1922.] The Ninth Indian Science Congress. 1.8.C, 21 
cliffs and scarps of 60 to 100 feet in height to simple quarry- 
ing operations 
n considering this mineral from an economic point of 
view, I do not want to describe the ordinary uses to which it 
acid from gypsum or because of sensational reports from 
Bombay that appeared in the papers of June 1919 regarding 
an easy and cheap process for this purpose in India). 
ome new facts have recently come to light in America 
regarding the use of it in agriculture, and it is these to whic 
wish to draw your attention for a few moments before I end 
potassium taken up through a double decomposition of potas- 
sium silicates with liberation of potassium sulphate. Thus the 
action of gypsum was supposed to be only indirectly beneficial. 
products is much larger than had been previously suspected. 
It was also found that the amount of sulphur trioxide removed 
from soils is also considerable, being for average crops of 7 
grains and straws 2/3 of the phosphorus pentoxide remov Hi 
whilst grasses of mixed meadow hay removed an equal quan 4 
ty of each, and members of the crucifers, e.g. cabbage an 
turnip, are heavy sulphur using crops and may remove near 
three times as much sulphur trioxide as phosphorus pentoxide. 

«* Research Bull.” No. 14, Wisconsin Agricul. Exp. Sta. ae 
Do. No. 174, Kentucky Do. or 
Do. No. 18, Iowa Do . 
Do. 
1 
2 
3 Jo. 
+ No. 163, Oregon Do. 1919. 
