leys ; ploughs in the pea or bean stubble for wheat ; 
and in some instances follows his wheat crops by 
a course of winter tares and winter barley, which 
is eat off in the spring, before the land is sowed 
for turnips. 
Peas and beans, in all instances, seem well adapted 
to prepare the ground for wheat; and in some 
rich lands, as in the alluvial soil of the Parret, 
mentioned in the Fourth Lecture, and at the foot 
of the South Downs in Sussex, they are raised in 
alternate crops for years together. Peas and beans 
contain, as appears from the analyses in the Third 
Lecture, a small quantity of a matter analogous 
to albumen ; but it seems that the azote, which 
forms a constituent part of this matter, is derived 
from the atmosphere. The dry bean leaf, when 
burnt, yields a smell approaching to that of de- 
composing animal matter ; and in its decay in the 
soil, may furnish principles capable of becoming a 
part of the gluten in wheat. 
In considering what vegetables are likely to be 
profitable on a particular soil , it is necessary always 
to attend, not only to the mean temperature of the 
climate, but likewise to the summer’s heat and 
winter’s cold. Thus, maize, or Indian corn, and 
the vine, require a very hot summer ; and the olive 
would be destroyed by our winter. It is unneces- 
sary, therefore, to say any thing of these plants, or 
similar plants, in relation to a British system of 
cultivation : but, in some of our colonies, particu- 
larly the Cape of Good Hope, almost all the vege- 
table productions of Italy, Portugal, or Spain, are 
or may be raised. The wines of the Cape may be 
y 2 
