18 THE PRODUCTION OF VOLATILE OILS AND PERFUMERY PLANTS. 



vaporized and driven up through the tube G (which should be covered 

 with asbestos to prevent radiation) and into the percolator, thence 

 into the condenser, where the vapors are condensed and drop back 

 into the material. A continuous extraction is thus obtained with a 

 minimum quantity of solvent. 



For the final recovery of the solvent from J., the apparatus, after 

 cooling, is disconnected at H and a screw cap attached to the neck 

 of A. The tube G is disconnected at the union E^ which may be con- 

 nected with the condenser in proper position, and heat applied to Z>. 

 The excess of the solvent is completely recovered in this manner, the 

 resultant oil or perfume being drained off by opening the cock, J . 



The chief disadvantage of an apjjaratus of this type is its narrow 

 field of usefulness, which is practically restricted to the separation 

 of perfume from flowers. ^^Hien this apparatus is used for the 

 extraction of other parts of the plant which may contain aromatic 

 substances, the oil is liable to be contaminated by resins, waxes, etc., 

 which would be extracted with the perfume by the solvent used. In 

 order to purify further the crude oil obtained, steam distillation must 

 be resorted to, in which case the delicate quality of the perfume 

 obtained by the cold extraction would probably suffer slight changes 

 induced by the steam. 



EXTRACTION WITH LIQUID FATS. 



The process of extraction with liquid fats is comparatively simple 

 and depends upon the ability of a liquid, fatty oil to absorb the odors 

 from flowers. For this purpose olive oil, lard, or other bland fixed 

 oils may be advantageously used. The oil is placed in a kettle or vat 

 (preferably porcelain lined) and heated to a temperature of 40° to 

 60° C. ; the flowers to be extracted are then introduced either directly 

 into the fatty oil or inclosed in coarse bags and suspended in the fat. 

 The material is maintained at this temperature for a time varying 

 from one-fourth to one and one-half days, when the mixture is either 

 drained to remove the flowers or the bags are removed and expressed 

 and recharged with fresh material. In this manner a perfumed oil is 

 produced from which the perfume may be extracted by shaking out 

 with strong alcohol, in which the odor is soluble and the fat insoluble. 

 The fatty oil, which still retains traces of the flowery fragrance, may 

 be used for further extraction of the same flowers. 



This method of maceration in liquid, fatty oil is carried on to some 

 extent in the perfume gardens of southern France and Germany, 

 where perfumed oils are largeh^ manufactured from such flowers as 

 rose, jasmine, violet, tuberose, cassie, etc. 



The extraction by maceration is advantageous because of its ease 

 of operation and manipulation, but owing to the fact that heat is 



195 



