326 



Mr. W. J. Sell and Prof. W. J. Lewis. [Feb. 1.4 



the dichlordichromate, hydrochloric acid being at the same time set 

 free, thus : 



{(CON 2 H4)^Cr 2 }^ r 3C1 + 2H 2 = {(COiN 2 H4)i 2 Cr 2 } 2 ^ r 2 207 +4HCl. 



It is extremely probable that this salt is the chief initial product of 

 the reaction between chromyl dichloride and urea, and that the subse- 

 quent addition of water decomposes it, as shown by the preceding 

 equation. Granting that a chlorochromate is formed (and as the 

 reaction takes place in presence of excess of chromyl dichloride, it is 

 difficult to resist this conclusion), the only salt of this character 

 which would normally decompose by water with production of the 

 dichlordichromate, is the compound under consideration. 



The following results were obtained on analysis. The numbers 

 refer to the dry salt, unless stated to the contrary : 



1. 0-4736 gram salt gave 0'28333 gram AgCl. 



2. 0"7059 ,, when precipitated with mercurous nitrate 



and the precipitate ignited, 0*14928 gram O 2 3 . 



3. 0-3938 gram salt, dissolved in dilute HC1, excess of KI added, 



and the iodine titrated with thiosulpnate, required 33'4 c.c. ; 

 each c.c. thiosulphate = 0'0032459 CrO 3 . 



4. 0-14235 gram, treated as in 3, required 12'2 c.c. same thiosul- 



phate. 



5. 0*4054 gram moistened with alcohol, dried and ignited, gave 



0-12925 gram Cr 2 3 . Deducting from this the Cr existing as 

 CrO 3 , gives 10' 74 Cr 2 3 , or 7'000 per cent. Cr. 



6. 1*1153 gram undried salt lost in vacuo over sulphuric acid 



0-03885 gram H 2 0. 



7. 0*7766 gram undried salt lost at 100 C. 0'0236 gram H 2 0. 



