52 
THE EFFECT OF REPEATED SMALL INJECTIONS UPON SENSI- 
TIVE GUINEA PIGS. 
We were interested in determining whether repeated small injections 
would immunize sensitive guinea pigs vdthout the production of ana- 
phylactic symptoms. For this purpose we injected a series of guinea 
pigs subcutaneously with normal serum in amounts too small to pro- 
duce apparent symptoms and repeated the injections daily for twenty 
days. One series received 0.001 c. c. subcutaneously (total 0.02 c. c.) 
the other series 0.01 c. c. subcutaneously (total 0.2 c. c.). It vdll be 
seen from the following table that these repeated injections had little, 
if any, effect upon the susceptibility of these guinea pigs. 
Table Xo. 46. — Effect of repeated small injections upon sensitive guinea pigs. 
G.P. 
No. 
First injection. 
Inter- 
val in 
days. 
Second injection. 
Result. 
971G 
0.23 c.c.toxine No. 7+1/600 c. c. 
antitoxic horse serum (Schr. 
II). 48 days later 20 subcu- 
taneous injections, each 0.001 
c. c., normal horse (Frank) 
serum daily. 
o2 
0.2 c. c. normal horse (Teddy) 
serum into brain. 
Very severe symp- 
toms. 
9673 
0.23 c. c. toxine No. 7+1/560 c. c. 
antitoxic horse serum (PD i 
08022). 48 days later 20 injee- ! 
tions 0.001 c. c. daily. 
2 
do 
Marked symptoms. 
9678 
0.23 c.c.toxine No. 7+1/520 c. c. 
antitoxic horse serum (PD j 
08022). 48 days later 20 injec- 
tions 0.001 c. c. daily. 
2 
do 
Marked symptoms. 
9714 
0.23 c. c. toxine No. 7+1/500 c. c. 
antitoxic horse serum (Schr. 
II). 48 days later 20 injec- 
tions 0.01 c. c. daily. 
2 
do 
Dead in 5 minutes. 
9715 ! 
do . 
2 
. ..do 
Marked symptoms. 
Marked symptoms. 
9677 
0.23 c. c. toxine No. 7+1/520 c. c. 
antitoxic horse serum (PD 
08022). 48 days later 20 injec- 
tions 0.01 c. c. dailj'. 
2 
do 
9155 
0.23 c. c. toxine No. 7+1/200 c. c. 
antitoxic horse serum (Cutter 
1856) . 60 days later 10 injec- 
tions 0.001 c. c. each, covering 
period of 20 days. 
11 
6 c. c. normal horse (roan) se- 
rum intraperitoneally. 
Dead in 120 minutes. 
9156 
0.23 c. c. toxine No. 7+1/240 c. c. 
antitoxic horse serum (Cutter 
1856). 60 days later 10 injec- 
tions 0.001 c. c. each, covering 
period of 20 days. 
11 
0.2 c. c. normal horse (roan) se- 
rum into brain. 
Dead in 7 minutes. 
9252 
0.23 c. c. toxine No. 7+1/400 c. c. 
antitoxic horse serum (Schr. 
II). 60 days later 10 injec- 
tions 0.001 c. c. each, covering 
period of 20 days. 
11 
6 c. c. normal horse (roan) se- 
rum subcutaneously. 
Dead in 90 minutes. 
a After last injection. 
