ABSTRACTS 125 



nated and the results might be considerd to give a strong indication that 

 certain bacterial activities in fields are very closely associated with 

 crop yields. Furthermore, the tentative conclusion presents itself 

 that tests of such bacterial activities in the laboratory may indicate 

 quite accurately the crop-producing power of a soil, or, at least, the 

 relative crop-producing power of several soils. If, further, more ex- 

 haustive tests confirm these preliminary observations, it may be possible 

 to secure advance information regarding the crop-producing power of 

 soils by means of laboratory tests of bacterial action in those soils. — 

 S. H. A. 



BACTERIOLOGY OF WATER AND SEWAGE 



Predicts Federal Control of Stream Pollution. Earle B. Phelps. 



Eng. Record, 1916, 73, 173^. 



Federal policy needed in the supervision of stream conditions and the 

 necessary administrative body to put it into effect. — F. B. 



Air Diffusers Tested at Milwaukee, {Wis.) Sewage Plant. T. Chalkley 

 Hatton. Eng. Record, 1916, 73, 255. 111. Sec. Amer. W. W. Assn. 

 1916. 



Filtros plate, composed of quartz sand baked, of uniform porosity 

 has given the most satisfactory results. The removal of 90 per cent of 

 suspended matter, 95 per cent bacteria and an effluent stable for 5 days 

 was secured at Milwaukee with the continuous flow tank by using 1.75 

 cubic feet of air per gallon sewage with 4 hours aeration, 20 per cent 

 activated sludge and from 10 to 15 minute sedimentation. The esti- 

 mated cost is S4.38 per million gallon excluding engine room and plant 

 attendance, and the cost of disposing of the sludge. — F. B. 



DAIRY BACTERIOLOGY 



Fermented Milks. L. A. Rogers. Bulletin 319, U. S. Dept. Agr. 



A brief resume of our present knowledge of this subject. The 

 therapeutic and food value of fermented milk is discussed together 

 with the method of preparation of buttermilk, kefir and yogurt. S. H. A. 



The Present Status of the Pasteurization of Milk. S. Henry Ayers. 



Bulletin 342. U. S. Dept. Agr. 



A summary of our present knowledge of the process of pasteurization. 

 The subjects discussed are: Meaning of the term pasteurization; 

 value of pasteurization; extent of pasteurization in the United States; 

 methods of pasteurization; advantages of low temperature pasteuri- 

 zation; temperatures and methods most suitable for pasteurization; 

 supervision of the process of pasteurization; handling pasteurized 

 milk; cost of pasteurizing milk; bacteria which survive pasteurization; 

 modern theories of pastemization; and the necessity for pasteurization. 

 — S. H. A. 



