83 
actinia poison: The crystalline thallassin, which had slight toxic 
action, but which in minimal doses caused pruritis, and congesting 
an albuminous body which was more toxic than the original sub- 
stance and caused the characteristic congestive conditions in the 
intestinal tract. 
Richet made further experiments with the congestin with relation 
to first and subsequent injections which gave him the same results 
as similar experiments with the actinia poison. The fatal dose for 
rabbits was 0.009 gm. per kilogram for the first injection; for the 
subsequent injection it was less than 0.0033. Richet designated 
this hypersensitiveness, caused by the first injection, by the term 
“ anaphylactic ’ ’ in contradistinction to prophylactic. This anaphy- 
laxis requires for its development a certain time. Three to four days 
after the first injection there is no hypersensitiveness. It continues 
a very long time and is still evident after one year. He did not suc- 
ceed in transmitting this hypersensitiveness by means of the serum 
of injected animals. He calls attention to similar phenomena in 
tuberculosis and tetanus. 
Knorr , a as also Behring and Kitashima , b found that guinea pigs 
develop an increasing sensitiveness against tetanus toxin. 
Serum and actinia poison are similar in that they are not sub- 
stances capable of seif-multiplication. On the other hand, there is 
this important difference between the two : The actinia poison causes 
after the first injection symptoms without a period of incubation, 
while the serum, even in the largest quantities, at the first injection 
almost without exception develops no immediate symptoms. 
So far as serum is concerned, we may assert that the same is not 
toxic in itself, but that the toxic body is developed through the 
reaction between the organism and the antibodies. 
Similar to serum are forms of animal albuminous substances as, 
for example, milk (Arthus) and spermatozoa (Wolff). 
Entirely analogous to the actinia poison is the hypersensitiveness 
found in tuberculosis. The question in tuberculosis has been more 
closely studied in its relation to hypersensitiveness ; another well- 
known fact is that in addition there also develops an immunity. 
Tuberculin is an extract which lacks the power of self-multiplica- 
tion, but is derived from an agent which has this power, and we 
would expect that infection with the tubercle bacillus would also 
carry the power of producing this Irypersensitiveness the same as is 
produced by the extract from dead tubercle bacilli. 
a Knorr: Experimentelle Untersuchungen iiber die Grenzen der Heilungsmogliehkeit 
des Tetanus, v. 102, 18. 
Von Behring and Kitashima: liber Verminderung und Steigerung der ererbten Gift- 
empfindlichkeit. Berl. klin. Woch., 1901, p. 157. 
