FOOD OF THE VEGETATING PLANT. CHAP. I. 



of the petals even after they have fallen, in their 

 still exhaling an agreeable though faint odour. But 

 in the former case, though the petals remain longer 

 attached to the plant, and retain their form and 

 colour, and appear to be fresh and fragrant; yet 

 when you put them to the test, they are found to 

 exhale a strong and fetid odour, the sure symptom 

 of inward putrefaction. 5 * 



But although we admit the great utility of at* 

 mospheric air, and even its absolute necessity to 

 the support of vegetable life, we must not attribute 

 to it more than is due, and conclude without proof 

 that air, together with water, forms the whole of 

 vegetable aliment. And yet in support of this 

 doctrine it has been said that many plants do 

 evidently effect the developement of their parts, 

 without the aid of any other nourishment beyond 

 that of air, rains, and dews ; and the Mosses and 

 Lichens, and some other tribes of plants have been 

 quoted as affording examples. 



It must be admitted no doubt that plants of slow 

 growth and tenacious of life, such as many of the 

 Mosses, and some of the succulent plants, do in- 

 deed effect the developement of their parts, without 

 the aid of any other nourishment beyond what they 

 derive from the atmosphere. But plants of rapid 

 growth, such as annuals, can never effect that de- 

 velopement without the aid of nourishment derived 

 from the soil. Saussure tried the experiment upon 

 * Saus. sur la Veg. chap. vi. sect. v. 



