790 
will be sufficient. For the same reason in some countries a minimum 
titre has been prescribed by law for a few sera. In Germany e.g. it 
has been fixed by law that antitetanus serum has to contain at least 
4, diphtheria serum at least 500 antitoxie units (A.U.) in one cc. 
serum. 
As, regarding the possibility that also our country might be drawn 
into the war, great quantities of antitetanus serum had io be pro- 
duced, to immunize the wounded against tetanus, the question rose, 
whether indeed there are sufficient reasons to refuse an antitetanus 
serum that contains less than 4 A.U. in 1 e.c. for this purpose. 
The research we have made to answer this question, has given 
a surprising result. For it has become clear to us, that the cheaper 
anti-tetanus serum with a titre of 2 A.U. is not only fit to immunize 
the wounded, but that it is even to be preferred for this purpose to 
the much more expensive product with a titre of 4 A.U. 
Whilst in the beginning of the European war many died of 
tetanus, this dreaded wound-disease tas now, so to say, entirely 
disappeared, thanks to the prophylactic injection of 20 antitoxic units 
into each wounded man. At present little is known about the titre of 
the antitetanus serum, which is used in the warfaring countries for 
prophylactic inoculations. Referring to Germany however, we have 
been told, that they inject serum of 4 A.U. as well as serum of 
2 A.U. When there came a shortness of tetanusantitoxine of + A.U., 
the German Gouvernment also allowed the injection of a serum 
with a titre of 2 A.U. 
According to theoretical considerations we had come to the suppo- 
sition, that the passive immunity caused by the injection of 20 A.U. 
in 10 ec, is not quite identie to the injection of 20 A.U. in 5c.c., 
as in the latter case the inoculated antitoxine might disappear sooner 
out of the organism than in the former case. 
It is not to be doubted, that the injection of horse serum causes 
the development of antibodies, which attack the horse serum and 
destroy it. Hence that from the 5" till 7° day after the injection, 
when in the mean time a certain quantity of antibodies has been 
produced, the horse serum and also the antitoxine for an important 
part disappear out of the blood, as Denne and HAMBURGER *) demon- 
strated. That the tetanus antitoxine and the horse albumen disappear 
out of the blood at the same time, is referred by these researchers 
to the fact, that the antitoxine is chemically united to the horse 
albumen. 
After the 5tr till 7 day a certain quantity of antitoxine and 
1) Wiener klin. Wochenschrift 1904 and 1905. 
