334 Mr Graham on the Absorption of Vapours by Liquids. 



came in six days 29 grains, a portion being dissolved by the 

 alcohol absorbed. A solution of bichloride of mercury in al- 

 cohol likewise exhibits an invaporating power when in an at- 

 mosphere of alcohol vapour. 



It would be curious to know whether alcohol is capable of 

 absorbing the vapour of water, as well as water is capable of 

 absorbing the vapour of alcohol. It is difficult to determine 

 the point directly, as the quantity of water absorbed might be 

 very minute ; but I am inclined to believe, from an indirect ex- 

 periment, that alcohol does not possess such an absorbing 

 power. A crystal of sulphate of soda was suspended over a 

 small quantity of absolute alcohol very carefully prepared, by 

 a thread, which was attached to the cork of the phial, for a pe- 

 riod of six months, without undergoing the slightest alteration 

 in appearance. Now, if alcohol had possessed the power to 

 absorb aqueous vapour, and to keep the atmosphere above it 

 in a dry state, so far as aqueous vapour is concerned, the crystal 

 would certainly have effloresced and fallen into powder. 



The phenomena presented when pieces of camphor are 

 placed at a little distance from alcohol are very remarkable. 

 A number of small pieces in a gauze bag were suspended with- 

 in a glass jar which contained a Httle alcohol. In a few hours 

 the camphor began to run into a liquid, which fell in drops, and 

 in twenty-four hours the whole camphor had left the bag in that 

 manner. It is evident, therefore, that solid camphor with re- 

 lation to alcohol vapour is deliquescent. Forty grains cam- 

 phor were suspended over alcohol, as in the previous case, with 

 the difference, that the camphor was contained in a little glass 

 capsule. Five days afterwards the capsule contained a solution 

 of camphor in alcohol weighing 105 grains. A little camphor, 

 however, had passed down to the alcohol below, to which it 

 communicated its taste and smell ; but the quantity was so 

 small that the alcohol, on being diluted with water, became only 

 slightly opalescent. The temperature of the atmosphere dur- 

 ing these experiments averaged about 55°. 



The salt subcarbonate of ammonia is known to be possessed 

 of considerable volatility, and also to be soluble in water. In- 

 closed with water in separate vessels it quickly passes over into 

 the water. Thirty grains of dry subcarbonate reduced to pow- 

 der were suspended in a glass capsule over a considerable 



