B. salrnonicida is recoverable from tap water up to 2 to 5 days. 

 Plehn (192ii) claims that pure water is harmful to the organism, and she 

 could not recover it in pure torni water (Munich) after 2 days. Table 1 

 gives the findings of various authorities in te^ water. 



In unsterilized natural (river) water, Williamson (1928) recovered 

 the organism up to 2 days and in sterilized natural water up to 5 days ir. 

 very scanty numbers. In natural waters containing many organisms, Duncan 

 (1932) found that the bacterium died out in 2/+ to 30 hours. 



B. salrnonicida survives from a few hours to 3 days in sea water. 

 In unsterilized sea water Williamson (1928) recovered the organism up 

 to 2 days and in sterilised sea vrater up to 3 days. Arkwright (1912) 

 recorded no grovrth after 19 hours in sterilized sea water and Duncan 

 (1932) after 2U to 30 hours in plain sea water. With mixtures of sea 

 water and ta? water in equal parts, Arkwright (1912) noted that none of 

 the bacteria could be recovered after 19 hours; but from a mixture 

 containing sea water 25 percent and tap water 75 percent, a fair growth 

 was obtained after U5 hours but none after 67 hours. Arkwright (1912) 

 also found that salt water (3 percent sodium chloride in distilled water) 

 had a destructive effect on the bacteria. Growth from agar plate was 

 emulsified in 500 cc, of this salt solution, and one drop taken after 

 2 days gave only one coloriy on an agar plate. 



Table 1. — Viability of B. salmonicida in tap water 



Authority Date 



Results 



Arkwright 1912 



Plehn 192^ 



Heme 1928 



Williamson 1928 



From sterile tap water the organism could be 

 recovered alive in diminished numbers after 

 5 days. 



Organism was recovered from pure town water 

 (Munich) after 2 days but not after 3 days. 



B. salmonicida persisted in tap water for 3 to 

 L, days. 



Organism was recovered from both sterilized and 

 unsterilized tap water after 3 days in very 

 scanty numbers. 



Diincan 1932 In tap water containing other microorganisms, 

 living B. salmonic ida were not detected after 

 L, days.'" 



