Method adopteu and now advocated for baeleriological diagnosis of leprosy is e‘eeedingly simple. A cover-slip is smeared 111111 11 (11'011 of the serum ob tained by scraping one of the leprosy nodules. This is stained with carbol fueltsin and &colorized with sulphuric acid and methylene - blue ( G abbett's fluid). It may then be examined under the microscope.
In tuberculous lesions of the skin the bacilli are always very scanty, and usually only a few are found in the en tire cover-slip; but in lepra each micro scopic field shows enormous numbers of them. The lepra bacilli also readily stain by the simple aniline dyes, while tubercle bacilli do not. In choosing a nodule front hiell to take the specimen, it is desirable to select one in an early stage of develop ment, before much scarring has taken place. Johnston and Jamieson (Montreal -Med. Jour., Jan., '97).
The bacillus of leprosy is found in all cases, big reliable cultures have not been obtainable so far; while experimental inoculations, as previously stated, have given no results. Still, fragments of nodules introduced into a rabbit's eye by :Keleher and Ortmann caused devel opment of the disease in the animal and death. Arning. thought he had success fully inoculated a condemned criminal with matter obtained directly from a leper, but the subject was subsequently found to belong to a family (including his son and nephew) in which the dis ease existed: a fact demonstrating his proclivity to the disease.
[Arning's case seems to show that pre vious inoculation experiments in man were negative because the subjects were in sufficiently good health to antagonize the influence of the pathogenic germ.
This would suggest that a subject ren dered susceptible by the various factors capable of inducing adynamia could temporarily become liable to infection when exposed to the disease, and remain so as long as his physical debility would last. Es en under these eircumstanees the period of intathatiou could be a pro longed one. ro.: NI. SAdot-s.] The life-hktory of the bacterium leprw is an extremely complicated af fair. Animal-. are not receptive to the microbe in all its forms of development. In one phase it loses its specific stain (Ziehl-Neelsen method), not only when passed through 1 per cent. of sulphuric
aeid solution. but when water only is although its clinical character kt ics remain the sainc. llarranikow (Brit. Jour. of Perm., Alarch, 1901).
The introduction of the virus through abrasions, scarification with medicinal substances and vaccination, which gether represented almost one-fourth of the etiological factors noted by Chew in his 1034 cases, demonstrates that trans mission by inoculation is, in reality, an important factor in the pathogenesis of the disease.
The bacilli are to be found in all tis sues and liquids of diseased areas only, and particularly in the lepromata.
Lepromata found to contain large num bers of bacilli. In recent cases the bacilli are almost all present in the cellular elements. Later they multiply, forming a globular mass, and the cell becomes gradually destroyed, freeing the bacilli. With the juice of a cutaneous non-ulcer ated leproma, inoculations made on blood serum and on glycerin-agar, the tubes being kept at a temperature of OS.6° F. Cultures developed in all the tubes. Growth was arrested at 6S° to 77° F. Gianturco (Gior. del Assoc. .Napolitana di Med., etc., '91).
In general, the bacilli develop at the same time in the fixed cells of the con nective tissue and the migratory cells. The proliferation of the cells is remark ably slow, notwithstanding the great number of bacilli, and is not induced in their immediate vicinity; in the periph ery of the bacillar foci the tissue is healthy. In the cells the bacilli multiply more and more and there finally form small, brownish, globular masses, in which the bacilli are very numerous and close to one another. At this stage the softening of the leprous nodules begins, the degenerative evolution of which thus differs decidedly from the caseous degen eration of tubercle. Lie (Archiv f. Derm. u. Syph., B. 29, H. 3, '95).
The bacillus is demonstrable in the 'mettles; the macules are of the same histo-pathological structure, whatever their clinical form; through gradual stages the maeules may pass into fully developed nodules, having the same na ture as the nodules.