52 Mr. Davy's Lecture on some new analytical Researches 
Having ascertained what quantity of ammonia was given 
off from the residuum, I endeavoured to discover what quan- 
tity of nitrogene it produced in combustion, and what quantity 
of oxygene it absorbed. The methods that I employed, were 
by introducing the trays into vessels filled with oxygene gas 
over mercury. The product often inflamed spontaneously, and 
could always be made to burn by a slight degree of heat. 
In the trial that I regard as the most accurate, two cubical 
inches and a half of oxygene were absorbed, and only a cubi- 
cal inch and one tenth of nitrogene evolved. 
Surprised at the smallness of the quantity of the nitrogene, 
I sought for ammonia in the products of these operations ; 
but various trials convinced me that none was formed. I 
examined the solid substances produced, expecting nitrous 
acid; but the matter proved to be dry potash, apparently pure, 
and not affording the slightest traces of acid. 
The quantity of nitrogene existing in the ammonia, which 
this residuum would have produced by the action of water, 
supposing the volatile alkali decomposed by electricity, would 
have equalled at least two cubical inches and a quarter. 
I heated the same proportions of residuum with the red oxide 
of mercury, and the red oxide of lead in vacuo, expecting 
that when oxygene was supplied in a gradual way, the result 
might be different from that of combustion ; but in neither of 
these cases did the quantity of nitrogene exceed a cubical inch 
and a half. 
But on what could this loss of nitrogene depend; had it 
entered into any unknown form with oxygene, or did it not 
really exist in the residuum in the same quantity, as in the 
ammonia produced from it ? 
