An American text-book of surgery : for practitioners and students / By Phineas S. Conner, M.D., Frederic S. Dennis, M.D., William W. Keen, M.D., Charles B. Nancrede, M.D., Roswell Park, M.D., Lewis S. Pilcher, M.D., Nicholas Senn, M.D., Francis J. Shepherd, M.D., Lewis A. Stimson, M.D., J. Collins Warren, M.D., and J. William White, M.D. Ed. by William W. Keen and J. William White.

  • William Williams Keen
Date:
1899
Catalogue details

Licence: Public Domain Mark

Credit: An American text-book of surgery : for practitioners and students / By Phineas S. Conner, M.D., Frederic S. Dennis, M.D., William W. Keen, M.D., Charles B. Nancrede, M.D., Roswell Park, M.D., Lewis S. Pilcher, M.D., Nicholas Senn, M.D., Francis J. Shepherd, M.D., Lewis A. Stimson, M.D., J. Collins Warren, M.D., and J. William White, M.D. Ed. by William W. Keen and J. William White. Source: Wellcome Collection.

Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.

    118/1392 (page 82)
    Tlie threat difficulty wliich lies in the way of further lulvance i.s the incom- pleteness of our knowledge of the toxins and antitoxins with which we have to deal. A short sketch of the general suhject will give the student some idea of the j)rohlenis involved. The starting-point lies in the fact that certain animals are found to he immune to the attacks of bacteria which are specially virulent to other ani- mals. Thus rats, dogs, and the carnivora generally are not harmed by anthrax bacilli, while mice, cattle, guinea-pigs, and rabbits are vet}' susceptible. Next, it was observed that all fresh blood had some bactericidal pi'operties which it lost if allowed to stand or was heated to .')0° C. (131° F.). The blood of different animals varied much in its germicidal powers. The potent part was found to lie in the serum, and not in the cellular elements of the blood. Still further study showed that though a given serum or blood might have but little bactericidal |)Ower, yet it might be able to modify the toxin in virtue of which the bacteria exerted their disease-producing power. It was argued that if the bloo<l-serum of immune animals was capable of protecting the immune aninial. that this protection could be conferred upon susceptible animals by the introduction of the serum into their circulation. But it was found that neither artificial immunity nor cures could be brought about in this way in any number of cases, but that artificial immunity could frequently be produced by the continued introduction of at first very small followed bv orraduallv increasing doses of the pathogenic bacteria or of their toxic products. The natural immunity is characterized for the most part by the presence in the blood-serum of alexins/ which have bactericidal properties, produce coagulation, and destroy blood-corpuscles; and are unstable and destroyed by heat (o0°-5o° C.; 122°-131° F.) and sunlight. The artificial immunity is induced by the development of antitoxins, which are neither bactericidal nor globucidal. are more resistant to sunlight, and are only destroyed by a temperature of 70°-s0° C. (158°-176° F.j. As to the mode of action of the antitoxins produced, there is still dispute. Their pro- duction is doubtless due to increased cell-activity called into play by the action of the bacteria, or their toxins, upon the tissues of the organism into which they have been introduced. Whether these plasma-cells and leucocytes, which are called into being by the toxin, secrete a distinct antitoxin, or a 'fi'rmi-nt which is capable of setting up cell-activity when introduced into the tissues of a person or animal suffering from the same bacterial disease, is as yet unde- cided, though the weight of authority inclines to the former supposition. The practical working is the same in either case. It is attempted to secure a blood-serum from an animal which Avill produce a large amount of serum of strong antitoxic potency. Whenever it can be employed, horse-serum pre- sents the most desired qualifications, as the blood can be easily obtained in large amounts, and when allowe<l to stand a clear amber-colored serum sepa- rates from the clot, and the simplicity of technique renders it easy to secure sterility. Tetanus.—The poison of tetanus is extremely virulent, as shown by the fact tliat a dose of 0.00005 c.c. of toxin will kill a jzuinea-pig, Avcighing 550 grams, in four days with tyj)ical symptoms. This will serve to ex])lain the seriousness of even smnll wounds thus infected, and the small number of bacilli usually present in them. Immunity to the poison of the tetanus bacillus can be gradually induced ' An alexin acts by destroying the bacteria; an antitoxin, by neutralizing their toxic product.