298 



ORIENTAL PLAGUE 



CHAP. 



2. — Cyllin 1 in 2200, 5 minutes' exposure. All tubes free of any 



growth. 



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From these experiments it follows: (1) that formalin 

 even 1 in 30 failed to disinfect B. pestis in fifteen 

 minutes ; (2) that phenol 1 in 80 failed to disinfect 

 B. pestis in five minutes, but did disinfect in ten 

 minutes ; and (3) that cyllin 1 in 2400 failed in five 

 minutes, but succeeded in ten minutes. 



From the following tables it will be seen that — 



(1) Phenol 1 in 80 is a stronger disinfectant for 

 B. pestis than formalin 1 in 30 ; and 



(2) Phenol 1 in 80 stands in about the same position 

 as cyllin 1 in 2400, inasmuch as both failed to completely 

 devitalise the B. pestis in five minutes, though they both 

 succeeded in doing so in ten minutes. Expressed in a 

 different form, cyllin possesses for watery emulsion of 

 B. pestis a disinfecting power which is more than 27 '5 

 (in fact about 30) times as great as that of absolute 

 phenol. 



Carbolic acid coefficient of formalin is under '37. 



