Dr. Baxter's report on an experimental study of certain disinfectants.

  • Baxter, Evan Buchanan, 1844-1885.
Date:
[1875]
Catalogue details

Licence: Public Domain Mark

Credit: Dr. Baxter's report on an experimental study of certain disinfectants. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    36/42 (page 250)
    App. No. 6. more ; by carbolic acid, when present in the proportion of ] per cent. OuDisinfectants, or morc- The time during which the microzymes were exposed to the by Dr. Baxter, action of the disinfectant did not appear to matter; intermixture having been thoroughly accomplished, the work was done. Apparent dis- crepancy between anti- septic and disin- fectant power. Attempt to eluci- date the nature of this dis- crepancy. Experiments with septic microzymes. The striking primd facie discrepancy between these figures and those obtained in the series of experiments performed with vaccine lymph, would have led to the abandonment of the inquiry, had not the results of Davaine’s experiments on the virus of charbon (p. 22.) awakened the suspicion that the discrepancy was more apparent than real. It is noteworthy that the difference was greatest in the case of chlorine and potassic permanganate ; least in the case of carbolic acid ; and that the figures obtained with the virus of glanders and of infective inflammation, were less widely removed from those representing the antiseptic power of the four agents, than those obtained in the case of vaccine. There are two alternative explanations possible : it may be that the particles of contagium differ so essentially from one another and from the germs of septic microzymes in their susceptibility to adverse conditions, that no common prospect, whether of destruction or survival, can be held out to all of them alike; ou the other hand, it is possible that the particles are all equally liable to perish when brought into contact with the same disinfectants; and that the discrepancy observed is entirely due to differences in the medium in which the particles may happen to float. The probability of the latter explanation is enhanced by the reflexion that septic microzymes, which are admittedly of one kind, vary widely in the degree of their resistance to destructive agencies, according to their physical condition and environment.* In order to obtain some evidence on which to found a judgment between these two conflicting views, the following experiments were carried out. It was obviously impossible to vary the nature of the medium in which the particles of vaccine virus are suspended—a medium strongly alkaline, and loaded with coagulable principles,—owing chiefly to the small quantity of material available for experiment. So that, in the first place, an attempt was made to alter the constitution of the medium containing septic microzymes, and by bringing it more nearly into relation with the albuminoid matrix of vaccine lymph, to ascertain whether changes made in this direction were attended by any corre- sponding change in the susceptibility of the septic germs to the action of chlorine and permanganate. I. Two solutions containing active microzymes in abundance, were prepared as follows : (a) by mixing 2 c.c. of turbid Cohn with 18 c.c. of water; (5) by mixing 2 c.c. of turbid Cohn with 18 c.c. of ovalbumin. The former was neutral, the latter feebly alkaline. Each solution wras divided into three parts, and potassic permanganate was introduced in the folio-wing proportions : la and 15 received '0125 per cent. 2a „ 25 „ ’00625 „ 3a „ 35 „ -003125 „ The solutions were all shaken and put under a bell-jar. Eight eprou- vettes, charged with sterilised test-liquid, having been prepared, six were inoculated from the above six solutions; the seventh received a drop of («); the eighth, a drop of (5). After a week had elapsed, it was found that the test-liquids inoculated from the three disinfected solutions wrhich * No particular evidence in support of this assertion need be given, for nearly all the facts adduced during the recent controversy ou spontaneous generation are illustrative of its truth.