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own; so little advance has yet been made towards a general concensus of opinion in this new subject, the rational study of the forms of the land.

In its fundamental principles the classification of features proposed by Major Powell will endure, for it is based on structure and process, not on external form alone. In some other respects it does not seem acceptable, for there is a certain inconsistency and incompleteness in its terminology that is disturbing. For example, diastrophism having been defined in the first monograph as meaning upheaval or subsidence, with or without faulting or flexure, and gradation having been defined as including all processes of disintegration, transportation and deposition, we read in the second monograph that diastrophic mountains and diastrophic hills result essentially from the action of gradational processes on uplifted masses; but that diastrophic valleys, diastrophic cliffs, diastrophic cataracts and diastrophic islands result from movement alone without degradation; and no place is given to mountains of essentially constructional form, corresponding in origin to the diastrophic valleys and cliffs. Valleys of gradation, cliffs of gradation and gradational cataracts result from processes of degradation; yet it must of course be understood that the land masses acted on by gradational processes had in these cases, as well as in the case of diastrophic mountains or hills, in some way gained an effective height above baselevel; hence it would be more consistent to call most mountains and hills 'gradational;' and thus reserve the adjective 'diastrophic' for mountains and hills made by diastrophism, like diastrophic valleys and diastrophic cliffs. Gradational islands are deposits of land waste near shore, and gradational hills are heaps of debris left directly or indirectly by glaciers; while sand dunes are given an equivalent value with gradational hills, in

stead of being placed with glacial hills under a general gradational heading.

Sea plains are plains of ultimate denudation with reference to the sea as the controlling baselevel; the sea plain may be enlarged by sedimentation along its margin, but no mention is made of the numerous plains resulting from the uplift of smooth sea-bottoms. Lake plains are formed with their baselevel depending on the level of lakes; lake-bottom plains, revealed by the deepening of the lake outlet ("the waters of the lake rush through the newly opened channel, and the lake is drained in whole or in part," is an unfortunate suggestion of a sudden change that must be very rare in nature), are included, but without special name, under the same heading with plains produced by denudation of the surrounding land down to lake level; and without any indication that the latter are rare and the former common.

The gradual change of opinion regarding the comparative efficacy of marine and subærial erosion gives some justification of the small share of space devoted to the processes of the seashore; but it is to be regretted that they are so disproportionately condensed. After nearly two pages about inland cliffs of gradation, sea cliffs are dismissed with less than two lines of text: "On sea coasts and lake shores, sapping is carried on by the waves, and cliffs are often produced." Floods are rather fully treated and flood plains are given about two pages, but deltas are dismissed with the briefest mention. Coast-forms in the second essay have less than two pages of the total thirty. The explicit omission of seashore features, or their postponement to a later monograph, would have been preferable to so brief a treatment.

Those who have enjoyed Major Powell's eloquent accounts of his western explorations will be glad to see again here something of the fervor of his style; but in a

few cases it has led him too far for the creation of the best impression on readers so literal-minded and so ready to accept and quote authority as teachers are. It is overeloquent to say: "The tides sweep back and forth across the surface of the sea, and alternately lash the shores with their crested waves," or "The purple cloud is painted with dust, and the sapphire sky is adamant on wings." After all the efforts to drive 'burning mountains' out of school geographies, it is disconcerting to read here about 'floods of fire' from volcanoes. In view of the importance of the gentler processes of nature, it is unfortunate to find in the closing summary of the second essay a very figurative expression regarding the three great physiographic processes: "How fire, earthquake and flood have been involved in fashioning the land and sea." The plainspoken teacher will have difficulty here in distinguishing between poetry and prose.

There are occasional brief or over-generalized statements that must raise unnecessary questions in the teacher's mind. In mentioning the tides, the apparent diurnal rotation of the moon around the earth is worded: 6 As the moon revolves about the earth from east to west.' A little later, it is said: "The seas are heated under the tropics;" but schoolmasters are the very persons who know that the tropics and the torrid zone are not one and the same. The surface currents of the ocean are referred entirely to convectional movement in the ocean itself; no surface currents being ascribed to the winds; and it is said that "all surface currents drift eastward in going towards the poles;" although this is wide open to qualification. It is inconsistent with the teachings of modern physics to speak of the flow of... heat from the fiery globes of space.'

