A handbook of local therapeutics / edited by Harrison Allen.

Date:
1893
Catalogue details

Licence: Public Domain Mark

Credit: A handbook of local therapeutics / edited by Harrison Allen. Source: Wellcome Collection.

    43/554 (page 31)
    solution of carbolic acid must be employed. The ordinary five per cent, (or I to 20) solution, which is used in the majority of surgical operations, requires more than a day to destroy the spores of anthrax. To use solutions stronger than this is impracticable, because of the benumbing influences that are produced on the hands of the surgeon, and also the increased danger of absorption. These results are, however, rare, since it is customary to regard a three per cent, solution in water as able to destroy all germs in a few seconds or minutes. The surgeon washes his hands and cleanses his instruments in such a solution, believing that he has thereby rendered them free from living organisms. We see now, however, that beyond the mere mechanical effect of washing, such precau- tions are of no avail whatever in the case of organisms as resistant as are anthrax spores. Carbolic acid cannot, therefore, be regarded as a reliable disinfectant, since it has not the power of destroying resisting spores under the condi- tions of practical disinfection. Schotte and Gaertner have shown that to destroy putrefaction-organisms in dry objects, 15 grains of carbolic acid vapor to the cubic metre are required, so that disinfection of rooms by this method is impracticable. Carbolic acid dissolved in oil and alcohol is inert. Anthrax spores were found to be unaffected after lying for upwards of three months in a five per cent, solution of carbolic acid in oil, and equally so by seventy days exposure to a five per cent, solution in alcohol. Even the sensitive anthrax bacilli were not destroyed by a five per cent, solution of carbolic acid in oil. If carbolic aCid comes in contact with substances containing water, for instance the tissues of the body, doubtless part of it will be taken up and exert some antiseptic action. In all other cases, as when it is sought to disinfect dry objects, such as instruments, silk, cat-gut, etc., by carbolized oil, there is no effect on even the least resisting micro-organisms, beyond that due to the oil itself. Bearing in mind that carbolic oil is inert, and that a two to five per cent, solution can make no impression upon spores in the brief time occupied by a surgical operation, and further that in order to prevent bacterial growth the carbolic acid must be present in the proportion of I to 400, it cannot any longer be a matter of surprise that in spite of the most scrupulous antiseptic precautions, bacteria often appear under a carbolized dressing. The strength of the two solutions of carbolic acid that are in general use in surgery is i to 20 and i to 40 ; the former is used for washing and dis- infecting recent wounds, suppurating surfaces, abscess cavities, etc. It IS also used in the spray diluted to half strength with steam (i to 40). The weaker solution is used for a bath to place instruments in during opera-