12 
Table No. 5. — Effect of heat upon sensitizing principle — Continued. 
G.P. 
No. 
First injection. 
Inter- 
val in 
days. 
Second injection. 
j 
Result. 
1 
1200 
Heated to 100° C. 
0.02 c. c. normal hotse (roan) 
25 
6 c. c. normal horse (roan ) sc- 
No symptoms. 
1201 
serum, diluted 1:3 with dis- 
tilled water and heated 100° 
for 1 hour, subcutaneously. 
do 
25 
rum intraperitoneally. 
0.25 c. c. normal horse (roan) 
No symptoms. 
1358 
1 c. c. normal horse (roan) se- 
35 
serum into brain. 
0J2 c. c. normal horse (roan) sc- 
No symptoms. 
1359 
rum, diluted 1 : 3 with distilled 
water and heated 100° for 1 
hour, subcutaneously. 
do 
i 
35 
rum into brain. 
do 
Symptoms (?). 
1360 
do 
. 35 
6 c. c. normal horse (roan) se- 
No symptoms. 
1361 
35 
rum intraperitoneally. 
6 c. c. normal horse (roan) sc- 
Symptoms (?). 
1362 
do 
i 
i 'y 
rum subcutaneously. 
do 
Symptoms (?). 
CAN GUINEA PIGS BE SENSITIZED IN THE BRAIN? 
We were led to make the following experiments in view of a state- 
ment made by Besredka and Steinhardt ® that guinea pigs were not 
sensitized when very small amounts are injected into the brain. Very 
minute amounts when injected into the brain in our experiments, as 
well as the few reported by Besredka and Steinhardt, proved negative. 
However, guinea pigs may be readily sensitized by intracerebral 
injections, provided quantities of 0.0001 c. c. or more are used. We 
obtained negative results with sensitizing doses of 0.00001 c. c. 
Table No. 6. — Intracerebral sensitization. 
G. P. 
No. 
First injection. 
Inter- 
val in 
days. 
Second injection. 
Result. 
1202 
0.25 c.c. normal horse (roan) se- 
1 25 
0 c. c. normal horse (roan) se- 
Severe symptoms. 
rum into brain. 
rum intraperitoneally. 
12ai 
do 
25 
0.25 c. c. same serum into brain. . 
Marked symptoms. 
1204 
0.1 c. c. normal horse (roan) se- 
25 
0 c. c. same serum intraperito- 
Mild symptoms. 
rum into brain. 
neally. 
1205 
do 
25 
0.25 c. c. same serum into brain. . 
Marked symptoms. 
1207 
0.01 c.c. normal horse (roan) se- 
25 
6 c. c. same serum intraperito- 
Severe symptoms. 
rum into brain. 
neally . 
1206 
do 
25 
0.25 c. c. same serum into brain. . 
Marked symptoms. 
1208 
0.001 c. c. normal horse (roan) 
25 
6 c. c. same senim intraperito- 
Severe symptoms. 
serum into brain. 
neally. 
1209 
do 
25 
0.25 c. c. same serum into brain. . 
Slight symptoms. 
1210 
0.0001 c. c. normal horse (roan) 
25 
6 c. c. same serum intraperito- 
Marked symptoms 
serum into brain. 
neally. 
1211 
do 
25 
0.25 c. c. same serum into brain. . 
Slight symptoms. 
1213 
1 0.00001 c.c. normalhorse (roan) 
25 
6 c. c. same serum intraperito- 
No symptoms. 
serum into brain. 
neally. 
1212 
do 
25 
0.25 c.c. same serum into brain. . 
No symptoms. 
a Ann. de I’lnst. Pasteur, vol. 21, 1907, p. 384. 
