ed the success of the particular system of husbandry
he advocated to the comminution of the soil, by which a larger number
of its particles are rendered sufficiently small to permit their ready
absorption by the roots. Popular opinion at that time was in favour of
the mechanical rather than the chemical explanation of agricultural
facts, and Tull's work had the effect of confirming this opinion, and
turning attention away from the application of chemistry to agriculture.
Indeed, no good results could have followed its study at that time, for
chemistry, especially in those departments bearing more immediately on
agriculture, was much too imperfect, and it was only towards the close
of the last century, when Lavoisier established its true principles,
that it became possible to pursue it with any prospect of success.

Very soon after Lavoisier's system was made known, Lord Dundonald
published his "Treatise on the Intimate Connexion between Chemistry and
Agriculture," in which the important bearings of the recent chemical
discoveries on the practice of agriculture were brought prominently
under the notice of the farmer, and almost at the same time De Saussure
commenced those remarkable researches, which extended over a long series
of years, and laid the foundation of almost all our accurate knowledge
of the chemistry of vegetation. Saussure traced with singular care and
accuracy the whole phenomena of the life of plants, and indicated the
mode in which the facts he established might be taken advantage of in
improving the cultivation of the soil. But neither his researches, nor
Lord Dundonald's more direct appeal to the farmer, excited the attention
they deserved, or produced any immediate effect on the progress of
agriculture. It was not till the year 1812 that the interest of
practical men was fairly awakened by a course of lectures given by Sir
Humphrey Davy, at the instance of Sir John Sinclair, who was at that
time president of the Board of Agriculture. In these lectures, written
with all the clearness and precision which characterised their author's
style, the results of De Saussure's experiments were for the first time
presented to the farmer in a form in which they could be easily
understood by him, the conclusions to which they led were distinctly
indicated, and a number of useful practical suggestions made, many of
which have been adopted into every-day practice, and become so
thoroughly incorporated with it, that t