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PROFESSOR H. H. CHAPMAN returns to the Yale Forest School to assume his duties as Harriman professor of forest management. He has been assistant district forester, in charge of silviculture at Albuquerque for the past two years.

Ar the recent commencement the following appointments were made in the department of zoology, college of liberal arts, Syracuse University: Dwight E. Minnich, Ph.D. (Harvard, '17), of Oxford, O., instructor in zoology; Harry S. Pizer, M.Sc., of Brooklyn, N. Y., assistant in zoology.

DR. FRANK A. HARTMAN, of the department of physiology, the University of Toronto, has been appointed head of the department of physiology at the University of Buffalo.

COLONEL J. G. ADAMI, F.R.S., professor of pathology, McGill University, Montreal, has been elected vice-chancellor of the university in succession to Sir Albert Dale.

PROFESSOR GRAFTON ELLIOT SMITH, professor of anatomy in the University of Manchester, has been appointed to the chair of anatomy at University College, London.

DISCUSSION AND CORRESPONDENCE TECTONIC FORM OF THE CONTINENTS OUR prevailing notion concerning continental mass is strictly geographic in significance. In our definition tectonics finds no place. Relation of sea and land is made causal and essential; whereas it is only accidental and trivial. The outstanding feature is a broad basin with high mountainous rim and a low sea-level interior. This is a statement of the observation of the late Professor J. D. Dana. In its larger, or telluric, aspects this definition is genetically without meaning.

In the final analysis of the major relief features of our globe the hydrosphere is for simplicity's sake left out of account. The effect then is as if the entire face of the earth were a land area. A condition is premised analogous to that of our waterless moon. Genetically the oceans serve only to obscure the tectonic essentials of relief expression.

Recent experimental reproductions, in spheroidal masses, of those broad basinal tracts that correspond to the oceanic depressions of the geoid are accompanied by results having curious significance. They point to the fact that we shall have to modify our basic conceptions concerning all the major deformations of the earth's crust.

Instead of distinguishing between continental elevations and oceanic depressions, a circumstance imposed by an unweening importance attached to the presence of the sea, a notion handed down from time immemorial, the proper discrimination to be made is between the cordilleran ridges of the continental borders and the intervening lowlands, whether above the level of the waters in the continental interiors, or beneath sea-level in the oceanic areas. On this basis the tracts which we are accustomed to designate the oceanic depressions and the sea-level interiors of the continents are arranged in the same taxonomic category. Consideration of any such datum plane as sealevel may be with full propriety entirely neglected. The meridional disposition of the continents thus comes to be readjusted as relatively narrow orographic ridges in place of broad basin-shaped plateaus.

The tectonic consideration of a waterless earth casts a new light upon the schematic form of our globe. In its logical consequences the contractional hypothesis finds expression in such figments of the imagination as the reseau pentagonal of Elie de Beaumont, and the tetrahedral globe of Lothian Green. To be sure the form known as the tetrahedron is of all geometric solids the one form which possesses the least volume in comparison with a given surface area, while the sphere contains the greatest bulk within the same surface; yet the collapse of the latter is not necessarily a crystallographic shape as that indicated by the former.

In the present state of our knowledge any schematic form of our earth is largely conjectural. However, it is suggested lately that in the case of a collapsing spheroid the initial tendency towards a faceted form would prob

ably not be directly in the line of any limiting shape, as a four-sided figure, but towards something intermediate between a limiting shape and the most general form, or a figure having twelve or twenty-four faces. That the rhombic dodecahedron is possibly the real plan, if there be any, although having in nature curved surfaces, seems to be borne out by the trend of the chief mountain ranges of the world, and by the situation of the main volcanic activities at the sharp solid angles or the points where each set of faces intersect.

