4$o Mr. Davy’s new analytical Researches 
boiled in the tube for electrization ; the ammonia was intro- 
duced after being long dried by caustic potash, from a receiver 
in which it had not been generated, and which had likewise 
been inverted over boiling mercury. The gas left no percep- 
tible residuum, when absorbed by water deprived of air by 
boiling. In this process, 15 measures of ammonia expanded, 
so as to fill 27 measures ; and the hydrogene by detonation 
with oxygene, over water freed as much as possible from air> 
proved to be to the nitrogene as 73.8 to 26'. 2. In the experi- 
ment three explosions were made, the oxygene being deficient 
in the first two ; so that no nitrogene could have been con- 
densed in the form of nitric acid. 
Except when precautions of this kind are employed, as I 
have before noticed, no accurate data can be obtained re- 
specting the proportions of permanent gases obtained from 
ammonia by electricity. 
When the gas is generated and decomposed over the same 
mercury, there is always a greater expansion than the true 
one ; and when the mercury is not boiled in the tube, and 
when common water is used, the nitrogene will be always 
over-rated, unless this error is counteracted by an opposite 
error, that of detonating with an excess of oxygene.* 
Dr. Henry had the kindness to send me the apparatus, in 
which he conceived, at that time, that he had witnessed the 
formation of water in the decomposition of ammonia by elec- 
* It will be seen by Dr. Henry’s letter, which immediately precedes this com- 
munication, that in repeating his processes, since this paper was written, he has 
gained results almost precisely the same as those indicated in the text; and there is 
every reason to believe, that 100 of ammonia in volume uniformly become 180, when 
decomposed by electricity, and that the gas produced consists in ioo parts of 7^ 
hydrogene and 26 nitrogene. 
