452 M. Schiitzenberger on Phosgene Gas. 



derived from the felspar ; for this is seen to be attacked, and 

 there are fused drops of alkaline chloride. But it is difficult to 

 determine the precise nature of the reaction. It is most probable 

 that chloride of silicon gives to the alkaline silicate part of its 

 chlorine in exchange for an equivalent quantity of oxygen. 



Comparing the formulae for the new body and for perchlori- 

 nated methylic oxide, 



^\SiCP ^\CC1 3 ' 



their analogy is at once seen ; and in accordance with it the 

 authors suggest as a name for the body either perchlorinated sili- 

 cimethylic ether, or oxide of trichlorosilicium. 



Schutzenberger* has described the following method for the 

 preparation of phosgene gas, which does not require the presence 

 of sunlight. When a mixture of carbonic oxide and vapour of 

 tetrachloride of carbon is passed over pumice heated to about 

 350°, the following action takes place : — 



2 Q CI 4 + €0 = 2 (CO CI 2 ) + C 2 CI 4 , 



The quantity produced under these conditions is considerable, 

 and the reaction may be used in practice. 



The carbonic oxide may with equal success be replaced by car- 

 bonic acid, which gives 



CCl 4 -f-C0 2 =2CGCl 2 . 



In trying the above reaction, using spongy platinum instead 

 of pumice, the formation of considerable quantities of oxy chloride 

 was observed; but it was also noticed that the platinum acted 

 otherwise than by its presence. A platinum compound is formed 

 which maybe collected in the cool parts of the tube as a bright- 

 yellow flocculent powder. As the new compound is destroyed 

 at a temperature a little higher than that at which it is formed, 

 it is important that the current of carbonic oxide be rapid, so 

 that the body may be carried away as rapidly as it is formed. 

 The new body melts at about 150° to a deep-yellow transpa- 

 rent liquid, which solidifies on cooling as a yellow crystalline 

 mass. At about 350° to 400° it boils and distils, but is mainly 

 decomposed into metallic platinum and oxychlorocarbonic acid. 

 Water decomposes it at once with formation of carbonic acid and 

 finely divided platinum, while the liquor gives the reactions of 

 hydrochloric acid. The analyses lead to the formula (CO) 3 Pt 2 CI 4 ; 

 but further experiments are necessary for settling this point. 



* Comptes Rendus, April 13, 1868. 



