38 COLORADO COLLEGE STUDIES. 



an interestin*;^ deposit of selenite in the Medicine Lodge 

 gypsum. It was a mass of several tons' weight forming 

 the roof of one of the small caves that open upon the river 

 valley a few miles west of the " plain," where the gypsum- 

 ledge occupies a position but little above the level of the 

 "bottom." The mass consisted of an interlocking and partly 

 interpenetrating group of huge crystals. It was found that 

 the latter, though readily cut, could only with great diffi- 

 culty be removed entire, owing to their toughness and their 

 interlocking relation. Chisels were driven into the mass 

 with difficulty. Prying wiih iron bars was little more 

 effectual and attended with similar results, the bending of 

 the crystals causing them to cleave into slabs and sections 

 or producing an intermolecular fracture that rendered them 

 opaque. By the destruction of perhaps an equal amount, 

 some 800 pounds' weight was obtained by two assistants 

 and myself as the result of several hours of hard work, and 

 was sent to the museum of Washburn College. The largest 

 crystal (now split into halves) measures a little over three 

 feet in length, is two feet wide and a foot thick, and in part 

 clear enough to read through. It is obliquely penetrated 

 by a comparatively small crystal at one extremity. It is 

 the largest crystal of selenite that the writer has ever seen; 

 but still larger masses are said to have been observed in the 

 Glass mountains. 



Some local use has been made of the Medicine Lodge 

 gypsum almost since the founding of the towns of Medicine 

 Lodge and Sun City; but within the last few years two 

 mills* have been built for the manufacture of plaster from it 

 on a commercial scale, and this is doubtless but the begin- 

 ning of a vast industry that will ultimately be built up in 

 this great gypsum-belt in southern Kansas, Oklahoma and 



*That of Best Brothers at Medicine Lodge, making Keene's 

 cement as one of its specialties; and the Standard Cement Company, 

 whose headquarters are at St. Joseph, Mo., and whose mill is on the 

 north side of the Medicine Lodge river, ia the west part of Barber 

 county, Bhipping from Croft. 



