478 Dr. Ure on the ultimate analysis of 
Cochineal seems to be made up of 
Carbon 
15 atoms - 
11.250 
50.20 
Hydrogen 
11 - 
1-375 
- - 6.15 
Oxygen 
8 
8.000 
- - 35-85 
Azote 
1 
1.750 
- 7.80 
22.37 5 100.00 
Cantharides approximate to 
Carbon 11 atoms - - 9.75 - - 49.4 
Hydrogen 10 - - 1.23 - - 6.3 
Oxygen 7 - - 7.00 - - 35.4 
Azote - 1 - - 1.75 - - 8.9 
19.75 100.0 
My result with urea differs so considerably in the propor- 
tion of azote, from that of Dr. Prout and M. Berard, that I 
am disposed to doubt of the accuracy of my experiments, 
though they were made with the utmost care, and were most 
consistent in the repetition. I could perceive no smell what- 
ever of nitrous gas in the gaseous products, which were made 
to traverse a column of copper filings 3 inches long, in a 
state of ignition. I shall renew the inquiry on urea, and em- 
ploy the lowest temperature compatible with the formation 
of carbonic acid. 
The prime equivalent of benzoic acid crystals, I find by 
saturation with water of ammonia, to be 14.5 ; and it con- 
sists apparently of 
Carbon 
13 atoms - 
- 9-75 - 
- 67.24 
Hydrogen 
6 
- 0.75 - 
- 5-16 
Oxygen 
4 — “ 
- 4.00 - 
- 27.60 
14.50 
100.00 
