t 
142 WISCONSIN STATE AGRICULTURAL SOCIETY. 
plants, and that therefore these plants cannot be successfully 
raised upon such soils. # . 
That if any soil be entirely deficient in some of the mineral 
or vegetable elements common to all the plants existing in na¬ 
ture, that soil is barren. 
That a soil may be barren for some plants, but not for others. 
That by restoring to the soil those elements in which it is 
deficient for the production of certain plants, those plants may 
be produced, climate permitting. 
That when a piece of land has been exhausted of indispen¬ 
sable soluble minerals by a long course of shallow cultivation, 
a fresh supply of those minerals may always, to some extent, 
be brought to the surface and made available by deeper plow¬ 
ing and subsoiling ; and that this method, though costly, is the 
simplest and cheapest way of restoring fertility to such worn 
out lands ; enabling the owner to further restore them by plow¬ 
ing under green crops or by pasturing. 
That nothing in nature is perishable or can be annihilated, 
and therefore, when a plant or other body disappears as an 
entity, either by combustion, fermentation, decomposition, etc., 
each of the molecules or atoms of which it was composed, still 
exists in nature, in new combinations. 
That air, as well as the fluid and volatile elements which it 
holds in suspension, are as necessary to vegetable as to animal 
life ; that some of these elements are constantly absorbed by 
and become assimilated with the plant during the process of 
growth and maturity. 
That when we return a crop to the earth, we restore to it all 
the soluble non-volatile elements drawn from the soil and also 
many of the volatile elements absorbed from the atmosphere 
during the process of its growth. 
That before these elements, so restored, can become avail¬ 
able for the production of new vegetation, total, or at least 
partial decomposition of the vegetable matter thus restored 
must take place, i. e ., the plants must be totally, or at least 
partially, resolved again into their component elements. 
That the most usual ways of returning plant-food to the 
