Part VIIL 
THE IMMUNITY TO HYPERSUSCEPTIBILITY OR ^‘ANTI- 
ANAPHYLAXIS/^ 
The immunity produced against the toxic action by repeated injec- 
tions of horse serum has been called anti-anaph}daxis by Besredka and 
Steinhardt." From our subsequent work we learn that this immunit}" 
is relatively not quite as lasting and definite as many instances of active 
immunity seen in the laboratory against bacterial infections. Guinea 
pigs that have received a number of prior injections of horse serum 
may again show symptoms when reinjected with large amounts. The 
S3miptoms in such cases are usually mild, and death has never occurred 
in an ‘‘immunized” guinea pig as a result of subsequent injections 
with horse serum. 
G. P. No. 410: 
January 15, 1906, 1 c. c. antitoxic horse serum (Natl. VIII, 17), subcutaneously. 
No symptoms. 
January 23, 1906, 1 c. c. antitoxic horse serum (Natl. V^III, 17) , subcutaneously. 
No symptoms. 
February 8, 1906, 6 c. c. antitoxic horse serum (Natl. VIII, 17), subcutaneously. 
No symptoms. 
February 14, 1906, 6 c. c. antitoxic horse serum (Natl. VIII, 17), subcutaneously. 
No symptoms. 
February 23, 1906, 6 c. c. antitoxic horse serum (Natl. VHI, 17), subcutaneously. 
No symptoms. 
March 29, 1906, 6 c. c. antitoxic horse serum (Natl. VIII, 18), subcutaneously. 
No symptoms. 
April 18, 1906, 6 c. c. antitoxic horse serum (Natl. VHI, 19), subcutaneously. 
No symptoms. 
May 16, 1906, 6 c. c. normal horse (roan) serum, subcutaneously. No symptoms. 
May 18 to June 27, 1906, normal horse (roan) serum, 1 c. c. daily, subcutaneously. 
No symptoms. 
September 7, 1906, 6 c. c. normal horse (roan) serum, intraperitoneally. No 
symptoms. 
G. P. No. 430: 
May 18 to June 27, 1906, 1 c. c. normal horse (roan) serum, daily, subcuta- 
neously. No symptoms. 
February 27, 1907, 6 c. c. normal horse (roan) serum, intraperitoneally. Severe 
symptoms. 
G. P. No. 427: 
May 18 to June 27, 1906, 1 c. c. normal horse (roan) serum, daily, subcutane- 
ously. No symptoms. 
February 27, 1907, 6 c. c. normal horse (roan) serum, intraperitoneally. Severe 
symptoms. 
«Ann. de I’lnst. Pasteur, V^ol. 21, No. 2, Feb. 25, 1907, pp. 117-12<. 
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