Viewed, then, in their telluric relations the continents are probably best regarded not as broad basins with upturned rims but as somewhat irregular, interrupted, meridianally disposed ridges. These ribs appear to be directly traceable in their genesis to released cumulative tension that depends upon the secular retardation of the earth's rotation. CHARLES KEYES

AMERICAN ASSISTANCE FOR RUSSIAN
EDUCATIONAL INSTITUTIONS

TO THE EDITOR OF SCIENCE: Revolution, war and anarchy threw Russia out of the rut of normal life. And in no phase of Russia's national life have the results been so disastrous as in public education, which can not be placed again on an adequate and normal footing without the assistance of the Allies.

Just before the war, there was adopted a plan for universal education, also for opening a number of higher institutions of learning, especially, technical and agricultural colleges. These educational institutions are open, but on account of complete lack of the supplies needed for conduct of studies and practical

work of the students, and, because it has been impossible to obtain apparatus, tools, etc., from Germany and Austria whence they formerly came, it becomes necessary to conduct the studies one-sidedly and incompletely and it is difficult to expect good results from such studies.

There is only one way of obtaining such supplies for Siberia, where several higher institutions of learning have recently been opened, and that is to purchase the supplies in the United States where, at present, most of

the laboratory instruments and other technical supplies, so far as I know, are manufactured and are quite satisfactory as to quality.

The writer, who came to this country as the representative of the Ministry of Agriculture, would like to dwell upon this mattter in reference to the laboratories and institutions in different branches of agriculture and experimental stations and also to throw light upon the general aspect of this question.

Equipment of the Russian educational institutions with necessary supplies is furthermore complicated by other circumstances, such as: lack of means and complete impossibility of making purchases for cash owing to very low exchange rate of the rouble at the present time. And, meanwhile, the matter of education is urgent and a way out of this difficult situation is possible only in case the American scientific and academic circles would realize that the problem of education in Russia at present is tragic, if they would have a desire to come to aid and organize such aid.

During the difficult struggle against the Bolsheviki, Siberia had an opportunity to become acquainted with and learned to appreciate the brotherly assistance of the American Red Cross in the matter of organizing hospitals and havens for refugees. The scientific educational matters as well as the work of the Red Cross may and must be outside of politics. It is sufficient to be in sympathy with a people in order to come to their assistance. And, if my American academic colleagues share this point of view and would give an impetus to this new movement in the matter convinced, the Americans would organize this of spiritual aid to Russia, then, I am firmly aid in as splendidly efficient a way as they have organized the Red Cross.

It is, however, self-evident that this aid must be given on an entirely different basis. There could be no question of charity, but simply the matter of facilitating the purchase of the necessary technical equipment by permitting purchases to be paid for in instal

ments.

I do not, by any means, offer my suggestion as the only feasible plan, but would only like

to indicate a plan which, it seems to me, could be realized and would suggest that it would be possible to work along the following lines: Let a competent American scientific-academic organization take up this matter. The writer can make a formal request on behalf of the Russian Ministry of Agriculture and the Ministry of Education. If the organization in question regards the matter favorably, i. e., it decides that it is expedient and necessary to render those portions of Russia which had been freed from the Bolshevik domination, assistance in the purchase of the books, the instruments, the glassware and other technical equipment for institutions of learning, laboratories and experimental stations, let such an organization enter into negotiation with firms who manufacture and supply the American scientific-academic institutions with technical supplies. The purpose of these negotiations would be the arrangement of easy terms of payment on the purchases which would be necessary. Further negotiations could be carried on by an authorized person who has lists of necessary articles and who might be assisted by the Russian Economic League or some other institution which does purchasing of different commodities for Russia. In this way, it will be something like a loan in goods, such loan being made with the spiritual aid of American scientific and academic circles and with certain concessions on the part of the American firms.

It might be mentioned that such concession should prove a very good business investment, since it would be an excellent foundation for substituting American apparatus and tools for the German articles which are the only ones used in Russian schools so far. This concession would be practically an equivalent of advertising American supplies in Russian educational institutions. The very fact of equipping the Russian institutions of learning with American supplies and having the Russian instructors work with the American-made apparatus and tools clears the way for general adoption of American apparatus and tools in Russia. The habit of using a certain kind of apparatus plays a more important part than may be supposed at first sight and it seems

that the time is ripe now to introduce in Russia the habit of using the products of American genius and industry.

