9 
RELATION OF THE AMOUNT OF THE SENSITIZING DOSE TO 
THE TIME INTERVAL. 
It seemed to us at one time in our work that animals injected 
with a large quantity of horse serum at the first injection had a more 
prolonged period of incubation or were less sensitive than guinea pigs 
given the usual minute amounts. We conjectured that this might 
have been due to the slow absorption of the serum, thus having 
somewhat the immunizing effect of repeated injections. We there- 
fore prepared four series of guinea pigs: One sensitized vdth 0.01 
c. c., a second with 0.1 c.c., a third with 1 c. c., and a fourth with 
8 c. c. of normal horse serum. All of these animals were subse- 
quently tested by intracerebral injections of the same normal horse 
serum. 
So far as may be judged from this work, the period of incubation 
is not appreciably prolonged by a large sensitizing dose. Further, 
the animals sensitized with horse serum alone, remain so for a long 
period of time (245 days). 
Table No. 4. — Relation of amount to sensitization. 
G.P. 
No. 
First injection. 
Inter- 
val in 
days. 
Second injection. 
Result. 
1 
1148 
0.01 c. c. normal horse (roan) 
14 
0.25 c. c. normal horse (roan) 
Marked symptoms. 
serum subcutaneously. 
serum into brain. 
1149 
do 
17 
do 
Dead in 5 minutes. 
1150 
do ■ 
24 ' 
do 
Severe symptoms. 
1151 
do 1 
38 
do 
Severe symptoms. 
U52 
do 
no 
do 
Dead in 6 minutes. 
1155 
do. 
155 
do 
Very severe symp- 
toms. 
1157 
245 
0.2 c. c. normal horse (roan) ' 
Mild symptoms. 
! 
serum into brain. 
1158 
0.1 c. c. normal horse (roan) 
i 
14 
0.25 c. c. normal horse (roan) 
Very severe symp- 
serum subcutaneously. 
serum into brain. 
toms. 
1159 
do 
17 
do 
Severe symptoms. 
1160 
do 
24 
do 
Severe symptoms. 
1161 
do ... 
38 
do 
Dead in 4 minutes. 
1163 
do 
no 
0.5 c. c. normal horse (roan) 
Dead in 4 minutes. 
serum into brain. 
1164 
do. 
155 
0.25 c. c. normal horse (roan) 
Very severe symp- 
serum into brain. 
toms. 
1165 
1 c. c. nonnal horse (roan) se- 
14 
0.25 c. c. normal horse (roan) 
Very severe symp- 
rum subcutaneously. 
serum into brain. 
toms. 
1166 
do 
17 
do 
Severe symptoms. 
1167 
do 
24 
do 
Severe symptoms. 
1168 
do 
24 
. ..do 
Severe symptoms. 
1169 
do . - . . 
no 
do 
Very severe symp- 
toms. 
1170 
do 
155 
do 
Very severe symp- 
toms. 
1162 
245 
0.2 c. c. normal horse (roan) 
Mild symptoms. 
serum into brain. 
45319—08 2 
