408 



SCIENCE. 



[N. S. Vol. I. No. 15. 



I do not wish to be understood as opposing 

 the preparation and furnishing of an uni- 

 versal card index; the schemes proposed are 

 beautiful in the glow and shimmer of their 

 optimism — reminding one of Chimmie 

 Fadden, " Up t' de limit an' strikin' er great 

 pace t' git on de odder side of it," but they 

 must be looked at from the practical busi- 

 ness point of view by those who are to de- 

 fray the cost, and who have, I feel sure, 

 other important uses for their money and 

 for the skilled brains required for such work, 

 and more definite information is wanted 

 with regard to the number of titles, etc., 

 which must be indexed annually upon such 

 a scheme before a wise decision can be 

 made. For general Biology, Morphol- 

 ogy, Physiology, Bacteriology and scientific 

 Pathology, and other subjects of scientific 

 importance connected with medicine, I think 

 that about 10,000 cards a year would be 

 sufficient if all second-hand matter and hash 

 were carefully excluded. 



Very truly yours, 



J. S. Billings. 



Washington. 



SCIENTIFIC LITERATURE. 

 The Qreat Ice Age and its Relation to the An- 

 tiquity of Man. By James G-eikib, LL. D., 

 D. C. L., F. R. S., etc. Murchison Pro- 

 fessor of Greology and Mineralogy in the 

 University of Edinburgh, formerly of H. 

 M. Geological Survey of Scotland. Third 

 Edition, largely reAvritten, with maps and 

 illustrations. New York, D. Appleton & 

 Company. 1895. 8vo., xxviii + 850. 

 Twenty-two years ago the first edition of 

 this book appeared in England . The author 

 then endeavored to give a systematic ac- 

 count of the Glacial Epoch, with special 

 reference to its changes of climate. In so 

 doing he entered first quite fully into the 

 geological history of glacial and post-glacial 

 Scotland, presenting many elementary mat- 

 ters, and taking more than half the book 



for this purpose. Afterwards he discussed 

 the glacial phenomena as exhibited in Eng- 

 land, Ireland, Scandiaavia, Switzerland 

 and North America. A newly acquired - 

 view with him related to the age of the 

 paleolithic deposits of southern England — 

 all of which he referred to inter-glacial and 

 pre-glacial times. It was this book that 

 fu'st called the attention of manj' geologists 

 to the doctrine of several periods of cold in 

 the ice age separated by as many times of 

 milder conditions. Like the early doctrine 

 of Agassiz and Buckland that the drift phe- 

 nomena were to be explained bj' the agency 

 of glaciers, so this theory of a series of cold 

 and warm periods has been vigorously con- 

 tested by geologists, but bids fair to be as 

 generally accepted as the former. In 1877 

 a second edition of the book appeared. The 

 author remarks in its preface that great 

 additions to our kncjsvlege of the facts had 

 been made, above those first presented, all 

 of which strengthened his argument that 

 the epoch was not one continuous age of ice, 

 but consisted of a series of alternate cold 

 and warm or genial periods ; while the 

 ancient cave-deposits cannot be assigned to 

 a later date than the last genial interval of 

 the ice age, and some of them were probably 

 still older. Among the more important 

 alterations he notes a change in the use 

 of the terms till and boulder clay. Instead 

 of calling one purelj'' glacial and the other 

 partly marine, both are referred more or 

 or less directlj' to the grinding action of 

 glaciers, and are strictly synonjnuous terms. 

 Likewise he modifies his view of the kames ; 

 none of them are now regarded as of 

 marine origin. There has been no great 

 submergence of Scotland since the close of 

 the glacial epoch, and thus the Scotch depos- 

 its are brought into much closer relationship 

 with those of England. In the interim he 

 made many personal studies of the English 

 phenomena until able to say positively that 

 after the deposition of the ossiferous gravels 



