57 
bell jar. It developed characteristic symptoms and died in fifteen 
minutes. 
G. P. No. 7028. Six c. c. antitoxic horse serum (Natl. IX, 17), intraperitoneally; 
immediately placed in an atmosphere of almost pure oxygen. Dead, 35 minntes. 
[Previous treatment; 54 days prior, 0.142 c. c. toxine No. 5+j^o c. c. antitoxic 
horse serum (Led. 8).] 
Control G. P. Kept 30 minutes in same atmosphere. No symptoms. 
[Previous treatment: 52 days prior, 0.142 c. c. toxine No. 5+2jo c. c. antitoxic 
horse serum (PDCo. 07555 A).] 
At the end of 30 minutes in oxygen atmosphere,^ given 6 c. c. antitoxic horse 
serum (Natl. IX, 17), intraperitoneally. Dead, 15 minutes. 
THE INFLUENCE OF DIPHTHERIA TOXINE UPON HYPERSUSCEPTIBILITY. 
The question was raised both Otto and us as to the influence of 
the diphtheria toxine in accentuating* the phenomenon of hypersus- 
ceptibility. 
While guinea pigs may be sensitized with fresh normal horse serum 
alone, it seemed to us and also to Otto that a greater degree of hyper- 
susceptibility is produced when sensitized with a mixture of diphthe- 
ria toxine and antitoxic horse serum than when the horse serum alone 
is given at the first injection. It seems, however, that this is by no 
means always the case. 
All the guinea pigs in the following series were sensitized with 
3^0 c. c. of antitoxic horse serum (Alex. A., 228) precipitated and 
dialyzed according to Gibson’s method. One-half the animals received, 
in addition, 0.2 c. c. toxine No. 7 (MLD = 0.006). After thirty-one 
days interval all the guinea pigs were tested with 3 c. c. normal horse 
serum (roan) into the peritoneal cavity. 
[All tested by injecting 3 c. c. normal horse (No. 15) serum intraperitoneally.] 
No. 
G. P. 
Previous treatment, 31 days prior. 
Result. 
720 
721 
c. c. precipitated antitoxic horse serum 
(Alex. A., 228), subcutaneously. 
do 
Dead, 28 minutes. 
Dead, 12 minutes. 
722 
do - 
Very severe symptoms. 
Dead, 44 minutes. 
723 
do 
724 
do 
Dead, 10 minutes. 
725 
do 
Very severe symptoms. 
Very severe symptoms. 
Very severe symptoms. 
Very severe symptoms. 
Very severe symptoms. 
Dead, 10 minutes. 
Very severe symptoms. 
Dead, 10 minutes. 
726 
do 
727 
do 
728 
do 
729 
do . 
710 
Ditto -|- 0.2 c. c. toxine No. 7 
711 
do 
712 
do -- 
713 
.do. 
Dead, 43 minutes. 
Dead, 31 minutes. 
Very severe symptoms. 
Dead, 27 minutes. 
Severe symptoms. 
Very severe symptoms. 
Dead, 92 minutes. 
714 
do 
715 
do 
716 
do 
717 
do 
718 
do 
719 
do 
