63 
G. P. No. 4470. Six c. c. of a mixture containing equal parts of antitoxic horse serum 
(Natl. VIII. 17) and normal guinea-pig spleen injected into the peritoneal cavity. No 
symptoms. For occasional irregularities see below. 
[Previous treatment: 26 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. T+^+j- c. c. antitoxic serum (Natl. IX. 17).] 
6 c. c. antitoxic horse serum (Natl. VIII. 17) injected into peritoneal cavity of same pig 
one day later. Symptoms, recovered. 
G. P. No. 4475. Six c. c. of a mixture containing equal parts of antitoxic horse serum 
(Natl. VIII. 17) and normal guinea-pig ovary injected into the peritoneal cavity. Death 
in 45 minutes. 
[Previous treatment: 26 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. 7+2^0 c. c. antitoxic serum (Natl. IX. 18).] 
G. P. No. 4466. Six c. c. of mixture containing equal parts of antitoxic horse serum 
(Natl. VIII. 17) and normal guinea-pig kidney injected into the peritoneal cavity. 
Death in 45 minutes. 
[Previous treatment: 26 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. 7+jip c. c. antitoxic serum (Natl. VIII. 17).] 
G. P. No. 4378. Six c. c. of a mixture containing equal parts of antitoxic horse serum 
(Natl. VIII. 17) and normal guinea-pig suprarenal injected into the peritoneal cavity. 
Death in 10 minutes. 
[Previous treatment : 31 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. 7+jdj-o c. c. antitoxic serum (Natl. V. 10).] 
G. P. No. 4464. Six c. c. of mixture containing equal parts of antitoxic horse serum 
(Natl. VIII. 17) and normal guinea-pig thyroid injected into the peritoneal cavity. 
Symptoms, recovered. 
[Previous treatment : 26 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. 7+2^ c. c. antitoxic serum (Natl. VIII. 17).] 
G. P. No. 4469. Six c. c. of a mixture containing equal parts of antitoxic horse serum 
(Natl. VIII. 17) and normal guinea-pig brain injected into the peritoneal cavity. Symp- 
toms, recovered. 
[Previous treatment: 26 days prior, inoculated subcutaneously with 0.22 c. c. toxine 
No. 7+^1+ c. c. antitoxic serum (Natl. IX. 17).] 
We may conclude from the above that neither the blood serum nor 
the organs of a normal guinea pig have any neutralizing action upon 
the toxicity of horse serum when injected into a sensitized guinea pig. 
Guinea pig 4470, which received an injection of horse serum plus 
the spleen pulp of a normal guinea pig, showed no symptoms. We 
therefore repeated this experiment as follows : 
G. P. No. 4493. Six c. c. of a mixture containing equal parts of antitoxic horse serum (Natl. 
IX. 19) and normal guinea-pig spleen injected into the peritoneal cavity. Symptoms, 
recovered. 
[Previous treatment: 27 days prior, inoculated subcutaneously with 0.19 c. c. toxine 
No. 7 + 1 unit horse serum (Standard B27).] 
We believe that occasional irregularities like this which have excep- 
tionally occurred in this work may be accounted for by the fact that 
sometimes when the stomach and intestines are full and distended the 
inoculating needle enters the intestinal tract instead of the peri- 
toneal cavity. While we suspected this possibility, it was proved to 
our satisfaction one day; after injecting a guinea pig, the intestinal 
