EXTRACTION OF AROMA. 



17 



The method employed commercially for the extraction of odors 

 by means of these volatile solvents embodies a process known as 

 continuous extraction. By this method the solvent, after percolating 

 through flowers and carrying with it in solution the odorous con- 

 stituents, is heated in a proper receiving 

 vessel and the vapors condensed and 

 utilized further for extracting any re- 

 maining odor. The advantage of this 

 method is the small amount of solvent 

 necessary for extraction and the con- 

 tinual percolation of fresh solvent 

 through the material. 



The accompanying illustration (fig. 

 1) represents an apparatus used for 

 this purpose, which consists chiefly of 

 the percolator, the receiving vessel, and 

 the condenser. 



The percolator, Z?, in the bottom of 

 which is placed a circular screen, is 

 charged with the flowers to be extracted, 

 and the removable cover, F, is attached 

 by means of clamps, as indicated. A 

 heavy gasket of cotton wicking or asbes- 

 tos (previously moistened) or rubber 

 is placed between the cover and the 

 l^ercolator to insure a tight connection. 

 To the bottom of the percolator at H is 

 attached the receiving vessel, ^i, and 

 the hot water steam bath, Z), by means 

 of a screw union. Into the cover, F, is 

 fitted a perforated rubber cork, through 

 which passes a glass tube, A'. The glass 

 tube, A', is further connected with the 

 condenser, 6', by means of a perforated 

 rubber stopper. The condenser may 

 be of the single-tube or worm variety, 

 the former being preferable. The tube 

 K is of glass for the purpose of enabling 

 the operator to observe the rapidity with 

 which the condensation of vapors is taking place. After pouring the 

 solvent through the condenser and into the percolator, heat (pref- 

 erably steam or hot water) is applied to the bath, D. The steam is 

 passed through the bath, Z?, in the direction indicated by the arrows. 

 The solvent which has percolated through the flowers in B is 

 59647°— Bui. 195—10 3 



Fig. 1. — Continuous extraction ap- 

 paratus. A, Ueceivins vessel : B, 

 percolator ; C, condenser ; D, 

 bath ; E, union ; F, cover ; O, 

 tube ; H, union ; .7, drain cock ; 

 K, glass tube. 



