History of the Water Supply of the World / arranged in a comprehensive form from eminent authorities, containing a description of the various methods of water supply, pollution and purification of waters, and sanitary effects, with analyses of potable waters, also geology and water strata of Hamilton county, Ohio, statistics of the Ohio river, proposed water supply of Cincinnati.

by Thomas J. Bell

Analysis of sand from filter beds (in 100,000 parts)

	ORGANIC	ORGANIC	ORGANIC
	MATTER.	CARBON.	NITROGEN.
As removed from filter bed, unwashed	1523.40	314.160	38.674
After washing	804.41	94.921	16.973

It can not be doubted that a small amount of organic matter undergoes oxidation and destruction during the passage of the water through the sand; but, independent of this, it appears, from the above analytical numbers, that one ton of dry sand, washed after previous use, is capable of removing from water and retaining 16.1 lbs. of peaty matter.

Chemical filtration may be arranged under the following heads:

1. By use of alum and borax to reduce turbidity.

2. Dr. Gunning’s experiment of the waters of the River Maas, by reducing the turbidity with .032 gramme of perchloride of iron into one litre of water.

3. Dr. Bischoff’s (Jr.) process of removing organic matter by spongy iron, prepared by heating hydrated oxide of iron with carbon.

4. Spencer’s process of sand filtration with crushed grains of a carbide of iron. The carbide, it is claimed, does not require frequent removal.

5. Sheet-iron strips placed in water decomposes organic matter rapidly. It is recommended by eminent authority.