432 
Agricultural Chemistry. 
vocated by Baron Liebig prior to his recently published work, 
and how we and others have understood that theory as so advo- 
cated, we now pass on to the third main division of our subject ; 
namely, to a consideration of the criticisms of our experi- 
ments and opinions regarding the growtli of icheat and turnips; 
and, in the course of this inquiry, we shall endeavour, by the aid 
of the experiments quoted by Baron Liebig, taken with others 
by their side, to relieve the points which they are calculated to 
elucidate, of the mystery and confusion in which Baron Liebig 
has sought to envelop them. 
In regard to our experiments on the growth of wheat, Baron 
Liebig says we have drawn the conclusions : — 
L " That the mineral constituents of -wheat cannot by themselves 
increase the fertility of land!^ 
2. " Tliat the produce'^in grain and straw, is rather proportional 
to the supply of ammonia." 
We do not object to the definitions here given of our con- 
clusions — subject of course to the amplifications and qualifica- 
tions which our own papers indicate. But, notwithstanding in a 
public discussion on this subject, we utterly repudiated the 
definition of some of our conclusions assumed by Baron Liebig 
in summing up, and giving his verdict on our opinions at the 
end of his Treatise, he did not scruple to repeat those palpably 
incorrect interpretations of our meaning. 
Let us now see, how it is that Baron Liebig seeks to show, 
that our own experiments contradict the above conclusions, 
Nos. 1 and 2. 
Before we can do this, however, we must first clear the ground 
of a most ingenious objection, by which, as he cannot deny our 
facts, he would seek to throw them aside, as utterly unfit to be the 
foundation for any general conclusions regarding any other land 
than our own, or regarding agricultural practices generally. 
Baron Liebig says, — 
" Mr. Lawes has shown, in the most convincing manner, that in his land 
the mineral constituents of wheat were present in the greatest abundance and 
in an available form ; and no one but Mr. Lawes himself can be surprised 
that, under siich cii'cumstances, by manuring with ammoniacal salts only, 
without any addition of mineral matter, he obtained during six years a 
higher produce than from the same land immanured; for theori/ jdainly pre- 
dicts such a rtsidt.'" — Frinciplcs, p. 78, 79. 
" Mr. Lawes, then, as appears from these passages, chose for his experiments 
a portion of land which, on account of its being so rich in available mineral 
constituents, and of its other qualities, was utterly unsuited to his purpose, 
and which ought to have been unhesitatingly rejected, if the object was to test 
the value of the mineral food of plants. And since the mineral manure, in 
these circumstances, could not jiossibly have the effect expected by Mr. Lawes, 
bis conclusions are destitute of all foundation in logic or in facts." — p. 59, (iO. 
Certainly, this is a very clever way of dismissing the whole of 
