(Physeter Macrocephalus, _Concretum sui generis_.)
Spermaceti. E.D.
QUALITIES. _Form_, flakes, which are unctuous, friable, and white.
_Odour_ and _taste_, scarcely perceptible. _Sp. Grav._ 9·433. It melts
at 112°. CHEMICAL COMPOSITION. It is a peculiar modification of fatty
matter. SOLUBILITY. It is insoluble in water and cold alcohol, but
soluble in hot alcohol, ether, and oil of turpentine, but it concretes
again as the fluids cool; in the fixed oils it is completely soluble.
The alkaline carbonates do not affect it, but it is partially dissolved
in the pure alkalies, and with hot ammonia it forms an emulsion which is
not decomposed on cooling. USES. It is demulcent and emollient, but it
possesses no advantages over the bland oils. FORMS OF EXHIBITION. It may
be suspended in water by means of mucilage or yolk of egg. (_Formulæ 76,
78, 79._) OFFICINAL PREPARATIONS. _Ceratum Simplex_. E. _Ceratum
Cetacei_. L. _Unguent. Cetacei_. L.D. From exposure to hot air, it
becomes rancid; but it may be again purified, by being washed in a warm
solution of potass.