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Annual Report of the 
composition, the organic matter in the soil produces a large quan¬ 
tity of carbonic acid, and large quantities of other acids—organic 
acids, humic acid, etc., and those acids hasten the decomposition of 
the soil. When the water is charged with them, the mineral mat¬ 
ter is taken up. 
Now there is some organic matter very probably taken in through 
the roots, but what we wish to keep in mind at all times, is, that 
the organic matter will take care of itself, if we will furnish a suf- 
I 
ficient amount of mineral material, or nitrogenous compounds. As 
we hasten the decomposition of the organic matter, we hasten the 
conditions that are necessary for the changing of the soil. 
There is a little too much chemistry in the composition of soils, 
for me to make it plain to you. All clay from fertile soils which 
have an absorptive power for the gases of the atmosphere, and for 
the material which is held in solution by the waters, have a large 
absorptive power for ammonia. I think, indeed, all fertilizing mater¬ 
ials which we can bring into soils are compound silicates. There are 
silicates of ash, alumina, and potassa, and the principal object is 
to obtain the potash in combination with them. 
The salts of lime will act upon the soil by taking the place of the 
potash; by allowing the potash to be set free and allowing the 
plants to take it. So all manures act largely in an indirect man¬ 
ner. 
We may put manures in the soil, which contain just those ingre- 
diants that the plants want. Stable manures contain considerable 
of just the organic ingrediant the soil wants in a form which is 
easily changed into the form needed for the plant. But the organic 
matter is not entirely useful for the decomposition of the soil, but 
partially so. Liebig’s theory was that there was not anything but 
organic matter. 
Question. I understood that the lime takes the place of the 
potash. 
Professor Daniells. The lime may do that. 
Question. I have seen instances of it, where it was put on the 
leaves of plants; for instance, potatoes that were looking yellow, they 
would then grow green and nice. 
Professor Daniells. Plants take in nothing but gases through 
the leaves; they do not take in any organic matter in that way. 
We have been experimenting on the University farm for sometime 
