Mr Graham on the Absorption of Vapours by Liquids. 327 



posed to the air did not present the shghtest appearance of 

 deliquescence. The basin of pure water in the second jar 

 had lost three grains in weight, but the solution of chloride 

 of sodium had increased in weight by 63 grains. This 

 solution possessed no power to absorb and condense vapour 

 from a temperature originally lower than that of the wa- 

 ter near it ; while the circumstance of a loss, rather than an 

 increase of weight, occurring in the other case, renders it im- 

 probable that any inequality of temperature took place during 

 the continuance of the experiment, and operated in this way. 

 The plain inference from the experiment was, that the chlo- 

 ride of sodium employed, although by itself not deliquescent, 

 or incapable of absorbing vapour, yet possessed that property 

 in a considerable degree when in solution, seeing that in six 

 days it had absorbed nearly half its weight of water, the 

 quantity of salt in solution being 143 grains, and the increase 

 of weight 63 grains. 



In a second preliminary experiment there were two cases 

 similar to the preceding, and besides, the same quantities of 

 saturated solutions of muriate of ammonia and of sulphate of 

 magnesia were inclosed in jars containing a little water in a 

 similar manner. The temperature on closing the jars was 

 about 58°, and very equable during the experiment. In four 

 days the basin of pure water was found to have lost 2.5 

 grains, but the solution of muriate of ammonia had increased 

 34 grains, of chloride of sodium 37 grains, and of sulphate of 

 magnesia 8 grains. The increase in the case of sulphate of 

 magnesia was the least, although it contained most saline mat- 

 ter. 



In the farther investigation of this subject, instead of sepa- 

 rate jars, low tin-canisters were employed, in which several 

 vessels with solutions might be arranged at the same time. 

 The vessels rested on a support of wire-cloth an inch from 

 the bottom of the canister, the lowest part of the canister be- 

 ing occupied with water to the depth of half an inch. The 

 canisters were provided with lids, which could be made air- 

 tight. It had been found that Wedgewood porcelain basins 

 unfailingly absorbed a portion of the water or of the saline so- 

 lution which they contained, varying from one to twelve grains. 



