ELIMINATION OF SPURIOUS TESTS FOR B. COLI 



353 



Thus while we cannot claim to have progressed to a point 

 where it is safe to dispense with the litmus lactose agar plate 

 and rely wholly upon the presumptive test, we have in the use 

 of gentian violet a method which offers promise of even such a 

 result in higher concentrations than we have used and in the 

 lower concentrations provides a method of eliminating the great 

 majority of spurious tests, obviating the necessity of much 

 futile plating with a consequent saving in time and material. 



REFERENCES. 



Amer. Public Health Association 1917 Standard methods for the examination 



of water and sewage. 3d edition. 

 Bachman, Frank 1917 Personal communication. 

 Churchman 1912 The selective bactericidal action of gentian violet. J. 



Exp. Med., 16, 221. 

 Clark and Lubs 1915 The differentiation of bacteria of the Colon-aerogenes 



family by the use of indicators. J. Infect. Dis., 17, 160. 

 Creel 1914 Examination of drinking water on railroad trains. Hyg. Lab. 



Bull. no. 100. 

 CuM.MiNG 1916 Investigation of the pollution and sanitary conditions of the 



Potomac water shed. Hyg. Lab. Bull. no. 104. 

 Drigalski and Conradi 1902 Ueber ein Verf ahren zum Nachweis der Typhus- 



bacillen. Ztschr. f. Hyg., 39, 283. 

 Fuller 1915 Biochemical and Engineering Aspects of Sanitary Water Supply. 



Jour. Franklin Inst., Ch. 30, 17. 

 Gillespie 1916 Report of the Bureau of Sanitary Engineering for November 



1916. Cal. State Board of Health Bull. December 1916, 12, 353. 

 Hall 1914 An improved (Durham) fermentation tube. Am. J. Pub. Health, 



4, 1173. 



1915 A new aerobic-anaerobic culture tube. Univ. of Calif. Pub. in 



Pathology, 2, 147. 

 Hall and Taber 1914 The effect of gentian violet on the Bacillus tetani, 



tetanus toxin and certain laboratory animals. J. Infect. Dis. 15, 566. 



