HAMILTON SCIENTIFIC ASSOCIATION 68 



in I^ondoii, contains the following : 



"Moreover there are external causes (of phthisis) as contagion, 

 which is the chiefest ; for this disease is so infectious that we may 

 observe women to be infected by their husbands, and men by their 

 wives, and all their children to die of the same, not only from the 

 infection of their parent's seed, but from the company of him that was 

 first affected, nd this contagion is more easily communicated to them 

 that are of kin. Wherefore, it is not safe for a brother or sister to enter 

 into the chamber for the miasmatic or vapors infective, which come 

 from the lungs and infect the whole air of the chamber, and being 

 drawn in by others (especially if they are in any way disposed to the 

 same disease), be;^et the same disease in their lungs." 



Villemin, in 1865. by the experiments of Buhl in 1857, 

 and by other facts, among them the resemblance of tubercle to 

 other diseases, was led to conclude it was infective and to 

 perform similar experiments to that of Klenke in 1843, who 

 had injected tubercular matter into the jugular vein of a 

 rabbit, and six months later found tuberculosis in its liver 

 and lungs. 



He inoculated rabbits and other animals with caseous 

 material, and in this way succeeded in transmitting the disease 

 from animal to animal and from man to animal, and that not 

 only with caseous material from the lung, but also with similar 

 material derived from other .sources e. g., b'-oken down 

 lymphatic glands, thus convincing himself that tuberculosis 

 was an infectious disea.se, and that caseous material was 

 tubercular in as much as it was the vehicle for carrying the 

 infection. So numerous were the investigators and so 

 uniform the results of their investigations along not identical, 

 but similar lines, that To7issm?it announced tuberculosis as 

 one of the most communicable of diseases. 



So complete and exhaustive were the series of experiments 

 that when certain observers objected on the ground that other 

 substances injected produced lesions simulating tuberculosis, 

 it was shown that material from such lesions was incapable of 

 exciting the disease again, or in other words, such tuberculosis 

 was non-communicable. Also, it was proven that the caseous 

 matter of supposed tubercle was infective by inhalation and 

 feeding as well as by inoculation. In fact, the causative 



