faction and waste of organic matter
enter into the pores of the charcoal, and there meet with the oxygen
previously absorbed from the atmosphere; oxidation ensues, and the
noxious effluvia are decomposed. Generally, however, the action is a
purely mechanical one, the gases being only absorbed. Its
pharmacological action depends on the same property; it absorbs the
gases of the stomach and intestines (hence its use in cases of
flatulence), and also liquids and solids. Wood-charcoal has also the
power of removing colouring matters from solutions, but this property is
possessed in a much higher degree by animal-charcoal.

_Animal-charcoal_ or _bone black_ is the carbonaceous residue obtained
by the dry distillation of bones; it contains only about 10% of carbon,
the remainder being calcium and magnesium phosphates (80%) and other
inorganic material originally present in the bones. It is generally
manufactured from the residues obtained in the glue (q.v.) and gelatin
(q.v.) industries. Its decolorizing power was applied in 1812 by Derosne
to the clarification of the syrups obtained in sugar-refining; but its
use in this direction has now greatly diminished, owing to the
introduction of more active and easily managed reagents. It is still
used to some extent in laboratory practice. The decolorizing power is
not permanent, becoming lost after using for some time; it may be
revived, however, by washing and reheating.

_Lampblack_ or _soot_ is the familiar product of the incomplete
combustion of oils, pitch, resins, tallow, &c. It is generally prepared
by burning pitch residues (see COAL-TAR) and condensing the product.
Thus obtained it is always oily, and, before using as a pigment, it must
be purified by ignition in closed crucibles (see CARBON).

CHARCOT, JEAN MARTIN (1825-1893), French physician, was born in Paris on
the 29th of November 1825. In 1853 he graduated as M.D. of Paris
University, and three years later was appointed physician of the Central
Hospital Bureau. In 1860 he became professor of pathological anatomy in
the medical faculty of Paris, and in 1862 began that famous connexion
with the Salpetriere which lasted to the end of his life. He was elected
to the Academy of Medicine in 1873, and ten years afterwards became a
member of the Institute. His death occurred suddenly on the 16th of
August 1893 at Morvan, where he had gone for a holiday. Charcot, who was
a good linguist and well acquainted with the l