Chemistry and Physics. 53 



nation of the facts upon which the atomic and molecular theory 

 is based. Teachers of chemistry will undoubtedly find the book 

 useful in furnishing suggestive problems for quantitative work. 



h. l. w. 



7. Anleitung zur Molekulargewichtsbestimmung, von Dr. G. 

 Fuchs, 8vo, pp. 41, Leipzig, 1895. (Engelmann. Price M 1.20.) — 

 This little book deals with the boiling-point and freezing-point 

 methods for determining molecular weights, which have been 

 elaborated by Professor Beckmann. Coming as it does from the 

 pen of one of Beckmann's pupils and from his own laboratory, it 

 may be considered an authoritative work upon the subject. The 

 historical and theoretical bearings of the subject are clearly out- 

 lined, but the book is especially intended for use as a laboratory 

 manual for students who are making molecular-weight determina- 

 tions by the methods under consideration. The operations are 

 well described and illustrated by figures, and the necessary 

 formulae and tables for making calculations are given and clearly 

 explained. h. l. w. 



8. A Laboratory Manual of Organic Chemistry ; by Lassar 

 Cohn. Translated by Alexander Smith, 12mo, pp. 403. 

 (Macmillan & Co., $2.25.) — This work is a compendium of lab- 

 oratory methods used in organic chemistry. The first part, 

 dealing with the general methods, contains chapters on baths, 

 crystallization, decolorizing of liquids, distillation, drying solids 

 and liquids, extraction, filtration, determination of melting- 

 points, determination of molecular weights, sealed tubes, and 

 sublimation. The second part, devoted to special methods, 

 embraces chapters on condensation, preparation of diazo bodies, 

 preparation of esters, fusion with caustic alkalies, preparation 

 of halogen compounds, preparation of nitro derivatives, oxi- 

 dation, reduction, preparation of salts, saponification, prepa- 

 ration of sulphuric acids, and remarks on organic analysis. 

 The methods are illustrated by numerous examples taken 

 from chemical literature, and the great number of references 

 indicates that a vast amount of reading was necessary for the 

 compilation of the book. The work of the translator is very 

 satisfactory. A number of changes in arrangement and additions 

 have been made, with the author's sanction, and another improve- 

 ment over the German edition is the use of smaller type for 

 matters of subordinate interest. The work has been very favor- 

 ably received in Germany, where it quickly reached a second 

 edition. It is undoubtedly a very important aid to the investi- 

 gator in organic chemistry, and the present translation will 

 doubtless find extensive use among English-speaking students. 



H. L. W. 



9. Organic Chemistry, The Fatty Compounds, by R. Lloyd 

 Whiteley, 12mo, pp. 290. London, ]895. (Longmans, Green & 

 Co.) — The author aims to give students an intelligible and con- 

 nected account of the theory of the subject, and also to provide 

 them with such information as shall enable them to gain a prac- 



