EXTRACTION OF AROMA. 19 



necessary for the rapid absorption of the perfume, another method 

 in which the fat is used as a cokl absorbing medium has been devised 

 and used. 



EXTRACTION WITH SOLID FATS. 



The process of absorption of perfumes in cold by means of fats, 

 the " enfieurage " process, has long been used for the extraction of the 

 more delicate odors, and is possibly more universally used than any 

 other process for the preparation of certain flower odors. 



The great avidity with which some solid fats absorb aromatic sub- 

 stances is the basis of the method. Odors of nearly every description 

 are absorbed by neutral solid fats when the latter are placed adjacent 

 to or in contact with the odoriferous substances. 



The enfleurage process, which is based upon this peculiar property 

 of fats, was originally carried out by spreading freshly picked flow- 

 ers upon a thin layer of lard spread upon glass plates, the flowers 

 being allowed to remain in contact with the lard until exhausted, 

 when the apparatus was charged with fresh flowers. In this manner 

 a perfumed pomade was produced containing the natural odor of the 

 flowers. 



For effecting a separation of the perfume from the solid fat, which 

 is desirable in some cases, advantage is taken of the comparative 

 insolubility of the fat in strong alcohol and the ready solubility of 

 the perfume. Therefore, in preparing the pure perfume, the per- 

 fumed iwmade is thoroughly and repeatedly agitated with alcohol, an 

 alcoholic extract or perfumed essence resulting. This resulting 

 extract is sometimes employed as such for producing delicate scents. 

 In order to obtain the pure oil from the alcoholic extract, the alcohol 

 is evaporated carefully in a vacuum, the concentrated oil or perfume 

 of the flowers remaining. These concentrated oils, although often 

 rather unpleasant in odor in extreme concentrations, produce an 

 exquisite aroma when diluted. 



The crude process of enfleurage just mentioned has been largely 

 modified in recent years in order to promote rapidity of operation, to 

 protect against loss of odor by nonabsorption, and to obviate the actual 

 contact of the flowers with the lard. ^Yhen the flowers are in actual 

 contact with the lard there is a tendency toward the absorption of 

 undesirable substances. 



A practical apparatus of this nature (fig. 2) consists of a box, 

 H, about 2 feet square and 6 feet high, so constructed as to be prac- 

 tically air-tight. In the lower portion of the box, which is supported 

 about 2 feet above the floor, is placed a layer of sponges, G, or other 

 porous material capable of holding moisture. The bottom of the 

 sponge tray may be constructed of light copper gauze or brass gauze 

 to permit the free access of air. Directly above are located the flower 



195 



