Agricultural Chemistrg. 
433 
our oxpeiiinental evidence : and, in a similar manner, experi- 
ments on ten thousand different soils might be dismissed as ex- 
ceptional, and therefore inapplicable to any other case than the 
particular one in which the result was obtained. In other words, 
the solution of general agricultural questions is not within the 
reach of field investigation ! 
But we propose to '"'show, that these assertions are " desti- 
tute of all foundation in logic or in facts," and that the land in 
question was perfectly adapted to the object in view in the expe- 
riments ; which was, not simply to test the value of the mineral 
food of plants, but to ascertain what was the nature of the 
manure required — mineral or otherwise — to restore the produc- 
tive capability for the increased growth of corn, whicli had been 
exhausted by an unusually severe course of cropping on an 
ordinary soil, and which, in the ordinary course of management, 
would have had its productiveness again increased, by the use 
of the ordinary means of farm-yard manure, fallow, or green 
cropping. 
We must repeat, then, that which we have reiterated so often 
that we are almost ashamed of again troubling our readers with 
the statement, namely, that whatever might be the quality of the 
soil selected (and it was certainly anything but one of the richest 
soils of Great Britain, as described by Baron Liebig), it was 
in a state of practical or agricultural exhaustion, when first sub- 
mitted to experiment. That is to say, it had grown a course 
of turnips, barley, peas, wheat, and oats, since the application of 
manure ; and it was by this treatment brought into such a con- 
dition of comparative or practical vmproductiveness, that no 
farmer paying rent for it, and no landlord letting it, would allow 
it again to grow corn Avithout manure in some form. It was, 
moreover, as we have already said, in such a state of practical or 
agricultural infertility, that the use of the ordinary means of 
manure, fallow, or green cropping, would very greatly increase its 
produce. And, whatever may be the opinion or the dictum of 
purely theoretical persons, however high their authority in their 
own department of knowledge, we do not hesitate to maintain 
before the intelligent practical man, that a soil which had been 
submitted to the exhausting treatment above described, and 
brought into the condition here^ stated, was in a fit and proper 
state for experimenting on with manures, in order to ascertain 
the nature of the exhaustion it had suffered by a course of agri- 
cultural cropping. 
But, in order to prove, that the soil icas in a state of agricultural 
exhaustion, and that it was in a condition to show the effects both 
of mineral and organic manures, we have ari'anged in the fol- 
lowing Table (I.), a condensed summary of nearly the whole of 
