in different chemical Processes on Fluor Spar. 411 
« compound of water, and inflammable bases, and oxygen, 
that water ought to be produced when it was made to com- 
bine with ammonia. It was not possible to make the ex- 
periment in glass vessels, as the acid acts with great vio- 
Jence on glass, producing silicated fluoric acid gas. I had 
recourse, therefore, to an apparatus made of platina. A 
small tray of platina was filled with pure liquid fluoric acid, 
and introduced into a tube of platina connected by proper 
stop-cocks with a mercurial gazometer, filled with am- 
monia; the end of the platina tube was closed by a brass 
stopper, and a communication made between the ammonia 
and the fluoric acid ; the ammonia was gradually absorbed, 
producing heat ; and white fumes sometimes rose into the 
gas-holder, so that it was necessary from time to time to 
cut off the communication; ammoniacal gas was supplied 
till no more absorption took place. When the tube was 
quite coo], the stopper was removed, and the result ex~ 
amined; the interior contained a white crystalline mass, 
but there was no appearance of fluid*. A polished brass 
tube, cooled by means of ice, was held over the aperture of 
the platina tube, and it was gently heated till the salt began 
to sublime, but no moisture was found condensed in the 
cold tube of brass. 
This experiment is unfavourable to the idea, that the li- 
quid fluoric acid contains water 5 and the following result 
is likewise unfavourable to the idea that it consists of an 
inflammable basis united to oxygen. Solid and pertectly 
dry fluate of ammonia was introduced into a tray of plata, 
with about an equal quantity of potassium, and the tray 
was heated in a small tube of glass connected with a mer- 
curial apparatus. A violent action took place, gas was 
disengaged with great violence, which remained for some 
time clouded ; the application of heat was continued till the 
tube was red: it was then suffered to cool, and the results 
examined. Much white matter, which proved to be fluate 
of potassa, had been carried by the violence of the action 
out of the tray of platina into the glass tube; and a little 
potassium had sublimed in the tube. The tray contained 
a considerable portion of potassium, and a saline matter, 
which bad all the characters of fluate of potassa. The gas 
disengaged, consisted of ammomia and hydrogen, to each 
. 
* It is necessary that pure liquid fluoric acid, 2.¢. that which has the 
lowest specific gravity, bp used for this experiment. ‘The first time that { 
made it, I obtained moisture, owing to my having formed the hydro-fluoric 
acid by means of sulphuric acid that had not been previously boiled, and 
which must have contained more than one proportion of water, 
other 
