DOCTRINE OF CONTAGIUM ViVUBI. 173 



Six successful inoculations with fluid peritoneal exudation. 



There is no difference of activity to be noticed between 

 fresh exudation and one that had been kept sealed up in a 

 capillary tute for several weeks. 



Solid lymph obtained from the peritoneal cavity of dis- 

 eased animals, having been dried at a temperature of about 

 38° C, proves very active. 



3. Experiments showing that parts of the diseased lung, 

 ulcerated intestine, and also diseased spleen, contain the 

 virus in an active state. Diseased parts of lung or intes- 

 tine, that were dried at a temperature of about 38° C, 

 retain their virulence unaltered. 



In all cases of pneumo-enteritis the trachea as well as the 

 bronchi contain frothy blood-containing mucous matter, 

 possessed of infectious property. It must therefore be 

 supposed that the breath of a diseased animal is charged 

 with the poison. On account of the diseased state of the 

 intestine also the dung is to be regarded as infectious. 



4. Experiments showing that infection is produced by co- 

 habitation with a diseased animal, or by keeping healthy 

 animals in a place whence a diseased animal had been 

 removed. 



5. Several experiments were made to see whether feeding 

 healthy animals on matter obtained from the diseased organs 

 (intestinal ulcers especially) produces the disease. The 

 experiment was always attended with success if a lesion, 

 i.e., abrasion existed in the mucous membrane of the mouth 

 or pharynx ; this was usually the case when the matter had 

 to be introduced into tlie mouth w^hile the animal was being 

 held by assistants. 



There were, however, two cases which appear to prove 

 that the disease cannot be produced by simple feeding. 



This was, unfortunately, at a time when I was not 

 yet acquainted with the fact that in many animals the 

 disease is of so mild a form that it can hardly be recognised 

 in the living. I have not made any post-mortem examina- 

 tion of those two animals. 



But since then I have made two other experiments, in 

 which the virus was brought directly into the stomach by 

 means of an india-rubber tube introduced joeryawces et ceso- 

 pluujum. In both these instances ^the animals became dis- 

 eased and their intestines were most conspicuously affected. 



From the last three series of experiments, we may con- 

 clude that the principal mode by which contagion of 

 pneumo-enteritis is carried out is through the instrumen 

 tality of the air and the food. 



VOL. XVIIl. NEW SER. M 



