Spermaceti (Gr. oπερμα, sperm, and κήτοζ, a whale), a solid crystalline fat, extracted from the oily fluids found in a triangular cavity by the right side of the nose and in the upper part of the head of the sperm whale or blunt-headed cachelot, and also in smaller quantities in some other species of the cetacea. The liquid contents boiled out from the head of the sperm-whale of ordinary size sometimes amount to more than 12 large barrels full. When cold they concrete into a spongy mass, from which the larger portion of the oil drains away, leaving the crude spermaceti. This filtration is made more effective by compression in bags in a hydraulic press; and the subsequent purification is effected by melting the residue in water and skimming off the impurities, and remelting in a weak potash lye, which removes nearly all traces of the oil. The spermaceti is then melted alone by steam heat, and ladled into pans, where it cools in white, semi-transparent, lamellar cakes. The last traces of oil may be removed by boiling once or more with alcohol, which dissolves the spermaceti, but when cold holds only the oil. Pure spermaceti, called cetine, has a foliaceous texture and a delicate whiteness.

It is semi-transparent, friable, unctuous to the touch, and resembles white wax in lustre and hardness. It is without taste and of hardly any odor; of specific gravity.940; melts at 120°; • dissolves readily in hot ether, and in the fatty and volatile oils, separating on cooling. At high temperatures it sublimes without decomposition if protected from the air. By the addition of a few drops of alcohol or of almond oil it may be powdered. Its ready inflammability in connection with its fusibility renders it well adapted for candles, which is the chief use made of it. (See Candle.) It has been employed in medicine, combined with sirup or mucilage, to protect'the throat in coughs and colds; and triturated with sugar candy with the addition of milk, it forms a simple nutritive mixture. In pharmacy its use is of greater importance as an ingredient in ointments and cerates. It is not readily saponified, and in this change it differs from the other fats in not yielding glycerine, but another base instead, termed ethal, a white, solid substance, fusible at 118°, and possessing the properties of a true alcohol.

It is also called cetylic or ethalic alcohol, and is represented by the formula C16H34O. The acid, into which also the spermaceti is resolved, is known as the cetylic, ethalic, or palmitic acid, and is represented by'the formula C16H32O2