104 



Dr. Klein on the 



[Feb. 14, 



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) prodnces the disease. The experiment was always attended 

 with success, if an abrasion existed in the mucous membrane of the 

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

 to be introduced into the mouth while 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 acquainted, yet, 

 with the fact that in many animals the disease is of so mild a form 

 that it can hardly be recognized in the living. I did not make any 

 post-mortem examination 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 per fauces et cesophagum. In both these 

 instances the animals became diseased and their intestines were most 

 conspicuously affected. 



From the last three series of experiments we may conclude that 

 the principal mode by which contagion of pneumo-enteritis is carried 

 out, is through the instrumentality of the air and the food. 



6. This series comprises experiments to prove that the virus can be 

 cultivated artificially, i.e., outside the body of an animal ; in the case 

 of splenic fever it has been successfully done by Dr. Koch. 



The experiments are seven in number, (&), two refer to cultivations 

 started with fluid peritoneal exudation ; (5), in the five others the 

 virus had been obtained by cultivation of dried lymph of the peri- 

 toneum of an animal suffering from the disease. 



(a.) The cultivation of the virus for the first two cases was carried 

 out thus : 



Fluid peritoneal exudation of a diseased animal had been collected 

 and sealed up on November 6, in a capillary glass tube. On the 

 following day there was present a small clot due to coagulation. A 

 minute speck of this clot was removed with the point of a clean 

 needle, and with it was inoculated a drop of fresh aqueous humour of 

 a healthy rabbit. This drop had been placed on a thin covering-glass, 

 which, after the inoculation, is inverted over a small " cell," made by 

 fixing a glass-ring* on an ordinary glass-slide. The covering-glass is 

 fastened on the glass-ring by means of a thin layer of pure olive-oil. 



* The glass ring I used is 0'5 to 2 millimetres high, about 2 mm. thick, and 

 about ] 8 mm. wide. If the preparation is to be observed on the hot-stage of the 

 microscope, instead of the ordinary glass-slide, one of only 05 mm. thickness is chosen 

 in order to bring the preparation more rapidly up to the desired temperature. 



