262 BACTERIA IN INFECTIOUS DISEASES. 



fluid ; and that the bacteria of putrefaction were 

 introduced from without, is likewise altogether 

 probable, inasmuch as we have no account of 

 special precautions having been taken to exclude 

 these ubiquitous organisms, and in view of what 

 has just been said as to their absence from the 

 blood and tissues of healthy animals. 



Panum found that a putrid solution boiled for 

 eleven hours still produces symptoms of putrid 

 poisoning, and that when such a fluid is evapo- 

 rated to dryness, and the residue extracted, first 

 with alcohol and then with water, the alcoholic 

 extract does not produce the symptoms, while the 

 watery extract does. There can be little doubt 

 that the watery extract injected contained living 

 bacterial germs, not from the putrid fluid operated 

 upon, but in the water used for making the ex- 

 tract (cold), in the syringe used for injecting it, or 

 possibly carried from the surface of the body of 

 the animal by the point of the needle used in 

 making the injection. According to this explana- 

 tion, germs introduced in the way indicated would 

 multiply and produce putrefactive decomposition 

 because the vitality of the tissues was reduced or 

 destroyed by the chemical poison; whereas if intro- 

 duced alone, even in vastly greater numbers, they 

 could do no harm, owing to the vital resistance of 

 the tissues. The writer has frequently injected 

 culture-fluids containing the bacteria of putrefac- 

 tion beneath the skin of a rabbit, without serious 

 result. But the smallest drop of fluid containing 



