Collected papers . the caseof disinfection of B. typhosus with phenol by Rideal and Walker (1903,p. 431), and by Martin and the author (1908, p. 661). 248 Disinfection TABLE IX. Disinfection of Staphylococcus pyogenes aureus with 0G /^ phenol at 20° C Experiments to show difference in resistance of a culture grown at 37° C. and one grown at 42° C. Exp. 23. 3. 09. (a) Culture grown at 37° C. Time, minutes = t Control123 4 = ^05 710 Amountof sampletaken,drops 2 3ilO Numbers counted on plates (agar) G56 679 GOO 709 554 659 616 516 587 616 613 510 544 460 765 932 1115 847 1017 1488 1410 1317 (/j)
Collected papers . the caseof disinfection of B. typhosus with phenol by Rideal and Walker (1903,p. 431), and by Martin and the author (1908, p. 661). 248 Disinfection TABLE IX. Disinfection of Staphylococcus pyogenes aureus with 0G /^ phenol at 20° C Experiments to show difference in resistance of a culture grown at 37° C. and one grown at 42° C. Exp. 23. 3. 09. (a) Culture grown at 37° C. Time, minutes = t Control123 4 = ^05 710 Amountof sampletaken,drops 2 3ilO Numbers counted on plates (agar) G56 679 GOO 709 554 659 616 516 587 616 613 510 544 460 765 932 1115 847 1017 1488 1410 1317 (/j) Culture grown at 42° C. Control 1 116 2 1 80 102 101 8 1 117 91 5 2 171 190 156 7 3 231 255 265 10 10 825 768 843 Mean no. of bacteria present in 1 drop disinfection Mean mixture, =A 667 667 621 621 597 597 605 605 505 505 = ^0848 424993 331 150-5 116 116 94-3 94-3 104 104 172-3 86-1250 83-4 812 81-2 K- 2-8242-7932-7762-7822-7032-6272-520 lo«— 2177 •076•091 -088 1 Mean 085 20641-9752-0171-9351-9211-910. Time, minutes Fig. 6. Disinfection of Staphylococcus pyogenes aureus with 0-6 ^q phenol at 20° C. (Table IX.)(a) 24 hours culture at 37° C. {b) 24 hours culture at 42° C. H. Chick 240 (2) General conclusions upon disinfection ivitli phenol. Disinfection with phenol may in general be considered to proceedin accordance with a logarithmic law so that the concentration of sur-vivors varies logarithmically with time, or, in other words, the rateof disinfection at any moment is proportional to the concentration of surviving bacteria ( — -, = Kn\. Of the species worked with, anthrax spores, B. tr/phosus, ^nd cuhnresof B. paratyphosus obtained by successive sub-culturing after shortperiods of growth, may be cited as proof of this assertion, withoutfurther remark. In my opinion, B. coli commune and Staphylococcuspyogenes aureus (if we allow for a short period of lag at the beginningof disinfection) may be added to this list. Eijkman, however, came to the conclusion that
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