1882.] of a Base containing Chromium and Urea. 



269 



1. *5531 grm. gave on combustion in oxygen "2061 C0 3 and 

 •169 H 2 0. 



2. "32175 grm. gave on combustion in oxygen '11865 C0 2 and 

 •1029 H 2 0. 



3. '3262 grm. gave on combustion in oxygen "1189 C0 2 and 

 •1045 H 2 0. 



4. '4147 grm. gave on combustion in oxygen '1499 C0 2 and 

 •1281 H 2 0. 



5. - 0541 grm. gave by Gottlieb's process very nearly equal volumes 

 of C0 2 and IS", weighing '01919 and '01267 respectively. 



6. '35065 grm. gave by Dumas' process 62 cub. centims. nitrogen at 

 0° C. and 760 millims. 



7. '324 grm. dissolved in water, excess of KI and HC1 added, and 

 the iodine titrated with thiosulphate, required 40 cub. centims., each 

 cub. centim. thiosulphate = '00306 Cr0 3 . 



8. '5253 grm. precipitated by mercurous nitrate gave '1628 grm. 

 Cr 2 3 . 



9. '9317 grm. precipitated by mercurous nitrate gave '2915 grm. 

 Cr 2 3 . 



10. The filtrate from '5253 grm. after precipitation with mercurous 

 nitrate gave, when evaporated and ignited, '1011 grm. Cr 2 3 . 



11. The mean of three concordant experiments gave on ignition 

 41*62 per cent. Cr 2 3 . DeductiDg from this the Cr existing as Cr0 3 , 

 gives 10'56 per cent. Cr 2 3 or 7'24 per cent. Cr. 



12. '4985 grm. crystallised salt (dried by pressure between bibulous 

 paper) lost "0181 grm. H 2 in vacuo over sulphuric acid, and no 

 further loss at 105° C. 



The Ghloroplatinate. 



When a hot solution of the dichromate is mixed with a solution of 

 platinic chloride, and the mixture allowed to cool, the chloroplatinate 

 crystallises out in long green silky needles. The compound is mode- 

 rately soluble in hot, but very sparingly in cold water. The sparing 

 solubility in cold water was made use of in preparing the bulk of this 

 salt from washings and drainings from other compounds. After one 

 or two crystallisations from hot water, the compound is obtained in a 

 state of purity. The examination of the body led to the formula 



{ (CON 2 H 4 ) 12 Cr 2 } (PtCl 6 ) 3 2H 2 



being assigned to it. 



The following results were obtained on analysis : — 



The numbers given refer to the dried compound unless stated to 



the contrary. 



1. '8698 grm. gave on combustion '2207 C0 2 and '2008 H 2 0. 



2. -95362 grm. „ „ '2331 C0 2 and '22662 H 2 0. 



VOL. XXXIII. U 



