20 QUATERCENTENARY STUDIES IN PATHOLOGY 



Klein, in a series of experiments, found that solutions of 1-200 killed 

 all non-sporing bacilli in 5 minutes, and a solution of 1-300 killed the 

 Streptococcus pyogenes. He found that solutions of i per 1,000 

 inhibited the growth of all spores and bacilli, except in the cases of B. 

 prodigiosus and B. typhosus, where a solution of 25 per 1,000 was 

 required. Fowler obtained the "phenol coefficient" of 5-5 with B. 

 typhosus and B. prodigiosus in the case of izal, and 8'5 in the case of 

 cyllin. Kenwood and Hewlett obtained the " phenol coefficient " of 57 

 with B. coli in the case of izal, and 5 '3 in the case of cyllin. 



Sapo-Cresol. — A poisonous disinfectant, with a very pronounced 

 creosote-like odour. It forms a dirty white emulsion when mixed with 

 water. So far as I am aware, no bacteriological report has appeared 

 on this substance, (c.f Wolf Arch, f Hyg., 1894, xx., p. 219,) 



Sanitas. — A pleasant odoriferous disinfectant. It contains hydrogen 

 peroxide, camphor, and thymol. When mixed with water, it forms a 

 clear fluid. 



Thresh, in a recent series of experiments, found that a 20 per cent, 

 solution of sanitas fluid kills B. typhosus in 5 minutes, and a 40 per 

 cent, solution kills B. diphtheriae in 20 minutes. Pure sanitas fluid 

 kills B. diphtheriae in i minute, and B. anthracis in 2 J minutes. A 5- 

 per cent. " sanitas emulsion " kills the B. diphtheriae in 30 minutes. A 

 7 J per cent. " emulsion " kills B typhosus in 2 J minutes. A 10 per 

 cent. " emulsion " kills B. anthracis and B. diphtheriae in 2 J minutes. 



The following was the procedure in the first series of the experiments 

 made by myself (Izal, sanitas, and sapo-cresol were not included in 

 this series) : — 



1. The germs taken were cultures of Staphylococcus pyogenes 



aureus, B. typhosus, and sporing anthrax, and they were 

 grown in bouillon, each tube containing exactly 10 c.c. 

 bouillon. The first two cultures were of 24 hours' growth, and 

 the latter of 7 days'. 



2. To each of these tubes enough of each disinfectant was added 



to give the different strengths of solution of disinfectant 

 determined upon. The tubes were then thoroughly shaken. 



3. At every 2 J minutes, up to 15 minutes, 7 loopfuls of the mixture 



were re-inoculated into fresh tubes of bouillon and incubated 

 at 37° C for 8 days. 



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