Oleum cerae; oil of wax; called also cerelaeum, from cera, and oleum, from being thinner than cerate, which is, in fact, the butter of wax, prepared by filling the upper part of the retort with fine sand, and distilling the wax through the sand. - Cut yellow wax in small pieces, and put as much into a retort as will fill nearly one half; then add as much clean white sand as will nearly fill the retort; after which place it in a sand furnace. At first an acid liquor arises, afterwards a thick oil, which sticks in the neck of the retort, unless it be heated by applying a live coal. The thick oil is also called the butter of wax, and maybe rectified into a thin oil by distilling it several times, without addition, in a sand heat: if it is thus rectified it never hardens again.

Boerhaave highly extols this oil as an emollient, and for healing chaps and roughness of the skin, for curing chilblains, and, with the assistance of exercise, for relaxing contracted tendons. It is rarely used on account of its empyreumatic smell, but it is wholly free from acrimony.

Cera alba, white wax, is the yellow wax artificially deprived of its colour, by reducing it into thin flakes, exposing them to the sun and air, and occasionally sprinkling them with water. When sufficiently whitened, it is melted and cast into thin cakes. Some whiten it first by dissolving it in hot water, forcing it through linen strainers into shallow metalline moulds, and then exposing it to the air. When wax is thus robbed of its colour, it has a less resolvent quality; but is altered in no other respect. It is sometimes adulterated with white oxide of lead, sometimes with tallow. Melting will discover the first, and the smell detect the other fraud.

The college of physicians of London give the following form for making the unguentum cerae, ointment of wax; formerly called unguentum album. Take of white wax, four ounces; spermaceti, three ounces; olive oil, a pint: let these be melted over a gentle fire, constantly and quickly stirring the compound until it grows cold. Ph. Lond. 1788.

The cerae unguentum cum hydrargyro is highly recommended in languid ulcers, and, as it acts favourably on the callous edges, it should be extended some distance round the sore. It consists of eight ounces of wax, and two of axunge, with six ounces of unguent. hydrargyri. A few drops of rectified spirit of wine renders wax more easily pulverisable. See Lewis's Mat. Med. Neumann's Chem. Works.

Cera dicardo. See Carduus pinea. Cera cinnamomi. Sec Cinnamomum. CeraeAE, (from a horn, called also Girri). So

Rufus Ephesius calls the cornua of the uterus.