0)1 the Nature of the Contagium of Rinderpest. 357 



measurements similar to those of M. Rollet for both English and 

 Germans. The value of such statistics for comparative purposes 

 would be very great. 



" On the Nature of the Contagium of Rinderpest. Preliminary 

 Communication." By Alexander Edington, M.B.. 

 F.R.S.E., Director Colonial Bacteriological Institute, Cape 

 Colony. Communicated by Sir James Crichton Browne, 

 M.D., LL.D., F.R.S. Received March 22,— Read June 3, 

 1897. 



In the following pages it is proposed to communicate to the Royal 

 Society the results of experiments made in South Africa on the 

 infectivity of the blood of animals affected with Rinderpest. The 

 experiments were all made on cattle kept under conditions in which 

 accidental spontaneous infection could with certainty be excluded. 

 These experiments had been concluded in 1896, before the arrival of 

 Dr. R. Koch in South Africa, and their results bad been communi- 

 cated to him on his arrival. 



1. The blood of an animal ill with rinderpest, when taken during 

 the febrile stage or previous to death, and injected subcutaneously or 

 intravenously into healthy cattle, produces the typical disease — 

 rinderpest, provided the blood is prevented from coagulating. 



2. The onset of coagulation and actual coagulation of the blood 

 exert a marked destructive influence on the virulence of such blood. 



3. The best method of obtaining virulent blood is to draw it asep- 

 tically from the jugular vein of an animal ill with rinderpest, and 

 to mix it immediately with a 1 per cent, solution of citrate of potash, 

 the latter previously well sterilised, in the proportion of 2 — 3 parts 

 of blood to 1 part of citrate of potash solution. Such blood, as has 

 been shown, remains fluid. 



4. This citrate of potash mixture of blood proves virulent in the 

 first few days, generally not exceeding six days; after six days' 

 keeping the virulence becomes rapidly weakened, so that after nine 

 days the blood mixture is altogether inert. 



5. Admixture of glyceric e to citrate blood does not ccc-teris paribus 

 interfere with the virulence of such blood. Glycerine added to fresh 

 blood does interfere with the virulence of the latter on account of 

 the coagulation of the blood. 



6. The nasal mucus of an infected animal when used fresh and 

 rubbed into the nostrils of normal cattle, produced in all instances typi- 

 cal rinderpest. We have never had a single failure in attempting to 

 produce the disease by this means. By keeping the nasal mucus, 

 even for a few hours, its virulence becomes markedly less. 



vol. lxi. 2 c 



