indicate that an immense area of the bottom of the eastern Pacific is covered with manganese nodules, and that they play an important part in the character of the bottom, not only in the area covered by this expedition; the area of manganese nodules probably extends to the northwest of our lines to join the stations where manganese nodules were found by the Albatross in 1899 in the Moser Basin, on the line San Francisco-Marquesas. This area may also extend south of our lines Callao-Easter Island, and join the line west of Valparaiso, where the Challenger obtained manganese nodules at many stations. I do not nean to imply that the manganese nodules are present to the exclusion of radiolarians and of Globigerinæ. It is probable that the layer of nodules is partly covered by them, and by the thick, sticky, dark chocolate-colored mud which is found wherever manganese nodules occur.

During this expedition we sounded every day while at sea and developed very fairly that part of the eastern Pacific which lies to the south and west of the line from Cape San Francisco to the Galapagos and west of a line from Galapagos to Acapulco, limiting an area occupied by the Albatross in 1891. The area developed by us is included by a line 3,200 miles in length from Acapulco to Manga Reva and the area north of a line from Manga Reva to Easter Island and from Easter Island to Callao. We developed on our line Galapagos to Manga Reva the western extension of the Albatross Plateau, and found it of a depth varying from 1,900 to somewhat less than 2,300 fathoms in a distance of nearly 3,000 miles; but about half-way from the Galapagos to Manga Reva we came upon a ridge of about 200 miles in length with a depth of 1,700 to 1,055 fathoms, dropping rapidly to the south to over 1,900 fathoms. I propose to call this elevation Garrett Ridge. Our line from Manga Reva to Acapulco

continued to show the western extension of the almost level bottom of the eastern Pacific. In a distance of 3,200 miles the depth varied only about 400 fathoms. This great area was practically a mare incognitum. Three soundings in latitude 20° south towards the Paumotus and five soundings in a northwesterly trend from Callao to Grey Deep are all the depths that were known previously of this great expanse of water. This existence of the great plateau dividing Barber Basin along the South American coast from Grey and Moser Basins to the west is most interesting. It recalls the division of the southern Atlantic into an eastern and western basin by a central connecting ridge. The Albatross Plateau joins the western extension of the Galapagos Plateau as developed by the Albatross in 1891.

The existence of a sounding of 2,554 fathoms near the equator in longitude 110° west would seem to indicate a small basin included in this plateau disconnected from Grey Deep and Moser Basin by its extension to the west. How far west towards these basins that extension reaches no soundings indicate as yet. It is interesting to note that along the Mexican coast there are a number of deep basins lying disconnected close to the shore just as we found a number of disconnected deeps close along the South American coast extending from off Callao to off Caldera, Chili, opposite high volcanoes or elevated chains of mountains. These basins and a great part of the steep Mexican continental shelf are deeper than the Albatross Plateau to the south and form a deep channel separating in places the plateau from the steep continental slope. The steepness of the continental shelf is well seen, especially off Acapulco and Manzanilla. One of the small basins along the Mexican coast, with 2,661 fathoms, lies off Sebastian Viscaino. Bay; another, with more than 2,900 fath

oms, is to the west of Manzanilla Bay; a third, to the southeast of Acapulco, has about the same depth, and a fourth, with 2,500 fathoms, is off San Jose, Guatemala. Our last sounding off Acapulco about 29 miles south of the lighthouse, in 2,494 fathoms, showed the western extension of one of these deep holes to the east of Acapulco. These basins off the west coast, close to the shore at the foot of a steep continental slope, are in great contrast to the wide continental shelves which characterize the east coast of Central America and the east coast of the United States.

The collections made during the present expedition will give ample material for extensive monographs on the holothurians, the siliceous sponges, the cephalopods, the jelly-fishes, the pelagic crustaceans, worms and fishes of the eastern Pacific, as well as on the bottom deposits and on the radiolarians and dinoflagellates, diatoms, and other protozoans collected by the tow nets. Small collections of plants were made at Easter Island and Manga Reva which may throw some light on the origin and distribution of the flora of the eastern Pacific.

SCIENTIFIC BOOKS.

Radioactivity. By E. RUTHERFORD, D.Sc., F.R.S., R.R.S.C., MacDonald Professor of Physics, McGill University, Montreal; Cambridge Physical Series. Cambridge, University Press, 1904.

