U ARTIFICIAL PRODUCTION OF TUBERCLE. 



older date, in which, after repeated injection of pus into the veins, he found 

 what he considered tuhercles in the lungs and liver. M. Lebert argues that 

 the effect of all these experiments was to produce tubercle ; but I think that 

 a striking difference exists between the results of these experiments and the 

 effects of inoculation, and the difference I notice is this, that there is no 

 evidence to be found of a constitutional affection having been produced in any 

 of these cases whose details he has given at length. It is on the constitutional 

 affection, and the multiple implication of many organs, that I lay especial 

 stress in reasoning on the proof of the tubercular affection produced by 

 inoculation. Multiple affections did not exist in any of this class of M. 

 Lebert's experiments, with the exception that, in the two dogs into whose 

 veins pus was injected, some granulations, like tubercle, were found in the 

 lungs and liver ; but the authenticity of the tuberculous nature of these was 

 not decisively established by microscopic proof. Perhaps, also, I may add 

 that, in the innumerable experiments of this nature that have been conducted 

 with a view to the illustration of the nature of pyaemia, the production of 

 tubercles — i.e., of grey granulations — has never been noticed, or, if at all, 

 they have not been observed with a frequency sufficient to establish the 

 possibility of this method of their origin. 



The experiments with charcoal and mercury appear to me to be equally 

 inconclusive. Out of ten experiments of this nature, in four only was there 

 a production of local granulations in the lungs, which originated in thickening 

 around the obstructed vessel, but sometimes extended beyond this; in one 

 only of these there were found a few granulations in adhesions of the pleura, 

 which did not contain mercury. In none, however, was there any implication 

 of other organs ; and, in this respect, these cases present so marked a differ- 

 ence from the effects of inoculation, that I cannot but believe that in them 

 tuberculosis was not produced as a constitutional disease. Local thickening 

 around an obstructed vessel is not necessarily tubercle ; and the same criticism 

 is, I think, applicable to the introduction of mercury, or of other irritating 

 substances into the bronchi. The effect has been a local inflammation ; but 

 not either local tubercle or a general constitutional affection. Another 

 important difference to be noticed in these granulations is the fact recorded 

 by M. Lebert, that the vessels around them were not obstructed in the manner 

 observed in tubercle. 



As to the manner in which septic substances act, there is room for a wide 

 diversity of opinion. One effect seems to be established, if the tubercular 

 character of the granulations under the skin be admitted — viz., that a local 

 irritant is capable of producing local tubercle; and the suspicion naturally 



