due to the portion of the electric field of the charges constituting the current which depends upon their acceleration. In the case of the open circuit under discussion the electromotive force along the central wire can not be calculated in any simple manner from Faraday's law, but it can be obtained at once from the series for the simultaneous electric field of a point charge given on page 40 of the writer's "Introduction to Electrodynamics." The necessary integration can be carried out without difficulty if we assume that the inner wire has a length small compared to that of the outer cylinder and is placed at the center of the latter. In this case the electric intensity along the axis is found to be

where both E and i are expressed in electromagnetic units and is half the angle subtended at the center of the tube by a diameter at either end. The current has been assumed to be uniform along the length of the tube, which would not be the case in the illustration previously mentioned. The electromotive force along the inner wire is obtained by multiplying this expression by the length of the wire. As the length of the outer conductor is increased cost approaches unity and E becomes great without limit.

The electromotive force is the same as if the current were concentrated in a generating line of the hollow cylinder instead of being spread over its surface. Therefore we can check the formula given above by considering the former inner conductor to be one side of a rectangular circuit lying in the plane of the two conductors just considered and extending to infinity on the side away from the generating line. If we calculate the electromotive force along the long sides of the rectangle by the method employed above we get an expression per unit width of the circuit equal to the second term in the formula above, but opposite in sign. As the electromotive force in the distant short side of the rectangle is negligible, the total electromotive force around the entire circuit is given by the first term of the formula, for a rectangle of unit width. But if we calculate the magnetic flux through the rectangle and then compute the electromotive force from Faraday's law we are led to the same expression. LEIGH PAGE

SLOANE PHYSICS LABORATORY,
YALE UNIVERSITY

SIR JAGADIS CHUNDER BOSE AND HIS LATEST BOOK

THE delicacy of the political situation in India, the prominence of the Bose family, the unusual taste for

biology possessed by one of its members, the strain of mysticism in the minds of all the East Indians with whom we come into contact-these factors and their sequelae have produced a singular situation in the scientific world. As a result biologists, or at least botanists, may be divided, without serum-diagnosis, as Bosephile or Bosephobe: and to have a neutral reaction is taken to indicate either a degree of ignorance or a feebleness of backbone quite deplorable.

In the first place, there is no question that Sir Jagadis Chunder Bose is the most distinguished biologist in India. The wealth of his family has secured for him freedom from economic anxiety, has built and supported for him the Bose Institute in Calcutta, where, under his directorship, the study of reactions to stimuli in the living and the lifeless is carried on in accordance with his tastes and methods.

Bose's recent book, "Plant Autographs and their Revelations," is the address of an enthusiast to an audience conscious of ignorance and desirous of enlightenment. From its dedication to his wife, "who has stood by me in all my struggles," to the last paragraph, "Not in matter but in thought, not in possession nor even in attainments, but in ideals, is to be found the seat of immortality," one sees the idealist, the mystic, dealing with facts too few in number, too incompletely understood, too imperfectly apprehended in their relations, quite too inaccurately measured and recorded, to justify conclusions put forward as knowledge. The conclusions are interesting, suggestive though not new, and are entirely legitimate if correctly labeled: but they are not science, they are not knowledge; they are belief, they are a philosophy of life, a guide and interpretation of conduct.

The trouble with Bose, as I see it with my occidental eyes and my American mind, is that while his curiosity is directed to biological phenomena, his mind is inadequately equipped with the information and the habits necessary for accurate study, and his reflections are addressed to philosophical problems. He is practical minded to the extent of using self-recording apparatus in his laboratory and social institutions in his human relations, but his ambitions exceed his capacities, his critical faculties are not applied to his methods and their results, his vocabulary outruns his findings. This may be illustrated by a quotation, typical of the whole book in spirit and defects: pp. 183-185. "Autographic Record of Assimilation:" "Water plants obtain their carbon from the carbonic acid dissolved in water. When sunlight falls upon these plants, carbonic gas is broken up, the carbon becomes fixed in the form of organic compounds known as carbohydrates, and an equal volume of oxygen is evolved which rises as a stream of bubbles from

