On the bubonic plague / by Alex. R. Ferguson.

  • Ferguson, Alexander Robert, 1870-1920.
Date:
1897-1898
Catalogue details

Licence: Public Domain Mark

Credit: On the bubonic plague / by Alex. R. Ferguson. Source: Wellcome Collection.

Provider: This material has been provided by The University of Glasgow Library. The original may be consulted at The University of Glasgow Library.

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    of the other disease-producing bacilli, that of plague may be spoken of as a short, thick bacillus. An approximate idea of its dimensions may be conveyed by the statement that 10,000 of them placed end to end, or 25,000 side by side, are required to cover a linear inch. The bacillus has distinctly rounded ends, and stains well by any of the simple aniline dyes in common use, e.g., fuchsin or gentian violet, A fact to be noted in stained preparations of the bacillus is that the terminal portions of the rod are stained much more deeply than the central zone—a characteristic to which the term polar staining is applied. Further, the existence of a capsule of quite appreciable breadth, in the form of a faintly-stained homogeneous envelope surround- ing the deeply-stained poles of the bacillus, can usually be deter- mined. As in the case of other encapsuled organisms, however, the bacillus loses this structure when grown under artificial con- ditions in the laboratory. The bacillus has no inherent power of motility, and careful examination has failed to reveal the existence of any mechanism, i.e., flagella, by which locomotion might be possible. The existence of spores also has not been demonstrated. In common with the other members of the large class of organisms to which it belongs, its multiplication is caused by fission—a slight increase in length—and the appearance of transverse septa or divisions characterising the bacilli during the process. Each of these subdivisions afterwards becomes free as a young bacillus, capable of undergoing the same change. This process, even under artificial conditions, proceeds with incalculable rapidity. Several of the characteristic features of the bacillus, to which attention has just been directed, are well illustrated by this micro-photograph [photograph handed round], taken by Dr. Bitter, of Cairo, and by the lantern slide prepared by Dr. Arch. Young in the Pathological Institute of the Western Infirmary. [Slide shown on screen.] The growth of the bacillus takes place readily on the usual nutritive media of the bacteriological laboratory, especially on ordinary peptone agar. On the latter medium, after 24 hours' incubation at 100° F., the growth is apparent as a greyish-white, moist-looking film, not unlike that of the bacillus of typhoid fever recently shown at a meeting of this Society, but difi'ering somewhat from this in the fact that the separate colonies of the bacillus are dotted over the surface of the medium in the form of minute round plaques, which only become confluent towards the lower portion of the tube. [Culture shown.]