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forward by me. There are some physiologists who main- 
tain that certain plants in particular situations are totally 
independent of the carbon of the soil. I have adopted the 
opinion that plants do derive a large portion of their carbon 
from the atmosphere ; but the experience of every practical 
farmer proves that they do not derive the whole of their 
carbon from the air, a considerable portion being obtained 
from the soil, more or less, according to circumstances. The 
experience of all ages has proved, that the application of 
manure to the soil is necessary in order that plants may 
grow well. 
There is another part of the paper that has been read to 
which I will advert : I refer to the effect of a certain 
quantity of alumina in the soil, in fitting it speedily for the 
growth of grass. I would beg to be understood clearly 
on this point. I do not know from my own experience 
whether or not a certain quantity of alumina is favourable 
to pasture lands ; but this is clear, that such lands can- 
not be productive, whatever the quantity of alumina which 
they contain, whether five or nine, twenty or fifty per cent, 
unless they contain a large quantity of other materials, of 
other substances, which the grass itself contains. I at- 
tempted at Liverpool to illustrate this point. In all pas- 
ture lands, cattle are fed either for the purpose of fattening 
or for their milk, from which butter and cheese is obtained. 
These are carried off from the land in the same way as cattle 
are. The bones and other portions of the solid parts of 
animals are derived from the soil. Plants draw their inor- 
ganic matter from the soil in which they grow, and animals 
obtain theirs from the plants. So also the milk, transformed 
into butter and cheese, contains certain earthy substances, — in 
a proportion not much less than they are found in the general 
bulk of the animal, — and these are carried off from the soil. 
All earthy matter is derived from the soil. The inference is 