2

the plant. The rate of evolution of oxygen indicates the rate of assimilation. Numerous difficulties were encountered in making this method practical; they have been overcome by my automatic recorder. A piece of a water plant, e.g., Hydrilla verticillata, is placed in a bottle completely filled with tank-water containing sufficient CO, in solution, the open end of which is closed by a special bubbling-apparatus, the bubbler, for measuring the oxygen evolved. The bubbler consists of a U-tube, the further end of which is closed by a drop of mercury acting as a valve. The oxygen evolved by the plant, entering the U-tube, produces an increasing pressure, which eventually lifts the mercury valve and allows the escape of a bubble of gas. The valve then immediately closes until it is lifted once more for the escape of another equal volume of gas. The movement of the mercury completes an electrical circuit, which either rings a bell or makes an electro-magnetic writer inscribe successive dots on a revolving drum (fig. 102). The automatic method eliminates all personal errors of observation; it is so extremely sensitive that it is possible to measure a deposit of carbohydrate as minute as a millionth of a gram. In illustration of the practical working of the apparatus I will give the following example. The plant with the apparatus is so placed as to face the northern light; the bell rings each time it has evolved a certain amount of oxygen representing an equal volume of absorbed CO2. If a person now stands obstructing the light, the assimilation is slowed down and the bell now strikes at longer intervals. When strong sunlight is thrown on the plant, the successive strokes on the bell become greatly quickened. The plant is such a sensitive detector of light that it may be employed as a photometer for indicating the slightest variations in the intensity of the light of the sky." I need not point out to the initiated the many individual faults, even errors, in this plausible and very interesting exposition, but certain comments may be made by the way. 1. Whatever may be the usage in India, or elsewhere in the English-speaking world, discussion has demonstrated that carbon fixation is a better term than assimilation, and that photosynthesis is still better because self-descriptive. 2. Water plants probably obtain as much carbon from carbonates and bicarbonates, where they are present, as from carbon dioxide which, in solution in water, may be called "carbonic acid." 3. "When sunlight falls upon these plants" much more happens than merely that "carbonic acid is broken up," for-to mention only one thing-the temperature rises, producing purely physical effects in the water, in the plant cells and tissues, and bubbles arise which are not wholly, and may not be even mainly, oxygen. Hence any apparatus devised to demonstrate photosynthesis and depending upon

evolution of gas in water of unknown composition, of undetermined temperature, in unmeasured light, should be used for demonstration, graphic representation, but never for one moment considered as measuring "a deposit of carbohydrate." This has been recognized for so long in botanical laboratories in this country that the method is employed only on the lecture table, or in elementary laboratory experimentation.

I do not need to multiply quotations. "Resonant recorder," "acuity of perception," "the plant biophytum is found to be eight times more sensitive than a European and four times more so than a Hindu"these also are fair samples of vocabulary, of deduction, and of aviation. It is a book as dangerous as it is fascinating. Would that it might be followed by a book of equal charm, but exhibiting the respect for the truth which keeps the occidental scientific man from mixing poetry, mysticism and grandiose generalization with his descriptions of the facts of nature! Nature is indeed more wonderful, more beautiful, more impressive than the products of man's imaginings, reflections and theorizings.

STANFORD UNIVERSITY

GEORGE J. PEIRCE

WHEN IS MID-WINTER?

I HAVE long intended to answer the communication by Charles H. Briggs in SCIENCE for April 29, regarding the date of midwinter, but have delayed until I could speak from observational data. I have never before heard the shortest day called the middle of winter. One should hardly expect the coldest weather to fall then, for though it is the day when the hemisphere receives least sunshine, yet the general run of weather should continue to grow colder so long as the solar energy received per day is insufficient to replace the heat radiated to space. For this reason the curve of temperature shows a lag in phase as against that of sunshine.

Our texts of descriptive astronomy and most almanacs tacitly accept the amount of this lag as a month and a half, making the four seasons coextensive with the four quadrants of the sun's apparent motion, thus calling the shortest day the beginning of winter. This. is an easy way of defining the seasons and one entirely independent of local conditions. Perhaps this last fact is one cause of its apparently wide accept

ance.

In addition to the astronomical definition, Webster and other lexicographers give as the "popular" definition of the seasons, groups of three months each,. beginning (for the U. S. A.) on March 1, June 1, September 1 and December 1, thereby antedating the astronomical seasons by three weeks. This has the

qualities of simplicity and independence of local conditions just as fully as the other, and is more convenient for tabular work. Just how popular and widely accepted it is I do not know. The Oficina Meteorológica Argentina uses it, transposed, of course, in all their summaries, but I must confess that I had not heard of this definition till I had occasion to look into their work.

A rational definition of the seasons should be based on the characteristics of the annual temperature curve. This will perforce introduce the local element, but that is not necessarily disadvantageous. Mr. Briggs defines midwinter in a way which seems logically sound and quite acceptable, though the 60° F. is perhaps a bit arbitrary. That his date of midwinter and half the coal supply does not agree with the proverb he cites vitiates neither, for the proverb refers to hay, which with other crops does not become available immediately the cold weather is over, but later in the growing season. Half the store of these should consequently remain some time after midwinter.

