L. V. BELL'S ADDRESS. 587 



wood and especially its fruit or seed, vary quite essentially in 

 the quantity of ashes, as well as the elements into which the 

 ashes are resolvable. 



The gaseous products of the burnt plant have precisely the 

 same nature, as those which result from the organic portion of 

 the soil, and nothing more. All vegetables, poisonous, medi- 

 cinal, nutritive, fragrant or nauseous, acid, tasteless or aromat- 

 ic, tender or tough, white or colored, are constituted of the four 

 gases before-mentioned, (and even one of these, nitrogen, is 

 occasionally absent,) and whatever is left in the ashes. 



Plants thus obtain all their inorganic and a portion of their 

 organic components from the ground, as is now proved beyond 

 question by experiment and analysis, notwithstanding there 

 are authorities on botany and vegetable physiology, published 

 within our own day, which express the idea that plants are 

 actually indebted to the ground for little, if anything, but 

 water, leaving the notorious fact, that one soil is more fertile 

 than another, unexplained. A portion of the organic materials 

 undoubtedly are obtained by absorption from the atmosphere? 

 through the leaves. Carbonic acid, for illustration, which is a 

 combination of carbon and oxygen, exists always in the air, a 

 small and uniform quantity being everywhere diffused through- 

 out it, whether the specimen be taken from the very top of 

 Mount Blanc or the lowest depth of the profoundest mine. 

 By the processes of that living chemistry ever in action, the 

 oxygen is separated from its combination and leaves the 

 carbon behind. When the woody structure is burnt under 

 circumstances to drive off some parts and leave others, we 

 know this carbon under its form of charcoal. The fact that a 

 plant closely covered with a glass vessel gives out oxygen, 

 which can be separated, is proof positive of this one of the 

 many facts of vegetable chemistry. 



Now in the ashes of plants, with a single possible exception 

 connected with alumina, and which may hereafter be proved 

 to be unreal, are found every one of the dozen or so of ingre- 

 dients, which are proved to exist in fertile soils. For example, 

 in the ashes of the potato, there is fifty six per cent, of potash, 

 thirteen of phosphoric acid, fourteen of sulphuric acid, nine of 

 iron, magnesia and lime, and four of silex. 



When thus much was demonstrated of the essentiality of a 



