WATER IN MURIATIC ACID GAS. 271 



transference from the one vessel to the other, and that this is 

 the source of the water which it yields. 



A supposition so directly at variance with the known pro- This snpposN 

 perties of this salt, required very ample proof, yet none was ^°rranted°by 

 given of it, farther than the assertion of the salt not yielding the tacts; 

 water when heated in a close vessel, while it affords it when 

 heated in an open vessel, this result being stated as affording 

 " a demonstration, that the water liberated in Mr. Murray's 

 experiment, was not derived from the muriatic gas, but from 

 the atmosphere." It affords, I remarked, (Journal, vol.32, 

 p. 18/,) no proof, since, admitting even the statement with, 

 regard to it to be correct, it might equally arise, since it is 

 proved, that the salt yields water when it is heated without 

 having been exposed to the air. 



I had proposed tjie obvious experiment by which the fact, and might 

 with regard to this supposed absorption of water, may be une- certained n bv S " 

 quivocally ascertained — that of forming the salt without ex- direct ex-peri- 

 posure to the air/and then ascertaining if, under such exposure, me t nt ' but was 

 it gains weight, which it must do if it absorbs water. The 

 mode of conducting the experiment, and the results, have 

 been already minutely detailed (Journal, vol. XXXII, p. 191.). 

 These results, proving that no water is absorbed, Messrs. Davys 

 have not attempted to controvert, but have rather thought pro- 

 per to avoid repeating the experiment, though it had been 

 urged against them, and is obviously decisive of the question — 

 for what reason I shall not conjecture. 



The importance of the, fact with regard to this supposed ab- Repetition of 



sorption is such, both from the supposition having been intro- ^ent^itTn 



duced to account for the production of water from the salt, Hope : Lord 



and from its having led, in consequence of that, to a form of Webb Se ^" 



1.11 1 1 * . . ,."a*' , mmr and Mr - 



experiment which has rendered the investigation more difficult Eilis being pre- 



and more liable to error, that I was desirous the experiment se " t * . A ve .*~ 



111 -i C J • 1 T 1 T-rr , , SCl AVlth WltJe 



should again be performed with every precaution. Lord Webb apai tures at 

 Seymour and Mr. Ellis were present, and the principal steps of cacu ontl **** 

 the experiment were executed by Dr. Hope. A vessel was ' 



selected, the interior of which might admit of a free exposure 

 to the air — it was pear-shaped, having a wide orifice at each 

 extremity, the one, one inch and a "half in diameter, the other, 

 one inch, its whole internal surface being equal to about 40 

 square inches. The orifices were closed with corks rendered 



air-tight 



