The following letters though not written for publie view, 
yet contain much matter which should not be lost. 
They are therefore thought worthy of being inserted 
among the transactions of the society. 
On Gypsum. 
Read June 13th, 1809. 
Port Royal, Virginia, January 30th, 1809. 
Dear Sir, 
I have postponed answering your two obliging letters 
of May last, hitherto, lest the very great pleasure of 
your correspondence, should seduce me to be trouble- 
some, in the number or length of my letters; and I fear 
you will allow my apology to be a good one, before you 
get to the end of this. 
Your warning against a reliance on gypsum, and ne- 
glecting manure, induces me to give you an idea of my 
practices respecting both, in hopes of obtaining your 
corrections. For many years I have enclosed all my ara- 
ble land at each farm, in one enclosure, and excluded 
grazing entirely, leaving the whole vegetable matter the 
land produces, to return, taking a crop of corn and one 
of wheat, every three or four years. To increase vege- 
table cover I sow large fields of clover, cutting only a 
small proportion for seed and for feeding green. ‘These 
are treated with plaister, and the clover is plowed in dry, 
when the field comes into culture. It is cheaper to 
plough it in dry than green, on account of the different 
seasons of the year for the operations; and however 
