Chemistry and Physics. 79 



from variations governed by chance. No satisfactory explanation 

 of this last circumstance is given, and it appears that Prout's 

 hypothesis modified by the " packing effect " can be applied only 

 to about one-third of the elements whose atomic weights are pretty 

 accurately known, and that these are among the lighter atomic 

 weights. — Jour. Amer. Chem. Soc, xxxvii, 1367, 1383. 



H. L. W. 



2. The Action of Chloroform upon Metallic Sulphates. — A. 

 Conduchb has obtained interesting results by studying the action 

 of chloroform vapor, carried along by means of a current of car- 

 bon dioxide, upon heated metallic sulphates. The reaction sup- 

 plies a method for the production of anhydrous chlorides. The 

 change is indicated by the formation of white vapors, and it 

 takes place at a rather low temperature : 250° C for CuS0 4 , 

 300° for NiS0 4 and FeS0 4 , 350° for MuS0 4 and PbS0 4 , 400° for 

 A1,(S0 4 ) 3 , 450° for MgS0 4 , 500° for BaS0 4 , CaS0 4 and Na 2 S0 4 . 

 Practically, however, a higher temperature is required to make 

 the reaction complete, and on the other hand, the vapor of chloro- 

 form decomposes between 400° and 500° with the production of 

 carbonaceous deposits, so that the chlorides are not obtained in 

 a pure condition when the temperature used is too high. The 

 reducing action of the chloroform may have an influence upon 

 the chloride produced in case a metal forms two chlorides. For 

 example, CuS0 4 yields pure CuCl, at 280-300°, while at about 

 400° CuCl is produced. In the cases of FeS0 4 and Fe 3 (S0 4 ) 3 

 mixtures of FeCl 2 and FeCl 3 are always obtained, the proportions 

 of which depend upon the temperature employed. — Comptes 

 JRendus, clviii, 1180. h. l. w. 



3. Explosives ; by Arthur Marshall. Large 8vo, pp. 624. 

 Philadelphia, 1915 (P. Blakiston's Son & Co. Price, $7.50 net). — 

 The author of this important work on the manufacture, proper- 

 ties, tests, and history of explosives, is the Chemical Inspector of 

 the British Indian Ordnance Department. No comprehensive 

 work on this subject has appeared in English within a period of 

 20 years, during which time very great changes and developments 

 have taken place in the industry, so that the present book will 

 undoubtedly supply a real want. The book treats the subject 

 very fully and ably, it contains 137 illustrations, and gives a very 

 interesting and useful account of this great branch of chemical 

 industry. h. l. w. 



4. Chemical Technology and Analysis of Oils, Fats, and 

 Waxes ; by J. Lewkowitsch, edited by George H. Warbur- 



ton. Vol. Ill, 8vo, pp. 483. London, 1915 (Macmillan and Co., 

 Limited. Price, $6.50 net). — The present, third volume, com- 

 pletes the fifth edition of this important work, which has been 

 entirely re-written and enlarged. The previous volumes have 

 been favorably noticed already in this Journal, hence it is only 

 necessary to point out that the present volume deals chiefly with 

 manufacturing operations, and that among the important and 

 interesting topics treated are edible oils and fats and their sub- 



