¥ 
By 
74 On Plaister of Park 
Query 4. What soils are the most proper for this ma- 
nure. 
Answer. Light soils, dry and sandy, or loamy. On 
clay I never succeed, though I have heard of its being 
used on clay with a degree of success.(6) On wet soils 
Thave always failed. I have strewed it on mossy swamps. 
On elevated spots in these swamps, it has killed the 
moss and thrown up white clover wonderfully; but has 
done nothing where the water around these spots con- 
(6) Where it has any success on clay, it is rare. The Presi- 
dent (whose lands at Mount Vernon and in its neighbourhood, 
are generally strong clay, or inclining thereto,) has frequently 
told me, that he has always been unsuccessful with plaister. 
I think he has tried it from one as far as twenty bushels to 
the acre, without any kind of benefit. That I might be accu- 
rate in this account, at my request, he was pleased to inform 
me, that he had “tried the plaister of Paris on his land 
(which is stiff and cold) at the rate of from one to twenty 
bushels to the acre.—It has been spread on grass and plough- 
ed land.—On the latter it has been ploughed in ;—harrow- 
ed in with a common tined harrow ; bush harrow :—and not 
harrowed at all. The effects in ezther and all the cases, were 
not more than if he had taken up as many bushels of the same 
earth and scattered them again over the surface of the ground. 
Yet he believes in, and is a friend to gypsum as a manure.” 
wards, by the extraordinary verdure of the grass (chiefly 
white clover) which grew spontaneously on it.* 
* This experiment is alluded to in my communication on salt. 2 vol. Memoirs. 173. But by a 
typographical error, pounds ave inserted for bushels. I went as far as 20 bushels to the acre, (or in 
that proportion) mast us¢lessly and mjuriously. R. P. 
September, 1910. 