6

Within recent years books dealing specifically with radioactivity or the cathode rays have naturally not been infrequent. Beginning with the pioneering treatise of Stark ('Elektricität in Gasen,' 1902), Madam Curie's account of radioactive substances, Villard's rayons cathodiques,' G. C. Schmidt's 'Kathodenstrahlen' (1904), Besson and D'Arsonval's 'Le radium' (1904), Blondlot's 'rayons N' (1904) and others, have followed in quick succession. But Mr. Rutherford's book is on quite a different scale from most of these, and written in a way that betrays consummate

mastery of the subject. One would have been grateful if he had given us merely a systematic account of his own researches. The book before us does much more than this, presenting a readable and most painstaking digest of the subject as a whole, or at least of that splendid part of it which owes its development chiefly to English genius.

In the introductory part separate chapters are devoted to radioactive substances, to the theory of ionization, and to methods of measurement. Then comes a long account of the nature of the radiations. The sharply articulated descriptions which follow, and the suggestions lavishly offered for the completion of most of them, are a feature of the book here and in succeeding chapters. The short account of the rate of emission of energy is absorbingly interesting, and would be startling if our expectation were not blunted by the expressions of astonishment so much in vogue in connection with this subject. In the chapter on radioactive matter, Mr. Rutherford develops the important principle that the activity of a product at any time is proportional to the number of atoms which remain unchanged at that time, a subject to which he has himself so prolifically contributed. This is supplemented by a long chapter on radioactive emanations, giving a succinct account of the work for which the Rumford medal of the Royal Society was recently awarded.

The interesting phenomenon of excited radioactivity, of which Rutherford shares the honor of discovery with the Curies, is next discussed in detail and leads naturally to the final résumé on radioactive processes, in which the full theory of atomic disintegration is developed. The consequences of this theory have been brilliantly substantiated, even in the more recent papers which Rutherford contributed to the congress at St. Louis and elsewhere. At the end of the chapter is a summary of the present state of our knowledge of the age of the sun and of the earth. book closes with an account of the radioactivity of ordinary materials.

The

We have noticed but few misprints: p. 55, m for u; p. 265, t for n; p. 336, omission of dt. We should have been grateful, however, for a

more generous use of italics. Mr. Rutherford is apt to express himself with no uncertain sound against the interminable drawl of less gifted investigators. Nevertheless, the subject of radioactivity, which is now in the glare of the footlights, may not be there indefinitely, and a more liberal variegation of the text for the benefit of the lazy reader, may not in any case be an unreasonable condescension.

To have produced a fresh book, broad in scope and accurate in its statements, on a subject which has now for years been the chief topic of animated discussion in the physical and other magazines, is Mr. Rutherford's great merit in this work, quite apart from its character as a summary of original investigation. CARL BARUS.

BROWN UNIVERSITY, PROVIDENCE, R. I.

Die Ernahrung der landwirtschaftlichen Nutztiere. Von Dr. O. KELLNER, Geh. Hofrat und Professor, Vorstand der Kgl. landw. Versuchstation Möckern. Berlin, Paul Parey. 1905. 8vo. Pp. viii 594. Cloth. Price 13 Marks.

Notwithstanding the vast amount of investigation upon stock-feeding problems which has been carried on during the last forty years in the experiment stations of Germany and later of the United States. as well as to a certain extent elsewhere, it is unfortunately true that the theoretical basis of the subject has shown relatively little advancement since Henneberg's earlier researches in the sixties. We still, as then, reckon largely with the socalled 'digestible nutrients' (protein, carbohydrates and fat) and still assume that their amount measures, at least approximately, the nutritive value of feeding stuffs. True, we have had an uneasy consciousness for some time that this was far from being strictly correct, but in the absence of any better method of comparison we have rather blinked the fact and each writer has followed in the footsteps of his predecessor with, perhaps, the addition, of late years, of some more or less critical statements regarding energy values.

