SPERM OIL. This is derived from the head matter of the sperm whale (I'hilst.ler macroceph alas). The blubber, i.e. the material con taining the wax, whim tried out yields a crude oily liquid composed chiefly of sperm oil and spermaceti (see below), the latter being subse quently removed by chilling and pressure. Sperm oil is a pale yellow thin liquid with a slight odor. Its specific gravity is from 0.875 to 0.880. If of good quality it contains very little free fatty acid. The composition of sperm oil is as yet in dispute. By some authorities it is said to contain dodecatyl and cetyl alcohols. Its viscosity, which is high for a low-gravity oil. does not change materially with rise of tempera ture as is the case with fatty oils. and, as it is a non-drying substance and not liable to become rancid, it has long been a favorite lubricant for light high-speed machinery. Sperm oil is often
largely adulterated, mainly with other fish oils. These are usually quite easy to detect by their odor, especially on heating. :Mineral oils can be best detected by the flash test. (See OILS.) As an illuminant sperm oil has been almost, en tirely superseded by the cheaper mineral oils.
BorrtExosE Om. This is derived from the so called Arctic sperm whale rostra tus). it is a liquid darker than sperm oil and has a peculiar and characteristic taste and odor. It is more likely to gum than sperm oil. But chemically considered the two liquid waxes are probably identical, the main constituent of either being the ester composed of dodecatyl alcohol and doeglic acid. Bottlenose nil is chief ly used as a lubricant and as an adulterant for sperm oil.