SWINE PLAGUE. 315 



collected and scaled up on November Gtli, in a capillary class 

 tube. On the following day there was present a small clot due 

 to coagulation. A minute sj^eck of this clot was removed with 

 the point of a clean needle, and with it was inoculated a drop of 

 fresh aqueous humor of a healthy rabbit. This drop had been 

 placed on a thin covering-glass, which, after the inoculation, 

 was inverted over a small " cell," made by fixing a glass ring on 

 an ordinary glass slide. The covering-glass was fastened on the 

 glass ring by means of a thin layer of pure olive oil. The 

 preparation was then kept in the incubator for twenty-four 

 hours at a temperature of 32° to 33"* C. After this time it was 

 used to inoculate a new drop of aqueous humor in a similar 

 manner to the one just described. We will call this the second 

 generation. 



" This new specimen was placed in the incubator, and kept 

 there at a temperature of 32° to 33° C. for another twenty-four 

 hours. In the same manner a third generation was started, by 

 inoculating a fresh drop of aqueous humor. After having 

 been kept in the incubator for several days, it was used to 

 inoculate two animals at different times. Both animals became 

 infected with the disease. 



" (&.) The other five experiments were carried out with virus 

 cultivated from solid lymph of the peritoneum of a diseased 

 animal. The lymph had been dried at 38° C. (see series 2). A 

 small particle of dried lymph is crushed into fine powder. With 

 a grauTile of this, a drop of fresh aqueous humor is inoculated 

 in the same manner as above described, — first generation. 



" After having been kept in the incubator for two or tliree days 

 at a temperature of 32° to 33° C, it is used to inoculate a second 

 generation, care being taken to use a trace only of the fluid part, 

 and not to come in direct contact with the origuial granule, 

 which may be still discerned in the preparation. 



" The specimen representing the second generation is kept in 

 the incubator for a day or two. It is then used to inoculate a 

 fresh preparation, — third generation. And, finally, this is used 

 for establishing a fourth generation. After having been kept in 

 the incubator, a part of it is used for inoculating two animals, 

 the inoculation being carried out at different times. 



" Both these animals became affected with tlie disease. 

 Another portion of tliis fourth generation was used to start a 



