Surgery : its theory and practice / by William Johnson Walsham.

  • William Walsham
Date:
1897
Catalogue details

Licence: Public Domain Mark

Credit: Surgery : its theory and practice / by William Johnson Walsham. Source: Wellcome Collection.

    27/898 page 11
    be carried from one point to another, as, in phthisis, from the lungs to the larynx or intestine. Diseased tissues jDroduced by one kind of bacteria may be secondarily infected by another kind; thus the lung affected by croupous pneumonia may sometimes be secondarily infected by tubercle bacilli, and the tuberculous tissue by the micrococci of suppuration. The tissues may be protected against the development of micro-organisms by the normal resistance of the body to the process of disease {natural mimtmiU/), or by an acquired resist- ance {('^c<][iiAi^d immunity). Of acquired immunity there have been several explanations offered. Thus it is believed that it may be brought about (a) by the exhaustion of the soil, i.e., the occurrence of a disease once is thought to protect against a second attack through the first disease having exhausted the supply of the material which is necessary for the development of the micro-organism of that particular disease; [h] by the chemical p^ducts formed pari passu with the bacteria acting as a poison to the bacteria and preventing their development; (c) by certain chemical constituents in the blood-serum which destroy the bacteria; {d) by the leucocytes collecting around the bacteria, and so killing them; and [e) by the leucocytes and tissue-cells absorbing and destroying the bacteria [phagocytosis). Metchnikoff and his pupils hold that the leucocytes are endued with a peculiar power of pro- tecting the organism, that they are attracted by the bacteria or their j)roducts ichemiotaxis), gather round them, absorb them into their substance, and so digest or destroy them. Other pathologists hold that the bacteria are first killed or weakened by the chemical products generated by the bacteria or by the disinfecting con- stituents in the blood-serum, and then only when dead or disabled are absorbed by the leucocytes and tissue-cells, and along with the devitalized tissues are in this way got rid of. The process of immunity cannot be discussed in this work, but it may be assumed with safety that immunity must depend on the power of the tissues, their cells and juices, to destroy the bacterial growth, and also to neutralize the bacterial poisons; i.e., with acquired immunity the body acquires both germicidal and antitoxic properties. An immunity may be produced by gradual administration of increasing doses of toxins or by a single administration of so-called antitoxins, bodies derived from the serum of a highly immunized animal. Antitoxins are now used in surgical practice in tetanus, erysij^elas and pyo- genic lesions, such as suppuration, gangrenous cellulitis, septicfX3mia and pyaemia, and also in diphtheria. It is therefore necessary to understand the principles of the antitoxic treatment, but this dis- cussion finds its most suitable place in the chapter on Tetanus. Amongst the pathogenic bacteria of surgical interest may be mentioned : the anthrax bacillus, the cause of malignant pustule ;
    digitised image 1
    digitised image 2
    digitised image 3