ON THE WATER IN MURIATE OF AMMONIA. ] go 



it and the force of cohesion is attained ; and in a soluble sub- 

 stance therefore must continue until it is dissolved. No such 

 property belongs however to muriate of ammonia; every 

 chemist knows, that in an atmosphere in a common state of 

 dryness it is not deliquescent, but remains dry for any 

 length of time. There is no reason to believe, that it is ca- 

 pable of absorbing water short of that quantity, which shall 

 produce sensible humidity; and it is altogether an extrava- 

 gant assumption, that it can absorb water with such rapidity, 

 as in a few minutes to imbibe that considerable quantity 

 which it yields when exposed to heat. With regard to any 

 hygrometric effect from the loose pulverulent state of the The salt can- 

 salt, it is not less extravagant to suppose, that it could not llct »ygro- 



!■, i . metrically. 



operate so speedily, or to such an extent as is necessary to 



account for the result of the experiment; or that it could 

 operate after the salt had been heated, so as to enable it to 

 afford the quantity which even then it yields*. 



Fortunately the determination of this point is not attended The point ea- 

 with any peculiar difficulty. It may be ascertained by ex- snv determin- 

 periment, whether the salt does absorb water or not from the e ' 

 air, and whether the water which it yields when heated is 

 derived from this source. 



I first performed the experiment of heating the salt with- Experiment 

 out its having been exposed to the air. In a small retort, described. 

 over dry quicksilver, 1 combined in successive portions 25 

 cubic inches of ammoniacal gas, which had been dried by 

 exposure to lime, with muriatic acid gas, which had been 

 exposed to muriate of lime, aading at the end an excess of 

 ammoniacal gas to rill the retort. The retort was then turned 

 over in such a manner, ihat the extremity of it aec* was 

 kept under the quicksilver, and an inserted jar ixHed w-'th ' 

 quicksilver was placed over it. The body of the retort '.einp- 

 surrounded with sand, heat was applied by an Arga d's i .mp 



* After the salt has afforded water by being heated, I ha I found it 

 to afford an additional portion, when it is exposed to a stronger Lett. 

 It is also stated in your Journal (vol. XXXI, p. . 3 -,) thai rater .nay 

 be obtained from the salt successively by heating it repeatedly, i"ii is 

 exposed to the atmosphere for a few minutes each time , aiv it is a '.' d, 

 that in this way I might have obtained water to the aruoum '.f thrice 

 the weight of the salt. T\o doubt, if the saitthus absorbs water, it may 

 continue to afford it to fifty times its weight. 



with 



