52 



uncertain means of excluding organisms is highly sig- 

 nificant of the relations between the two. 



That form of septic infection known as pyaemia is dis- 

 tinguished by abscess formation in external organs from 

 which fact alone it is evident that bacteria must play an 

 essential part in the disease. Yet there is abundant 

 direct evidence to the same effect : these metastatic 

 abscesses always contain bacteria ; these organisms exist 

 not simply in the pus and in the inflamed tissue constitu- 

 ting the abscess wall, but also in a zone external to the 

 territory already involved in inflammation ; the invasion 

 by organisms may therefore apparently precede the in- 

 flammatory re-action ; further, incipient inflammation 

 and suppuration are observed around minute emboli 

 consisting of micrococci ; and finally, although throm- 

 bosis and embolism occur in various pathological condi- 

 tions, no suppuration occurs in such fibrinous masses, nor 

 in the adjacent tissues, unless bacteria also be present. 

 These anatomical facts are quite in accord with the inde- 

 pendent evidence of experimental research. Panum 

 found that the injection into the jugular vein of minute 

 balls of wax or mercury caused the formation of emboli 

 in the lungs, but that no suppuration occurred around 

 them ; he then combined embolic formation with putrid 

 infection by the injection of putrid fluids just before or 

 just after the formation of efhiboli, through the incorpora- 

 tion of wax, mercury fibrin or cheese particles ; and varied 

 the experiment by the artificial induction of superficial 

 phlegmonous inflammation, in the course of which the 

 formation of emboli was secured by injections as before. 

 The result was always the production of simple, non-sup 

 purating embolic masses ; the substitution of fresh blood- 

 clots for the wax, mercury, etc., whereby a closer approxi- 

 mation to the natural embolic process was secured, gave 

 the same results. Emboli caused by intra-venous injec- 

 tion of particles of putrid flesh, however, were promptly 

 followed by suppuration. Other experimental researches 

 into the formation of embolic (metastatic) abscesses 

 by Virchow, Billroth, Weber, Waldeyer, Cohnheim 



