658 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chkmistry and Physics. 



1. Annual Report of the International Committee on Atomic 

 Weights. — At the meeting of the International Congress of 

 Applied Chemistry in 1912 a resolution was passed favoring delay 

 in changes in the table of atomic weights. In accordance with 

 the desire so expressed no changes have since been made, but 

 several now seem necessary to the committee. These changes are 

 small and relate to C, S, He, Sn, Pb, Ra, Yt, Pr, Yb, Lu and IT. 

 The changes made in the more important cases are as follows : 





Carbon 



Sulphur 



Tin 



Lead 



Uranium 



revious 



12-00 



32-07 



119-0 



207-10 



238-5 



ew, "1916". 



12-005 



32-06 



118-7 



207-20 



238-2 



These changes will have but little influence upon ordinary cal- 

 culations. For instance, the change will give 27 - 28 instead of 

 27*27 as the percentage of carbon in C0 2 , and it will give 78-77 

 instead of 78-81 as the percentage of tin in Sn0 2 . h. l. w. 



2. The Analysis of the Non-Ferrous Metals, by Fred Ibbot- 

 son and Leslie Aitchisox. 8vo, pp. 230. London, 1915 

 (Longmans, Green and Co.). — The aim of this book is to pre- 

 sent methods of analysis in which either accuracy and con- 

 venience or accuracy and speed are combined. It gives a general 

 discussion of the apparatus and methods of electrolytic analysis 

 as well as a general presentation of the effects of temperature 

 and varying amounts of hydrochloric acid upon precipitations 

 with hydrogen sulphide. Various methods are described for the 

 determination of lead, copper, bismuth, antimony, tin, arsenic, 

 aluminium, chromium, nickel, cobalt, and zinc, and finally the 

 analysis of commercial alloys is discussed. The book is an excel- 

 lent one, being well written and giving the best modern methods, 

 and there is no doubt that many analysts may obtain much useful 

 information from it. The authors do not consider the work com- 

 plete or final, and hence it is to be expected that a few good 

 methods extensively used by American chemists are not included. 

 It may be mentioned as a matter of minor importance that the 

 authors adhere to the old opinion that copper sulphide must be 

 washed with cold water containing hydrogen sulphide so that it 

 will not " oxidize " and pass into the nitrate, whereas, it is a fact 

 that this precipitate can be washed with the greatest ease with 

 hot water. The supposed oxidation when cold water is used is 

 evidently due to the formation of colloidal copper sulphide which 

 is not formed at all when hot water is used. h. l. w. 



3. A Course in Quantitative Chemical Analysis / by Nicholas 

 Knight. 12mo, pp. 153. New York and Chicago, 1915 (The 

 A. S. Barnes Company). — This book appears to be a very unsat- 



