35 
On Haidingerite, a new Mineral species. 
The results were within the limits of those obtained from air*. We may then 
establish it as a general law, that all gases expand in the same manner, and in like 
quantities, for equal increments of temperature 
The determinations which wc have just given would suffice, if it were only 
required to know the volume of a gas at any temperature, as measured by the 
mercurial thermometer or the reverse; hut the object we had proposed, was to 
compare the progressive expansions' of mercury and air, and this is not yet fully 
attained. In fact, as a thermometer only indicates the difference of expansion of 
the fluid and its containing vessel, it is evident, these differences cannot be pro- 
portional to the absolute expansions of this liquid, excepting in the single Case in 
which the expansions of the two bodies happen to follow the same law. If, for 
example, the vessel were to expand in a less ratio than the liquid which it contains, 
it is clear the differences of the thermometer would appear to have an increasing 
ratio, even though the rate of expansion of the liquid were uniform In the reverse 
case, a partial and unequal compensation would take piece, which would also dis- 
turb the regularity of the results. It became necessary then. to inquire into the 
changes which, in elevated temperatures, the absolute expansions of one of the two 
bodies suffer which aroused in the construction oi a thermometer. 
When we consider all the difficulties inherent in the question of the expansion 
of solids, even within the boiling point of water, how much more must we think 
of those of a still different kind, introduced into the question in extending the in- 
quiry to the higher temperatures. After a full examination of erery experiment- 
al resource which we could look to, the uncertainty of attaining to success such as 
we wished for, and the enormous complication of the apparatus which it would be 
necessary to employ ; we determined finally for the direct measurement of the*ibso- 
lute expansion of mercury— This shall be the subject of the next section. 
II. Haidingerite , an Ore of Antimony , of a neio species, found in 
Auvergne- By M. P. Bertliier. 
[Repertory of Patent Inventions, (Atmales dfe Chirnie, xxxv, 35], August, J827.)J 
Sulphuret of antitiumy exists in a great number of places, in the gneis forma- 
tion which occupies Auvergne. It is found there sometimes in regular veins 
(Ji ms j, sometimes in masses ; but if the beds are very numerous, unfortunately 
they are, at the same time, almost always but little productive. On this account, 
the people w ho work them are obliged t<> attach M great many at once, to be able to 
keep the supply uniform. 
The Auvergne sulphuret of antimony is in general sufficiently pure, and regulus 
of a good quality is obtained from it ; but a few years since, some was discovered 
near the village of Chazelles, in a vein Which was soon obliged to be abandoned, 
because the ore which it yielded gave the manufacturers of regulus a dull antimony, 
which the consumers were unwilling to use ; tW person working it, having sent me 
some specimens of this mineral, I discovered that it constitutes a new and distinct 
species, and I have named it 17 nidi nt/erite, iivhonotlr of Mr. Haidinger, a learned mi- 
neralogist, residing in Bdiuburgh, who eveTy day enriches science by his researches, 
and whose friend I have the advantage Of being. 
Haidingerite has not yet been found in regular forms ; but it exhibits in some 
cavities, rudiments of prismatic crystals, which, though not rigorously deter- 
minable, are yt t sufficient to assure ns, thfet its prinbipal form is not the same as 
that of sulphuret of antimony. ^The new mineral is commonly, in masses confus- 
edly lamellar, mixed with hyaline quartz, light chestnut coloured ferriferous carbon- 
ate of lirne, and pyrites, in cubical grains ; its colour is iron gray ; its suriace is fre- 
quently covered with rainbow tints ; it has not by a great deal, so much brilliancy 
as sulphuret of antimony, and its shade does not at all incline .to blue ; it does not 
impart the smallest motion to the magnetic needle. I have not been able to procure 
pieces sufficiently pure, to enable me to take its specific gravity. 
I purified a certain quantity of it for analysis, by pounding, sifting, and washing 
it, by which means I separated the greatest part of the quartz and pyrites, and the 
whole of the carbonate of lime. 
Before the blowpipe, the powder readily fuses ; but it exhibits no peculiar cha- 
racter ; muriatic acid attacks it easily* the action commencing even in the cold ; 
* The volume of hydrogen being 1 at 0°, we found it 2.1003 at the temperature of 
300° of the mercurial thermometer. The extremes of the determinations with com- 
mon air, under the same circumstances, were 2.0948 and 2.1027. 
