IOWA ACADEMY OF SCIENCES. 107 



FesOs and A2IO3 0.26 



SiO: 0.12 



Total yy.99 per cent. 



Each of the seven specimens examined is nearly pure 

 calcium and magnesium carbonates. The admixtures of 

 iron, alumina, and silica are quite insignificant. 



B. Potable Waters of Mount Vernon — 



1. Prof. W. //. Notions Well. The well is eighty feet 

 deep and draws its water supply from sand situated 

 between an upper yellow and a lower blue till. The num- 

 bers in this and in the succeeding analyses express the 

 parts of the substances in a million parts of water in con- 

 formity with the report of the committee of the American 

 Association for the Advancement of Science.* The water 

 was analyzed in May, 1900, by F. E. Welstead. 



Total solids at 110° 364.8 



CaCOs 218.2 



M g C O3 105.8 



Si02 21 6 



Feii03 and AhOs 2.6 



NaCl and KCl 19.8 



Na-iCOa and K2CO3 2.8 



CO2 free and partly united 15 9 



Nitrates 0.05 



Free ammonia 0.00 



Albuminoid ammonia 0.00 



2. Professor A. Collins Well. Analyzed May, 1900, by 

 E. A. Rayner. The depth of the well is one hundred and 

 twenty feet. A dense blue till begins at a depth of eighty- 

 five feet, and extends as far down as the excavation was 

 made. In the upper yellow till, a layer of sand and gravel 

 was found at a depth of seventy to seventy-five feet. 



Total solids at llO'' 359.8 



CaCOs 1 95.00 



MgCOs 102.4 



SiOi 21.2 



Fe203 and AI2O3 1.6 



*Journalof .\nalytical Chemistry. Vol. Ill, page 398. 



