74 



sputum, but by no other sputum, nor even by this after 

 boiling or treatment with corrosive sublimate or nitration 

 through carbolized tow ; that general tuberculosis with- 

 out caseous exudate follows the introduction of a minute 

 tuberculous particle, but of nothing else, into the eye ; 

 until it shall be possible to offer another explanation, we 

 must admit that there is a something peculiar to tubercu- 

 losis and not common to all tubercles. To assert with 

 Niemeyer that the disease originates de novo in a cheesy 

 mass, is to assume that because there is no intentional 

 or conscious introduction of an infectious agent therefore 

 none occurs. Surely no surgeon ever intentionally or 

 consciously introduced pyaemic matter into a wound ; 

 yet infectious pyaemia was formerly the scourge of hos- 

 pitals. Septicaemia, erysipelas, diphtheria, and pyaemia 

 are none the less infectious because there is especially 

 in the so-called spontaneous cases of each no discover- 

 able possibility of contact with previous subjects of the 

 same disease. Infection, in other word-s, does not neces- 

 sarily imply contagion. No man becomes syphilitic un- 

 less there be incorporated into his body material from an 

 individual previously syphilitic ; no man acquires scabies 

 without contact with a sufferer from itch ; but pyaemia, 

 erysipelas, diphtheria, anthrax, and tuberculosis are ac- 

 quired not only by transfer from subjects of the respec- 

 tive diseases, but also without such transfer. The puru- 

 lent secretions of a wound are doubtless favorable soil 

 for the retention and propagation of pyaemic or erysipe- 

 latous virus ; the catarrhal products in the throat for the 

 origin of diphtheritic infection ; the cheesy products of a 

 bronchitis or of mechanical irritation for the location and 

 propagation of the tuberculous infective agent ; but none 

 of these are necessary. Pyaemia, erysipelas, diphtheria, 

 anthrax, tuberculosis occur not only by demonstrable con- 

 tagion, not only after a simple wound without demon- 

 strable contagion, but also without either demonstrable 

 contagion or even a simple wound i.e., spontaneously. 



Yet in the face of this perfect analogy with other in- 

 fectious diseases, in the face of the experimental proof 



