity (italics are mine) does it follow that the parallelogram law holds for forces? I would answer both of these questions in the affirmative. We have no right to apply vector operations to "any kind" of quantity. We ought to assure ourselves that the quantity in question is a "directed quantity" before treating it as such. But having once assured ourselves of this fact we need not hesitate to apply to it the parallelogram law or any other law of directed quantities. Vector algebra is the science of directed lines, or displacements, in space as ordinary algebra is the science of numbers. We do not hesitate to apply the laws of ordinary algebra to quantities which can be represented by numbers, we need no more have any compunction about applying the laws of vectors to quantities which can be represented by directed lines. The expression "the law of parallelogram of forces" is a provincialism for which there is about as little justification as there would be for a "law of the addition of apples" in arithmetic. The addition law of arithmetic is a law of numbers and is not Sim peculiar to apples; it can be applied to apples not because they have certain desirable properties, but because they can be counted. ilarly, the parallelogram law is a law of displacements or directed lines, and not at all characteristic of forces, but it can be applied to forces because these have among other physical properties those of direction and of magnitude and consequently may be represented by directed lines. This is the precise point of view which I have adopted in my book toward the directed magnitudes of mechanics. After giving a clear and concise exposition of the laws of addition and resolution of vectors in the first chapter I have applied them to directed quantities without hesitation. This mode of procedure is not only correct, but it is straightforward and simple, as the reviewer admits when he says: If the author is correct . . . then certainly the theory underlying the composition and resolution of directed quantities becomes very simple. The second question which Professor Rettger raises has to do with my formulation of the principle underlying the science of dynamics. In my book I have based dynamics upon the following principle, which I have called the action principle: The vector sum of all the external actions to which a system of particles or any part of it is subject at any instant vanishes. ΣΑ = 0. A particle may be acted upon by other particles and by the ether. The action of one particle upon another particle is known as a force. The action of the ether upon a particle I have called a kinetic reaction. Therefore the action principle states Σ(F+ q)=0, where F denotes a force and q a kinetic reaction. The kinetic reaction on a particle is oppositely directed from and proportional to the acceleration and the constant of proportionality is the characteristic constant of the Therefore we have particle known as mass. (F-ma) = 0. Commenting upon this principle, Professor Rettger says: The reviewer does not wish to say that the author is wrong in his conception. All he wishes to say is that he entirely fails to appreciate the author's point of view. This lack of appreciation is due, it seems to me, to a lack of clear understanding, indicated by the following questions, of the nature and function of the kinetic reaction. Why is it that the ether acts on a body only when it is being accelerated and not when the body is moving with constant velocity? If kinetic reaction is the action of the ether on a particle, and if it is the same kind of a quantity as force (is a force in fact), and if the resultant force F acting on a particle and the kinetic reaction q are always equal in magnitude but opposite in direction (both equal to ma in magnitude), why is the body not in equilibrium? If in the first of these questions the term why" is used in the metaphysical sense, there is no answer for it, except possibly the equally metaphysical answer "because." On the other hand, if it is used to mean "how is this fact correlated with other facts?" I would state that the answer belongs to electrodynamics and not to mechanics and would refer the reviewer to a modern treatise on electrodynamics, Lorentz's book on "Electron Theory," for instance, where the question is answered at length. Answering the second question, one might state: "The body is not in equilibrium for the same reason that a particle revolving in a circle is not in static equilibrium in spite of the fact that the so-called 'centrifugal' and 'centripetal' forces acting upon the particle are equal and oppositely directed." I am afraid the reviewer has overlooked the fact that a particle is in static equilibrium when and only when the sum of the forces due to other material bodies acting upon the particle equals zero. When this condition is not satisfied the particle is accelerated and by virtue of the acceleration the kinetic reaction comes into play. This kinetic reaction is equal and opposite to the resultant of the forces due to the material bodies. If it were not for the kinetic reaction a finite force would have given a body an infinite velocity in a finite time. The kinetic reaction is of the same nature as a force and might be called a force, but that would tend to confound the cause with the effect. It would further necessitate changing the statement of the conditions of equilibrium as well as of motion. It was in order to keep the old concept of force as an action which causes acceleration and to distinguish between cause and effect that I