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The corrections of small things is a vexatious matter. It is little less than a nuisance to the author to have to stop for so

small a trifle as the choice between 'under the tropics' and 'within the tropics.' This distracts him from the main line of thought along which he is constructing his essay. Minute corrections call for mental characteristics that are petty in comparison with the creative ability that produces the essay itself; and from an author as independent and original as Major Powell self-correction of these relatively trifling verbal matters is hardly to be expected. Yet it will be unfortunate if the editing of the future monographs does not involve such revisions as will reduce their inconsistencies to a minimum; for when teachers discover that they can take exception to certain parts of their text, their confidence in the rest of it is weakened. They have not as a rule much sense of perspective in these matters; and, as with book-keepers, a little error is in their opinion about as dangerous as a great one. They are confirmed in this habit of thought by the character of the contests, of which they are frequent witnesses, that grow out of the rivalry of publishers and the strife of book agents. Knowing this, the best way to prevent the confirmation of the habit is to give it no opportunity for practice. Even though the personality of the author be in a measure lost, it is best to scrutinize very carefully all books intended for school teachers, and exclude from them every statement and phrase that will distract the reader from the essential line of thought and set him to differing from the author on matters of subordinate value. For this purpose an experienced book agent makes a most useful proof-reader; and his services should be secured, if possible, by those who are acting for the National Geographic Society in the supervision of these monographs. His advice will be found very serviceable to authors whose previous practice in writing has been on essays for scientific journals and governmental reports.

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Butterflies and Moths (British). By W. FURNEAUX. London, Longmans. 1894. 12°. This is by no means a complete treatise on these insects, which would be quite impossible in the 350 pages to which it is lim-, ited; but rather a selection has been made of such as the author thinks would prove most desirable. The number of British butterflies, however, is so limited (66 species) that place is found for all of them. A brief description and general account is given of each species mentioned, together with a figure of most of them; a certain amount of attention is paid to the early stages and especially to the caterpillar; but the book is very weak indeed on all points as to classification, the common characters of groups being hardly hinted at; it is therefore intended almost exclusively for the amateur, and not for the serious student. The introduction, which occupies about a third of the book, and is of as much interest to an outsider as to a Briton, is ехсерtionally good for a work of this class, though here again it is lean as regards all matters of structure or classification. The illustrations in the text, and they are numerous, are with few exceptions unusually good; those on the twelve colored plates not so good. The figure of the egg of Pieris brassica, on p. 14, is upside down.

S. H. S.

The Pygmies. By A. DE QUARTREFAGES. Translated by FREDERICK STARR. Illustrated. Pp. 255. D. Appleton & Co. 1895.

This volume forms number 2 of the Anthropological Series, edited by Professor Starr, of the University of Chicago. The original appeared in Paris about eight years ago, and the name of the distinguished author, as well as the interest of the subject, insured it considerable attention.

He approaches the topic historically with a chapter on the accounts of the pygmies

which are found in classical writings, and an attempt to analyze them in the light of modern research. Turning to later sources, a full history is supplied of what was known ten years ago of the dwarf tribes of Melanesia, of the Mincopies of the Andaman islands, of the Negritos of Indonesia, of the Negrillos of Central Africa, and of the Hottentots and Bushmen of the southern portions of that continent. Special attention is given to the physical peculiarities of the tribes mentioned and to their sociologic condition. A chapter of some length is devoted to the religious beliefs of the Bushmen and Hottentots, successfully controverting the statement often advanced that these humble peoples had no religion at all. The illustrations, thirty-one in number, are fairly well done, though printed rather carelessly. The translator has accomplished his task well, and the text reads pleasantly.

It is to be regretted that the large material accumulated in the last ten years on this subject was not more freely called upon. Mr. Haliburton, Professor Kollman and Dr. Virchow have contributed monographs which should not be overlooked. Emin Bey's anthropometric reports on the Negrillos are the best we have; but these names are not referred to. We should have liked, also, a chapter on the causes which bring about decrease in stature, a physiological study of its etiology. Probably any people would become dwarfs under given conditions, and the trait is therefore not a racial one. D. G. BRINTON.

An Introduction to Structural Botany (Flowering Plants). By D. H. SCOTT. London and New York, Macmillan & Co. 288 pp. 113 figs. $1.00.

The author intends that this shall be a book for beginners. Three types are chosen to illustrate the structure of the flowering plants, the wall flower (Cheiranthus Cheiri

L.); the white lily (Lilium candidum L.); and the Spruce fir (Picea excelsa Link). He has also introduced a chapter of 32 pages on the 'physiology of nutrition.' The language of the book is exceedingly simple. Some of the original figures are very good. In general it may be stated that the subjectmatter is well treated. The author intends at some future time to present in a similar way the cryptogamic types.

The fact that the author begins the study of structural botany with the highest types will be objected to by most modern botanists. Many will also question the advisability of attempting to present structural botany in an elementary way.

ALBERT SCHNEIDER.

NOTES AND NEWS.

ARGON.

