424 



THE POPULAR SCIENCE MONTHLY. 



the valley of the Zibagy and tributary 

 streams, in the sands, in pot-holes, and in 

 gravel-banks. The diamonds appear to 

 have been washed out of the Devonian sand- 

 stone of that region, but the author thinks 

 they were previously derived from meta- 

 morphic rocks, and deposited in the sands 

 which afterward went to lorm these sand- 

 stones. That they did not originate in the 

 latter is proved, he thinks, by the fact that 

 it contains no traces of metamorphism or of 

 crystallization. 



First Step in Chemical Peinciples. An 

 Introduction to Modern Chemistry, in- 

 tended especially for Beginners. By 

 Henry Leffman, M. D. Philadelphia : 

 Edward Stern & Co. Pp. 52. Price, 

 50 cents. 



A beginner of some maturity of mind, 

 say a young medical student, who knew 

 nothing whatever of the subject, might de- 

 rive advantage from reading over this brief 

 introduction; but it is not a "First Step" 

 in any sense that it could be used in a pri- 

 mary school to start young beginners. It 

 contains a very readable summary of chem- 

 ical principles, but they are presented in the 

 elaborated thought and technical language 

 of the developed science. 



The Young Folks' Cyclopedia of Common 

 Things. By John D. Champlin, Jr. 

 With numerous Illustrations. New 

 York: Henry Holt & Co. Pp. 690. 

 Price, $3. 



Mr. Champlin has here hit upon an ex- 

 cellent idea, and has carried it out very 

 successfully. There was room for a popular 

 book on common things much more full 

 than the current " familiar science " manu- 

 als. A great deal of miscellaneous infor- 

 mation on ordinary objects and subjects has 

 been collated and digested in alphabetical 

 order convenient for reference, and the edi- 

 tor is right in calling attention at the outset 

 to the need of encouraging in the young 

 the practice of consulting works of refer- 

 ence. The volume will be found most use- 

 ful in families, as both the knowledge it 

 imparts and the form of its presentation 

 are well suited to satisfy the curiosity of 

 young minds. A good deal of information 

 is given about the common sciences, such as 

 astronomy, chemistry, physics, natural his- 



tory, and physiology, and about heat, light, 

 air, electricity, and the parts and operations 

 of the human system. There is much about 

 the modes of manufacture of common arti- 

 cles, and the natural history of the more 

 familiar and important animals and plants 

 is fully presented. The book is compiled 

 with judgment, Mr. Champlin having under- 

 gone his apprenticeship at this kind of 

 work on the " American Cyclopaedia." We 

 are glad to notice that Holt puts the book 

 at a quite reasonable price. 



Twenty Lessons in Inorganic Chemistry. 

 By W. G. Valentin, F. C. S. G. P. 

 Putnam's Sons. Pp. 184. Price, $1. 



This claims to be an elementary book 

 for students to begin with, but the begin- 

 ning must be in the old lecture-room form 

 of instruction. The author says : " It is not 

 enough, as every teacher knows, to exhibit 

 experiments before a class, unless they are 

 made subservient to explain the theory of 

 the science, and to place it on a sound basis. 

 All theoretical explanations should be based 

 upon experiments which fix it upon the 

 memory. This is the plan which I have 

 laid down for my guidance." As might 

 therefore be expected, the book is filled with 

 illustrations and descriptions of lecture- 

 room experiments, and the usually accom- 

 panying explanations and information. It 

 is clear, accurate, and well executed. 



The Value of Life. A Reply to Mr. Mal- 

 lock's Essay, " Is Life worth Living ? " 

 New York : G. P. Putnam's Sons. Pp. 

 253. Price, $1.50. 



An anonymous writer, thinking Mr. Mal- 

 lock's book worth answering, has replied to 

 his arguments very fully and ably in this 

 volume. The book is written from the Pos- 

 itivist point of view, in the more special 

 sense of the term. By Positivism, Mr. Mal- 

 lock means those later tendencies and the- 

 ories of science which bear upon the higher 

 questions of religion, morality, and polity, 

 and as illustrated in the writings of such 

 thinkers as Clifford, Huxley, Tyndall, and 

 Mill, but Mr. Mallock's critic rather means 

 by " Positivism " the doctrines of Comte ; 

 and this reply is chiefly interesting as deal- 

 ing with Mr. Mallock's questions from that 

 point of view. 



