No. 200.] 
341 
near this place and at Fairportj but the quantity of plaster contained in 
it is too small for working. 
The workable beds of gypsum are almost wholly confined to the 
southern part of the formation. Along the valley of Allen's creek and 
Mill creek, two miles north, most of the plaster of Monroe county is 
obtained. Both these places are in the town of Wheatland. In the 
towns of Riga and Chili gypsum is found in thin seams, and small no- 
dules disseminated throughout the rock. In these places, marls, which 
readily crumble on exposure to the air, caa be substituted for gypsum. 
Until within a few years, the value of plaster as a manure, or stimulant 
for vegetation, has not been generally appreciated, but it is now much 
used; the demand is constantly increasing, and will doubtless continue 
to do so. It is mostly employed on grass lands, particularly on clover 
as preparatory to a crop of wheat. It is also used on wheat crops in 
the fall and spring; and Indian corn is much benefitted by the use of 
plaster. One bushel to the acre is generally considered a sufficient 
quantity for grass crops. 
The manner in which plaster affects vegetation appears generally not 
to be understood; but it is doubtless by attracting moisture, and with it 
carbonic acid, from the atmosphere, and thus furnishing nourishment to 
the plant. Experiments prove that the perceptible effect, at least, of 
plaster, is the absorption of moisture from the atmosphere. In the use 
of this, as w^ell as many other manures, the fact is overlooked, that 
plants are supported in a great degree by carbonic acid, and that much 
of this food is taken up by that part of the plant above ground. In this 
view of the case, any substance, above or beneath the surface, which 
presents carbonic acid to the plant, affords it food. Thus many sub- 
stances which do not enter into the composition of plants, afford much 
food for them, either by absorbing it from other bodies and giving it to 
the plant, or affording it from their own decomposition. 
At present, about 5,000 tons of plaster per annum are obtained from 
the town of Wheatland; of this quantity, 4,000 tons are used in Mon- 
roe county. This, however, is not the whole amount used in the coun- 
ty, as much plaster is brought from counties further east. Of the 5,000 
tons, 1,500 tons are obtained from Mr. Garbutt's farm, in the north part 
of Wheatland; 1,000 tons from Messrs. Sage and Harman's, the adjoin- 
ing farm; and 1,000 tons from the Messrs. McVean's farm, on lot 49. 
The remaining 1,500 tons are supplied from an extensive deposit at 
Garbutt's mills, on Allen's creek. Ground plaster is sold for three dol- 
lars per ton. 
