INTRODUCTION, 19 
must not be forgotten that their growth is not altogether 
parallel. There are facts in art for which science can, as 
yet, furnish no adequate explanation. Art, though no 
older than science, grew at first more rapidly in vigor and 
in stature. Agriculture was practised hundreds and 
thousands of years ago, with a success that does not com- 
pare unfavorably with ours. Nearly all the essential points 
of modern cultivation were regarded by the Romans be- 
fore the Christian era. The annals of the Chinese show 
that their wonderful skill and knowledge were in use at a 
vastly earlier date. 
So much of science as can be attained through man’s 
unaided senses, reached considerable perfection early in 
the world’s history. But that part of science which re- 
lates to things invisible to the unassisted eye, could not 
be developed until the telescope and the microscope had 
been invented, until the increasing experience of man and 
his improved art had created and made cheap the other in- 
ventions by whose aid the mind can penetrate the veil of 
nature. Art, guided at first by a very crude and imperfectly 
developed. science, has, within a comparatively recent pe- 
riod, multiplied those instruments and means of research 
whereby science has expanded to her present proportions. 
The progress of agriculture is the joint work of theory 
and practice. In many departments great advances have 
been made during the last hundred years; especially is this 
true in all that relates to implements and machines, and to 
the improvement of domestic animals. It is, however, in 
just these departments that an improved theory has had 
sway. More recent is the development of agriculture in its 
chemical and physiological aspects. In these directions the 
present century, or we might almost say the last 30 years, 
has seen more accomplished than all previous time. 
The first book in the English language on the subjects 
which occupy a good part of the following pages, was 
written by a Scotch nobleman, the Earl of Dundonald, and 
