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THE AGRICULTURAL JOURNAL. 



certainly suffer after bile inoculation, 

 and unfortunately it will infect others 

 previously uninfected until about the 

 eighth day after the bile treatment. No- 

 thing is more difficult — nay, more impos- 

 sible—in an infected area, than to be sure 

 that any particular herd or animal is 

 clean. During the incubation period, i.e., 

 four or five days, this is absolutely im- 

 possible, and during the first three or four 

 days of the fever, the only suspicious 

 circumstances which could be noticed 

 would be an abnormally high tempera- 

 ture. Thus from a period of from seven 

 to nine days after infection, it would be 

 dirficult, and by an ordinary inspection 

 impossible to give any opinion as to the 

 condition of a herd with regard to rinder- 

 pest infection in any infected area. Yet 

 those who believe in the infectivity of 

 rinderpe t bile, base their belief on ex- 

 periences gained in an infected area under 

 the conditions such as I have just de- 

 scribed. Even the fact that the same bile 

 used on the same day in different herds 

 is credited with different results does not 

 convince them that the experiences on 

 which they rely are not trustworthy. 

 Thus in two or more herds inoculated by 

 the same operator, on the same day, and 

 with the same sample of bile, I have more 

 than once known riuderpest to occur 

 afterwards in one herd and not in the 

 other, and sometimes the infected herd 

 has been very considerably smaller than 

 the uninfected. 



I was afforded an opportunity to test 

 the possibility of bile infection on a fairly 

 large scale. 1 was allowed to inoculate 

 160 animals near Britstown, which were 

 then supposed to be free from disease. 

 Speaking fronsi memory, ten samples of 

 bile were used, yet not an animal was in- 

 fected. The most extraordinary fact with 

 regard to this experiment, and one which 

 will illustrate the difiiculty of offering 

 anj' opinion as to the freedom of a dis- 

 trict or herd from the disease is the 

 following: — On July l.'3th, when I oper- 

 ated at lii'itstown, there was no known 

 c.ise of the disease, nearer than Prieska, 

 several hours distant, yet it was next 

 heard of on a farm half way between De 

 Aar an<l Britstown. In fact the first re- 

 port which lepched me was that the 

 animals 1 had treated had Ijeen aitacked. 

 It was sim})ly a matter of chance tliat the 



herd at Britstown had not been infected 

 ' before that at De Aar— three hours further 

 from the nearest known infected centre. 

 Had this occurred no one for a moment 

 would have doubted that the disease had 

 been conveyed by protective inoculation. 



My recent experiences have been as 

 follows : In Basutoland, an infected area, 

 rinderpest has followed inoculation in 

 some cases. In Pretoria, where it is true 

 the disease was present but not widely 

 spread, we have inoculated 338 clean 

 animals with 22 different samples of bile, 

 and rinderpest has not once resulted. It 

 is true some of the oxen thus treated 

 have sin-ce had rinderpest, but only after 

 the bile immunity has worn out, as it 

 sometimes does, a few months after in- 

 oculation. Anyone interested in the 

 matter will find the facts on which I rely 

 for my opinion, in the South African 

 Medical Journal " of November, 181)7, and 

 in a small pamphlet entitled " Rinderpest 

 Investigation," September 11th, 1897, 

 } published by the Agricultural Depart- 

 j ment of the Cape Colony. There is 

 another remark upon which I should 

 make some! observation. Mr. Pitchford 

 says, " In arguing upon this inhibitive or 

 restraining power of rinderpest bile, Koch 

 went so far as to suggest that bile from 

 quite healthy cattle could so modify the 

 virus of rinderpest blood that a useful 

 vaccine could be produced thereby." I 

 have heard Koch make a similar state- 

 ment. He proved that ordinary healthy 

 bile could destroy a small quantity of 

 rinderpest bile, and, acting on his sugges- 

 tion, I have shown, first, that it is possible, 

 by the action of bile on rinderpest blood, 

 to produce a mild disease from which the 

 animal recovers ; and, second, that the 

 bile exerts this power by the action of the 

 taurocholate and glycocholate of soda 

 contained in it. Whether a useful vaccine 

 could be made in this way I am unable 

 to say, because early in July, 1897, the 

 possibility of producing a powerful serum 

 was practically assured, and I gave up ex- 

 perimenting with bile. 



The experiments of Messrs. Nencki, N. 

 Sieber and Wyznikiewiez, described in 

 the Central Blatt fur Bakteriologie Paris- 

 tenkunde, und Infectious Krankheiten, of 

 March 31st, 18'J8, have been repeated, 

 but, as was to have been expected the 

 results described by them are not to be 



