ae ee) 8 ee 
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indicates a limit of from three to six. Kept at 36° to 40° ©. it becomes inactive 
after two days (Theiler) ; dried blood may remain virulent for four (Koch) ; 
glycerine, phenol, and other antiseptic substances, even if used in minute amounts. 
cause rapid deterioration (Koch, Theiler, Semmer); if it is mixed with other 
organisms it is quickly killed. The virus resists alkalies longer than it does 
acids (Nicolle and Adil-Bey) ; sun destroys it in five minutes (Braddon), but ordi- 
nary daylight has little effect (Woronzow and Eckert). Semmer states that 
material will remain virulent during four to six weeks at ordinary temperatures 
and that a spleen kept on ice was still capable of causing the disease after six 
months, At 58° to 60° the virus loses its power in a few seconds, at 52° in 
half an hour, and at 37° to 45° C, there is a gradual loss. In vacuo the deterior- 
ation is still more rapid (Nicolle and Adil-Bey). Semmer makes the statement 
that the virus, heated to 45° to 50° C. during fifteen to thirty minutes, loses its 
virulence but will give a stable and lasting immunity. On the other hand, Nicolle 
and Adil-Bey found that blood heated to 60° ©. lost. its power of carrying the 
infection and would then not confer immunity. Semmer also states that a 
temperature of —20° C. brought about an attenuation and Nicolle and Adil-Bey 
found that blood kept in the cold for two months had lost all virulence, 
Dilution with different substances gives varying results. Virulent blood mixed 
with glycerine becomes inactive (Koch). Nicolle and Adil-Bey found that 1/60 
cubie centimeter of virulent blood diluted with 1.5 cubic centimeters of normal 
saline solution was capable of transmitting the infection, but if a like amount of 
the former was added to 500 of the latter, the virulence was lost. Virulent blood 
mixed with normal bile or bile salts retains none of its activity (Adani). 
Purely physical processes may also have an effect. It is said that centrifugal- 
ized blood does not cause the disease (Kolle) and that defibrinated blood will give 
a temporary immunity (Rogers). 
Hxperiments on filtering virulent blood.—The results attained by experiments 
on filtration vary. Nicolle and Adil-Bey state that the organism passes normal 
Berkefeld and Berkefeld amincie filters and Yersin found that the filtrate obtained 
by passing rinderpest blood through Chamberland F candles would cause the 
disease. On the other hand, Nicolle and Adil-Bey say’ that the organism does 
not pass a Chamberland F and Yersin says a Chamberland B gives an inactive 
filtrate. 
Our experiments are as follows: 
In 1905, four animals were chosen from a herd of native nonimmunes (Sibuyan). 
One of these (Chart 1, No. 905) was used as a control and received no blood, but 
was kept under exactly the same conditions as the others; another (Chart 2, 
No. 907) was used as a blood control and received 1 cubic centimeter of virulent 
blood, diluted with 5 cubic centimeters of an 0.8 per cent saline solution; a third 
(Chart 3, No. 908) was given 5 cubic centimeters of a filtrate from virulent blood, 
which was collected by passing through a Pasteur-Chamberland F candle. under 
a pressure of 1.75 kilograms per square centimeter and then diluted with 5 volumes 
of the same salt solution; a fourth animal (Chart 4, No. 904) received 100 cubic 
centimenters of the unfiltered blood used for No. 3. The first bull had a normal 
temperature during twelve days, at the end of which time it was inoculated with 
60 cubic centimeters of virulent blood; it then reacted on the third day and was 
bled to death three days thereafter; at autopsy typical lesions of rinderpest were 
present. The second animal showed a reaction on the seventh day and a_post- 
mortem made some days later gave convincing proof of the presence of the disease. 
The third one reacted mildly on the ninth day; three days subsequent thereto 60 
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