58 
Journal of the Mitchell Society. [ June 
If you were to see it, you would be astonished; it is truly 
wonderful.' ” 
From his experiments with this land Liebig was led to form 
the opinion that it was possible, by giving the soil proper 
physical quality and composition, to bring about a state of 
things in which sufficient ammonia to maintain its fertility can 
be collecteed or condensed from the air. He recognized not 
only that certain elements were necessary in a fertile soil, 
but more — and what certain soil chemists have been slow to 
recognize — that these elements must occur in certain combi- 
nations as minerals to be available as plant-food. He found, 
too, that certain earths and other substances might be added 
to soils, which would withdraw to some extent soluble salts 
from their solutions, removing from the soil substances 
injurious to plant life. Liebig was greatly interested in the 
experiments made in England by Sir Thomas Way on the 
absorptive power of soils, and was the first to recognize the 
true value of these experiments to agriculture. 
Thus it was that a chemist sixty years ago recognized that 
the study of soils was as much the province of the geologist, 
the mineralogist, and the physicist, as of the chemist; and 
the work with which he is credited in Denmark shows that 
he also regarded it as within the province of the botanist. 
So greatly did he value the structural features and mineral 
composition of a soil as indicators of its fertility, that he said: 
“In matters of this kind the farmer must pursue his own 
course he must not put the least faith in the 
assertion of any foolish chemist who wants to prove to him 
analytically that his field contains an inexhaustible store of 
this or that nutritive substance.” 
In other words, Liebig saw that it is not so much the 
chemical elements in a soil as their mineral combination which 
determines their available plant food, and the geologists 
have found that very different rocks may be made from the 
same molten magma under different conditions of cooling. 
And it was Liebig who pointed out to the farmers that they 
