]^2 ON THE WATER IN MURIATE OF AMMONIA. 



lhat any part of this increase of weight arose from the 

 absorption of humidity. It was more probably owing to 

 the ammoniacal gas not being entirely expelled, when the 

 stopper was first withdrawn, but being retained by a slight 

 force in the interstices of the salt, and being only slowly 

 detached by the atmospheric air. It was also not a uniform 

 result, and in a, subsequent experiment, in which the gasses 

 were combined in a globe furnished with a stop cock, 

 there was rather a very slight diminution of weight. The 

 two experiments therefore are conclusive in proving, that 

 this salt does not absorb humidity from the atmosphere. 

 Farther proof ^ Iie other experiment afforded a very satisfactory de-< 

 that it doss monstraiion, that the muriate of ammonia formed by the 

 combination of its constituent gasses has no power of ab- 

 sorbing water either by chemicui attraction, or by what is 

 named hygtometfie affinity. In the experiment in which 

 water was expelled from the salt by heat, the mouth of the 

 retort or of the tube was closed, and the moisture con-? 

 densed on its sides was thus submitted to the action of the 

 salt in the most favourable manner; it must therefore have 

 been quickly absorbed, had the salt any power of attracting 

 water, such as has been supposed ; but it remained without 

 any diminution for a number of hours; and even after 

 tweniy-four hours the globules of water remained apparent. 

 It is impossible to cunceive a result, which can prove more 

 satisfactorily that the salt has no such power. 

 These expe These experiments then I consider as conclusive in 



meiits conclu re f utlU g the supposition, by which it has been attempted 

 to account for the water afforded by this salt when it is 

 heated, that it is water which it has absorbed from the at- 

 mosphere. It is found, that it affords water when it is heated 

 without having been exposed to the atmosphere; that the 

 quantity it does afford is, as nearly as can be estimated, 

 as great as that which it yields when it has been previously 

 exposed; that it does not absorb humidity from atmos- 

 pheric air in its usual state of dryness ; and that it does 

 not even reabsorb the water, which has been expelled from 

 it by heat. The original experiment then, I trust, I may 

 consider as remaining in full force, and as affording a 

 conclusive proof of the existence of water in muriatic acid 

 gas, and a proof of course of the fa'sity of the hypothesis 

 which Mr. Davy has endeavoured to defend. I 