Partly to furnish Mr. Briggs data from South America for comparison and partly to clarify my own ideas on the matter, I have summarized the La Plata temperature record1 and have selected several other stations of wide geographical distribution from among the many discussed in the Anales de la Oficina Meteorológica Argentina. Since some stations have their annual range entirely above and another entirely below the 60° F. used by Mr. Briggs, a departure from his procedure was necessary. I have used as base line the general mean of the station and have defined midsummer and midwinter as the dates whose ordinates bisect the areas between the mean temperature and the observed temperature above it and below it, respectively.

From the table it will be seen that midsummer in 1 The readings at 7 A. M., 2 P. M. and 9 P. M. over ten (eleven) day intervals were averaged and then the corresponding decades of each year combined.

Argentina, as determined, agrees closely with midwinter in the Twin Cities as defined by Mr. Briggs. On the other hand, our midwinter is appreciably earlier than the date he deduces for midsummer. There is also an indication of later dates for midwinter as one moves southward while the date of midsummer varies less uniformly and by a less amount. I remember well the resentment felt as a boy when, on the occasion of a cold snap a week or so before Christmas, one of my elders remarked that winter had not yet begun. Perhaps this started vaguely the idea which has since become a conviction, that in the astronomical definition of the seasons the lag is grossly overestimated. In order to determine its true amount I have considered a tentative definition of the seasons on the basis of the temperature curve as follows:

That part of the curve of annual variation of temperature containing the maximum (minimum) and subtended by a horizontal chord 91 days in length is to be considered summer (winter); the intervening ascending (descending) portion is to be considered spring (autumn.)

Selecting from among the dozen stations used above those five with the longest series and applying this tentative definition to the smoothed (9c′ = a + 2b + 3c + 2d+e) decade temperatures, I obtain as the first days of summer and winter the dates given below:

There

How well we remember the last of these international congresses in 1912! There was the gathering in Washington in Continental Hall, where the leader of each national delegation spoke following the playing of his national anthem by the Marine Band. was a notable afternoon with the President of the United States, the reception, the half-day of sightseeing and then the special trains to New York where the work of the congress was conducted.

Columbia University and the College of the City of New York fairly swarmed with hundreds of chemists. The meetings, held on the sectional plan according to subject, were open to all and at stated times the congress gathered to hear the principal addresses delivered by representatives of the leading foreign countries. Here we heard the glowing account of the development of the arc process in Norway by Eyde himself. Bernthsen demonstrated that nitrogen and hydrogen could be compelled to combine to form ammonia. Perkin discoursed on synthetic rubber, and the address of Ciamician on photochemistry remains a classic. No one who saw the multitude of products of industrial chemistry which Duisberg brought from Germany will ever forget that occasion in the great hall at City College. Of course there were banquets, sight-seeing, garden parties and receptions, but they were incidental. The congress did real work, as the twenty-nine volumes now on our shelves amply testify. The International Congress was able to function without a continuous organization and without a paid secretariat and headquarters subject to national influ

that place and left it to him to form his own organization, work out the details and proceed. The war spoiled the congress planned for 1915, which was to have been in Russia, under the chairmanship of Dr. Walden, the eminent scientist who is the visiting lecturer at Cornell this semester.

It is history that the war gave rise to scientific organizations in several countries, and it is but natural that these should have been the ones to form a new international organization. With the effect of the war still upon them, conditions were at first imposed which prevented the adherence of the former enemy countries to the new union, but fortunately those difficulties have been remedied and any country, the science of which can be represented through a central national body, is welcome.

At first the principal business of the International Union of Pure and Applied Chemistry, which is sponsored by the International Research Council, was the creation of good will and better understandings and beginning anew the promotion of scientific work on a true international basis. Although some committees for scientific work have been formed, it is patent that the union has added little, if anything, to the sum total of scientific knowledge and has devoted itself more to questions of policy and diplomacy through social activities. This has been going on for eight years, but for the last year or two the active members of the union have come to realize that if it is to survive and perform a useful function its program must be changed.

