446 Dr. Henry's Experiments on Ammonia. 
Forty-eight measures of ammonia, being fired with 6& 
nitrous gas, (=53 pure) both gases were completely decom- 
posed ; and a residue left consisting of 61 nitrogen and 9 
hydrogen. Sixty measures of ammonia and 41 nitrous gas 
( = 36*, 1 pure) gave, after firing, a mixture composed of 10 
ammonia, 53-j nitrogen, and 30^ hydrogen. But taking for 
granted that 100 measures of nitrous gas, according to your 
analysis, hold in combination a quantity of oxygen equal to 
measures of oxygen gas, and of nitrogen equal to 48-j 
measures, and assuming the proportions of the nitrogen and 
hydrogen in ammonia, to be those established by your ex- 
periments and my own. It will appear from an easy calcula- 
tion, that the proportion of nitrogen, in the above residua, a 
little exceeds, and that of the hydrogen rather falls short of 
what might have been expected. I have not yet been able to 
reconcile these differences, by the numerous trials required in 
a process of so much delicacy ; and I reserve the enquiry 
for a season of more leisure. The foregoing statement, I 
wish to be considered as merely announcing the general fact 
of the combustibility of a mixture of ammonia and nitrous 
gas, a property which chiefly derives importance, from its 
being capable of application to a new method of analysing the 
latter. 
Before concluding this letter, I shall briefly state the re- 
sults of some experiments, which I have lately made in con- 
junction with Mr. Dalton, on a subject that formerly occu- 
pied much of my attention ; viz. the effect of electricity on the 
aeriform compounds of carbon and hydrogen. Subsequent 
