3H 
Mr. Hatchett's Analysis of 
Bucquet says, that when it has lost the water of crystalli- 
zation, it becomes red hot, and melts without being volatilized. 
Lastly, M. Fourcroy mentions it in the following man- 
ner : “ As it contains much water of crystallization, it imine- 
“ diately liquefies by a very moderate heat ; but by degrees it 
s< becomes dry, in proportion as the water of crystallization is 
{< dissipated. In this state it first becomes red hot, and soon 
** melts without being volatilized, according to Bucquet ; but 
“ M, Baume' asserts that it is demi-volatile. In repeating 
“ this experiment I have observed, that in fact a part of this 
“ salt is sublimed, but a portion remains fixed in the vessel, and 
“ without doubt it is concerning this that Bucquet speaks."* 
When so many eminent chemists concurred in nearly the 
same assertion, I was not a little surprised to observe, in some 
experiments (which I made for a very different purpose), that 
the whole of the sulphate of ammoniac was not only volati- 
lized by heat, but also that the distillation of it was accompa- 
nied with some remarkable phasnomena. 
I therefore diluted some very pure concentrated sulphuric 
acid with an equal quantity of distilled water, and having sa- 
turated it with ammoniac, I gradually evaporated it till it be- 
came a concrete salt. 
EXPERIMENT I, 
I put two ounces of the salt into a glass retort, capable of 
containing three times the quantity, then fitted on a receiver 
without any luting, and placed the retort in a small open fur- 
nace over some lighted charcoal 
The salt in the retort speedily liquefied, and a small portion 
• Ele'm tnsd' Histoire Nature lie et dc Cbimie, Tom. II. p. 93. 
