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most cultivated soils contain it in sufficient quanti- 
ties for the use of the grasses. In the common 
course of cultivation, gypsum is furnished in the 
manure ; for it is contained in stable dung, and in 
the dung of all cattle fed on grass ; and it is not 
taken up in corn crops, or crops of peas and beans, 
and in very small quantities in turnip crops ; but 
where lands are exclusively devoted to past urage 
and hay, it will be continually consumed. I have 
examined four different soils cultivated by a series 
of common courses of crops for gypsum. One 
was a light sand from Norfolk ; another a clay, 
bearing good wheat, from Middlesex ; the third a 
sand from Sussex ; the fourth a clay from Essex. 
I found gypsum in all of them ; and in the Mid- 
lesex soil it amounted nearly to one per cent. 
Lord Dundas informs me, that having tried gypsum 
without any benefit on two of his estates in York- 
shire, he was induced to have the soil examined 
for gypsum according to the process described in 
the Fourth Lecture, and this substance was found 
in both the soils. 
Should these statements be confirmed by future 
enquiries, a practical inference of some value may 
be derived from them. It is possible that lands 
which have ceased to bear good crops of clover, or 
artificial grasses, may be restored by being manured 
with gypsum. I have mentioned that this sub- 
stance is found in Oxfordshire ; it is likewise 
abundant in many other parts of England; in 
Gloucestershire, Somersetshire, Derbyshire, York- 
shire, &c. and requires only pulverization for its 
preparation. 
