19 
THE EFFECT OF VARIOUS CHEMICAL SUBSTANCES UPON THE 
TOXICITY OF HORSE SERUM. 
Further attempts were made to influence the toxic action of horse 
serum by treating the guinea pig with various chemicals. 
In the following series the sensitized animals were given a subcu- 
taneous injection of various substances the day before the second 
injection of serum. No favorable influence upon the anaphylactic 
state was obtained by the substances used, namely, pancreatin, 
potassium oxalate, pepsin, sodium sulphate, magnesium sulphate, 
peptone, calcium chlorate, and calcium acetate. 
Table No. 12. — Effect of various chemicals. 
G. P. 
No. 
First injection. 
Inter- 
val in 
days. 
Second injection. 
Result. 
8545 
0.24 c. c. toxine 42+1/640 c. c. 
antitoxic horse serum (Alex. 
A249) . 
32 
1 gm. pancreatin; next day 0.5 
c. c. normal horse (roan) se- 
rum into brain. 
Dead in 4 minutes. 
8553 
0.24 c. c. toxine 42+1/680 c. c. 
antitoxic horse serum (Alex. 
A249) . 
32 
1 gm. potassium oxalate; next 
day serum as above. 
Dead in 5 minutes. 
8552 
0.24 c. c. toxine 42+1/680 c. c. 
antitoxic horse serum (Alex. 
A249). 
32 
0.5 gm. pepsin; next day serum 
as above. 
Dead in 2 minutes. 
8532 
0.24 c. e. toxine 42+1/620 c. c. 
antitoxic horse serum (Alex. 
A249) . 
32 
0.1 gm. sodium sulphate; next 
day serum as above. 
Dead in 3 minutes. 
8534 
0.24 c. c. toxine 42+1/600 c. c. 
antitoxic horse serum (Alex. 
A249). 
32 
0.1 gm. magnesium sulphate; 
next day serum as above. 
Dead in 2 minutes. 
8383 
0.24 c. c. toxine 42+1/370 c. c. 
antitoxic horse serum (PD 
08033). 
32 
0.2 gm. peptone; next day se- 
rum as above. 
Dead in 2 minutes. 
8408 
0.24 c. c. toxine 42+1/260 c. c. 
antitoxic horse serum (Cut- 
ter 1838). 
32 ; 
0.1 gm. calcium chlorate; next 
day semm as above. 
Dead in 2 minutes. 
8535 
0.24 c. c. toxine 42+1/600 c. c. 
antitoxic horse serum (Alex. 
A249) . 
32 
0,1 gm. calcium acetate; next 
day serum as above. 
Dead in 3 minutes. 
IODINE. 
Obermayer and Pick ® found that when the aromatic radicals of a 
protein are combined with various substances the protein loses the 
power to produce precipitins of closely limited specificity for the 
original species. Their results suggest that the aromatic groups of 
the molecule are most closely related to the species specificity.^ 
This indicates that the striking specificity of proteins of different 
species depends upon the aromatic groups of the protein molecule, 
« Obermayer, Fr., and Pick, E. P.: Ueber die chemischen Grundlagen der Artei- 
genschaften der Eiweisskorper. Wiener klin. Woch., vol. 19, 1906, p. 327. 
^ Wells, H. Gideon: The present status of our knowledge of the chemistry of the 
processes of immunity. Arch. Internal Med., vol. 1, No. 2, February 15, 1908, p. 262. 
