[ 38 J 
In this account no notice is taken of the water of cryftalli- 
zation, for in faét common falt does not appear to contain any ; 
that which is got rid of by heat feems to me to be merely ac- 
cidental. Mr. Wild, who has attended fo fuccefsfully to every 
thing relating to this falt, affirms that g11 grs. of it lofe but 
7,1 by decrepitation*. Mr. Storr found it to lofe none in any 
heat below 590°. As common falt does not efcape in any confi- 
-derable degree during the evaporation of its folution, and retains 
its acid in the ftrongeft heat, the refults of Mefirs. Wenzel and 
Wiegleb, and particularly that of the latter, agree very nearly 
with the foregoing. ; 
Accorpinc to Mr. Wenzel 71,5 of pure mineral alkali were 
faturated by 266,5 of his fpirit of falt, and the refiduum after 
fubtracting 1 gr. of earth and expofure to ignition weighed 
131,5 grs.; this quantity, therefore, contained 71,5 grs. of alkali, 
and 60 of the ftrongeft acid. Hence too grs. pure mineral 
alkali fhould take up nearly 84 of the ftrongeft acid, and pro- 
duce 184 of common falt; and fecondly, 100 parts common falt 
contain 54,37 of alkali, and 45,63 of the ftrongeft acid. 
AccorDING to Mr. Weigleb 105 grs. of common falt contain 
56 of alkali, and 49 of the. ftrongeft acid. Hence 100 parts 
contain 53,5 of alkali, and 46,5 of acid. Hence 100 parts pure 
alkali 
* Beytrage zu Salkzunde, p. 94. 
