1905.] 



with reference to the Purification of Sewage. 



265 



Table VII. — Results of Inoculating into Nitrite Medium of Five Strains 

 of a " Symbiotic " Culture of Nitrate-Producer, " d," after Successive 

 Generations in Bouillon. + indicates a positive, + + an intense reaction.^ 









"d 1" 



"d2" 



" d 3 " 



" d 4 " 



" d 5 " 



Dates of 



Date of 



Date of 

 testing 

 preceding 

 cultures. 























successive 



inoculation 























inoculation 

 into 

 bouillon. 



from bouillon 

 into nitrite 

 medium. 



Nitrites. 



Nitrates. 



Nitrites. 



Nitrates. 



Nitrites. 



Nitrates. 



Nitrites. 



Nitrates. 



Nitrites. 



Nitrates. 



17.12.03 - 



23.12.03 



12.1.04 







+ + 







+ + 







+ + 











12.1.04 - 



18.1.04 



3.2.04 



+ + 











+ + 







+ + 







+ + 







+ + 



18.1.04 -» 



26.1.04 



10.3.04 



+ + 











+ + 







+ + 







+ + 



+ + 







26.1.04 - 



3.2.01 



10.3.04 



+ + 







+ + 







+ 



+ 







+ + 



+ + 







Table VIII. — Showing the Different Behaviour of Pure and of " Symbiotic " 

 Bouillon-Cultures of the Nitrate-Producer when Inoculated into 

 Nitrite Medium, the latter tested for nitrites and nitrates 31 days 

 after inoculation ; + indicates a definite, + + an intense reaction.J 



Eeactions of 

 the nitrite 





Pure cultures, 



bouillon clear. 





" Symbiotic " cultures, bouillon 

 showing growth. 



medium. 



No. 25. 



No. 39. 



No. 67. 



No. 49. j No. 29. 



No. 12. 



No. 21. 



Nitrite 



+ + 



+ + 



+ + 



+ + 



+ + 



+ + 















+ 



+ 



Nitrate 



























+ + |+ + 



+ + 



+ + 



+ 



4- 



Cultures No. 49 and No. 29 were strains of culture " d " ; cultures No. 12 and No. 21 were of 

 different origin. 



X With cultures still containing nitrites, evaporation with ammonium chloride preceded the 

 diphenylamine test for nitrates. 



