QUALITATIVE BACTERIOLOGICAL ANALYSIS. 2.57 



the same platinum needle and plated out in gelatine, 

 following results were obtained : 



The 



A control plate, made immediately after the inoculation, 

 showed 1440 colonies. 



(1) 10 c.c. sterile well-water 



(2) do. + 1 drop 10 per cent, di-sodium phosphate 



(3) do. + 2 drops do. do. 



(4) do. + 2 do. do. do. 



(1) 10 c.c. sterile well-water 



Plate after twenty - 

 four hours.* 



520 

 3,360 

 7,560 

 6,540 



Plate after twenty- 

 four hours. 



580 

 7,440 

 28,680 

 31,560 



54,720 



(2) do. + 1 drop 10 per cent, sodium carbonate 



(3) do. +2 drops do. do. 



(4) do. +3 do. do. do. 



(5) do. + 2 drops 10 per cent, sodium chloride, and) 



1 drop sodium carbonate / 



A control plate, made immediately after the inoculation, 

 showed 1800 colonies. From these experiments Trenkmann 

 concluded that in waters containing no sodium chloride or 

 other sodium salts, the cholera bacilli diminished in numbers, 

 whilst in others they multiplied almost in proportion to the 

 :salt added. The greatest multiplication was seen with a com- 

 bination of sodium chloride and sodium carbonate. Trenk- 

 mann also found that potassium salts gave rise to a similar 

 multiplication of the cholera spirilla. 



(1) 10 c.c. sterile well-water 



Plate after twenty- 

 four hours. 



1,020 



4,200 

 38,520 

 43,320 



9,000 



19,860 



22,740 



R 



