C H E M 
If a bit of camphor be laid on glafs, or in a very clean 
faucer, and juit covered with pure water, the water will 
immediately recede, and leave a dry circle round the 
camphor. If a bit <?f camphor be put upon very pure 
water, it will move about with great rapidity. If a fmall 
drop of any liquid odorous body, or oil, be thrown on 
the furface of the water, the motion ceafes immediately. 
If drops be drawn from the furface of a glafs of water, 
and dropped into the glafs where the bit of camphor is in 
motion, at the 50th or 60th drop the motion ceafes; but 
it continues, if the water be only touched with a bit of 
metal well polifhed. If the bit of camphor be now put 
into the water which has been touched by the wax, the 
rotatory motion of the camphor begins as ufual, but in a 
few feconds it ceafes of itl'elf. The camphor, thus placed 
upon water, diffolves falter than in moiftair; and in dif- 
folving it acquires a round form, and becomes tranfpa- 
rent. This folution takes place only at the point of con¬ 
tain of the air and water, as Venturi proved by the fol¬ 
lowing experiment: If a cylindrical piece of camphor be 
put in water, and loaded I'o that about one half fliall. be 
under the furface, it will corrode a little above the fur¬ 
face of the water, fo that by degrees it feparates into two 
pieces. 
Argil, or pure alumine, has the property of decom- 
pofing camphor. Take one part of camphor and fix of 
argil; dry the clay, and reduce it to powder, then pafs 
it through filk; reduce the camphor to powder by means 
of alcohol; and mix the whole together in a mortar. 
When well mixed, add a little w’ater, not too much, but 
juft enough to form a pafte, and make it up into balls 
about as big as an olive ; place thefe on a hair-cloth, and 
leave them to dfy in the (hade. When perfeftly dry, put 
them into a retort, which place on a fand-bath ; fix on a 
receiver, which is previoufiy to contain fome diftilled 
water, and then lute the joinings clofe. When the ap¬ 
paratus is thus difpofed, heat the retort gradually, keep¬ 
ing it for fome hours at a low heat; then increafe the 
fire. If the fire has not been (kilfully managed, it may 
happen that part of the camphor is fublimed in the neck 
of the retort; continue the operation however till no 
more oil is leen to run ; then flop the fire ; and, when the 
apparatus is cool, unlute, and take the fublimed cam¬ 
phor out of the neck of the retort, as well as what re¬ 
mains at the bottom. Beat the whole in a mortar, and 
repeat the operation as before, until, with a ftrong heat, 
there is neither fublimation nor oil. 
Alumine may alfo be ufedto advantage in thisdecom- 
pofition. This alumin is to be prepared by means of 
ammoniac; walh it with diftilled water to make it as 
pure as poflible; then dry it (lightly. Take two parts 
of alumine, or three if wet, tojme part of camphor ; and 
proceed as above direfted. In either cafe, there will be 
found in the receiver a volatile oil of a gold-yellow co¬ 
lour, floating on the furface of the water. This oil is of 
a lliarp biting tafte, but leaves a fenfe of coolnefs on the 
tongue; its fmell is aromatic, like thyme or rofemary. 
It entirely evaporates by free expofure to the air. With 
alkalis it forms favonules ; it is l’oluble in alcohol. The 
diftilled water contained in the receiver, is very aromatic, 
pungent, reddening- tincture of turnfole, and effervefcing 
with alkaline carbonats, which proves that fome acids is 
formed during the operation. What remains in the re¬ 
tort is of a fine black colour, and weighs more than the 
clay or alumine ufedin the operation: this matter is car¬ 
bon intimately mixed with the alumine. To feparate the 
carbon from the alumine, and have it pure, the alumine 
muft be faturated with an acid. 
Acids dilfolve camphor. Sulphuric acid, alfifted by 
heat, diffolves it, and becomes red. The nitric acid dil- 
folves it without any inteftine motion, and forms a yellow 
liquid, which,becaule itfloats on theacid, has been called 
improperly oil of camphor ; but this preparation is very 
imperfect; for, it cannot be mixed with any other fub- 
ftance without the camphor being revived. The mu¬ 
riatic acid, in the ftate of gas, difiolves camphor; as do 
VOL. IV. No. 20i. 
