209 
the compounds of chromium. 
Carbonic acid - 4*6 or 2-75 
Green oxide - 17*16 or io- 25 
Water - - 8*3 or 4'96 
30*0 6 
The slight excess of green oxide and water in this analysis 
was, I believe, occasioned by the great caution employed in 
dissolving the salt in nitric acid ; for I was so apprehensive 
of evaporating a portion of the nitric acid that I applied heat 
very cautiously, and stopt the process before the whole 
powder was dissolved. In another analysis of a portion of a 
similar dicarbonate, prepared in a different way, I obtained 
Carbonic acid 
- - 2*75 
Green oxide 
9'33 
Water 
3-87 
Here there is a deficiency of oxide and water ; but this might 
be owing to errors in the analysis. 
Finding that carbonate of soda, when employed to precipi- 
tate muriate of chromium, gives only a dicarbonate, I thought 
it not unlikely that a neutral carbonate might be formed by 
employing a solution of bicarbonate of potash to precipitate 
muriate of chromium. The matter obtained by this process 
was light blue, and resembled the dicarbonate in its external 
qualities. It was dried without the application of any artifi- 
cial heat. Its composition determined in the same manner as 
above described was found to be 
1 atom carbonic acid - 2*75 
5 atoms protoxide - 25 
21 atoms water - - 23*625 
51*375 
E e 
MDCCCXXVII, 
