216 Scientific Intelligence. 



SCIENTIFIC INTELLIGENCE 



I. Chemistry and Physics. 



1. The Reduction of Ferric Salts with Mercury. — LeRoy W. 

 McCay and William T. Anderson, Jr., of Princeton University, 

 have applied this method of reduction to the volumetric deter- 

 mination of iron with very satisfactory results in regard to con- 

 venience and accuracy. It appears that the fact that metallic 

 mercury will reduce ferric chloride to the ferrous salt has been 

 known since 1842, and that Bovar suggested its analytical appli- 

 cation in 1911, but the method seems to have attracted little 

 attention. 



The present investigators carried out the reductions by shaking 

 solutions of ferric chloride containing hydrochloric acid with 

 about 20 cc. of pure mercury in a long, narrow, glass-stoppered 

 bottle of about 800 cc. capacity. The shaking should be vigorous, 

 so as to break up the mercury into tiny globules, and it should be 

 continued for about 5 minutes. After filtering the liquid and 

 washing the residual mercury and mercurous chloride the iron 

 was titrated, either by the Zimmermann-Reinhardt modification 

 of the permanganate method or by the dichromate method, with 

 excellent results as shown by the test-analyses. 



The authors found that solutions of ferric sulphate containing 

 sulphuric acid were only partially reduced by the operation, but 

 that when a little more than the theoretical amount of sodium 

 chloride was present the reaction was complete with the forma- 

 tion of mercurous chloride. 



It appears that this rapid and accurate method is worthy of 

 extensive practical application, for it has the advantage over the 

 use of zinc, for, instance in the Jones reductor, in the fact that 

 titanic acid is not reduced by mercury, and also because the 

 mercury process seems to be freer from accidental sources of 

 error. 



The authors have found that when shaken with mercury in 

 the presence of hydrochloric acid reduction takes place with fer- 

 ricyanides, chromates, molybdates, vanadates, and antimonates, 

 and they are investigating some of these reactions. — Jour. Amer. 

 Chem. Soc, 43, 2372. h. l. w. 



2. Synthetic Gasoline. — A German process for making gaso- 

 line, called the Burgess process, has been developed by the orig- 

 inators of the Haber process for the fixation of atmospheric nitro- 

 gen by combining it with hydrogen. In carrying out this process 

 hydrogen is passed over carbon at 200 atmospheres pressure and 

 at a temperature of 700° C, whereby hydrocarbons are formed. 

 It is stated that the process has been examined by an American 

 engineer, who has reported that the method is in actual operation 



