Clierriistry and Physics. 65 



cavities of the mass which has been fused. The formulas given 

 are, 



PbS • Bi,S3 • 2 BiSC], 



PbS • Bi^S3 • 2BiSBr, and 



PbS • Bi^S3 • 2BiSL 



No evidence is given to show that the halogens are combined 

 with bismuth rather than lead, hence it is not clear why the 

 above formulas have been adopted instead of simpler ones which 

 are perhaps more plausible on account of their less complicated 

 form; for instance, PbCl^ * 281283. — Comptes Benches, cxxxiv, 

 1061. H. L. w. 



5. The Atomic Weight of TJraniwn. — Richards and Meei- 

 GOLD have made a new investigation upon the atomic weight of 

 uranium by analyzing uranium bromide, UBr^. The method 

 differs essentially from any that has been used hitherto for the 

 purpose, and apparently the results are more reliable than those 

 of previous investigators. The results show that this atomic 

 weight is about a unit lower than the value that has been pre- 

 viously accepted, the average of several closely agreeing deter- 

 minations being 238-53. — Proc. Amer. Acad., xxxvii, N"o. 14. 



H. L. w. 



6. First Book of Qicalitatioe Chemistry ; by Peescott and 

 SuLLiVAX. Eleventh Edition. 8vo, pp. 148. New York, 1902 

 (D. Van Nostrand Company, price $1.50). — This text-book, 

 which has been in use since 1879, has now been entirely re-written 

 in order to present the subject in the light of the modern theories 

 of solution and of mass-action. Some attention is paid also to 

 the classification of the Periodic System. The first 37 pages of 

 the book are devoted to an introduction, chiefly of theoretical 

 character, including concise presentations of the subjects of 

 electrolytic dissociation, chemical equilibrium, solubility, etc. In 

 the practical part of the book only a moderate amount of use is 

 made of the ionic theory. The equations introduced are limited 

 to the more difficult ones, and these are given without regard to 

 ions. The book contains many satisfactory variations from the 

 time-honored methods that have come down through Eresenius 

 from Will and Rose, but it is surprising that the calcium sulphate 

 method for testing for strontium, which was abandoned by 

 Eresenius, is retained here, since the treatment of the nitrates 

 with amyl alcohol is a much more satisfactory method. 



The course outlined in this book is a rather extensive one, 

 which is better adapted for beginners in college than for younger 

 students. Abbreviated tables for analysis are adopted, but they 

 are used in connection with many explanatory notes. Many 

 teachers would prefer to have these aids to thoughtless labora- 

 tory work omitted altogether. h. l. av. 



7. Crru7idriss der qualitativen Analyse, von Dr. Wilh. Bott- 

 GEE. 8vo, pp. xxii, 249. Leipzig, 1902 (Wilhelm Engelmann). 

 — This text-book on qualitative analysis has been written from 



Am. Jour. Sci. — Fourth Series, Yol. XIY, No. 79.— July, 1802. 

 5 



