ON FLUORINE. 
79 
subject almost new. The occasion so rarely happens to me to 
prepare these oils, that my researches can do little, but I hope 
that they will be taken up by some person more favorably 
situated. A new and interesting field of inquiry is presented. 
Journ. de Pharmacie. 
ART. XIX. — ON FLUORINE. By G. J. Knox and the Rev. 
Thomas Knox. 
The authors having taken a summary view of all the re- 
searches on fluorine up to the date of the commencement of 
their experiments, in April, 1836, proceeded to describe the 
vessels of fluorspar which they used in their first experiments, 
and exhibited those which were latterly found best adapted 
for examining the gas. These vessels were of fluorspar 
wrapped with iron wire for the purpose of equalizing the tem- 
perature, so as to prevent the vessels splitting on a sudden 
application of heat. In place of a flat cover for the vessels, 
fluorspar receivers were used, the cavities of which were 
filled with ground stoppers of the same materials. On moving 
the receivers over the mouth of the vessel the stoppers fall 
in, and their places are occupied by the gaseous contents of 
the vessel. On the top of each of the vessels is placed a flat 
slab of fluorspar, which answers the purpose of a table, upon 
which the receivers of the gas can be moved. On the slab 
are four small depressions, in which are placed the substances 
upon which the action of the gas is to be observed, and over 
which the receivers, when filled with gas, can be slid. In 
opposite sides of these receivers are drilled holes, into which 
are fitted, air tight, clear crystals of fluorspar, through which 
the color of any gas in the receiver may be distinctly observed. 
The vessels are supported on a stand over a lamp. 
On heating pure fluoride of mercury in these vessels, with 
dry chlorine, the authors obtained a colorless gas, (as seen 
through the fluor,) having a heavy smell, not pungent, or 
