INTRODUCTORY 



This work is designed to follow the physical, chemi- 

 cal, and microscopic examination of water. The 

 physical examination usually applies to odor, color, and 

 turbidity. The chemical examination determines the 

 oxygen consumed, dissolved oxygen, free and albumi- 

 noid ammonia, nitrites, nitrates chlorin, and hardness. 

 The microscopic examination refers to algae, protozoa, 

 etc. Many factors influence the results obtained by 

 any of these examinations, and in order to gain a clear 

 insight into existing conditions judgment on the quality 

 of water should not be passed unless all these examina- 

 tions and a bacteriological examination have been 

 completed. 



References — 



Savage, The Bacteriological Examination of Water Supplies, 

 London, 1906. 



Horrocks, The Bacteriological Examination of Water, London, 

 1901. 



Prescott and Winslow, Elements of Water Bacteriology, New 

 York, 19 14. 



Ohlmiiller and Spitta, Die Untersuchung and Beurteilung 

 des Wassers und Abwassers, Berlin, 1910. 



Kinnicut, Winslow, and Pratt, Sewage Disposal, New York, 

 1910. 



Hazen, The Filtration of Public Water Works, New York, 

 1900. 



Standard Methods for the Examination of Water and Sewage . 

 American Public Health Association, 755 Boylston 

 Street, Boston, Mass. 



Bacteriological Standards for Drinking Water. Reprint 

 No. 232 from the Public Health Reports, 1914, Wash- 

 ington, D.C., Government Printing Office, 1914- 

 143 



