68 PATHOGENIC BACTERIA. 



from one culture-medium to another, this being proved 

 by Haff kine, who in experimenting with aqueous humor 

 has shown that its germicidal actions are largely imagin- 

 ary, and due to the dispersion of the organisms in a large 

 amount of watery liquid. When the micro-organisms 

 are introduced into it in such a manner as to remain 

 together, they grow well. If the tube be shaken, so as 

 to distribute them, they die. Again, Adami has shown 

 that when blood is shed there is almost always a pro- 

 nounced destruction of corpuscles, and suggests that the 

 antibiotic property of the shed blood may be due to 

 solution of the nucleins formerly in the substance of the 

 leucocytes. Jetter endeavored to prove the germicidal 

 action of the serum to be due to certain salts which it 

 contained. His experiments, which consisted in observ- 

 ing the action of solutions of various salts in mixtures 

 of water, glycerin, and gelatin, were justly condemned 

 by Buchner on the ground that such mixtures, though 

 they might contain constituents of blood-serum, were far 

 from approximating the normal serum in composition. 



Wyssokowitsch, however, surely argued against hu- 

 moral germicide when he showed that the spores of Ba- 

 cillus subtilis could reside in the spleen for three months 

 uninjured. 



In supporting their theory the humoralists experimented 

 by placing beneath the skin micro-organisms enclosed in 

 little bags of pith, collodium, etc. These bags allowed 

 the fluids of the body free access to the bacteria, but 

 would shut out the phagocytes. By these means Hiippe 

 and Iviibarsch have repeatedly seen the bacteria grow 

 well, while the attempts of Baumgarten have failed. 

 Such experiments are by no means conclusive, for we 

 should remember that the operation necessary and the 

 presence of the foreign body in which the bacteria are 

 encased produce an inflammatory transudate which may 

 have properties very different* from those of the normal 

 juices. 



How much of the immunity which animals enjoy de- 



