216 APPARATUS AND PROCESS FOR THE RAPID CONGELATION OF WATER. 



I now submit to the society, for publication in their Transactions, an en- 

 graving and description of the apparatus employed agreeably to the recent 

 modification to which I have adverted. 



The retort (A) contains water covered by a stratum of hydric ether, com- 

 monly called sulphuric ether. The vessel (B) holds a stratum of sulphuric 

 acid, of which the depth, at the deepest part, is about two inches. Into the 

 tubulure in the side of this vessel the beak of the retort is ground to fit air- 

 tight, and is made to receive one end of a recurved tube, of which the lower 

 end descends about half an inch below the surface of the acid. A mercury 

 bottle, (C,) of which the mouth is closed so as to be air-tight, is furnished with 

 two cocks, one of which communicates, through a pipe, with an air-pump, the 

 other, in like manner, with the vessel (B.) This bottle is previously ex- 

 hausted, and kept in a state of exhaustion by closing both of the cocks. The 

 pump being put into operation and the cocks opened, the power of the acid in 

 absorbing the vapour, co-operating with that of the pump, and the vacuum in 

 the bottle, in exhausting the air and vapour from the retort, causes an explo- 

 sive vaporization of the ether and a rapid congelation of the water. It is upon 

 the novelty of the last mentioned phenomena, and of the means employed in 

 their production, that I rest the pretension of this brief communication to a 

 place in a volume of the society's Transactions. 



