786 



SCIENCE. 



[N.S. Vol. XVII. No. 437. 



itself. The attempt is interesting and, we 

 must admit, very successful. The only serious 

 omission we note is that of double and com.- 

 ples salts. There is a brief reference to the 

 double mercuric iodids, a paragraph on alums, 

 some discussion of double cyanids and chloro- 

 platinates, but no consideration of double 

 salts from a theoretic standpoint nor any men- 

 tion of Werner's hypothesis. When one con- 

 siders the number, variety and importance of 

 double salts, he can not but feel that this 

 omission is a defect in a book of this scope. 



The book will be interesting and profitable 

 reading for every teacher of chemistry, nor 

 should any advanced student of chemistry 

 fail to go carefully through it. It will bo 

 particularly valuable for those teachers whose 

 student days were before the reign of the 

 present physical chemists. How the book will 

 fare as a text-book remains to be proven. In 

 the judgment of the reviewer it would make 

 a hard task for a beginner and should only 

 be used for students who have a considerable 

 knowledge of descriptive chemistry. With 

 this view, however, the author of the book 

 evidently differs. 



The book is well gotten up, the type is 

 clear, and the proof-reading has been almost 

 perfectly done; the illustrations, though not 

 numerous, are mostly new and really illustra- 

 tive, and the book closes with a copious index. 

 One other commendation must, not be omitted. 

 The style of the author is excellent. It is 

 clear, never heavy, and at times almost con- 

 versational. This makes the book easy read- 

 ing. Some may object to the author's en- 

 thusiasm; we do not. We like to read of the 

 ' beautiful investigations ' of Moissan with the 

 electric furnace, we like to hear Wohler called 

 the ' great ' German chemist, and we appre- 

 ciate a book the better whose author is not 

 so much engrossed with theory but that he 

 can close, its pages with the words, speaking 

 of magnesium plato-cyanid : ' It is question- 

 able whether another compound of equal 

 beauty is known in the whole field of chem- 

 istry.' 



The last book before us, that of Professor 

 Holleman, of the University of Groningen, 

 was first published in 1898, and two years later 



a German translation appeared. The Eng- 

 lish translation has the further advantage of 

 having been completely revised by the author, 

 so that it is practically a revised edition. 



This book bears in many respects a marked 

 resemblance to that of Dr. Jones, so much 

 so, indeed, that it would be superfluous to 

 give an extended review of it. The aims and 

 the scope of the books are the same, the meth- 

 ods used are similar, and the order in which 

 the different subjects are taken up does not 

 differ materially. Holleman's book lacks 

 wholly the dogmatic atmosphere we have 

 noticed in that of Jones, but it also lacks the 

 enthusiasm of the latter, although it is very 

 readable. Holleman treats the principles of 

 physical chemistry rather more fully than 

 Jones, and he introduces more mathematics, 

 though the mathematics used is always ele- 

 mentary. It seems as if this makes the sub- 

 ject matter simpler and clearer, but many 

 may think otherwise. Holleman is also fuller 

 in his treatment of subjects connected with 

 practical and technical chemistry. Taken al- 

 together, it is impossible for the reviewer to 

 decide which book would probably prove more 

 successful in the class room, but both will 

 prove very helpful to a teacher. 



There is not quite the same freedom from 

 errors that is found in Jones's, and it is occa- 

 sionally evident that the book was not origin- 

 ally written with reference to use in America. 

 This is particularly true in some eases of 

 metallurgical practice. The translation is 

 exceedingly well done, and does not read like 

 a translation, though now and then expres- 

 sions creep in which reveal the fact, as well 

 as others which are English rather than Amer- 

 ican. For example : ' it is not supplied with 

 a steam pipe either ' ; * ferric hydrate serves 

 as a counter-irritant ' (for arsenic) ; ' silicon 

 trichloride is obtained as a side-product ' ; 

 ' SnS falls down as a powder'; ' SnS„ falls 

 out as a powder ' ; ' it (minium) has a pretty 

 red color ' ; ' soda crystals weather,' and efflo- 

 rescence seems invariably to be spoken of as 

 weathering ; ' having very different properties 

 than liquids,' and ' than ' is frequently used 

 after ' different ' ; ' axles of railway carriages ' ; 

 ' metallic crustations ' ; 'it dissolves without 



