690 Scientific Intelligence. 



and the present second edition has received a considerable amount 

 of modification on account of recent advances in the science. The 

 subject is treated in a broad sense, as the book deals with the 

 fundamental laws of chemical combination, the general proper- 

 ties of gases, the determination of atomic weights, the periodic 

 law, the properties of liquids, the kinetic theory of gases, the 

 properties of solids, mixtures, solubility and miscibility, proper- 

 ties of dilute solutions, dissolution and vaporization, and the 

 determination of molecular weights. The topics are generally 

 well presented from an advanced point of view, and the book 

 appears to be an excellent and interesting one for the use of 

 students of physical chemistry and teachers. h. l. w. 



7. Elements of General Science, Revised Edition; by Otis 

 William Caldwell and William Lewis Eikenberry. Pp. xii, 

 404; with 181 figures. Boston, 1918 (Ginn and Co.).— "The 

 course presented in this book is the result of ten years of experi- 

 ment in secondary schools. ' ' The main object of the course is to 

 develop a usable fund of knowledge about common things and 

 helpful and trustworthy habits of considering common experi- 

 ences in the field of science. "The unity of this introductory 

 course in science is secured by use of the logical interrelations 

 between the topics which compose the course. No attempt is 

 made to maintain the unity of any one of the different sciences. 

 Experience shows that after use of this course pupils do not feel 

 that they ' ' have had ' ' any of the differentiated sciences, as physi- 

 ography, physics, chemistry, or biology. They are, however, 

 much interested in the later study of the differentiated sciences. 

 The topics of the course are readily grouped under six major 

 divisions. ' ' The titles of these six Parts are : The Air ; Water 

 and its Uses; The Earth in Relation to other Astronomical 

 Bodies; The Earth's Crust; and Life upon the Earth. The new 

 edition has been almost entirely rewritten, and a laboratory man- 

 ual has been prepared to serve as a guide in the performance of 

 experiments and demonstrations. 



For lack of space it is not possible to enter into details con- 

 cerning the discrete contents of the thirty-three chapters. Suf- 

 fice it to say that the selection of material is excellent and that 

 the manner of presentation leaves nothing to be desired. The 

 diagrams and half-tone figures are clear cut and attractive, and 

 the entire book is unusually interesting, instructive, and up to 

 date. The volume deserves the careful attention of principals 

 of high schools and other directors of education not only on 

 account of its intrinsic merit but also because it contains a wealth 

 of information concerning germ diseases, bacteria, flies, mosqui- 

 toes, alcohol, hygiene, sanitation, reproduction in plants and ani- 

 mals, etc., the thorough acquisition of which knowledge should 

 have a most salutary influence upon the general welfare of 

 society in the future. h. -s. u. 



