Page:Popular Science Monthly Volume 52.djvu/100

88 to change the character of some of the essences. A still more important objection is that the vapor may bring over some undesirable constituents existing in the plant, or by its action on some of the constituents may produce new substances in no way allied to the perfume. Impurities produced in this way communicate to the newly distilled essence what may be called the taste of the retort. Such inconveniences, of relatively little account in the coarse extracts, are very important in the more delicate distillations.

A process used at Grasse for conserving the more delicate qualities of the perfumes, and which constitutes a method original to the Maritime Alps, consists in the employment of grease for the composition of perfumed pomades. A grease of suitable consistence which will not become rancid is obtained by preparing a mixture of lard and beef fat and subjecting it to thorough refining processes. The perfume is incorporated with this base by a process of warm maceration, or by absorption.

For maceration the fat is melted in the marine bath and brought to a temperature of 60° or 70° C, as measured by the skill of the attendants rather than by the thermometer; the rose leaves, or whatever is to be treated, are introduced, thoroughly immersed; after a few hours the mixture is passed through strainers and drained, so as to separate the grease from the flowers as completely as possible. What grease remains on the rose leaves is washed off with warm water. The process is repeated with the same grease and with other flowers, and so goes on for fifteen or twenty days, according to the quality of the pomade that is desired. Some of this pomade is consumed as it stands; but by far the greater part is used for making extracts, or alcoholic infusions of the perfume. For this purpose the pomade is introduced with a suitable quantity of alcohol into a shaker, consisting of a cylinder in which a screw beater is kept going all the time. The mixture is thus actively beaten up, and, as the perfume has more affinity for the alcohol than for the grease, the grease in time becomes nearly inodorous, and the alcohol is charged with the greater part of the perfume. The grease is then sent to the soap maker, for it is not fit to be used again for a pomade.

The question may be asked, and has been asked, Why use the intervention of grease in the process of extraction? Why not apply alcohol or some substance of similar powers directly? Chemists have offered ether, sulphide of carbon, chloride of methyl, chloroform, and other scientifically prepared solvents, to have them rejected, and have blamed the manufacturers of Grasse for adhering to barbarous processes, and for their inability to escape their antiquated routine. A more scientific spirit would lead them to inquire