92 LIPIDES (fats and RELATED SUBSTANCES) 



bination with fatty acids, that is, as esters. An example of an individual 

 wax ester is cetyl palmitate: 



O 



II 

 CHalCHO hCHjOCCCH.) uCHi 



The natural waxes are mixtures of many such esters and often contain 

 hydrocarbons as well. 



Occurrence and importance 



Waxes are widely distributed in nature, both in plant and animal ma- 

 terial. They are generally found on the external surfaces, where they 

 serve as a protective coating and prevent undue evaporation of moisture. 

 They keep the feathers of birds and the wool and hair of animals soft 

 and pliable. Some of the important natural waxes are as follows: bees- 

 wax, secreted by the honey bee; lanolin (wool wax or degras), a waxy 

 material obtained from wool; spermaceti and sperm oil, saHd and liquid 

 waxes, respectively, which are separated from the oily liquid in the head 

 of the sperm whale ; Chinese wax, the secretion of an insect ; and carnauba 

 wax, a coating found on the leaves of the carnauba (Brazil) palm. Waxes 

 are important commercial materials and are extensively used in the 

 manufacture of candles, floor polishes, and varnishes. Many industrial 

 waxes, however, are synthetic products made from higher chlorinated 

 hydrocarbons, etc. 



Properties 



The waxes are, as a rule, solid materials that have a melting point 

 between 60° and 80°C. They are insoluble in water and are poor con- 

 ductors of heat. Waxes are much more resistant to saponification than 

 fats or oils. Light, air, bacteria, molds, and other agents that readily 

 bring about changes in the fats have little or no effect upon the waxes. 

 Because of these properties it is evident that they are particularly suitable 

 for the protection of the surfaces of animals and plants. 



Composition 



Waxes can be separated into their constituents by saponification with 

 alkali, which slowly forms soaps of the acidic components, and extrac- 

 tion of the aqueous soap solution with ether. The ether dissolves the 

 nonsaponifiable material (higher alcohols and hydrocarbons), which in 

 the case of waxes amounts to about 50 per cent of the original weight 

 (note difference from fats, p. 81). A list of the chief components of 

 several natural waxes is given in Table 4-8. 



