12 University Geological Survey of Kansas. 
future the agriculturist will find it greatly to his interest to 
use crushed gypsum extensively as a fertilizer. At the present 
time, so far as is known, not a single farmer in the whole state 
has ever tried, to any considerable extent, its application to see 
whether or not it would materially increase his crop production. 
It is earnestly hoped that the extended and able discussion of 
the use of gypsum as a fertilizer given by Professor Grimsley will 
stimulate Kansas farmers to experimenting on different kinds 
of soils and on different crops to determine whether they may 
not be able greatly to increase the productiveness of their farms, 
and at the same time increase the market for one of the staple 
Kansas mineral products. That chapter particularly is ear- 
nestly commended to the careful attention of the great class of 
our citizenship, the Kansas farmers. 
It is not believed by the writer that the present methods of 
manufacturing plaster from the different grades of gypsum are 
entirely what they should be. The future certainly will de- 
velop material improvements. The manufacturing process is 
so simple and the chemical changes to be accomplished are so 
few that it would certainly seem more refined methods of cal- 
cining the raw gypsum should be invented. The old-fashioned 
kettle with the ponderous agitating machinery connected there- 
with is not in good keeping with the modern advancements in 
the mechanic arts. 
Since the gypsum earth plasters have been preved to be more 
desirable for some purposes than the purer plaster of Paris 
made from the gypsum rock, apparently it should not be a 
difficult task to imitate nature in the production of proper 
mixtures of pure gypsum with earthy materials to produce a 
plaster similar in every way to that made from the gypsum 
earth. It would seem that the problem is less difficult than 
that long ago solved for the manufacture of Portland cement. 
Could a few improvements as above outlined be put into 
operation, and could the great abundance of cheap fuel in the 
southeastern part of our state be brought in touch with the 
vast gypsum deposits in the gypsum area, Kansas could supply 
the markets with the different gypsum plasters for the whole 
