Cera Alba. White Wax. Cera Flava. Yellow Wax.
History. — Wax is a peculiar concrete substance, which exists in small quantities in various plants; it is likewise a product of the common bee, Apis Mellifica of naturalists, which constructs with it the cells for food and ova. It is a proper secretion of the insect, discharged in the form of scales under the wings of the belly. The wax produced by the bee is the officinal article, of which there are two kinds, Yellow wax and White wax.
Yellow Wax is obtained directly from the comb, which, after having been deprived of its honey, is melted in boiling water, strained, again melted and poured into suitable vessels; as the liquid cools the wax concretes, forming the yellow wax of commerce. Our markets are chiefly supplied from the Western States and North Carolina, also from Cuba. It has a grayish-yellow color, a peculiar rather agreeable odor, and a slight peculiar taste. It possesses considerable firmness and tenacity, though rather soft and unctuous to the touch, but no greasiness, has a granular fracture, is smooth and glossy when cut with a knife, does not adhere to the fingers, nor to the teeth when chewed, is softened by a moderate heat, and melts at 142°; its specific gravity is 0.960 to 0.965. Its odor, color, and taste, depend upon some associated principle not forming any of its essential constituents.
White Wax is prepared by exposing thin layers of yellow wax to air, sunshine, and moisture, when it loses its color, nearly all of its odor, and becomes yellowish-white. In factories where this bleaching process is carried on to a considerable extent, the melted wax is made to fall upon a revolving cylinder, kept constantly wet, upon which it concretes, forming thin ribbon-like layers, which are removed from the cylinders, spread upon linen cloths stretched on frames, and exposed to the air, and light; being occasionally watered and turned. To render it perfectly white, this process has to be repeated two or three times, when it is melted and cast into small circular cakes. Chlorine will also decolorize it, but the wax becomes somewhat changed in its character. Pure white wax is white, shining, diaphanous in thin layers, inodorous, insipid, harder and less unctuous to the touch than the yellow, soft and ductile at 95° F., melts at 155° F., and of specific gravity 0.966. At a high temperature it boils, and in close vessels distils over with little alteration ; at a red heat its vapor inflames, burning with a dense white brightness. It is insoluble in water, cold alcohol, or ether, but is slightly soluble in boiling alcohol or ether, which deposits it upon cooling. It readily dissolves in fixed and volatile oils, and combines by fusion with fats and resins ; boiled with caustic alkaline solutions it is imperfectly saponified. The ultimate constituents of wax are twenty equivalents of carbon, twenty of hydrogen, and one of oxygen, (C20 H20 O). When treated with nitric acid, wax is almost entirely converted into succinic acid. According to Dr. John, wax consists of two proximate principles, Cerin and Myricin, the former constituting about 70 per cent. of the wax, fusible at 143°, soluble in boiling alcohol, partly saponifiable by boiling with caustic potassa, and yielding margaric acid, a little oleic acid, and an unsaponifiable fatty matter called Cerain; the latter fusible at 149°, sparingly soluble even in boiling alcohol, and incapable of undergoing saponification. Lewy and Ettling consider cerin, myricin, and cerain to be isomeric, but Hess affirms they are not distinct principles at all, and that wax is essentially a single proximate principle. Mr. B. C. Brodie considers cerin, when pure, as an acid having the constitution C54 H54 O4 , and which he terms Cerotic acid, which is fusible at 172° F., and on cooling concretes into a very crystalline mass. Myricin, when entirely freed from cerotic acid, is saponifiable with difficulty, and from the results of saponification he isolated Palmitic acid (C32 H32 O4) and a peculiar substance, Melissine (C60 H62 O4), which he views as a wax-alcohol, convertible into mellissic acid by the loss of two equivalents of hydrogen, and the gain of two of oxygen.
Both yellow and white wax are liable to adulterations. Resin may be suspected by the fracture being smooth and shining instead of granular, also by its solubility in cold alcohol. Insoluble substances may be discovered and separated by melting and straining the wax. Tallow and suet, by the greasiness imparted, by the softness they communicate to the wax, and its greater fusibility, also by its unpleasant odor when melted. Fatty matters may also be detected by their rendering hot lime-water turbid, when agitated with chips of the suspected wax, and then allowed to rest. Chloroform dissolves stearin and stearic acid completely, but only 25 per cent, of wax; then, if wax, treated with six or eight parts of chloroform, loses more than one-fourth of its weight, it is impure. If the wax contains starch, boil it in water and add tincture of iodine to it, which will produce a blue color. Pereira states that the whiteness of the circular cakes of wax is owing to the presence of spermaceti, and that pure wax is yellowish-white. (For Myrtle wax see Myrica Cerifera.)
Properties and Uses. — Wax has but little effect upon the system, though it has been recommended in diarrhea, dysentery, and inflammation of the alimentary mucous membrane combined with olive oil, and the yelk of egg. Its principal employment is in the formation of ointments, cerates, and plasters, of which it forms an ingredient imparting to them due consistence and tenacity.