Wisconsin state agricultural society. 
found, by actual analysis and calculation, that there are seven 
tons of carbon in the form of carbonic acid suspended over each 
acre of the earth’s surface, and he found not only carbon, but all 
the organic elements of plant food. These elements are not only 
brought to the roots of plants by rains, but they enter into the 
circulation by absorption through the leaves. 
There is no fact in vegetable physiology better established than 
this, and now what we want is to discover a plant which may be 
profitable as a crop and yet excel all others in its power of catch¬ 
ing and holding these elements which are afloat. Clover has been 
found to be this plant, and the only theory by which clover can 
be a source of permanent benefit, is, that it does catch and hold 
these floating elements. If it is, simply, that its deeply plung¬ 
ing roots improve the surface at the expense of the subsoil, then 
that source will gradually fail and our land will only become ex¬ 
hausted to a greater depth, but it is found that clover enriches 
both the surface and the subsoil. 
Boussingault’s experiments ought to conclusively settle this 
question. He transplanted young clover plants to a soil which 
had been deprived of all organic matter, protecting them from rain 
and dust and watering them only with distilled water. He says, 
“ For some days they seemed to languish, but by and by they be¬ 
came remarkably vigorous. In a month the clover had grown to 
twice its original height, and the leaves were of the most beauti¬ 
ful green; the plants had in all respects as fine an appearance as 
the clover of the same age which had been left growing in the 
field.” 
After giving the table of his analysis of the plants * which I will 
not introduce, he says : “ Thus in two months’ growth at the cost 
of air and water, the clover had, so to say, tripled its quantity of 
organic matter, and the weight of nitrogen contained in it was very 
nearly doubled.” 
I dwell upon this because I am of the opinion that unless a man 
believes that his clover does absolutely enrich his soil by adding 
to it that which it does not already possess, he will see no suffi¬ 
cient inducement for planting it. 
*Boussingault, page 47. 
