INDEX. 241 



And yet, with all this practical skill in decoction, and accu- 

 mulative industry in observation and nomenclature, so far are 

 our scientific men from arriving, by any decoctive process of 

 their own knowledge, at general results useful to ordinary 

 human creatures, that when I wish now to separate, for young 

 scholars, in first massive arrangement of vegetable productions, 

 the Substances of Plants from their Essences ; that is to say, 

 the weighable and measurable body of the plant from its 

 practically immeasurable, if not imponderable, spirit, I find 

 in my three volumes of close-printed chemistry, no informa- 

 tion whatever respecting the quality of volatility in matter, 

 except this one sentence : 



" The disposition of various substances to yield vapour is 

 very different : and the difference depends doubtless on the 

 relative power of cohesion with which they are endowed." * 



Even in this not extremely pregnant, though extremely cau- 

 tious, sentence, two conditions of matter are confused, no 

 notice being taken of the difference in manner of dissolution 

 between a vitally fragrant and a mortally putrid substance. 



It is still more curious that when I look for more definite 

 instruction on such points to the higher ranks of botanists, I 

 find in the index to Dr. Lindley's ' Introduction to Botany ' 

 seven hundred pages of close print not one of the four 

 words 'Volatile,' 'Essence,' 'Scent,' or 'Perfume.' I examine 

 the index to Gray's ' Structural and Systematic Botany,' with 

 precisely the same success. I next consult Professors Balfour 

 and Grindon, and am met by the same dignified silence. 

 Finally, I think over the possible chances in French, and try 

 in Figuier's indices to the ' Histoire des Plantes ' for ' Odeur ' 

 no such word ! * Parfum ' no such word. ' Essence ' no 

 such word. * Encens ' no such word. I try at last ' Pois de 

 Senteur,' at a venture, and am referred to a page which de- 

 scribes their going to sleep. 



Left thus to my own resources, I must be content for the 

 present to bring the subject at least under safe laws of nomen- 

 clature. It is possible that modern chemistry may be entirely 



* "Elements of Chemistry," p. 44. By Edward Turner; edited by 

 Justus Liebig and William Gregory. Taylor and Walton, 1840. 



