Tuberculosis. 407 



cow upon a sound lung, gives the latter tuberculous infection. 

 It is a matter of ever}' day experience to the veterinarian. Two 

 oxen or cows are kept in the same stable, take their food from a 

 common rack or manger, lie in the same stall, and respire nose 

 to nose. The one is, to all appearances, perfectly sound, the 

 other is in as good a condition, and is vigorous, but it coughs 

 from time to time, and its breath is foul. Soon we notice that 

 the animal that does not cough, eats with less appetite, he loses 

 flesh and soon he is unequivocally affected with the same malady 

 as the first.' The foregoing quotations show clearly that in 

 spite of the misleading teachings of Broussais and others, the 

 doctrine of contagion in tuberculosis could not be overcome, 

 and that up to the time of the remarkable experiments of Vil- 

 lemin, in 1865, it maintained its hold upon the minds of extensive 

 and careful observers. In animals, especially, the evidence was 

 so frequent and clear, animal following animal in the same stall, 

 and eating from the same infected manger, only to be infected in 

 turn, and two animals stalled together, and licking the same 

 manger with their prehensile tongues, transmitting the infection 

 with certainty the one to the other, were facts that could not pos- 

 sibly be ignored. Other cattle in the same building might escape 

 for a length of time, but the eating in common from the same 

 fatal manger, by a tuberculous and a healthy animal, quickly 

 sealed the fate of the latter. 



"Physicians, too, who were compelled to investigate the 

 causes of the extraordinary fatality from tuberculosis in the 

 armies and navies, could not shut their eyes to the fact not- 

 withstanding that they came to the task strongly prejudiced 

 through education against the acceptance of contagion. Thus, 

 Dr. Bryson, in his report to the Epidemiological Society, in i860, 

 on consumption in the several ships of the English navy on the 

 Mediterranean station, says distinctly that the disease appeared 

 to be propagated by contagion. Dr. Parkes, quoting this in his 

 Practical Hygiene, says : ' It may be inferred that pus cells were 

 largely thrown off during coughing, and floating through the 

 air, were received into the lungs of other persons. The produc- 

 tion of phthisis in animals confirms this view. The case of 

 monkeys in the zoological gardens, narrated by Dr. Arnot, is a 

 striking instance. Cows in close stables frequently die of 



