514 EXPERIMENT STATION RECORD. 



" The quantity of chlorin immediately absorbed can not be estimated from 

 the determination of the oxygen-consumed factor of the sewage effluent. 



" The cost per annum for each 1,000 gals, of sewage treated under the vary- 

 ing conditions experimented with is estimated as follows : 



"St. Mary's of the Springs, Ohio (average daily flow 12,000 gals.), crude 

 sewage, copper sulphate, $18.55. 



" Westerville, Ohio (average daily flow 41,000 gals.) eflluent from contact 

 filter, copper sulphate, $11,77. 



"Boys' Industrial School, Lancaster, Ohio (average daily flow 100.000 gals.), 

 sand filter effluent, copper sulphate, $6.93 ; chlorin, $5.78. 



"Marion, Ohio (average daily flow 600,000 gals.), sand filter effluent, cop])er 

 sulphate, $4.86; chlorin, $2.43; contact filter effluent, chlorin, $2.73; septic 

 tank effluent, chlorin, $8.83. In case the effluent from the septic tank contains 

 much suspended matter a heavier application of chlorin is necessary. 



" These figures probably approximate the cost for treatment in any city whose 

 sewage is not mai-kedly influenced by industrial wastes. In the small plants . 

 here discussed depreciation has not been included in the cost data ; it is, of 

 course, a factor which must not be overlooked for operating costs on a larger 

 scale." 



On the m.echanisni of biological purification by means of bacterial contact 

 and percolating' beds, A. Cai.mkttk {Ncv. Hug. ct Pol. l^anit.. 2!) (1907), Xo. 6, 

 pp. 498-508). — This subject is briefly discussed and the general conclusion is 

 drawn that contact and pei'colating beds furnish a simple. pi*actical, and eco- 

 nomical method of purification which meets all legitimate requirements of 

 hygienists and safeguards the public health. 



SOILS— FERTILIZERS. 



Origin and classification of cultivated soils, V. A. Fernandez (Heraldo 

 Agr., 7 (1907), Nos. G, pp. 5, 6; 7, pp. //-6').— The usual classification based 

 upon the relative proportions of sand, clay, lime, and humus is described, and 

 the pro])erties of soils containing varying proportions of these constituents arc 

 discussed. 



Bibliography of the geology of Connecticut, H, E. Gregory (Conn. State 

 Geol. and Nat. Hist. Survey Bui. 8, pp. 123). — A number of references to liter- 

 ature relating to soils of the State are included in this bibliography. 



Notes on the geology of the Winnfield sheet, G. D. Harris (Geol. Survey 

 La. Bui. 5, pp. 36, pis. 9, figs. 6). — This is an account of a topographic and geo- 

 logical survey made under the direction of the Louisiana Experiment Stations 

 of the Winn Parish, which is typical of a greater part of the hill land of 

 northern Louisiana. Information relating to economic products (water, salt, 

 gas, limestone, and building stone) is also given. 



Maryland Geological Survey, Calvert County (Baltimore, 1907, pp. 227, pis. 

 Ui, figs. 11, maps 3). — This is a report on the geological character, climate, 

 hydrography, and resources of this area accompanied by toi)ographic, geologic, 

 and agricultural soil maps. 



Maryland Geological Survey, St. Marys County (Baltimore, 1907, pp. 209. 

 pis. 16. figs, 12, maps 3; rev. in Amer. Jour. Sci., J), ser., 24 (1907), No. IJ/O, 

 p. 181). — This report deals with studies of physiography, geology, economic 

 resources, soils, climate, hydrography, magnetic declination, and forests ot 

 this area. 



Composition of soils from various parts of the eastern counties, England, 

 T. H. MiDDLETON (Cambridge Univ., Dept. Agr., Guide to Hxpts., 1907. pp. 



