Microhic Diseases Individually Considered. 165 



a violent inflammatory reaction ; the region becomes 

 hot, painful and tumefied ; the engorgement rapidly 

 extends to neighboring regions and becomes crepitant, 

 emphysematous, in consequence of the internal forma- 

 tion of gas (carbonic acid, hydrogen, carburetted and 

 sulfuretted hydrogen, etc.). Soon the central part 

 becomes insensible and presents all the symptoms of 

 mortification. Gaseous infiltration may be wanting 

 when death supervenes too quickly. The latter ar- 

 rives at the end of twelve to fifteen hours in the 

 guinea pig. The autopsy shows great detachment of 

 the tissues, their infiltration with a sanious fluid and 

 fetid gases, gangrenous patches of greater or less ex- 

 tent, and often great extension in all directions of the 

 original inflammation. 



Intra-vascular inoculation may be followed by the 

 same changes when a solution of continuity of the 

 circulatory apparatus allows the germs to penetrate 

 into the connective tissue and multiply there, shel- 

 tered from the oxygen of the blood. 



The disease is transmissible from the mother to the 

 foetus. . 



Etiology and pathogeny. — The septic vibrio is almost 

 every-where present — in the soil, the dust of hay, in 

 most putrid substances and also in the digestive canal 

 of healthy animals. But in this last situation it is 

 iuofiensive; after death, however, the oxygen be- 

 coming deficient in the tissues which during life op- 

 pose themselves to its penetration, it invades these 

 tissues, multiplies there, and in this way we are able 

 to establish its presence in the blood (first of the 

 portal vein, then throughout the economy) and on 

 the surface of the abdominal viscera. Similarly, 



