Bc'\ >” tn peat ate peeeatmtins 
Fiuorie Acid of Gay Lussac. 355 
An ebullition was soon heard in the alembic, and occa- 
sionally there was a puff of dense fluoric acid vapor, from 
the mouth of the receiver, which, to avoid explosion, was 
allowed to remain a little loose around the tube. We did 
not measure the acid which we obtained, but Judged that it 
was about one ounce in quantity. 
The fumes that occasionally broke out from the appara- 
tus, instantly and powerfully corroded some articles of glass 
that were near by, and the contact of them with the skin 
or lungs, was most anxiously avoided. For this purpose, 
the hands were covered with very thick gloves, and the 
acid was never poured from the bottle, except under the 
ue. 
Whenever the bottle was opened, a dense cloud of 
white vapor appeared, and when a drop of the acid was al- 
lowed to fall into water, it produced much the same com- 
motion and noise as red hot iron; excuing great heat and 
ebullition. A few drops placed i in a small concave copper 
dish, instantly inflamed aA waich burnt with a 
bri ght light, and was immediately dissipated. 
A drop of the acid, let fall into.a dry wine-glass, or upon 
a dry glass plate, promptly corroded and dissolved the 
surface, with as much energy as that with which sulphuric 
acid acts on potash. 
the purpose of procuring an acid adapted to the 
purpose of etching on glass, the experiment was repeated, 
with this difference, that half an ounce of water was placed 
in the receiver. This acid however, proved too powerful 
pak bya aon theta same ae were perfectly etched in 
the course of a minute or two. The progress of the corrosion 
in the parts denuded by the graver, could be distinctly seen. 
The same portion of acid, by ‘pouring | it fi ‘om one plate to 
h 
as 
another, served to etc : d with 
Lussac and Thenard, made oy th melting together comm: Mer peor ine 
