con i t 
100° On Plaister of Paris: 
.. [See note (r).] And when soconnected,a small quan- 
tity of such manures or substances will give it activity. 
The auxiliaries necessary to draw forth the powers of 
the plaister, are within the reach of every farmer, of 
common industry and moderate capacity. The first ap- 
plication, without other assistance than that it finds in the 
earth, from the decayed and decaying roots, and other 
vegetable substances, will throw him up forage, and 
enable him to increase his stock. The more stock, the 
_ more animal manure for summer or winter crops, prepa- 
vey ratory to therepetition of plaister, with clover. ‘The green 
| ~ manures only cost the seed which produces them. With 
e - these auxiliaries, I am satisfied, by actual and long 
experience, that the gypsum may be repeated as safely, 
and with more benefit and less expence, than can any 
other manure, on soils suitable for its application—a cir- 
cumstance which ought always to be kept in view. 
in a state of putrefaction. It also is before shewn, that the 
vitriolic acid in plaister, disengages from the substances con- 
taining, them, all the gases.* This theory, therefore explains 
and coroborates the fact—that the plaister operates with 
most power, when it finds animal or vegetable putreiactions 
(dung, buckwheat ploughed in, &c. &c.) in the earth in 
which it is strewed. It, of course, shews why it will not ope- 
rate at all, when the animal or vegetable substances, or other 
bodies containing the gases, are mot in places where it is 
strewed. , 
*And no doubt it finds in the earth chemical agents (whatever they may be) which by superior 
affinitics decompose the gypsum, and set the sulphuric acid free, to perform its operations. 
R.. P. 
September, 1810. 
