CAM 
straw is put. The camphor is volatilized, 
and attaches itself to the straw. It is a 
little impure, but is purified in Europe by a 
second sublimation. The camphor of com- 
merce, from its mode of preparation, is in 
tire form of large semi-spherical cakes : 
when broken, it appears in fragments of a 
texture somewhat striated, having a degree 
of ductilitj", in consequence of which it can 
be compressed, and is not easily reduced 
to powder;, of a white colour, and semi- 
transparent ; a little unctuous to the feel ; 
having a very strong, peculiar, and i-ather 
fragrant odour, and a taste which is pungent 
and bitter. It is also susceptible of crystalli- 
zation : when slowly sublimed, or when 
slowly precipitated from its solution in wa- 
ter by the affusion of alcohol, it appears in 
the form of acicular prisms. 
Camphor, though a concrete substance, is 
even more volatile than the essential oils. 
It evaporates quickly at the common tem- 
perature of the atmosphere, losing in 
weight, and an angular fragment becoming 
spherical ; and at a temperature between 
100 and 150, it sublimes in close vessels un- 
changed. It is highly inflammable, kindles 
very readily, and burns witli the emission 
of much light, and witli a dense black 
smoke, which condenses into a smooth light 
charcoal. Carbonic acid gas Ls produced, 
and a portion of the peculiar acid which has 
been named camphoric acid. 
Camphor is very sparingly soluble in wa- 
ter. When triturated with it, it merely 
communicates its smell and taste to the wa- 
ter, which remains odorous, and somewhat 
pungent, even when filtrated ; but no ap- 
preciable quantity is dissolved. A pheno- 
menon which has excited some attention is 
presented, when pieces of camphor are 
placed on the surface of pure water. They 
soon begin to move with rapidity, and 
while moving dissolve, the solution taking 
place at the line where the water and the 
air are in contact ; as is proved by immers- 
ing a cylinder of camphor in water part of 
its length: it becomes excavated, and at 
length is cut through, exactly on a level 
witli the surface of the water. 
Camphor is abundantly soluble in alcohol: 
tlie solution is immediately decomposed, 
and tlie camphor precipitated in the form 
of a white powder, by the affusion of water ; 
but if the water be very slowly added, and 
merely in such a quantity as to weaken the 
affinity of the alcohol to the camphor, the 
latter, in separating, presents a deutritic 
crystallization. It is also soluble in ex- 
pressed and essential oils. The alkalis do 
CAM 
not dissolve camphor, or produce in it any 
sensible change. Of the earths, magnesia 
appears to exert some action on it, as, when 
they are triturated together, the camphor 
is reduced to a smooth impalpable powder, 
which is easily diffused in water. The ac- 
tion of the stronger acids on camphor is 
peculiar, and presents some singular results. 
By distilling nitric acid from camphor, it 
is more completely changed, and by this 
process is converted into an acid which has 
received 'the name of camphoric acid. The 
process consists in distilling from four 
ounces of camphor in a retort, 1 lb. of ni- 
tric acid, so far diluted as to be of the spe- 
cific gravity of 1.33, the heat being gra- 
dually applied by the medium of a sand- 
bath : nitric oxide and carbonic acid gases 
are disengaged ; part of the camphor rises 
in vapour, while the other part receives 
oxygen from the acid. 
Camphoric acid, thus produced, is diffe- 
rent from all the known acids. It has a 
slightly acid bitter taste, and reddens infu- 
sion of litmus. Its crystals efflorescie on 
exposure to the air ; they are sparingly so- 
luble in cold water, an ounce of water at 
50“ of Fahrenheit not dissolving more than 
6 grains ; at 212°, about 48 grains are dis- 
solved. When the acid is placed on ig- 
nited fuel, it emits a dense aromatic va- 
pour, and is entirely dissipated. By ap- 
plying heat to it in close vessels, it first 
melts and sublimes, but by a higher heat 
its properties are changed ; it no longer 
reddens litmus, acqqires an aromatic smell, 
its taste is less penetrating, and it is no 
longer soluble in water, or in sulphuric or 
muriatic acid. Nitric acid heated on it 
turns it yellow and dissolves it. 
Camphoric acid is soluble in the mineral 
acids : it is likewise soluble in alcohol, and 
in the volatile and fixed oils. It produces 
no change in sulphur. The salts formed by 
this acid, with the alkaline, earthy, and 
metallic bases, are named Camphorates, 
Their properties have been examined by 
Lagrange. Their taste is somewhat bitter : 
they are decomposed by heat, the acid be- 
ing sublimed : and they all exhibit a blue 
flame when heated before the blow-pipe, 
The alkaline and earthy camphorates are 
formed by adding the camphoric acid to the 
alkali or earth, either pure, or in the state 
of carbonate ; the carbonic acid, in the 
latter case, being disengaged. 
Caiviphorates, J See the preceding 
Camphoric Acid, J article. 
Camphor tree, the tree from which flia 
