354 Fluoric Acid of Gay Lussac. 
Arr. XXIL—Flworic Acid of Gay ment its pppliiatts 
* to the eiching of glass.—EpiTor 
As we have not seen any notice, that this powerful acid 
has been obtained in this country, we will briefly mention, 
that we procured it in full strength, during the late winter, and 
comparing it with the account given in the. lg tis in the 
“Recherches Physico-Chimiques,” of Messrs. Gay Lussac 
and Thenard, observed with much satisfaction that its prop- 
erties fully justify their statement; not that we think their 
researches or those of Sir. H. Davy, needed confirmation, 
but, notices of interesting facts by different persons eapepialy 
in different countries are not without utility.. 
The leaden apparatus, recommended for procuring pure 
fluoric acid, we have found so liable to fusion, and besides 
the failure of the axpeimssi pe the loss of the apparatus, 
the fumes are so noxious and even dangerous, that we were 
induced to resort to the use of vessels of pure silver. For this 
purpose, an alembic* was made of the capacity of 16 fluid 
ounces, with a head and tube of the capacity of two and a 
half, and the tube was made to fit > inna aed the mouth of a 
silver receiver of the capacity of three and a half ounces. 
The latter (see the apperains : represented at fig. 7, plate 10.) 
was made, in the form of a bott le, and furnished with a ‘sil- 
ver stopper, ground so as to fit air tight; it being intended to 
serve, both asa receiver, and a containing vessel, for the 
acid, thus obviating the necessity of transferring it into 
another vessel, 
Two ounces of very pure fluor spar from Shawneetown 
were introduced into the alembic, and four ounces of sul- 
phuric acid were added; there should be no excess of acid, 
lest it should attack the silver. . The whole apparatus was 
placed under a flue; the receiver was rake cold by ice, and 
a few live coals being applied beneath the alembic, served 
to disengage the acid, which was condensed in the receiver, 
without the aid of water. 
*The alembic was made thick and heavy, and furnished og a silver 
cap, so pe ae on be used without iY head, as a . cruci oon 
tof the entire a t embic-he: receiver, 
Sek ehdnt slaty dollage ys reer wh rai. 