[ S T R Y. 337 
likewife the fulphureous and fluoric acid gales. If water 
be added to thefe folutions, they become turbid, and the 
camphor is feparated in flocks, which float on the furface 
of the liquid, and does not appear to have fuftained any 
change in its properties. If oxygenated muriatic gas be 
put into oil of camphor prepared with nitric acid, it im¬ 
mediately changes to a role-colour, and becomes yel¬ 
low a moment afterwards, which laft colour remains to 
the end of the operation. 
CAMPHORIC ACID. 
The nitric acid a£ls upon camphor in a manner dif¬ 
ferent from what we have hitherto noticed. Kofegarton 
found, that, by diftilling over camphor eight times the 
quantity of nitric acid, an acid was produced which had 
different qualities from the oxalic acid. But the nature 
and habitudes of the camphoric acid have been more re¬ 
cently inveftigated by Bouillon la Grange. This che- 
mift prepares the camphoric acid, by diftilling four ounces 
of camphor in a fand-bath with one pound of nitric acid, 
at 36°. During the diftillation, a confiderable quantity 
of nitrous gas and carbonic acid gas are difengaged. One 
portion of the camphor is volatilized, while the other 
l'eizes on the oxygen of the nitric acid. When vapours 
ceafe to be difengaged, the veffelsare to be unluted, and 
the camphor which has been fublimed returned into the 
retort, and a frelh portion of acid added to it. The pro- 
cefs of diftillation is to be repeated in this manner, till 
the whole of the camphor is converted into an acid; 
four pounds fourteen ounces of nitric acid are required 
to acidify four ounces of camphor. The moft certain 
mark of complete 'acidification, is the cryftallization of 
the liquor which remains in the retort. This acid is pu¬ 
rified, by diffolving it in warm water, filtering the folu¬ 
tion, and evaporating it till a thin pellicle forms on the 
furface; the camphoric acid then cryftallizes by cool¬ 
ing. The camphoric acid may be formed more fpeedily, 
by ufing a ftronger nitric acid. But in this cafe a 
portion of the camphor is loft, by being diflipated a- 
long with the gas. La Grange has all'o a method of 
extracting it by means of oxygen gas. ExtraCt the oxy¬ 
gen gas from fuper-oxygenated muriat of potafli; fiil 
a jar with it, which place in the mercurial pneumatic 
ciftern, and introduce a little water into it. Then 
put a bit of camphor, and a morfel of phofphorus,. 
in a cupel ; have a bent tube, one extremity of which 
muft be in the jar, and the other in the pneumatic cif¬ 
tern, under a jar filled with water. Things thus dif¬ 
pofed, light the phofphorus with a red-hot iron wire : the 
phofphorus flames, and then the camphor. The flame 
produced by the camphor is very bright; much caloric 
is difengaged ; the jar is covered with black matter, 
which by degrees comes off, and covers the water placed 
over the mercury in the jar : this is carbon ; a gas is col¬ 
lected at the fame time, which has all the propet ties of 
carbonic acid gas. The water contained in the jar is 
very odorous, and contains camphoric acid in folution. 
Camphoric acid has a (lightly acid bitter tafte, and 
reddens the tinClure of turnfole. It cryftallizes; audits 
cryltals refemble thofe of muriat of ammoniac. It efflo. 
refees x in the air, and diffolves difficultly in cold water. 
An ounce of this fluid, in the ordinary temperature of 
the atmofphere, is required to dilfolve fix grains of cam¬ 
phoric acid; but the fame quantity of boiling water dif¬ 
folves forty-eight grains. This acid is wholly diflipated 
on burning charcoal, emitting a thick aromatic finoke In 
a more gentle heat it melts, and is fublimed. When dif¬ 
tilled alone, it firft melts, and then fublimes. Mineral 
acids dilfolve it entirely. It decompofes fulphat and mu¬ 
riat of iron. Fixed and volatile oils diffdlve it; it is I'o- 
luble alfo in alcohol, and is rot precipitated by water; 
in which it differs from the benzoic acid, which is pre¬ 
cipitated by water from its alcoholic folution. It unites 
readily with earths and alkalis ; thefe combinations are 
called camphorats . 
Of Camphorats. —The camphorats of lime, magne- 
4. R fia. 
