Cetaceum. Spermaceti. A concretion prepared from the oily matter of the head of Physeter macrocephalus, or Sperm Whale; inhabiting the Pacific and Indian Oceans.

Description. A semi-concrete oily substance, which is contained in numerous cells situated in the large cavity of the upper jaw of the sperm whale. The oily matter, on standing, separates into an oil, and a peculiar substance, capable of crystallization, spermaceti. The oil is poured off, and the spermaceti collected.

Spermaceti occurs in white crystalline cakes, slightly unctuous; it fuses at 112° Pah., and when quite free from oil has been named Cetin. It has little odour or taste, can be reduced to powder by the addition of a little rectified spirit; is scarcely unctuous to the touch; should not melt under 100°. It is combustible, soluble in the fixed oils, and in boiling ether or alcohol. By the action of an alkali it is broken up into an acid, the Ethalic or Cetylic, and a substance somewhat analogous to glycerin, called Ethal or Cety. lic alcohol (C32 H34 O4). Ethalic acid is isomeric with palmitic (C32 H32 O4). Spermaceti or cetin may be regarded as a palmitate or cetylate of the oxide of cetyl (C32 H33 O, C32 H3l O3)= C64 H64 O4).

Off. Prep. Unguentum Cetacei. Ointment of Spermaceti. (Spermaceti, five ounces; white wax, two ounces; almond oil, twenty fluid ounces, or a sufficiency.)

Therapeutics. Emollient; formerly given internally, but now chiefly used externally as an emollient application.