Mr. Henry’s Experiments on Ammonia. 439 
These general observations will tend to render the fol- 
lowing experiments more intelligible. They may be divided 
into two classes, 1st, those in which ammonia was fired 
with an excessive proportion of oxygen ; and 2dly, those in 
w 7 hich the oxygen, used in the first combustion, was insufficient* 
or barely adequate, to saturate the whole hydrogen of the 
alkali. 
I. Decomposition of Ammonia by an Excess of oxygen Gas. 
Twenty-two measures and a third of ammonia were mixed 
with 44I- oxygen containing 43 of pure gas. The total 6y 
became 34 when exploded. Water did not produce any far- 
ther diminution, but sulphuret of lime left only 8 measures. 
Now, 34 — 8 = 26 shews the quantity of oxygen gas, which 
escaped condensation ; and this, deducted from the original 
quantity (43) gives 17 measures for the amount of the oxy- 
gen expended. The last number 17, being multiplied by 2, 
gives 34 for the hydrogen apparently consumed. The final 
residue 8 — 1.66 (the nitrogen introduced by the oxygen 
gas) = 6.34 is the nitrogen obtained from 22-t of ammonia; 
and if to this the hydrogen be added, 40.34 measures of per- 
manent gas will be the total result. Hence 100 measures of 
the gas producible from ammonia, should contain 84.29 hy- 
drogen and 15.71 nitrogen ; numbers too remote from those, 
which have been already assigned, to be considered even as 
approximations to the truth. The error arises from the com- 
bination of oxygen, during combustion, not only with the hy- 
drogen, but with the nitrogen of the alkali, the latter of which 
consequently appears deficient, and the former proportionably 
in excess. 
3L2 