I hope sincerely, that the suggestion set forth in this letter may be received sympathetically by the American scientists as well as by the special manufacturing and publishing firms which might be concerned with the carrying out of such a plan. I am ready to enter into all necessary negotiations in respect to this matter and I thank in advance any one who will be kind enough to help me with advice or suggestion concerning my efforts in this direction. N. BORODIN

FLATIRON BUILDING, ROOM 1010,

NEW YORK CITY

SCIENTIFIC BOOKS

The Elements of Astronomy. By CHARLES A. YOUNG. Boston, Ginn & Co. 1919. Pp. x + 508.

Lessons in Astronomy. By CHARLES A. YOUNG. Boston, Ginn & Co. 1919. Pp. ix + 420.

These are new and revised editions of the most excellent text-books of the late Professor Charles A. Young. From the time this series first appeared some thirty years ago, these books have held high rank among the many that have been written. They show a wide grasp of the fundamentals of astronomy, and these fundamentals are presented to the student in a clear and comprehensive manner.

The author's presentation of the problems involved in the study of the motions of the planets is especially noteworthy. For the mathematician these motions involve the greatest complications and require the most intricate formulas, yet Professor Young places the essential facts before the student in a simple and clear manner. By the aid of a few diagrams and some apt illustrations, the fundamentals of celestial mechanics are plained, and explained so clearly that the youngest student should have no difficulty in understanding the problems and in grasping the essential facts and principles.

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The present edition was revised by Miss

Anne S. Young, who retained the greater part of the original text and made such changes only as were necessary to bring it down to date. In general the changes were made with discrimination and the text shows an improvement. Astronomy, however, is not a complete science, and changes and improvements are continually being made. This is especially true of the applications of astronomy to practical matters. In some cases there have been marked improvements in the ideas and methods of thirty years ago, and too rigid an adherence to the original text on the part of Miss Young detracts from the general excellence of the revision. In the discussion of the tides, for example, there has apparently been no change, and the old theory of a world tide, originating in the Pacific and Indian Oceans, has been adhered to. No mention is made of the new theory advanced by the Coast and Geodetic Survey that the tides are purely local phenomena; that the tides of each locality originate in and are confined to that ocean basin of which the particular locality is a part; that the tides of the North Atlantic have no connection with those of the Pacific.

The "Lessons are for beginners, the "Elements" for the more advanced students. Both books are excellent and no better text-books have yet appeared for these classes of students. CHARLES LANE POOR

SPECIAL ARTICLES FURTHER STUDIES IN COLLOID CHEMISTRY AND SOAP

THE following summarizes experimental findings and theoretical deductions which continue studies reported in these pages last year.1

I

Our previous work had emphasized not only how from pure soaps and water most typical lyophilic colloid systems may be produced but in what way the chemical constitution of the soaps and variations in concentration, tem

1 Martin H. Fischer and Marian O. Hooker, "Ternary Systems and the Behavior of Protoplasm," SCIENCE, 48, 143, 1918.

perature, presence of electrolytes and nonelectrolytes, etc., changes the physical properties of these colloid systems. Practically all attempts to explain such changes are to-day electrical in nature. Without denying that electrical phenomena sometimes play a rôle, our newer experiments show that it may be very small or need not function at all.

Typical lyophilic colloid systems may be made of pure soaps in the practical or complete absence of all water. The pure soaps yield such colloid systems with the various absolute alcohols, benzene, toluene, chloroform, carbon tetrachloride and ethyl ether. We feel that our future definitions of lyophilic colloid systems and the understanding of their processes of swelling, gelation, syneresis, reversibility of sol and gel states, hysteresis, etc., must be expressed in the broader terms of mutual solubility. As the hope of getting all phenomena of “solution” reduced to electrical terms seems remote, the hope of getting these fundamental colloid chemical findings reduced to a similar level seems equally remote.

