SECT. I. WATER. 45 



too small a proportion to the increased weight of 

 the willow to deserve any notice in the calcu- 

 lation.* 



Boyle dried a quantity of earth in an oven, which Boyle, 

 after having weighed he put into an earthen pot. 

 He then sowed some Gourd seed in the earth and 

 watered it with spring or rain water. A plant was 

 ultimately produced that weighed three pounds ; 

 and in a subsequent experiment, a plant that 

 weighed four pounds ; and yet the weight of the 

 earth, when dried and weighed again, was not per- 

 ceptibly diminished. This seemed to give weight 

 to the foregoing conclusion. 



Du Hamel placed some bulbous roots merely in DuHamer,. 

 moss or wet sponges, and they vegetated ; and n^ 

 Beans and Peas when so treated even flourished 

 and produced fruit.*}- Bonnet in repeating the ex- 

 periments of Du Hamel had the same result; and 

 in trying its operation upon vines, found that they 

 produced excellent grapes. Nothing further seemed 

 necessary to determine the point at issue ; and it 

 was accordingly believed that water is the sole food 

 of plants, and that the other substances which they 

 may contain are formed merely from the water, by 

 virtue of the vital energy of the plant. 



But though these experiments have the appear- 

 ance of being somewhat decisive, yet there are 

 others by the same experimenters which are not 

 quite so favourable to the opinion they were in- 



* Phys. des Arb. liv. v. chap. i. + Ibid. 