The union is too much restricted in membership and in the number of individuals involved to accomplish its own ends. At present it brings together far too few really to hasten the day of better international relationships. If augmented in numbers it meets too often, and at the basis of it all is the neglect of its real opportunity again to make available the advantages of the world international congress. It is conceivable that some of the work of the union would require the meeting of a small group more frequently than once in three years, provided the union can be looked upon as a sort of nucleus or holding organization to which is entrusted the promotion of chemistry, international so far as the science is concerned. This involves assuming responsibility for a scientific congress to be held very much along the lines of the old international congress.

This subject from time to time has been forcefully brought to the attention of the officials of the union and was discussed at the Washington meeting when Ernst Cohen, the president, stressed the importance of organizing a truly international congress of chemistry along democratic lines. At the recent meeting in Warsaw articles providing for such congresses were pre

sented and incorporated into new statutes of the union. These articles were passed unanimously, but according to the union's rules must be held over until the next meeting, scheduled to take place in Holland in July, 1928. In order to avoid undue delay a committee has been set up charged with the formulation of detailed 522 plans for such international congresses. It is expected, therefore, that with the adoption of the new statutes the union will be in position to act upon the report of the committee. It seems unfortunate that there should be even a year's delay for many are becoming impatient, and it is already fifteen years since the chemists of the world have gathered together in a congress organized along democratic lines and devoted to science.

We hope that the International Union of Pure and Applied Chemistry will take leadership in this matter and make the most of its opportunities. It would be unfortunate should it be found necessary to set up any other organization. Industrial and Engineering Chemistry.

SCIENTIFIC BOOKS

Handbook of the Echinoderms of the British Isles. By TH. MORTENSEN. 471 pages, with 269 textfigures. Humphrey Milford, Oxford University Press, 1927.

IT is indeed gratifying that the Oxford Press should consider it possible to undertake the publication and general distribution of a large book dealing with a group as little known to the public as are echinoderms. The paper, printing, illustrations and binding are what we have learned to expect from the Oxford Press and are all that could be desired for such a volume. As the author occupies a preeminent position as a student of echinoderms, it is not strange that this handbook is by far the best general account of the group that has ever appeared. Taken as a whole, and considering the purpose in view, the volume is beyond praise. It is attractive in appearance, natural and thoroughly usable in arrangement, reliable in content and exhaustively complete for the area included. The number and quality of the illustrations are notable and enormously enhance the value of the book. Of course, there are some errors of both omission and commission, but they are chiefly of a trivial character or involve matters where there is room for difference of opinion. One detail that invites criticism is the use of capitals for specific names, derived from personal names. This is usual among botanists, but most zoologists long since abandoned it. Dr. Mortensen has, however, clung to botanical custom.

In an interesting preface Dr. Mortensen explains the inception of the book and the reasons for including under the term British Isles an area vastly more extensive than the term usually connotes. The whole Northeastern Atlantic Ocean from Iceland to the Cape Verde Islands is included within the scope of the book so far as the deep water forms are concerned; of course, only those littoral forms are inIcluded which are known from the British Isles themselves or may reasonably be expected to occur there. Hence the book will be of service not only in Great Britain but in most parts of Western Europe and, in connection with deep sea work, far to the north, west and south of the British Isles.

The book opens with an admirable general account of echinoderms, covering in a few pages the main features of the structure, development, larval forms and distribution of the group and concluding with a key to the five well-marked classes of Recent forms. Similar treatment of each of these five classes makes up the remainder of the book, some 30 pages being given to the crinoids, 103 to the asteroids, 109 to the ophiurans, 96 to the echini and 88 to the holothurians.

The section dealing with the crinoids, or sea-lilies, treats of a dozen species, actually known from the area under consideration, each of which is figured either wholly or as regards essential parts. The artificial keys, however, include no fewer than 24 species of 20 genera, distributed in 8 families; these additional forms are those which may be expected to occur in the region. The treatment of the crinoids is notable for its freedom from unnecessary technicalities and details, while at the same time it is thoroughly modern and includes the latest available information about these relatively rare animals.

The use of the term sea-star, instead of starfish, is the first thing that catches the eye in the section dealing with the asteroids. This is a natural and sensible change and it is to be hoped that all zoologists will note and adopt it; perhaps it is too much to hope that the inaccurate term "starfish" will disappear at once from literature, but let us hope its days are numbered. The classification of the seastars is still in a state of flux, certain of the recognized families and orders being well-defined natural groups, while others are unsatisfactory and artificial. Dr. Mortensen has adopted as simple and usable a system as the complexity of the problem permits, recognizing 3 orders, represented in the British area by 20 families. There are 67 genera and 114 species represented in the numerous and very valuable keys, but only 47 of the species are actually known from the region concerned. Of these, 43 are well figured,