920 



SCIENCE. 



[N. S. Vol. XX. No. 522. 



can be no certainty whether these leaves be- 

 long to the genus Populus. Mr. Seward is 

 content to place them in the general group 

 Phyllites. It is greatly to be hoped that the 

 Stonesfield beds may be more thoroughly 

 searched for further material of this class. 



Lester F. Ward. 



Geology of the City of New York, with a 

 geological map. By L. P. Gratacap, A.M., 

 of the American Museum of Natural His- 

 tory. Second edition. 1904. Privately is- 

 sued. Royal 8vo. Pp. 119 ; 35 figs., 3 plates. 

 Interest in nature-study has become of great 

 and increasing importance in our general sys- 

 tem of secondary schools. Both teachers and 

 pupils are being led to observe more clearly 

 the world about them, and are coming to know 

 the plants, animals and rocks. In a great 

 center of population like New York city the 

 teachers and pupils make up a well-nigh 

 countless multitude, and as regards the local 

 geology the call for a book of instruction and 

 reference is very urgent, as is the need for 

 good but elementary lectures. The latter 

 need, the authorities of the American Museum 

 of Natural History with their rich equipment 

 in specimens, lantern slides and charts, have 

 met; and the former need, the author of the 

 work before us has satisfied in a very interest- 

 ing and attractive way. Congratulations are 

 due him that the book has reached a second 

 edition. 



The work opens with a brief geographical 

 outline and takes up next the topographical 

 features of the four constituent boroughs. 

 The original outlines of Manhattan Island 

 have of course suffered great modification and 

 a very interesting and detailed record of these 

 is given. The matter is timely, because the 

 tendency to remove and forget the ancient 

 landmark, is all too great in American cities 

 and an interest in early local history and a 

 fondness for one's home and dwelling place 

 are all too slightly developed. 



A discussion of the rock formations follows 

 with some very good pictures illustrating their 

 mode of occurrence and structural features. 

 The author is almost ultra-conscientious in 

 his endeavor to give due credit to the several 



writers who are cited. The topic of the water- 

 ways receives attention, as does that of the 

 bibliography and of the minerals. Following 

 these the other boroughs than Manhattan are 

 passed in review and a discussion of the gla- 

 cial geology closes the work. 



Mr. Gratacap still adheres to the Archaean 

 age of the metamorphic rocks of Manhattan 

 Island (p. 45) as against the Palseozoic de- 

 terminations more especially of Professor J. 

 D. Dana and Dr. P. J. H. Merrill, and as the 

 latter's views have been fully set forth it 

 would be of interest to hear the other side 

 defended at length. 



Mr. Gratacap ought to have included in the 

 preparation of his work a table of contents 

 and an index. It is a great handicap to the 

 usefulness of a book of 119 pages, with many- 

 figures and a map, to lack these essentials. 



J. P. Kemp. 



Materialen der Stereochemie, in Form von. 



Jahresherichten. Edited by C. A. Bischoff. 



Vols. I. and II., pp. cxxvi -|- 1978. Braun- 

 schweig, P. Vieweg nnd Sohn. 



This comprehensive work consisting of two 

 large volumes aggregating over two thousand 

 pages, is a continuation of the well-known 

 work on the same subject, published in 1894 

 by the same author in company with Professor 

 P. Walden. This collaborator has also assisted 

 occasionally in the new compilation, but the 

 great bulk of the work has been done by Pro- 

 fessor Bischoff. The matter is developed year 

 by year, each yearly section being divided into 

 four subdivisions, namely: 



I., General Stereochemistry; II., Optical 

 Isomerism; III., Geometric Isomerism of Op- 

 tically Inactive Bodies; IV., Relations Be- 

 tween Space-distribution and Chemical Reac- 

 tions. 



Obviously the form of arrangement de- 

 mands elaborate indexing; hence the editor 

 has prefaced his work by a table of contents 

 of 126 pages, and given it an index of 99 

 pages as epilogue. Even as it is, the table of 

 contents almost needs an especial index of its 

 own. 



The work is characterized by the qualities 

 which are already familiar in the earlier work. 



