Volume 1

Chemical technology and analysis of oils, fats, and waxes / by J. Lewkowitsch.

  • Julius Lewkowitsch
Date:
1904
Catalogue details

Licence: Attribution-NonCommercial 4.0 International (CC BY-NC 4.0)

Credit: Chemical technology and analysis of oils, fats, and waxes / by J. Lewkowitsch. Source: Wellcome Collection.

    53/454 (page 33)
    PROPERTIES OF NATURAL WAXES 3a 2. Properties of Natural Waxes With the exception of carnauba wax and beeswax, the waxes have not been examined yet so thoroughly that general statements can be made under this head. In the case of these two waxes, however, the occurrence of hydrocarbons has been placed beyond doubt. The hydrocarbons of beeswax belong mostly to the ethane series; their melting points are somewhat high. The hydrocarbon found in carnauba wax is very likely a member of the same series. The liquid waxes occurring in sperm oil most probably represent compounds of unsaturated alcohols of the series CnH2}lO, with un- saturated fatty acids.1 Whereas in the case of fats, the occurrence of free fatty acids must be considered as an indication of decomposition having taken place, the same cannot be said with certainty of the waxes; at any rate in the present state of our knowledge. A certain proportion of free fatty acids is characteristic of carnauba wax, beeswax, and (natural) wool fat, whilst the liquid waxes and spermaceti are neutral in their fresh state. [Perhaps the conjecture is permissible that the occurrence of free fatty acids is due to a secondary action, if we bear in mind that in the waxes containing free fatty acids simultaneously free alcohols are present. Glycerol being so easily soluble in water, it is evident that in the case of fats the “ alcohol ” escapes detection.] Therefore these waxes contain notable amounts of “ unsaponifiable matter ” (partly due to presence of hydrocarbons). In their physical properties the liquid and solid waxes resemble very much the fatty oils and fats. They behave similarly to solvents ; and, like fats, the waxes in a liquid condition or in solution leave a grease-spot on paper. It will, therefore, suffice to emphasise the points of difference. The liquid waxes are readily distinguished from fatty oils by their lower specific gravity,—from 0‘875 to 0-881. On heating, the waxes do not emit the odour of acrolein, since glycerol is absent. When distilled destructively, the esters are converted into hydrocarbons. They do not turn rancid on keeping, owing to the stability of the esters (and the stability of their fatty acids). Although insoluble in water, the solid waxes have the property of forming emulsions with water, so much so that large quantities of water can be incorporated with them (chap, xiv.), yielding salve-like substances. 1 Lewkowitscli, Journ. Soc. Chem. Ind. 1892, 135. I VOL. I D