refrained from applying the term force to kinetic reactions. The concept of kinetic reaction is not new. It has been known to other authors of textbooks of mechanic as centrifugal force, inertia force, or inertia reaction. The thing that is new about kinetic reaction in my book is the full recognition it receives and the clear cut treatment which differentiates it from accelerating forces. I have preferred the name kinetic reaction to inertia reaction because it is just as much an acceleration-reaction as an inertia-reaction. I claim that the point of view which I have adopted in my book has important philosophical and pedagogical advantages over the common point of view. The former has enabled me to differentiate between purely geometrical laws and dynamical principles, between kinematical relations and dynamical equations, between what is fundamental and what is derived in mechanics. I have postulated a single dynamical principle which is not only simple and sound, but is correlated with the equally fundamental principles of electrodynamics. Upon this single principle I have based the entire subject, deriving from it all the other dynamical laws and principles used in elementary mechanics, such as Newton's three laws of motion, the principles of the conservation of energy, of linear momentum and of angular momentum. Before closing this communication I would like to call the attention of teachers of mechanics to the following principle which I have introduced in the second edition of my book and have called it the angular action principle. The vector sum of all the external angular action to which a system of particles or any part of it is subject at any instant vanishes: ΣΑ = 0, made precisely the same observations on the behavior of colonies of the same species of harvestmen (Phalangida) in the neighborhood of Austin, Texas. These colonies are not uncommon, nesting in masses on the lower surfaces of overhanging rocks along the canyons of the Colorado River and its tributaries and in the Edwards Plateau region. The colony described by Newman was unusually large, as I do not recall seeing any that were much more than a foot or a foot and a half in diameter and comprising, perhaps, between two and three hundred individuals. The rhythmic, simultaneous, up and down movement of the creatures on their long sensitive legs, when disturbed, is very striking. Merely approaching the spot where the Phalangids are congregated is sufficient to set the whole assemblage vibrating. The stimulus in this case is probably the air-current produced by the sudden approach of the observer and is probably propagated, as Newman suggests, by contact among the interlaced legs. In many cases of synchronic behavior, however, other stimuli must be assumed. In fireflies the initiation of the simultaneous flashes must be due to optic stimuli, as it is in people endeavoring to keep in step with one another, but the continuation of the established rhythm would seem to depend on a kind of "Einfühlung." Such is undoubtedly the impression produced on one who witnesses the rapid wheeling movements of a herd of prong-horned antelopes on our western plains or the flight of certain birds. Some years ago I observed that pelicans flying in single file over the Bay of Panama exhibited a very pronounced synchronism in the beat of their wings. In this case I was led to assume that after the members of a flock had established the synchronism, probably by visual stimuli, it was kept up by a fine sense of rhythm on the part of each individual. BUSSEY INSTITUTION W. M. WHEELER MORE COMPLETE TITLES TO THE EDITOR OF SCIENCE: When the student of the structure or the functions of animals needs to consult the literature dealing with any form on which he has worked, he meets at the outset with the difficulty that a large number of papers to which he turns fail to show in their titles the names of the animals that were used. In view of this familiar, but none the less unfortunate, state of affairs, I wish to inquire through your columns whether there is any valid objection to the suggestion that authors in some way incorporate in their titles the names of the animals used for their investigations. In some cases common names would answer, but more often the binomial Latin form would be required. In the case of little known forms, and especially in the case of insects, it would be of great help if the family or order were also given. Should there be no serious obstacle to the step here suggested, the improvement could easily be inaugurated by the concerted action of the editorial boards of our several biological journals and those heads of departments and bureaus through whose hands forthcoming manuscripts naturally pass. HENRY H. DONALDSON THE WISTAR INSTITUTE, PHILADELPHIA, PA., February 3, 1917 SCIENTIFIC BOOKS Milk and Its Hygienic Relations. By JANET E. LANE-CLAYPON, M.D., D.Sc. Longmans, Green & Co. 1916. This admirable book has been published under the direction of the Medical Research Committee (National Health Insurance, England). The chief aim of the author "is to present a survey of the existing knowledge upon such aspects of the milk question as hitherto has been inaccessible or difficult to obtain by most of those desiring it." The scope of the book includes a consideration of the composition, "biological properties," and cellular content of milk; the nutritive value of raw, boiled and dried milk; the presence of organisms liable to cause disease, and milk-borne epidemics; the sanitary production of milk, types of bacteria, methods of |