Dr. Kellner's book marks a new departure

in the literature of the subject. Its wellknown author was the first to suggest, in the year 1880, in connection with investigations upon the nutrition of working horses, that the values of different feeding stuffs might be compared upon the basis of their content of potential energy. Within a comparatively few years thereafter the study of the food as a source of energy to the animal organism was systematically taken up by Rubner and the foundations of the subject were laid. Since then a large amount of investigation upon the nutrition of carnivorous animals and of man has been executed in which Rubner's work has furnished the guiding idea. As regards the nutrition of domestic herbivorous animals, however, scarcely any investigations had been made from this standpoint when, in 1893, Dr. Kellner was called to the directorship of the Möckern Experiment Station. There he at once took up the subject, his first results and an outline of his methods being published in 1896. Since that time the work has been carried forward vigorously under his direction and most important results have been secured.

The present book embodies the results of Kellner's investigations, including many that have as yet been published only in abstract, but covers a much broader field than a mere compendium of this work and is an attempt to treat the subject of stock feeding systematically from the new standpoint. The book is divided into three parts. Part I. treats of the composition, digestibility and utilization of feeding stuffs, containing chapters upon the constituents of feeding stuffs, the digestibility of the feed, the utilization of the digested materials in the animal body, the metabolism of matter and energy under various conditions and the influence of muscular work on metabolism. Part II. treats of feeding stuffs, covering such subjects as methods of harvesting and preserving, the preparation of feeding stuffs and a somewhat detailed description of the different feeds. Part III. treats of the feeding of farm animals under the conditions of agricultural practise, including maintenance feeding, the fattening of mature animals, the feeding of working animals, the feeding of

growing animals and the feeding of milking animals.

Part I., and especially the chapters upon metabolism, will be of much interest to the student of nutrition in general, but the special value of the book is found in Part III., in which is made the first serious attempt to apply the more recent knowledge regarding the energy relations of feeding stuffs to practical use. It abandons definitely the assumption which has underlain nearly all previous works of this character that the digestible nutrients, so-called, of a feeding stuff are a measure of its value. In place of this, Kellner puts the actual productive value as worked out by his own investigations and which is shown to differ very widely in many cases from the indications given by the digestible nutrients. While he does not fail to point out that the basis for an undertaking of this sort is still somewhat narrow, yet he believes that the time is ripe for a beginning. He has accordingly, in the appendix, given a series of tables in which the productive value of feeding stuffs is estimated, largely upon the basis of his own results, while the so-called feeding standards are also expressed upon the same basis.

While it is, perhaps, to be regretted that the author has expressed his feeding values in the form of starch equivalents instead of boldly adopting the terminology of energy, and while it can not be denied that his tables are based to a considerable degree upon estimates, nevertheless the book promises to mark a distinct stage of development in the theory of stock feeding and will be welcomed by the large number of those who have become dissatisfied with the present conventional methods in this subject. H. P. ARMSBY.

SCIENTIFIC JOURNALS AND ARTICLES. THE contents of the American Journal of Mathematics are as follows:

ALEXANDER CHESSIN: 'On a Class of Differential Equations.'

L. P. EISENHART: Surfaces with the Same Spherical Representation of their Lines of Curvature as Pseudospherical Surfaces.'

VIRGIL SNYDER: 'On the Forms of Sextic Scrolls having no Rectilinear Directrix.'

LEONARD EUGENE DICKSON: Determination of the Ternary Modular Groups.'

THE April issue of the Journal of Nervous and Mental Disease opens with a paper by Dr. William P. Spratling and Dr. Roswell Park, on Bilateral Sympathectomy for the Relief of Epilepsy,' with report of three cases, and notes on the physiologic effects of cutting the sympathetic, and on the histologic changes found in the cases in question. The microscopical findings are illustrated by two plates. Dr. F. W. Langdon follows with a paper on myelomalacia, with especial reference to diagnosis and treatment, illustrated by charts, and Dr. Arthur Conklin Brush discusses the medico-legal aspects of traumatic epilepsy. The Society Proceedings reported this month include the meeting of the Boston Society of Psychiatry and Neurology held November 17, 1904, and that of the Chicago Neurological Society of the same date.

SOCIETIES AND ACADEMIES.

THE GEOLOGICAL SOCIETY OF WASHINGTON.

THE 166th meeting was held on March 22. The regular program included:

The Coal Measures of Brazil: Dr. I. C. WHITE.

