hen lime,
marl, and chalk are to be used, &c.[1]

The Royal Agricultural Society say that chemistry is unable to explain
the productiveness of soils. But why is it unable? One reason is, that
supposing everything required by the plant to be present in the soil,
yet if the soil be either too wet, or too dry, too cohesive, or loose,
the plant will not flourish; and chemical analysis does not declare
this, for it affords no information respecting the mechanical division
in which substances exist in the soil. Again, the chemical analysis of
soils, to be worth anything, must be conducted with more rigid accuracy
than those published by English writers. To detect one cwt. of gypsum in
an acre there would be only one quarter of a grain in a pound of soil,
or in 100 grains only three and a half thousandth of a grain (35/10000
or,00035 grs.), or to discover if sufficient alumina existed in a field
for the production of red clover there must be ascertained if it
contained (one hundred thousandth),00001 per cent. The analyses even by
Sprengel do not afford us the quantity of nitrogen in each soil, or the
capacity of the soil for this substance; while it is well known that
most manures, as well as the different kinds of food, are valuable in
proportion to the quantity contained by them, and it is highly probable,
_ceteris paribus_, that the quantity of nitrogen found existing in soil,
and the soil's capacity for containing that substance, would afford an
easy indication of its immediate fertility, and also of its requiring
great or small quantities of nitrogenous manures in its future
cultivation.[2]

Chemistry, however, outsteps her province when it is attempted to
explain how vegetable productions are formed in the plants by chemical
forces; for the recent discoveries of Schwann, Henle, and Schleiden,
prove that all the functions of the plant are performed by the means of
simple vesicles and cells--that absorption, assimilation, fixation of
carbon from the atmosphere, respiration, exhalation, secretion, and
reproduction are all effected by single cells, of which the lower plants
almost entirely consist--that the cell absorbs alimentary matters
through the spongioles of the root, and that the fluid received thus
undergoes the first steps of the organizing process--that the inorganic
elements are changed into the simplest proximate principles by cells--so
also are the further changes into the regular secretions of the plant,
the