On the infectivity of the blood and other fluids in some forms of septic disease, and the reputed occurrence therein of an increase of virulence in successive inoculations / by G.F. Dowdeswell ; communicated by M. Foster.

  • Dowdeswell, G.F.
Date:
[1883]
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Licence: Public Domain Mark

Credit: On the infectivity of the blood and other fluids in some forms of septic disease, and the reputed occurrence therein of an increase of virulence in successive inoculations / by G.F. Dowdeswell ; communicated by M. Foster. 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.

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    involved has recently acquired fresh importance in reference to the relations of the lower fungi to disease, and the occurrence in them, as lately asserted by Dr. Hans Buchner,* P. Grawitz,f and others, of a transmutation of physiological species under altered conditions. In observations recently made upon septichsemia in the mouse, J and other experiments, I obtained results which seemed to me to negative the occurrence of any progressive increase of virulence in the blood in successive inoculations, or of any transformation, physio- logical or morphological, in the organisms present, an opinion which was confirmed and the question discussed by Dr. R. Koch,§ in a work recently published. In the case of the mouse, from the small size of the animal and the blood in most cases being more or less coagulated when examined, it was not easy to obtain accurately measured minute fractional quan- tities, by successive dilutions, for the purposes of experiment; for which reason, and also as it was with reference chiefly to the blood of the rabbit that the statements had originally been made, I selected that animal for the investigation of this question by the following methods. To originate infection in the same manner as in other experiments on the same subject, putrid blood was used, generally that of the ox; but I have also employed that of the pig, sheep, &c., or of the rabbit itself, all with similar results. Of such blood, diluted with an equal bulk of normal saline solution and strained, a few drops were injected into the subcutaneous tissue of the back or abdomen, by means of a Pravaz syringe. In the subsequent high dilutions five or ten drops were generally injected, and these comparatively large quantities were employed in order that there might be less chance of error in the quantity of blood actually received by the animal, than would be the case with smaller injections, e.g., of one drop, as used by Davaine; though his method probably reduces the liability to formation of abscesses at the site of injection, with the accompanying failure of infection, which, however, only occurred to me in a few instances. In these experiments, where it was requisite to guard against the possi- bility of accidental infection or contamination, instead of a syringe I used a glass tube drawn out to a fine point; this is readily inserted under the skin of the back in young animals, still more so under that of the abdomen. When the quantity to be injected requires to bo accurately measured, it is easy once for all to calibrate the tubing by the usual method, and extemporise a graduated pipette, containing a given quantity, between two marks of the file. * “ Sitzber. k. B. Akad. Wiss. zu Miincken,” 1880. t Virchow, “ Archiv.,” Bd. 81, H. 2, s. 355. t “Qrly. Journ. Micros. Sc.,” N.S., No. 85, January, 1882, pp. 66-75. § “ Untersuch. ii. d. AEtiol. d. Wundinfectionskrankkeiten, &c.,” Leipzig, 1878.