IOWA ACADEMY OF SCIENCES. 
107 
FeaOs and A 2 IO 3 0.26 
SiOs 0.12 
Total 99.99 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. H. Norton’s 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 
CaCO : 218.2 
MgCOa 105.8 
SiC 2 21.6 
Fe^Os and ALOs 2.6 
NaCl and KC1 19.8 
Na-iCQs and K 2 CO 3 2.8 
CO 2 free and partly united 15.9 
Nitrates 0.05 
Free ammonia 0.00 
Albuminoid ammonia 0.00 
2. Professor A. Collin s 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 110° 359.8 
CaCOs 195.00 
MgCOs 102.4 
SiO 21.2 
I e203 and AI 2 O 3 1.6 
Journal of Analytical Chemistry. Vol. Ill, page 398. 
