1889.] On Salts of a Base containing Chromium and Urea. 339 

 Calculated. Observed. 



&& 60 6 59 53 



6 y A 60 2 



or =_oz 33 38 33 38 (mean of 4 measurements.) 



o(811) 44 56J 44 34 



o(922) 55 39i 55 49 



op = OTT 63 23 63 29| 



ol 90 90 8-^ (mean of 5 measurements.) 



rz 32 8J 32 6" 



ox 29 57 30 5 



bx 64 23 65 3 



xb 115 37 115 8J 



l tl x 64 23 63 38J 



No satisfactory cleavage was perceived on the crystals. 



The Sulphatoperiodide. 



This salt is precipitated in silky yellowish-brown needles when a 

 solution of iodine in potassium iodide is added to a solution of the 

 sulphate or any other salt of the base containing sulphuric acid. It 

 is practically insoluble in cold water, dissolving, however, to a small 

 extent in hot water from which it crystallises on cooling in brown 

 needles. The solvent action of water is not materially affected by the 

 presence of potassium iodide, and it is insoluble in the usual neutral 

 menstrua. On boiling with water the compound is decomposed, 

 iodine to the extent of about two-thirds of the total amount present 

 escaping with the steam. The composition of this remarkable salt 

 would appear to be (CO.N 2 H 4 )i 2 Cr 2 (S0 4 ) 2 I 2 I 4 . 



The following results were obtained on analysis : 



1. 0*48315 gram salt gave 0'375 gram silver iodide. 



2. 1-05455 0-824 



3. 1-204 0-3248 BaSO 4 . 



4. 0-6785 0-1843 



5. 0-3282 0-02965 Cr 2 3 . 



6. 0-6503 distilled with water, the evolved I collected 



in KI, titrated with thiosulphate, required 12'13 c.c. (each 

 c.c. = 0-014035 gram I). The residual liquor gave 017542 

 gram Agl and 0'00805 gram Ag. 



