74 SCIENTIFIC AGRICULTURE. 



original gypsum. This property fits it admirably 

 for taking casts of statuary, for forming the " hard 

 finish " on the plastered walls of our houses, and for 

 stucco-work of all kinds. Dentists use it in large 

 quantities for taking casts of the mouth, and for 

 other purposes in their work, while it is useful to 

 artists in forming models from which to copy and 

 perfect the creations of their genius (32). 



167. Gypsum is found in nature as a mineral, 

 generally as a white compact mass, though sometimes 

 in a transparent crystalline condition, as in the min- 

 eral selenite. Alabaster is also a form in which this 

 mineral is found, and used in the manufacture of 

 vases and other ornamental work. The rock is quite 

 soft, easily scratched with a knife, and whitens on 

 being heated. It contains about twenty-one per 

 cent, of water. As a fertilizer, it furnishes lime and 

 sulphur to plants, and is thought to have the power 

 of absorbing ammonia from the air and supplying it 

 to the plant. To this important property Liebig 

 ascribes much of its wonderful effect upon young 

 grass and wheat. It is usual to sow it broadcast 

 over wheat and grass during the early spring, and to 

 drop it with corn at the time of planting, or to drop 

 a small portion on each hill of corn after the corn 

 has been thinned. Corn moistened with water and 

 rolled in plaster at the time of planting, will get 

 a more vigorous start, and be the better enabled 

 to stand an early drought. Cotton-seed may also 

 be very advantageously rolled in plaster previous 



