MR. NICHOLS' ADDRESS. 



powder constitutes the soil, yet tlie largest portion of it is still very 

 far from being fine enough to be appropriated by plants. Minute 

 atoms of granite, of limestone and feldspar, scarcely perceptible 

 without the aid of the microscope, pervade every soil, and must 

 be further acted upon by carbonic acid from the air, by rain, by 

 mechanical forces, &c., before it is of any use to your maize plants, 

 your tubers, your grains and vines. 



It will be understood then, that you may possess land, rich, per- 

 haps, in the mineral substance which a peculiar grain requires, and 

 yet after successive crops it may languish and ftiil, for the want of 

 a substance already in the soil, but which is not in a condition to 

 be used by the grain. And here we see the connection of Chemis- 

 try with the business of the farmer in the tillage of his lands. 

 He plies vigorously the plough, the hoe, and the cultivator, he digs, 

 he pulverizes, he I'everses the condition of the soil, bringing up to 

 the surface that which is buried, and burying that which is upon the 

 surface, and does he suppose that the vigor he thereby imparts to 

 the soil and plants, is derivative solely from the mechanical effects 

 of his labors ? There are great benefits thus produced Avhich are 

 very far from being mechanical. It is indeed beneficial to loosen 

 the soil so as to prevent binding, and to aid in the percolation of 

 water through the same, but some of the greatest benefits of active 

 tillage are strictly chemical in their nature. By stirring the soil, 

 atmospheric air is let into it, and the carbonic acid it contains fixes 

 its corrosive teeth into those minute grains of rock, and rends them 

 asunder. They are thus so changed, that instead of being rejected 

 by the hungry plants, they are seized with avidity, and consumed. 

 And further, by tillage there are chemical effects produced in 

 that part of the soil not mineral or inorganic, by which decay, or 

 putrifactive change is carried forward and plant food produce'd in 

 large quaatities. Thus chemistry conclusively shows that by me- 

 chanical labor alone upon a soil, that nutriment is afforded, which 

 .is equivalent to the application of manure, and hence "with these 

 distinctly in mind, no farmer need be surprised at the energy with 

 which his cr|ps shoot forward, after the application of the hoe and 

 cultivator. 



It was chemistry which taught the husbandman the importance 



of subsoil ploughing. There are many farmers who are unable, as 

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