STIMULATING MANURES. 67 



All the soft and fibrous portions of plants, are evidently 

 the product of the elaboration carried in their organs, of 

 the juices and gases by which they are nourished. The 

 saline particles, which plants contain, are unchanged, and 

 such as are furnished by the soil. 



Whatever may be the variety of products presented to 

 us by the vegetable kingdom, the elements which compose 

 them are few in number. They contain only oxygen, car- 

 bon, hydrogen, and azote, combined in an immense variety 

 of proportions ; some hundredths more or less, in the propor- 

 tions of these constituent principles, often cause an aston- 

 ishing difference in the character of their products. It is 

 this which occasions the slightest alteration produced in the 

 organs to give rise to new compounds, bearing no resem- 

 blance to the first. 



No one has ever disputed that the juices, the oils, the 

 resins, the fibre, and other essential parts of vegetation, 

 are the result of the action of the different organs of 

 plants ; and that the elements composing them were those 

 of the bodies by which they are nourished, and which 

 each combines in a manner peculiar to itself, and fitted to 

 its own Organization. There is, in all this, nothing like 

 creation, but simply decomposition upon one side, and, upon 

 the other, a new combination of the elements, in different 

 proportions. 



Many philosophers, in other instances very correct, have 

 asserted that plants themselves form, even by the act of vege- 

 tation, salts and earths ; but, as science has advanced, it 

 has been ascertained that none of the experiments cited by 

 them have been made with exactness. Some have watered 

 plants with distilled water ; others have raised them in 

 washed sand ; nearly all have allowed free access of the 

 air to them ; many have analyzed, with a certain degree 

 of care, the soil upon which they raised their plants ; and 

 nearly all have concluded, that the salts and earths which 

 they found in them, and of which they could demonstrate 

 neither the existence, nor even the quantity if found, in 

 the different substances concurring to produce vegetation, 

 must be the work of the plant. But does not the often 

 disturbed atmosphere frequently change the salts, and the 

 earths, which it deposits upon plants 1 Does not the dust 

 which it carries, alight upon the upper surfaces of leaves 

 and branches 1 Water, the best distilled, according to the 