Dr. White discussed the character and distribution of the coal-bearing beds of southern Brazil. The series consists of coarse conglomerates, and gray sandstones at the base, alternating with blue and gray shales up to 350 to 400 feet above the granite upon which the measures rest in the states of Santa Catharina and Rio Grande do Sul, where his principal studies were prosecuted during the past year. Above these basal sandstones, the coal beds occur three to four in number through a thickness of 200-250 feet of alternating gray sandstones, clays and shales. There are two principal coals, the 'Bonita' bed at the base, and the Barro Branco' near the top of the coal series. The coal is high in both ash and sulphur, but can be used successfully for locomotives, stationary boilers, etc., in a region. where imported coal costs not less than $10 per ton at the seacoast.

Above the coal-bearing member succeeds a series of sparingly reddish clays, and gray sandy shales and sandstones which are followed by light blue shales up to a horizon of dark limy shales which in the states of Paraná and São Paulo contain numerous reptilian remains, Stereosternum tumidum of Cope having been found at this horizon, as well as many fossil stems of trees, etc.

Dr. White found at this horizon in Paraná what Osborn pronounces a new form, specifically and possibly generically different from Cope's. It resembles Mesosaurus tenuidens of Gervais from the Karoo beds of South Africa.

Above the black shales, red beds of alternating shale and sandstone become conspicuous, while capping the same is a great massive conglomerate sandstone often baked and vitrified by the immense outflows of diabase, and basaltic eruptives which penetrate the series at all angles, and which piled in enormous masses on top of the sedimentaries make up the Serra Geral. The entire sedimentary series has a thickness of 2,250-2,500 feet.

Two prolific horizons for fossil plants were discovered by Dr. White, one only 200 feet above the base of the series, and the other 150 feet higher. In these was discovered the genus Glossopteris and other forms, some of which are new to science, and which have been entrusted for study and description to Mr. David White. The evidence from the fossil plants and animal remains appears to place these rocks in the Permian, and to correlate the formation with the Karoo beds of South Africa, and the Gondwana series of India.

The Dwyka and Talchir conglomerates of those countries appear to have a corresponding representative in the coarse conglomerates which rest upon the granite in Santa Catharina and Rio Grande do Sul, fifty to sixty miles inland, from the Atlantic coast.

Dr. White will return to Brazil during the present summer to finish up his studies of this coal series for the Brazilian government. Flora of the Brazilian Coal Measures: Mr. DAVID WHITE.

The paleobotanical material collected by Dr. I. C. White was discussed with special refer

ence to its relation to the Glossopteris province. The greater part of the material is from two horizons and localities. The first, near Minas, Santa Catharina province, in a bed below the productive coals and only about 200 feet above the old crystallines, reveals Glossopteris indica, Gangamopteris obovata, G. cyclopteroides, Phyllotheca cf. australis and Noeggerathiopsis Hislopi, besides several new generic and specific types. The second important collection, from the roof of the Irapua coal, in the province of Rio Grande do Sul, at a horizon determined by Dr. White as about 150 feet higher, it being among the productive coals, contains Glossopteris indica, Noeggerathiopsis Hislopi, Ottokaria sp. and Cardiocarpon sp. The occurrence of Lepidodendron Pedroanum, Lepidophloios laricinus and the lepidophytic spores, previously reported from Brazil and especially interesting as showing the contact of the Glossopteris, or Paleoantarctican, flora with the northern Carboniferous flora, becomes all the more interesting and important in view of their local stratigraphic position which was found by Dr. White to be still a little higher than that of the plants last named. The inclusion of southern Brazil in the Indo-Australo-South African or Glossopteris' province is, therefore, fully confirmed by the evidence thus brought to hand. The Glossopteris, found abundant though fragmentary at Irapua, represents the form described by Seward from South Africa, where it is similarly associated with representatives of the northern lepidophytes. The new material tends to corroborate the conclusion reached by M. Zeiller, that the Brazilian coals are probably of Permian or possibly latest Coal Measures age, their place being apparently in the KarharbariNewcastle stage.

Mr. W. T. Schaller described the 'Tourmaline Mines of California.'

GEO. OTIS SMITH, Secretary.

THE CHEMICAL SOCIETY OF WASHINGTON.

THE 158th regular meeting of the society was held Thursday evening, April 13, in the