wiiicii, not being able to escape from the economy, produces 

 capillary phlebitis, od. That it is dependent on a property 

 possessed by pus of coagulatiag the blood. 4ih. That it is 

 caused by the presence of a peculiar poison, "which contaminates 

 the system." — (Benntmt.) 



The first theory is fovmded upon the assumption that pus cells 

 differ from the white globides of the blood ; "whereas in reality no 

 actual difference, either in size, structure, or beha^viour, on the 

 addition of re-agents can be detected ; therefore, if the capillaries 

 are sufficiently large to admit the passage of the "white blood 

 globule, they must consequently bo large enough to admit the 

 passage of the pus ceU. 



The second explanation "was advanced by Cruveilhier, "who. 

 on injecting mercury, ink, and other substances into the blood 

 of a living animal, foimd that abscesses were formed wherever 

 these accumulated ; hence it seemed to follow that the impaction 

 of certain substances in the tissues may induce local inflamma- 

 tions, and lead to abscesses ; but that such is not the necessary 

 restdt of admixture of pus with the blood is proved not only 

 by the previous observations, but by numerous experiments of 

 Lebert and S^dillot, in which the animals recovered. 



The third doctrine was advanced by Mr. Henry Lee, and 

 resulted from observing that when pus was mingled with 

 recently drawn blood, it coagulated more rapidly and more 

 firmly than under ordinary circumstances. 



But although this may be true as regards pus when mixed 

 with recently dra"wn blood, it doe? not follow that it induces 

 coagulation of living blood in the vessels of an animal ; and 

 numerous experiments by Lebeit, S^dillot, Bennett, and the 

 late Professor Barlow, show that such does not take place : in 

 some cases death followed, in others the aTiiprifllH lived, and the 

 pus corpuscles were dissolved. 



The fourth theory is based upon the opinion that good pus is 

 innocuous, and that the bad effects occasionally produced depend 

 on its becoming putrid, or being otherwise altered. It is now 

 generally believed that pyaemia is due to a poisonous principle 

 associated with the pus ; hence it is proposed to substitute the 

 terms ichorsemia (Vibchow), or septicaemia (Vogel), for pyaemia. 



The signs of pyaemia may not manifest themselves for some 

 time after the primary abscess has discharged itself; never in 



