58 On Gypsum. 
field, in whichunplaistered wheat was sown. Where the 
land was sandy, the unplaistered wheat was best, owing 
to the great growth of bird-foot clover among the plais- 
tered. This discovered the effect of gypsum on that an- 
nual grass. Where this grass’ did not appear, there was 
no difference between the plaistered and unplaistered 
wheat. From the spring of 1806 to this time, the un- 
plaistered slips have been distinctly marked, by a vast 
inferiority of the weeds and grass naturally produced. 
November 23d. Sowed three bushels of plaister on 
one and an half acres of wheat, left unplaistered for 
the purpose in the field last mentioned, on the surface. 
Weather moist. No effect on the wheat, on the ground, 
or in the growth to this day, though the plaister was of 
the same kind with that used in the last experiment. 
1806, March and April. Sowed 200 acres of clover 
with plaister, at different times when the weather was 
dry, moist, windy and still, part at three pecks—a 
bushel and five pecks to the acre, leaving a slip of 
20 feet wide across a field, to ascertain the goodness 
of the plaister, which was of a hard white kind, 
that hitherto used being soft and streaked. ‘The clover 
in this strip was bad, on each side of it, fine. No ap- 
parent difierence was produced by weather, quantity, 
or times of sowing. ‘The whole crop far surpassed in 
goodness whatever such lands had produced before, 
except the slip, as to which Pharaoh’s dream seemed 
reversed. 
April and May. Rolled all my seed corn as usual, 
leaving slips unplaistered. An excessive drought. No 
difference between these slips and the rest of the field. 
The following year when that grass grew, tufts of luxu- 
