to serve as Manure. 85 
equally decided in its choice of poor sand. The Mangel evinced 
its superiority 24 in clay. As to the wet and dry clovers, to 
change their soil is to destroy them. In the wheats, to mistake 
the soil for which thev are intended is to blight them more or 
less each year. I have been constantly able to banish and bring 
on the blight by this means. There are several wheats for each 
sort of land, so that the identical plant may be changed as often 
as is necessary. The experiment of the farming plants tried 
three years successively, and the quantity of manure given them, 
though differing in quality, was as nearly as possible the same 
in measure. 
How is it possible to conceive that the same manure can suit 
each soil? A hot gravel which wants cooling, moisture, and nu- 
triment; a cold stiff clay which requires dispersion, pulverizing, 
dryness and support; a rich earth which calls only for lime to 
reduce its acidity; or a poor sand that demands binding, nourish- 
ment and moisture; a limestone which, like the clay, wants pul- 
verizing, support and warmth. The hot gravel is more admira- 
bly manured with marl and ashes: the clay after drying is best 
assisted with sand and good rotten dung, which divides, warms and 
supports it: a rich earth wanting only lime to reduce its acid: 
the poor sand, marl, or clay and chalk mixed with long dung. » 
Thus there is a sort of law by which the most ‘unlearned or 
careless farmer might plant his vegetables, put in his corn, ac- 
commodate his various plants according to their soil; in short, 
make good husbandry by thus proceeding by rule, and by means 
of the most trifling trials comprehend the earth of which each 
field was composed. I taught several farmers the method of 
attaining this simple piece of knowledge without trouble or ex- 
peuse. Thus, if the stiffness of a clay is to be ascertained, by 
way of properly adapting its manure, which is absolutely neces- 
sary, fori a‘small bason of it, and pour in a cup of water: the 
time the water is passing off will at once show its strength by 
its retentive qualities, and of course the nutriment it requires. 
If marl, the quantity of acid necessary to saturate and decompose 
it will show its goodness, since Sir H. Davy says that 50 per 
cent. of lime is sufficient to make it tolerable good manure ; if 
60, as some I have found at Exmouth, it is very excellent marl ; 
the rest is a sort of soapy clay, which adds to its value. If sand, 
if the soil is washed in four times its weight of water, the sand 
will subside at bottom and show of what else it consists. How 
often is clay found as a subsoil to sand! If it was therefore ex- 
amined, it is only mixing and adding long dung, and the whole 
becomes compounded for many plants. How often does a far- 
mer go to great expense to procure that which he would find 
in his next field! If the farmer tries his sand, it is necessary he 
should 
