SECT. I. WATER. 49 



drying to 40.2Q, which were found by experiment 

 to contain 10.96 of charcoal. He then took a 

 number of plants of the same species, and placed 

 them by the roots in bottles filled with distilled 

 water ; exposing them to the sun on the outside of 

 a window, but sheltering them from the rain. 

 After ten weeks of vegetation the ICO parts of 

 mint weighed in their green state to 21 6 parts, 

 which were reduced by drying to 62. They had 

 augmented therefore in dried vegetable matter 

 21.71 parts; but they had augmented also in their 

 quantity of carbon : for the 62 parts of dried 

 vegetable substance furnished 15.78 of charcoal.* 

 A similar result was obtained from a similar expe- Though 

 riment upon Beans, from which we may infer the bfishes'the 

 accuracy of Saussure, and the consequent inaccuracy 

 of Hassenfratz, who was no doubt misled by some 

 circumstance not taken into the account. Perhaps 

 the plants on which he made his experiments were 

 not sufficiently exposed to the light of the sun ; 

 so that if he corrected one error he committed also 

 another. While we maintain, therefore, that water 

 is not the sole food of plants, and is not convertible 

 into the whole of the ingredients of the vegetable 

 substance, even with the aid of the vital energy ; 

 We must at the same time admit that plants, though 

 vegetating merely in water, do yet augment the 

 quantity of their carbon. 



* Sur la Veg. chap. ii. sect v. 

 VOL. II. X 



