HO PATHOGENIC BACTERIA. 



Raswedenow ! found that the removal of the spleen was 

 a weakening factor in the immunization of animals. 

 Kurlow 2 did not find the spleen more important than 

 other organs in overcoming infections, and Kanthack 

 found that its removal had practically no influence upon 

 the natural immunity of animals to pyocyaneus infection. 



h. Diseased conditions of the animal are almost always 

 associated with reduction of immunity because of the 

 depressed vitality. Thus, in diabetes mellitus furuncles 

 and carbuncles are very frequent, and local areas of gan- 

 grene which may be dependent upon infection are fre- 

 quent. In Flexner's 3 studies of the terminal infections it 

 was common to find that in cases of nephritis the organs 

 contained pyogenic cocci. 



Pansini and Calabreuse found that the addition of uric 

 acid to blood serum diminished its bactericidal activity. 

 Glucose exerts a similar effect. Platania observed that 

 the administration of phloridzin by exciting glycosuria 

 destroyed immunity. 



i. Mixed Infections. — Clinically it is a familiar fact that 

 in typhoid fever and in influenza pneumonia is apt to 

 occur, both from the activity of the micro-organisms of 

 the primary infection and from others frequently harm- 

 less in health whose activities depend upon the general 

 diminution of vitality. Probably for the same reason the 

 occurrence of an acute infectious process like influenza 

 commonly causes rapid spread of an existing chronic 

 affection such as tuberculosis. 



Roger found that when animals immune to malignant 

 edema were simultaneously inoculated with it and 1-2 

 c.c. of a bouillon culture of Bacillus prodigiosus, they 

 would succumb to the malignant edema. Giarre observed 

 that if an adult guinea-pig, which is refractory to infec- 

 tion by the pneumococcus, were subsequently inoculated 

 with diphtheria, it readily died of pneumococcus septi- 



1 Zeitschrift fur Hygiene, 1896, xxi., 3. 



4 Archiv filr Hygiene, 1889, lx., p. 450. 



* Journal of Experimental Medicine, 1896, vol. i., No. 3. 



