28 Dr. Murray's Experiments on - {Jaws 
obtained in that mode of conducting the experiment which affords 
the least favourable result, and were it even admitted to all the 
extent to which it can be supposed to exist, is inadequate to 
accouut for the larger quantity obtained in the other. 
That the entire quantity of water contaimed in the muriatic 
acid gas is not to be looked for is evident from the nature of the 
* ammoniacal salt, particularly its volatility, whence the due degree 
of heat to effect the separation of the water cannot be applied. 
If the other muriates yield the greater part of their water, only 
when raised nearly to a red heat (which is the case), it is not to 
be supposed that muriate of ammonia shall do so at a tempera- 
ture so much lower as that which it can sustain without volatili- 
zation. . What is to be expected is a certain portion of water, 
greater as the arrangements employed are better adapted to 
obviate the peculiar difficulty attending the experiment. There 
is a production of water in every form of it ; and there exists no 
just argument whence it can be inferred that the quantity is less 
than what ought to be obtained. On the opposite doctrine, none 
whatever should appear. 
To effect the more perfect separation of the water from the 
muriate of ammonia, | had performed the additional experiment 
of passing the salt formed from the combination of the two gases, 
in vapour through ignited charcoal, on the principle that by the 
interposition of the charcoal, the transmission of the vapour 
would be impeded, and it would be exposed to a more extensive 
surface, at which a high temperature would operate, while some 
effect might also be obtained from the affinities exerted by the 
carbonaceous matter. To remove any ambiguity from the effect 
of the charcoal, it was previously exposed in an iron tube to a 
very intense heat, until all production of elastic fluid had ceased ; 
and removed while still warm into a tube of Wedgewood’s porce- 
lain, containing the muriate of ammonia, which was then placed 
across a furnace so as to be raised'to a red heat. As soon as 
the vapour of the salt passed through the ignited charcoal, gas 
was disengaged, which was conveyed by a curved glass tube 
adapted to the porcelain one, and received in a jar over quick- 
silver. Moisture was at the same time pretty copiously deposited, 
condensing both in the glass tube in globules, and being brought 
in vapour with the gas, which it rendered opaque, and condensing 
on the surface of the quicksilver within the jars. The elastic 
fluid consisted of carburetted hydrogen and carbonic acid, pro- 
ducts evidently of the decomposition by the ignited charcoal of 
a portion of the liberated water. In this experiment, then, the 
result was still more satisfactory than in the other. That no 
ambiguity arose from any effect of the charcoal in affording 
water, is evident from this, that the water appeared at the 
moment the salt began to pass in vapour, and at a temperature 
far below that at which the charcoal had ceased to afford any 
eas. In another variation of the experiment, muriate of ammonia 
