ON THE FOOD OF PLANTS. 105 



" periment, 5760 grs. of that water contain only 

 " one-third of a grain of earth. But, thirdly, it 

 " also follows, that water contributes still more to 

 " the nourishment of plants, besides the service it 

 " renders them in distributing the nutritive parts 

 *' throughout the whole structure, forming itself 

 " a constituent part of all of them, as may be un- 

 " derstood from modern experiments. Dr. Injen- 

 " houz, and M. Senebier have shown, that the 

 " leaves of plants exposed to the sun, produced 

 " pure air: now water has of late been proved to 

 " contain about 8.7 per cent, of pure air, the re- 

 " mainder being inflammable air. Water is then 

 " decomposed by the assistance of light within the 

 " vegetable ; its inflammable part is employed in the 

 "formation of oils, resins, gums, <r. Its pure 

 " air is partly applied to the production of vege- 

 " table acids, and partly expelled as excrement." 

 He further says, " To M. Hazenfrez we owe 

 " the discovery that coal is an essential ingre- 

 " dient in the food of all vegetables. Though 

 " hitherto little attended to, it appears to be 

 " one of the primeval principles, as ancient as 

 " the present constitution of our globe ; for it is 

 " formed in fixed air, of which it constitutes 

 " above one-fourth part, and fixed air exists in 

 "lime-stones, and other substances, which date 

 " from the first origin of things. 