M. BERTHELOT has communicated to the Academy of Sciences the fuller details which he promised concerning his experiments upon argon. Towards the end of February he received from Professor Ramsay 37 cubic centimètres of the gas, with which small quantity he has obtained positive results of the greatest interest. Following the process by which he formerly effected the direct combination of nitrogen with various organic compounds, he finds. that argon is equally absorbed by these bodies, though apparently with somewhat less facility. The action of the silent discharge upon a mixture of argon and benzene vapor is accompanied by a feeble violet luminosity visible in the dark. In one of five experiments he found that a fluorescent substance was produced, which developed a magnificent greenish light and a peculiar spectrum. M. Berthelot took 100 M. Berthelot took 100 volumes of Professor Ramsay's gas, added a drop or two of the hydrocarbon, and exposed the mixture to the silent discharge at moderate tension for about ten hours. The ex

cess of benzene vapor being removed in the usual way, the mixture was found to have been reduced to 89 volumes. More benzene was then added, and the experiment was repeated with higher tension, which in three hours produced a reduction of volume equal to 25 per cent. On again submitting the gaseous residue with benzene to very high tension discharge he found the final result to be 32 volumes. Analysis showed this residue to contain only 17 volumes of argon, the other 15 volumes being hydrogen, free or combined, and benzene vapor. In other words, M. Berthelot has effected the combination of 83 per cent. of the argon under experiment, and was prevented only by the dimensions of his apparatus from carrying the condensation yet further.

The quantity at his disposal was too small to permit of complete examination of its products, but he is able to say that they resemble those produced when nitrogen mixed with benzene is submitted to the silent discharge. That is to say, they consist of a yellow resinous matter condensed on the surface of the glass tubes employed. This matter on being heated decomposes, forming volatile products and a carbonaceous residue. The volatile products restore the color of reddened litmus paper, proving the production of alkali by the decomposition, though the quantity of matter at command was too small to allow of its nature being demonstrated. In any case, M. Berthelot concludes, the conditions in which argon is condensed by hydrocarbons tend to assimilate it yet more closely with nitrogen.

He adds that if it were permitted to assume 42 instead of 40 as the molecular weight of argon-an assumption which the limits of error in the experiments hitherto made do not, in his opinion, exclude this weight would represent one and a half times that of nitrogen; in other words, argon

would stand to nitrogen in the same relation as ozone to oxygen. There is, however, the fundamental difference that argon and nitrogen are not transformable into one another, any more than the isomeric or polymeric metals. Without insisting upon points which are still conjectural, M. Berthelot observes that in any case he has demonstrated that the inactivity of argon disappears in the conditions he describes. When the gas can be obtained in considerable quantities, he says it will be easy by ordinary chemical methods to take these primary combinations, or their analogues obtainable with oxygen, hydrogen, or water, as a point of departure for the preparation of the normal series of more simple compounds.-London Times.

AT the anniversary meeting of the Chemical Society, Professor Ramsay stated that he had examined the gas (which according to an observation of Hillebrand's was nitrogen) given off by the mineral clevite when treated with sulphuric acid, and discovered that it contained argon. Spectroscopic examination showed a very bright yellow line nearly coincident with the yellow sodium line. This line was found to be identical in position with the yellow line observed in the spectrum of the sun's chromosphere, and attributed to the hypothetical element helium. Whether helium could be separated from argon remained to be seen. Mr. Crookes gave some additional particulars of the spectrum of the gas from clevite. He found certain coincidences with the band spectrum of nitrogen, particularly in the ultra violet region, but some lines were present which were not found in the nitrogen spectrum, and vice versa.

DR. B. BRAUNER, Professor of Chemistry in the Bohemian University, Prague, has written to Nature, suggesting that argon possibly exists in nebulæ. He points out that a strong argon line, measured by Mr. Crookes, has practically the same wave

length as the chief nebula line, and thinks that the line at 3729.8 in the 'blue' spectrum of the new substance represents the line at 3730, found in the spectra of nebulæ and white stars.

PALEONTOLOGY.

PROFESSOR H. J. SEELEY has recently published a paper in the Philosophical Transactions upon The Reputed Mammals from the Karroo Formation of Cape Colony, in which he reconsiders the evidence as to the mammalian nature of Theriodesmus and of Tritylodon. He established the former genus some years ago upon a fore-arm; the latter was established by Richard Owen in 1884, upon a skull. In his previous papers the author has described both of these types as mammalian, and the skull has invariably been placed with the mesozoic Monotremes, owing to the resemblances which its teeth present, both in the crown and in the multiple fangs, to other mammals of this very ancient and widespread group of multituberculates. Professor Seeley, in his renewed examination of the skull of Tritylodon, believes that he finds evidences of 'postfrontal' and 'pre-frontal,' and possibly of a 'transverse' bone, as in the Theriodont reptiles. This evidence he considers overweighs the distinctively mammalian characters of the teeth. If it is subsequently confirmed by more satisfactory material this will be another example of the independent development of what we have always considered distinctively mammalian characters within the reptilian class. Another remarkable species of an undoubted reptile is the Diademodon tetragonus, in which the single-fanged or reptilian molar teeth are capped with crowns which bear a most striking resemblance to a low-crowned quadritubercular mammalian molar. These discoveries in the Karroo Formation promise to yield most interesting and surprising results, although if the position here taken

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