582 SELECTIONS FROM ADDRESSES. 



than animal magnetism now is. But the earlier disciples 

 never reached the more difficult exploit of making a true analy- 

 sis of animal and vegetable matters, and were not put into 

 the way of finding out the never-ceasing relations existing 

 between the earth and what it bears. The ashes of plants, 

 that small per centage of residuum left, and which we now 

 know, bears a constant and essential relation to the kind of 

 vegetable, they considered as a mere uncertain, accidental 

 impurity, which was not worth regarding in vegetable chemis- 

 try or physiology. 



The great doctrine upon which all scientific agriculture is 

 grounded, and which each year has done something to bring 

 into practical use, is, that the ingredients or elements found in 

 the soil are the same which exist in the plants, and that the 

 minutest quantity is as indispensable to the growth and pro- 

 duct of the plant as the largest. The two parts in one-thou- 

 sand of phosphoric or sulphuric acid are as essential in making 

 the crop of wheat yield its grain, as the one-hundred parts of 

 animal or vegetable decayed matter. This doctrine, the key to 

 all agriculture henceforth, they never dreamed of. 



Let us make the briefest synopsis of what modern chemistry 

 has taught us of the relations between plants and soils. I am 

 the more inclined to occupy your time in this, inasmuch as it 

 has not formed so far as I have been informed, the topic of any 

 of the addresses before you on previous years. Some mind 

 may at least be refreshed and turned to a further investigation 

 of this great modern starting point of a true and progressive 

 agriculture. Whoever takes up a handful of soil and atten- 

 tively spreads it around, ^vill not fail to see that it is made up 

 of two great components, a stony or earthy part, and a part of 

 woody or animal remains, or mould. Subjecting the specimen, 

 after it has been freed from all water by drying, to a red heat, 

 the latter portion will be burnt up, as we call it ; in other words 

 will be dissipated into gases or vapors. 



We here get the great division of the soil into its organic 

 portion, being the vegetable and animal parts which once had 

 life in some form, and which however changed by decay, re- 

 tain the elements peculiar to such former shapes, and inorganic^ 

 which comprises the rocks, great and small, however worn 



