the Cultivation of the Bacillus of Tubercle. 



199 



It will be seen that in many of the tabes a free growth was 

 observed as early as the end of the first fortnight. 



Out of the total number in this series of 37, in thirty-six instances 

 there was free growth on the medium employed, on both kinds of 

 paper, and all kinds of condensed fluid. Eleven of them were grown 

 at a temperature of about 20° C. In only one instance was there 

 complete failure (vapour from healthy breath). 



Most of these tubes have been left intact, in order that they may be 

 inspected; but six of them were removed, stained, and examined 

 microscopically, in order to determine whether they were true 

 cultures ; this they proved to be. 



Two of the cultures, after two months' growth, were sent away to 

 be inoculated into guinea-pig's, but both they and the original culture 

 were found to be non-virulent.* 



Microscopic Examination. 



Nearly all the earlier cultures, in which there appeared to have 

 been any growth, were submitted to microscopical examination. In 

 all the specimens in which this examination did not show distinct 

 signs of growth the result was put down as "nil," even though a 

 small number of bacilli might have been found. These few bacilli 

 might have come from the inoculation. It was not difficult to recog- 

 nise the abundant growth of a true cultivation. 



These examinations, however, gave remarkable results in a large 

 number of the specimens grown upon paper. Many of the bacilli 

 were gigantic in size, and a considerable number of them showed 

 distinct branching. Others were knobbed at one end or at both 

 ends, when they looked like miniature "life preservers." In many 

 of the specimens the culture seemed to have penetrated into the sub- 

 stance of the paper. 



The bearing of these researches upon the subject of the prophyl- 

 axis against tuberculosis seems to be of some importance. 



They prove that any one of the various organically charged vapours, 

 whether coming from healthy or from diseased lungs, from the air of 

 cellars, or from comparatively pure ground, forms an excellent culti- 

 vating medium for the bacillus of tubercle when kept away from the 

 disinfecting influence of air and light. 



This power of promoting its growth is particularly manifest when 

 the supporting substance is common wall-paper, though it is quite 

 apparent when very pure filter-paper is used. 



It is further proved that, on these substances, the growth of the 

 bacillus may take place at the ordinary temperatures of dwelling- 



* A further research, with cultures of the bacillus of undoubted virulence, has 

 now been undertaken. 



