[4g] 
It is evident he was led into this miftake by not knowing the 
proportion of water that enters into mild concrete volatile 
alkali. 
Mr. Wenzel affigns to this falt a much larger. proportion of 
acid, though even his appears to me too low; by his com- 
putation 41 parts pure volatile alkali, faturated with nitrous acid, 
afford 127 of nitrous ammoniac, dried by four hours expofure 
to a heat of 212°; but it muft be remarked that its decom- 
pofition begins at a much lower heat, as Mr. Cornette has 
obferved*, and it fublimes at the heat of 234°. However, 
from this experiment it follows that 100 parts pure volatile 
alkali take 205 of the ftrongeft nitrous acid, and afford 305 of 
nitrous ammoniac. 
I mape this experiment according to my antient method, with 
the following refult: I faturated 200 grs. of mild concrete vola- 
tile alkali with fpirit of nitre, whofe fpecific gravity was 1,1538, 
984 gts. of it were requifite, the lofs of air was roo grs. the 
folution, gently evaporated in a heat of 70° or at moft 80°, afforded 
a mafs of falt moftly cryftallized, which weighed 296 grs.; here 
the quantity of pure alkali, according to the rule of proportion 
above laid down, was 78,6; and if too parts pure volatile alkali 
afforded 416 of nitrous ammoniac, as I have above determined, 
78,6 fhould produce 327 nearly, yet I found but 296, therefore 
31 were loft, probably during the evaporation. 
of 
* Mem. Paris 1783, p. 746.. 
