NATURAL AND ARTIFICIAL PERFUMES. 89 



if there were not some reason for preferring grease. Most of the 

 substitutes recommended have more liberal affinities than grease. 

 Alcohol, for instance, unites readily with water, and with water 

 takes substances held in solution by it, which are extremely undesir- 

 able in a perfume; and so with the other substances, according to 

 their several properties. Grease has a narrow elective affinity, and 

 takes just what is wanted and nothing else. Various petroleum 

 substances have been proposed recently as extractors, and much may 

 be said 'prima facie in favor of them; but experiments with them 

 have not yet given satisfactory results. 



In the process of absorption or enfleurage wooden frames fur- 

 nished with glass bottoms are used. These, fitting closely together, 

 are placed one upon another, so that a small inclosed space is left 

 between every two of them, or a sort of greenhouse with glass above 

 and below, inclosed with wood. The surfaces of the glasses are 

 coated with grease, on which a layer of flowers is placed. The flow- 

 ers are left there to shed their perfume, which is absorbed by the 

 grease, for twenty-four hours, when they are removed and new 

 flowers are put in their places. This is continued for two or three 

 months, at the end of which time the pomade is ready for treatment 

 as in the maceration process. The flowers to which this process is 

 best adapted are the jasmine, tuberose, and mignonette. This en- 

 fleurage process has likewise drawn criticism, if not contempt, from 

 men of science; and the question has been asked why a different 

 treatment is given to these from that pursued with other flowers. 



If we observe flowers with regard to their odors, we shall find 

 that they may be divided into two categories: those which contain 

 their perfume already formed, or have at least a considerable re- 

 serve of it, and those which have no reserve, but develop and emit 

 their fragrance as they grow. When we rub roses or orange blos- 

 soms, for example flowers of the former class we perceive their 

 fragrance very plainly. Such flowers may be treated by distilla- 

 tion, by the warm pomade process, or by extraction with volatile 

 solvents, with results of a greater or less degree of perfection, but 

 always positive; while if we rub a flower of jasmine, convallaria, 

 or violet which are of the second class we perceive nothing but 

 a slight pungent odor in the same plant which an instant before was 

 exhaling a pervading fragrance. In crushing it we have killed it, 

 and it produces no more perfume. Such flowers are not suitable 

 for distillation or maceration or the action of volatile solvents, be- 

 cause there is nothing to be extracted from them. 



The production and exhalation of odor go on while the plant 

 continues to live and vegetate, even after it has been cut. When, 

 therefore, it is placed in the limited atmosphere of these absorbing 



