CHAP. II. SIMPLE PRODUCTS. 477 



Thenard, who have deduced from a series of the 

 most minute and delicate experiments the three fol- 

 lowing propositions, which they have dignified by 

 the name of laws of vegetable nature : * 



1st, Vegetable substances are always acid when 

 the oxygene they contain is to the hydrogene in a 

 greater proportion than in water. 



2dly, Vegetable substances are always resinous, or 

 oily, or spirituous, when the oxygene they contain is 

 to the hydrogene in a smaller proportion than in 

 water. 



3dly, Vegetable substances are neither acid nor 

 resinous, but saccharine or mucilaginous, or ana- 

 logous to woody fibre or starch, when the oxygene 

 and hydrogene they contain are in the same propor- 

 tion as in water. 



Perhaps the induction of particular proofs is not 

 yet sufficiently complete to warrant the above conclu- 

 sions in their utmost extent. But enough has been 

 established, by the above or by other chemists, to 

 satisfy the scientific inquirer that the closest analogy 

 exists between several compounds that differ widely 

 in their sensible qualities ; as well as to elucidate 

 several processes in nature and art by which certain 

 vegetable substances/ are convertible into one another. 

 And hence an additional proof of the great power 

 and wisdom of the Creator, who, from a few simple 

 and primary elements combined in peculiar propor- 

 tions, educes all that variety and profusion of corn- 

 * Traite de Chera. Element, torn. iii. chap. iii. 



