8 
conviction that this phenomenon of hypersusceptibility has an impor- 
tant bearing on the prevention and cure of certain infectious pro- 
cesses. Our Tvork this year upon the hypersusceptibility produced 
by the bactei'ial proteids strengthens this belief, for our results prove 
that the phenomenon of hypersusceptibility to certain proteid sub- 
stances extracted from the bacterial cell is follovred by a definite 
immunity against infection by the micro-organism. 
Since our studies last j^ear several papers have been published 
which, in the main, have corroborated our findmgs. 
!^[cClintock and King” gave ten guinea pigs from to 1 c. c. of 
horse serum by the stomach and thirteen days later 6 c. c. of serum, 
either subcutaneous!}" or intraperitoneally, without causing symptoms 
in any of them. They conclude that the sensitizing action of horse 
serum given by the mouth is not nearly so great as when given subcu- 
taneously or intraperitoneally. This is in confirmation of our reported 
experiments. j 
Currie^ has studied the effect of repeated injections of horse serum ! 
in persons admitted for treatment in the city of Glasgow Fever and j 
Smallpox Hospital at Belvidere. He concludes that it is apparent j 
from the facts detailed by him that repeated injections of horse serum 
induce symptoms of supersensitation in man, but it is also apparent 
that the same facts lend no countenance to the suggestion that the 
death of persons suffering from diphtheria is to be apprehended as the 
result of repeated injections of antidiphtheric serum. 
Besredka and Steinhardt^ studied with much care certain features of 
hypersusceptibility to horse serum in guinea pigs; they note that 
the French serums are much less toxic than those used by Otto in 
Frankfurt and the serums used by us. Besredka and Steinhardt had 
a mortality of about 25 per cent when 5 c. c. of serum was given 
intraperitoneally at the second injection, whereas death was the rule 
in our experiments under similar conditions. Most of their work was 
done with doses of 0.05 to 0.25 c. c. given directly into the brain, 
which either killed or caused grave symptoms in susceptible guinea 
pigs. Besredka and Steinhardt lay stress upon the production of 
‘‘anti-anaphylaxis,'’ which we termed ‘‘ immunity.’’ They found that 
a single injection of serum given into the peritoneum of a sensitized , 
guinea pig conferred immunity to a subsequent injection of 0.25 c. c. 
into the brain; in one case the anti- anaphylaxis was present one and a 
« McClintock, Charles T., and King, Walter E.: The oral administration of anti- 
toxins for prevention of diphtheria, tetanus, and possibly sepsis. Journ.infec. diseases, 
Vol. 3, Ko. 5, Oct., 1906, pp. 700-720. 
Currie, J. K.: On the supersensitation of persons suffering from diphtheria by 
repeated injections of horse serum. Journ. hyg., Vol. 7, Ko. 1, Jan., 1907, pp. 35-60. 
Besredka, A., and Steinhardt, Edna: De I’anaphylaxie et de Tanti-anaphylaxie 
\ds-a-vis du serum de cheval. Ann. de Tlnst. Pasteur, Vol. 21, Xo. 2, Eeb. 25, 1907, > 
pp. 117-127. 
