134 Oti the Feculti of Green Planfs. 



fe>r we need only cast our eves on those of Rouellc, Mac- 

 qiier, Baume, Sage, Pannentier, &c., to be convinced that 

 the word f'ecula has not led these authors into comparisons 

 so unworthy ot their judgment as to arrange in the same 

 cla?=« green lecula, the remains of sohd parts, and starch. 



We shall now proceed to green feculse, and shall observe 

 that in laboratories, in apothecaries' shops, and still less in 

 the hands of a chemist so celebrated for exactness as Rou- 

 elle, the chopped straw of green plants has never been con- 

 founded with that beautiful liquid velvet expressed from their 

 leaves, or with the emulsive product which passes in com- 

 plete freshness through the cloth, and which by its exces- 

 sive fineness, and the splendour of its colour, is so superior 

 to their herbaceous filaments. 



If it were true that the fecula is a body homogeneous 

 with tlie rest of the plant, if it were possible to consider it 

 only as a part which differs in no other respect than that of 

 having been better pounded, would not complete trituration 

 of the remainder be sufficient to convert it also into fecula ? 

 When a fresh herb is pounded, the pestle breaks and bruises 

 its tissue, but does not pulverize it. 



And this contusion of a few moments is too far from re- 

 senibling dry pulverization to admit of any comparison be- 

 tween its fecula and moistened powder. If an aqueous 

 plant, such as sedum for example, be bruised on a piece 

 of marble by means of a roller, its expressed juice will give 

 fecula. It is not to trituration that fecula is indebted for 

 its velvety appearance, its fineness, and impalpability, v.hich 

 distinguish it from powder : it is molecular by its nature, 

 and perhaps even crystallized in the fibrous meshes where 

 vegetation deposits it. 



" Rouelle asserts," says FourCroy, " that feculs con- 

 tain a principle which may be compared to animal matters," 

 &c. Rouelle has done more : very little disposed to be 

 satisfied with simple assertions, he proved it not by analo- 

 gies and aml'igi/oi/s properties, but by a series of convincing 

 facts, by comparisons which obtained general assent only 

 because they united the greatest characters then known, 

 and which arc yet known, in animal substances. Otlierwise 

 whence could Rouelle deduce analogies to compare, as he 

 does, green fecula to the gluten of wheat? What is there 

 common in the appearance of these two products to serve 

 as a basis for comparison ? To find points of comparison, 

 it would be necessary to examine in an intimate manner 

 their composition and chemical properties ; and this is what 

 this la!)orious cheinist does. Comparisons of this kind de- 

 duced from analysis served as 4 basis for the meaioir which 



