L. V. BELL'S ADDRESS. 581 



a f^ood illustration between the highest reach of experimental 

 skill and scientific accuracy. 



I have not compared the authorities closely enough to de- 

 termine the date at which the true chemistry of agriculture 

 made its first step, or the name of the earliest in this pursuit. 

 Suffice it to say, that it is only some fifteen years back, that 

 its history commences. During this lapse of time, a vast many 

 students of the science have devoted themselves to its elucida- 

 tion in all countries where chemistry is cultivated. For the 

 first time in the history of the world, the farmer can now take 

 a sample of his soil to the chemist, and say, " Sir, will or will 

 not this earth produce wheat or flax ?" and the chemist can 

 reply, " It cannot." " Can you inform me how I can make it 

 produce the one or the other ?" " I can." And his replies 

 shall be certain, carrying with them the demonstration of 

 mathematical truth. Suppose the question had been asked a 

 few years ago, " Why are guano, or crushed bones, or gypsum, 

 a good manure in one place, and upon one crop, and not in 

 another place for the same crop ?" Could any better answer 

 have been made, than that experiment showed that it was 

 sometimes useful and sometimes valueless ? It is so, because 

 it is so. Now the chemist tells you that the article is a ma- 

 nure, because it contains certain elements which are essential 

 to the composition of the given plant, and if the plant can get 

 them readily enough from the soil as it is, by its elective pow- 

 ers, it requires no such addition ; if it cannot, the guano or 

 other material meets its exigency. He proves his science by 

 synthesis and analysis. He takes another plant which he finds 

 has no such component element and it grows in the soil which 

 has refused to sustain the first plant. He adds the requisite 

 element, — the before languishing plant revives and flourishes. 



Analyses of mineral substances are among the easiest pro- 

 cesses of the chemical laboratory, upon which the pupil com- 

 mences his earliest manipulations. It was of course, to be 

 expected that the general characters of the earthy crust would 

 have been discovered by the earliest investigators, after chemis- 

 try became a science, for as before intimated, prior to the days 

 of Lavoisier, who was guillotined in the French Revolution, 

 chemistry was scarcely more entitled to the name of a science, 



