Part VHL 
ACTION OF HORSE SERUM UPON MAN AND OTHER ANIMALS. 
MAN. 
It may be that man can not be sensitized in the same way that 
we have shown is the case with guinea pigs. We made no human 
experiments, but have experimental data done by others which has 
a direct bearing on this question. 
Pirquet and Schick injected children with antitoxic horse serum 
at intervals. 
It has been customary to immunize numbers of children when 
exposed to diphtheria with antitoxic horse serum at intervals of from 
three to four weeks. 
We have no doubt that there are many such instances on record 
and, so far as we know, this practice has never caused death. 
Repeated injections of horse serum into man is not an infrequent 
occurrence. Patients suffering with diphtheria are often given 
injections of antitoxic serum at short and frequent intervals. It is 
also not rare for persons to have several attacks of diphtheria at long 
intervals and to be treated each time with antidiphtheric serum. 
Certain serums, for example, the antitubercle serum of Maragliano, 
or the antirheumatic serum of Menzer are habitually used by giving 
injections at intervals of days or weeks. 
In all of these cases of frequent and repeated injections the amount 
which has been injected and the interval between the injections must 
be taken into account in relation to this work. Pirquet and Schick 
in their work on Serumkrankeit give the following instances in which 
children received two injections of horse serum at intervals of from 
sixteen to forty-two days between the first and second injections. 
Leopold H . — October 3, 1902. 100 c. c. scarlet-fever serum (Moser). Eight days fol- 
lowing this injection symptoms of the serum disease appeared and lasted several weeks. 
December 2, 1902. Fifty days after the first injection patient received 2 c. c. anti- 
diphtheric serum under skin of arm. 
In fifteen minutes following this second injection stormy symptoms set in. The boy 
began to cry and complained of nausea. Edema of the lip set in and soon spread over 
the whole face. In several hours general urticaria. 
( 55 ) 
