34 



Cincinnati Society of Natural History 

 Sample ok Ohio River AV^atkr, 



2 Leeds. I o.oi 15 

 3|Stuntz. [0.0070 



0.0240 16.20 

 0.01561 15.80 



9.00 

 11.40 



7.20 

 4.66 



0.805 

 1-33 



6.4 

 8-3 



18S2 



March 



18S0 



Nov. I 



Deductions. 



Since i Drop (Table, Series 18.) clarifies i Liter of water 

 in i<S hours, we have the Minimum Cost of the clarification of 

 1,000,000 Gallons of Water as follows : 



i8.7X3.2X7.48=$4-i6. 



To this must be added the cost of dissolving the materials and 

 running the solution into the water. 



There will be introduced into the reservoir something over 200 

 jjounds of solids for each million gallons'of water. 



Effect on the Sewage. 

 (Supplementary Table to Series 18.) 



It will be seen that the water of Series 18 is river water con- 

 taining a large amount of Sewage. (Compare samples o and 1 

 with 2 and 3.) 



Taking the Albuminoid Ammonia as data for the amount of 

 Sewage, we find it reduced in the clarified water from 1.4098 to 

 0.8390 parts in the 100,000, over 40 per cent. 



This sample and the samples of clarified canal water will serve 

 to illustrate the general fact that, clear water is not necessarily 

 pure water. 



Water Clarified by Filtration After Precipiiation 

 Bv Alum. 



The following experiments were made on water clarified b\- the 

 process of the Hyatt P'ilter Company, of Newark, N. J. 



The specimens were collected from the pipes of their filters in 

 the Gibson House and in the building of the Commercial Gazette in 

 Cincinnati. 



The filters of this company are funnel shaped tanks of boiler 

 iron, constructed so that the water led into the bottom of the tank 

 under considerable pressure, rises several feet through a compact 

 mixture of sand and finely crushed coke, which separates the solids 

 held in suspension. The water on its way to the tank comes in 



