110 TUBERCULOSIS. 



to the floor and walls through the dirty habits of many of the 

 patients. His experiments extended over a very considerable 

 period, and to the rooms of private patients in hospitals, in 

 Imiatic asylums, &c.; he even found bacilli in the streets and open 

 spaces in a certain proportion of cases where tuberculous patients 

 were collected together. These results have the greater value 

 from the fact that in no case did he consider his experiments 

 complete unless the dust with which he was experimenting, 

 when inoculated into animals, produced the disease." 



1 think I am justified in saying that in the opinion of the 

 highest authorities we incur a greater risk of infection from 

 phthisical patients than from any other source. August Weis- 

 mann, -in his volume on the " Germ Plasm," expresses the 

 opinion that the transmission of abnormal predispositions and 

 infection of the germ or telegony, as he prefers to call it, might 

 combine to bring about the transference of a disease from one 

 generation to another ; and he adds : — " Without desiring to 

 enroach upon the domain of pathology, I am inclined to suppose 

 that this is the case as regards ' hereditary ' tuberculosis ; there 

 is no doubt about the occurrence of a ' tuberculous habit ' — that 

 is, a certain complication of structural peculiarities which is 

 commonly connected with the disease, such as narrowness of 

 the chest, for instance." The same writer, in his volume on 

 " Heredity," quotes in a footnote an interesting case which I 

 may mention here as follows : — " A direct transmission of the 

 germs of disease through the reproductive cells has lately been 

 rendered probable in the case of tuberculosis, for the bacilli have 

 been found in tubercles in the lungs of an eight-months' foetal 

 calf, the mother being affected at the time with acute tuberculosis. 

 However, it is not impossible that infection may have arisen 

 through the placenta." Chauveau's anthrax experiments do 

 not, however, support this suggestion ; on the contrary, they 

 seem to indicate that the placenta is a natural filter which is 

 impervious to bacilli. Fraenkel, on the same subject, says — ■ 

 " Not a single indubitable case of congenital tuberculosis (estab- 

 lished before or during birth) has thus far been observed in man. 

 Johne and Malvoz have, it is true, found tubercle bacilli twice 

 in cattle in the organs of embryos." Whether then there be 

 true heredity or not, may we not assume that there is at least 



