IOWA ACADEMY OP SCIENCES. 63 



The following is the description of each of the eight 

 strata in this pit, beginning with the top : 



Tliickness in 

 Feet. 



D —1 . Clay , variegated 5 



D — 2 . Shale , streaked in color 4 



D — 3. Shale, solid chocolate brown color, clear definition. 5 



D — 4. Shale, solid color, clear to poor definicion 5 



D — 5 . Shale , variegated , clear to poor definition 3 



D — 6. Shale, sandy, solid color 10 



D — 7. Shale, sandy, clear definition, solid color, granu- 

 lated texture, pulverizes in the hand: thickness. 5 

 D — 8. Shale, gray, clear definition. This clay forms 38 

 to 40 per cent of the bank and runs to underly- 

 ing coal 23 



(4.) The Flint Brick Company is located in Oak Park 

 upon the Des Moines river. Seven samples were analyzed 

 from this pit. A complete description of the strata was 

 not obtainable at the time the samj)les were taken. 



THE SANITARY ANALYSES OF SOME IOWA DEEP 

 WELL WATERS. 



RY J. B. WEEMS. 



In the investigation of deep well waters the interest in 

 many cases has been limited to the mineral substances, 

 and little attention given to the sanitary analysis. This is 

 a natural result when it is realized that these waters con 

 tain large amounts of solids and the possibility of contam- 

 ination by sewage or other products is very slight indeed. 

 In connection with the work of the Department of Agri- 

 cultural Chemistry of the Agricultural College, analyses of 

 a number of samples of water from the deep wells of the 

 state have been made and the results brought together in 

 hope that they may be of interest. The methods used do 

 not require any explanation as they are those which have 

 been generally used for analyzing water. The oxygen 



