558 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE. 



I. Chemistry and Physics. 



1. A New Volumetric Method for the Determination of Cobalt 

 in the Presence of Nickel. Albert Metzl describes his method 

 as follows: The cobalt solution in a flask should not have a 

 volume of more than 100 cc . To this is added, for each 0*1 g. of 

 cobalt, 15 cc of " 10 volume" hydrogen peroxide, 30 cc of 5 per cent 

 sodium bicarbonate, and 30 cc of 10 per cent sodium hydroxide. 

 Then it is well shaken and heated over a wire gauze for from 20 

 to 23 minutes to destroy the excess of hydrogen peroxide. Then 

 it is cooled, potassium iodide and dilute sulphuric acid are added, 

 and the liberated iodine is determined by means of thiosulphate 

 solution. One iodine atom corresponds to one of cobalt, since the 

 latter is oxidized to hydrated Co 2 3 . The author gives very 

 satisfactory results with widely varying proportions of cobalt and 

 nickel. He has devised a modilication of the method where 

 the oxidation takes place in the presence of ammonium chloride 

 and ammonium hydroxide, but in this case it is difficult to destroy 

 the whole of the hydrogen peroxide by boiling, so that long boil- 

 ing and the employment of restricted amounts of ammonia and 

 ammonium chloride were required. — Zeitschr. analyt. t'/iem., ltii, 

 538. H. L. AV. 



2. The Hydrogeinzation, of Oils ; by Carleton Ellis. 8vo, 

 pp.340. New York, 1914 (D. Van Nostrand Company. Price, 

 $4 net). — This book deals with a verj' interesting and important 

 recent development in industrial chemistry which consists in the 

 combination of hydrogen with the oils, thus converting them into 

 more valuable solid fats. The process at the same time often 

 removes disagreeable odors and in addition it lessens the tendency 

 of the fats to become rancid. This "hardening" process is 

 already applied on a very large scale to cottonseed oil, various 

 nut-oils, fish oils, etc., in order to produce fats suitable for lard 

 and butter substitutes, for soap making, and so on. Certain 

 catalytic agents are necessary for effecting the combination of 

 hydrogen with the unsaturated oils, the most important of which 

 appears to be metallic nickel. The book under consideration 

 treats the subject very thoroughly, particularly in connection 

 with the patent literature. The methods of Ivydrogenation, the 

 various catalyzers, the analytical constants of the products, edible 

 hydrogenated oils and the utilization of the products in soap 

 making are all extensively discussed, while a very elaborate treat- 

 ment of the technical methods for the production and purification 

 of hydrogen gas is also included. n. l. w. 



3 Methods of Quantitative Organic Analysis ; by P. C. R. 

 Kingscott and'R. S. G Knight. 8vo, pp. 283. London, 1914 

 (Longmans, Green and Co. Price $2 net). — This is a useful book 

 for advanced students in organic chemistry. The first chapter 



