53 
some new Objects in Chemical Philosophy. 
inches of ammonia were decomposed, the weight of the oxi- 
dated matter was so minute as to be scarcely sensible. By the 
use of a freezing mixture of muriate of lime and ice, which 
diminished the temperature to — 15 0 , there was a very feeble 
indication given of the addition of hygrometrical moisture. 
In these experiments the increase of the gas was uniformly 
(within a range of five parts,) from 10c to 185, and the hy- 
drogene was to the nitrogene, in the average proportions of 
from 73.74 to 27.26 ; the proper corrections being made, and 
the precautions before referred to, being taken.* 
Assuming the common estimations of the specific gravity 
of ammonia, of hydrogene, and nitrogene, the conclusions 
which I have advanced in the Bakerian lecture for 1807, 
would be supported by these new experiments, but as the 
* Philosophical Transactions 1809, page 459. M. Bsrthollet, Jun. in the 
second volume of the Memoirs of Arcueil, has given a paper on the decomposition of 
ammonia, and he enters into an examination of my idea of the oxygene, separated in 
the electrical decomposition of ammonia, which he supposes I rate at 20 per cent, and 
at the same time he confutes some experiments which he is pleased to attribute to me, of 
the combustion of charcoal and iron in ammonia. His arguments and his facts upon 
these points, appear to me perfectly conclusive ; but as I never formed such an 
opinion, as that 20 of oxygene were separated in the experiment, and never imagined 
such results as the combustion of iron and charcoal in ammonia, and never published 
any thing which could receive such an interpretation, I shall not enter into any cri- 
ticism on this part of his paper. The experiments of this ingenious chemist on the 
direct decomposition of ammonia,seem to have been conducted with much care, except 
as to the circumstance of his not boiling the quicksilver ; which 1 conceive has occa- 
sioned him to over-rate the increase of volume. At all events a loss of weight is more 
to be expected than an increase of weight, in all very refined experiments of this kind. 
It is possible that the volume may be exactly doubled, and that the nitrogene may be 
to the hydrogene as one to three ; but, neither the numerous experiments of Dr. 
IIenrv, nor those that I have tried, establish this; it is one of the hypothetical 
inferences that may be made, but it cannot be regarded as an absolute tact. 
