Geology and Natural History. 159 



10. Die JSfeue Welt der Flussigen Kristalle * by O. Lehmann. 

 8vo, pp. 388. Leipzig, 1911 (Akademische Yerlagsgesellschaft). 

 — To anyone acquainted only with ordinary crystals, the idea 

 of a liquid crystal — a substance which, if deformed, will flow back 

 into crystalline shape — is hard to grasp. Professor Lehman is 

 the discoverer of this class of substances and has done more work 

 in the field than has any other investigator, so he speaks with 

 authority. 



Rather curiously, liquid crystals are hardly mentioned in the 

 first hundred and fifty pages of the book. Instead various other 

 subjects are considered which are often only remotely connected 

 with liquid crystals but which have been investigated by the 

 author at one time or another. For instance, there is an account 

 of the author's discovery of the transition temperature and a 

 description of his crystallization miscroscope. The description of 

 liquid crystals, their preparation and properties, occupies about 

 a hundred pages and appears to be very well presented. There 

 are chapters following which it is difficult to account for in a 

 book of this character — chapters, for instance, on the growth of 

 living things, latent life and soul (latentes Leben und Seele), 

 atom souls (Atomseelen), and muscle power (Muskelkraft). 



Taken as a whole, the book is an account of the author's scien- 

 tific work rather than an account of liquid crystals. The part 

 devoted to the latter appears to be very good. The rest may be 

 excellent, but it is on subjects having little to do with the title 

 page. h. w. f. 



II. Geology and Natural History. 



1. Thirty-second Annual Report of the United States Geo- 

 logical Survey. George Otis Smith, Director. Pp. 143 ; 

 2 maps. Washington, 1911. — The operations of the Survey 

 for the year 1910-11 continue the gratifying record made in 

 previous years. When the value and amount of work is com- 

 pared with the aggregate cost ($1,477,440) it seems evident 

 that no governmental bureau is yielding greater returns in pro- 

 portion to the amount expended. It is satisfactory to note that 

 the Survey is becoming each year more generally useful to the 

 various departments involved with governmental administration. 

 More than any other bureau it stands as a scientific adviser to the 

 government in all matters relating to the development of natural 

 resources. In the development of plans for wiser distribution 

 and control of public lands, water supply, irrigation, coal, oil, and 

 ore deposits, it is essential that some bureau possessing high skill 

 and freedom from political control should be given charge; and it 

 speaks well for the reputation of the Survey that this particular 

 bureau should be relied upon to furnish accurate and unbiased 

 information as the basis for legislative enactments. Because of 

 the changes in the Department of the Interior which have placed 



