174 



DR. E. KLEI'r^. 



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 success- 

 fully done by Dr, Koch. 



The experiments are seven in number — {a) two refer to 

 cultivations started with fluid peritoneal exudation ; (b) in 

 the five others the virus had been obtained by cultivation of 

 dried lymph of the peritoneum 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 re- 

 moved 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 ringi 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 preparation was then 

 kept in the incubator for twenty-four hours at a temperature 

 of S2 — 33° C. After this time it was used to inoculate a new 

 drop of aqueous humour in a similar manner as 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 — S3° C. for further twenty-four 

 hours. In the same manner a third generation was started 

 by inoculating a fresh drop of aqueous humour. After having 

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

 inoculate two animals at different times. Both animals 

 became smitten with the disease. 



(d) 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 3S° C. (See 

 Series 2). A small particle of dried lymph is crushed into 

 fine powder. With a granule of this a drop of fresh aqueous 

 humour is inoculated in the same manner as above described 

 — First generation. 



After having been kept in the incubator for two or three 



' The glass ring I used is 06 to 2 millimetres high, about 2 mm. thick, 

 and about 18 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. 



