488 Scientific Intelligence. 



linear dimension of the domain, the direction of electrization 

 being such that in general any molecule attracts its six immediate 

 neighbors. It is proposed to look upon atoms as electrized,. just 

 as we speak of a magnet as being magnetized. In regard to 

 total energy, each molecule behaves as if it had an electric 

 moment proportional to the linear dimensions of its domain, 

 whereas in the matter of mutual energy each molecule has an 

 electric moment of amount E S (E charge, S distance between 

 poles) which is investigated in connection with the laws of molec- 

 ular attraction. — Phil. Mag., May, 1909, pp. 657-670. J. t. 



8. Physical Measurements ; by A. Wilmek Duff and Arthur 

 W. Ewell. Pp. 211. New Haven, 1908 (Dorman Lithographing 

 Co.). — This is an excellent laboratory manual containing ninety- 

 one experiments of considerable range of difficulty. The intro- 

 ductory discussions and the descriptions of experiments are 

 marked by a very commendable brevity and by a generality of 

 treatment which gives the essential principles of the matter with- 

 out going into the details of apparatus which vary from one 

 laboratory to another. References are given to standard text- 

 books in which details can be looked up if necessary. The experi- 

 ments are well chosen, and the whole atmosphere of the book is 

 that of sound and accurate work. A somewhat unusual feature 

 is the inclusion of a section on physical chemistry, in which are 

 grouped some experiments not often found in text-books on 

 physics, together with others which are ordinarily found scattered 

 among the various subdivisions of the subject (heat, electricity, 

 light), but of which the chief interest is physico-chemical. The 

 figures are simple line drawings of small size ; they are usually 

 clear, but some of the more complicated diagrams would be 

 improved by being drawn to a larger scale. As a whole the 

 book should prove very useful to laboratory teachers, h. a. b. 



II. Geology and Natural History. 



1. Monograph on the Higher Crustacea of the Carboniferous 

 Pocks of Scotland y by B. N. Peach. Mem. Geol. Surv. Great 

 Britain, Pal., 1908, pp. 82, pis. 12. — In this quarto work are 

 described in great detail 41 species and varieties of Schizopoda 

 based on more than 2000 specimens from the Carboniferous rocks 

 of Scotland, the accumulation since 1880. The excellent wash 

 drawings are by Dr. Peach and are reproduced by the Collotype 

 process. There are 34 named forms grouped under the genera 

 Tealliocaris, new (with 6 species), Pseudogalathea (3), Anthra- 

 paloemon (1), Pygocephalus (1), Perimecturus, new (6), Palceo- 

 caris (2), Palaem.ysis, new (3), Anthracophausia, new (2), 

 Crangopsis (10). All of these are grouped under existing fam- 

 ilies as defined by Sars, of the Mysid and Euphausiid groups of 

 Schizopoda, except Per imec turns. The individuals rarely attain 

 a length of 1^ inches, but a species of the last-named genus has a 

 body length of 5 inches. c. s. 



