Researches on tuberculosis : the Weber-Parkes Prize essay.

  • Ransome, Arthur, 1834-1922.
Date:
1898
Catalogue details

Licence: Public Domain Mark

Credit: Researches on tuberculosis : the Weber-Parkes Prize essay. Source: Wellcome Collection.

Provider: This material has been provided by the Harvey Cushing/John Hay Whitney Medical Library at Yale University, through the Medical Heritage Library. The original may be consulted at the Harvey Cushing/John Hay Whitney Medical Library at Yale University.

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    me in the work ; and we made an attempt to determine how short a period of exposure to light and air would suffice to destroy the virulent action of the microbe. The experiments were made both with pure cultivations and with dried sputum, the latter in some cases scraped and reduced to dust. Guinea-pigs were used for the inoculations. The details of the preliminary experiments and their results are given in a Report made to the British Medical Association, and published in the ' British Medical Journal,' February 16, 1895. In the first place it was necessary to test the virulence of the cultivations about to be used, and to compare these tests with the results of inoculations made with non-tuberculous material. These experiments are detailed in Table II. of that Report. Others relating to the avian bacillus are given in Table III. In all these inoculations there is absolutely no instance of failure ; and the amount of tuberculosis produced was, in all cases but one, pro- portional to the number of days the animals were kept alive after inoculation. On the other hand, no trace of tubercle followed any of the inoculations with non-tuberculous material. The effect of ' drying' was next tried upon the virulence of both pure cultivations and of tuberculous sputum. This simply means that the specimens were kept in the dark, in closed capsules, so that but little air had access to them. It was thus found that moderate desiccation slightly retards the first manifestations of tuberculosis ; prolonged drying ultimately kills the bacillus. After 130 days' drying, the virulence, in three experiments, was altogether destroyed. These results are detailed in Table IV. of the Report. In Table V. similar results are shown from tuberculous sputum ; but, in this case, after 54 days' keeping sputum was found to be still very virulent. For our immediate purpose we must now pass on to the re- sults contained in the following Tables, XII., XIII., and XIV (pp. 20, 21). These tables are intended to show the influence of free ventila- tion and of sunshine, or of both combined, both upon pure cultivations and upon tuberculous sputum. So far as the experiments go (detailed in Table XII., ' Simple Ventilation in the Dark'), they show that ventilation diminishes, but does not necessarily destroy, virulence. In one instance (No. 170) in which the sputum was not broken up, after three days' exposure to a good current of air, it gave tubercle to a guinea-pig; and in