Text book of comparative general pathology for practitioners and students of veterinary medicine / by Th. Kitt; authorized translation by William W. Cadbury ; edited with notes and additional illustrations by Allen J. Smith.

  • Kitt, Th. (Theodor), 1858-1941.
Date:
1906
Catalogue details

Licence: In copyright

Credit: Text book of comparative general pathology for practitioners and students of veterinary medicine / by Th. Kitt; authorized translation by William W. Cadbury ; edited with notes and additional illustrations by Allen J. Smith. Source: Wellcome Collection.

    39/504 (page 19)
    Protective Substances. *9 school attribute solely to non-intelligent attraction from without are really due to an inherent power of a low intelligent char- acter of the organisms showing them. These latter would attribute even to individual cells as the phagocytes, a low but actual volitional power to either originate or refrain from efforts to approach the foreign particles referred to.] The proto- plasm of the phagocytes apparently can secrete digestive juices [there is reason to think that certain granules seen in leucocytes are of the nature of ferments], through the action of which they are able to assimilate nutritive matter and dissolve foreign bodies. In this latter manner, in part at least, it is possible that the virus of infectious diseases may be removed from the tissues. Nuttall first pointed out that in the blood plasma of healthy ani- mals there exist certain substances which are capable of dissolv- ing the body matter of bacteria, and of thus destroying them. These substances, called alexins by Büchner, and complements by Ehrlich (by others addiments and cytoses), are products of the cells, which are either given off by the living cells (Büchner) or are set free by cellular destruction (Metschnikoff) ; and are found in varying amount in the circulating blood of the indi- vidual animals. An excellent example of these substances is seen in the effect, discovered by Behring, of the serum of white rats upon the anthrax bacillus. If hundreds of thousands of anthrax germs are placed in some serum from a white rat (at 3y° C.) it will be noticed after ten or fifteen minutes that the bacilli liave become swollen and degenerated (granulär), and after from four to seven hours that they have completely dis- appeared. Canine or ovine serum does not possess this power, but should a few drops of rats’ serum be added to sheep serum the bactericidal action will immediately appear. The serum of the horse also has a strong bactericidal power. It must be clear that the cause of natural immunity cannot be attributed to the bactericidal action of the serum alone, for both rats and horses are susceptible to anthrax; it must be thought of, as already men- tioned, as dependent in part upon the lack of affinitv of the living cells for the toxines of the infection, and in part upon their phagocvtic power. Just as among different animal species and individuals there may be some one kind which is more highly resistant to poisons than the rest, so there may be met others exhibiting an excessive susceptib'ility to such