Of the list of effective "solvents," the alcohols have received most study. The solvation capacity of the different soaps (as measured by the maximum amount of alchohol that will be taken up to yield a "dry" or non-syneretic gel at ordinary temperatures) varies in the case of absolute ethyl alcohol for molar equivalents of the sodium soaps of the acetic series of fatty acids from practically zero in the lowermost member to over 27 liters per gram molecule in the case of sodium arachidate. When the solvation capacity of unit weights of any one soap for different alcohols is compared, it is found that this is different not only as mon-, di- or triatomic alcohols are used but different, also, for the different alcohols in any one of the series. For the monatomic alcohols, for example, the solvation capacity increases progressively and smoothly as the position of the alcohol rises in the series. A gram of sodium stearate will just form a gel at room temperature, for example, with 50 c.c. of methyl alcohol, but the same amount of the same soap will form a gel with over 132 c.c. of amyl alcohol. When sodium oleate is the soap employed all the absolute

absorption capacities for the different alcohols lie lower, but their order remains the same

II

If we attempt to say why we obtain these typical colloid systems from such a variety of materials we may begin with the fundamental and now generally accepted conclusion that colloid systems result whenever one material is divided into a second with the degree of subdivision coarser than molecular. A suspension colloid results whenever the colloidally dispersed phase is not a solvent for the "dispersing medium "; a hydrophilic or lyophilic colloid whenever the dispersing medium is such a solvent (and independently of the fact that the subdivided phase is solid, liquid or gaseous at the temperature employed). When soap is dissolved in acetone and the temperature is lowered the soap falls out as a colloidally dispersed suspension colloid because the acetone is not soluble in the soap; but the same soap dissolved in an alcohol, toluene or carbon tetrachloride, comes out as a lyophilic colloid because these solvents are soluble in the precipitating soap.

But the physical characteristics of the ultimately resulting system are not yet explained when we have thus taken into account the mutual solubility characteristics of their phases. In any given case, as with a given soap and its "solvent," four possible results and consequently four main types of ultimate system may be foreseen. At the top exists a non-colloid, "molecular" or ionized" " solution" of soap (soaped-solvent). For example may be cited a fairly concentrated solution of soap at a higher temperature. At the bottom is found another "solution" but of the solvent in the soap (solvated-soap). Between these extremes exist two main types of mixed systems, namely, one below the top which is a dispersion of solvated-soap in soaped-solvent, and another, above the bottom, which is a dispersion of soaped-solvent in solvated-soap. These are respectively the sols and gels about which we talk. A concentrated solution of soap in any solvent, it will at once be apparent, passes successively, on lowering of the temperature and when not too much solvent is

used, from the top of this series through the two middle zones to the bottom.

All the systems below the true solution at the top and above the true solution at the bottom are "colloid." Gel formation is characteristic of the middle zones. Such gels are "dry" anywhere below the point where enough solvated-soap falls out on lowering the temperature to yield a continuous external phase enclosing the soaped-solvent. Just above this point they sweat, the amount of such "syneresis" obviously increasing progressively as the amount of solvated-soap becomes inadequate to form a continuous external phase. If the "syneresis" is very great we no longer apply the term, for the syneretic liquid (soapedsolvent) now forms the continuous external phase. The colloid system is said to have remained or to have passed into the "sol" state.

Since change or rate of change in temperature (as well as other factors) affects the solubilities of the two phases in each other unequally it is obvious that the sum total of changes in any system need not be identical at any given moment and at any given temperature when the temperature is being approached from a higher level with the sum total of these same changes when the same temperature is being reached from a lower level. The attainment of equilibrium takes time and so the systems hold over the characteristics of the systems from which they came. This is the "hysteresis" of lyophilic colloid systems.

III

The effects of adding different hydroxides and different neutral salts in increasing concentration to standard soap 66 solutions" has received further study. In order to understand the effects observed and their explanation it is well to divide the experimental findings into three groups while keeping in mind the solubility characteristics of the pure soaps themselves in water and for water.2

1. Soaps are formed more soluble in the dispersion medium. The viscosity of the soap mixture regularly falls. This happens when

2 See our previous paper, Martin H. Fischer and Marian O. Hooker, SCIENCE, 48, 143, 1918.

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