158 University Geological Survey of Kansas. 
nates in addition to the hydrated calcium sulphate, and from 
what we know of the methods of deposition, it naturally fol- 
lows that there is a possibility of a great range of composition. 
Some light may be thrown on the relative ‘solubility of the 
beds of gypsite by the inspection of the analysis of a sample of 
water formerly used at one of the mills, and which had pre- 
sumably leached through deposits of this material. In 1000 
parts of the water the following constituents, probably united 
as here given, were found: 
SHINO, Gravel Vingolhlole WAM, ooccadsconcoobvsescooocs 0.0136 
linxoyay Gravel, gyllivbaaurAeNOM, OCS) 5 cc occ cbc cog esso cog cE obUs 0.0048 
Caleramysulphate yyw ees Mens ee ew ane ea Ua enne nn vate 1.9606 
Sodium sulpliate yeas Seis cece a NE nee 0.0499 
Masmesiumycarbonatemne st erat enna area aera 0.3001 
SOGIUM CarboMate we edae yh tepe eed a NNR eta een) oar 0.0473 
Sodium chloOrid Grn pees args et Gael ae eR ae 0.0749 
doy Fret Lenn peti AE nae ean E Aree un meet ME re Te 2.4512 
Comparing this with the gypsum deposits below, it will be 
noticed that the more soluble substances—sodium sulphate, 
sodium carbonate, and sodium chloride—are wanting in the 
mineral, though in some cases it is no doubt true that small 
quantities of alkaline salts remain undissolved by the water 
that has percolated through the bank. 
Suppose this water is exposed to the air and gradually evapo- 
rates, it would deposit all its salts with their water of crystalli- 
zation, but gradually this water would leave the efilorescent 
salts like sodium sulphate and sodium carbonate, so that elimi- 
nating this water the mass would have the composition : 
Silicayandpinsolublemesiqducy eee e teeter erre 0.46 per cent. 
ironyandvalumunum) ox Cesare Sere eee eer 0.18 uP 
Calcium sulphate, plus water (CaSO,+2H.O)........ 83.51 B0 
SHON ONAN, SUV NEMO cocooscccosucnvsueds MEER AEH Males Wate ar 163 Oe 
Macnesiumyucarbonate seertatr tert Decne eer: 1), dal a 
Sodiumucarbonateromesta se see ee eee bee ee 1.58 os 
Sodium Chlorid ete eek ae et eee Men Paras 2.53 Be 
ARO CaS sic asthe cutie ee ee ACE PDE a 100. 
This mass when exposed to the action of water would soon 
loose its sodium sulphate, sodium carbonate, and sodium chlo- 
ride, as these are the more soluble salts, and thus the per cent. 
