Compounds of Nitrogen. 503 
The nitrogen was by experiment - - 27.15 
By calculation it ought to have been, 
From the nitrous oxide 26 
Do. carbonic oxide .75 - - - 26.75 
Difference...... aaenda ste bebo mnoen sop 0.40 
No person, I believe, who is much ex- 
perienced in processes of this nature, will 
Jook for a nearer approach to accuracy, than 
in the results of the experiment which has 
been just described; for the carbonic acid 
falls short by only 4, of the theoretical pro- 
portion; while the nitrogen exceeds that 
proportion by only ~., and the oxygen by 
+s: ‘The experiment was several times re- 
peated, with approximations fully as near as 
the above to those which the law of volumes 
would require. 
When the object in view is solely or chiefly 
to determine the quantity of oxygen in nitrous 
oxide, there can be no source of fallacy in 
the use of a slight excess of carbonic oxide. 
For this purpose I made several experiments, 
which agreed so closely in their results, that 
it may be sufficient to particularize one of 
them as a specimen of the rest. 
Carbonic oxide 21 measures. 
Nitrous oxide 19 do. = 18.4 pure + 0.6 nitrogen. 
— 
40 
40 after combustion. 
21.5 after potash ; containing no free oxy- 
[gen. 
