87 
we may introduce, it is not possible to shorten the period of incuba- 
tion. Beclere, Chambon and Menard 0 have shown that, in the vac- 
cination of calves, the eruption does not appear sooner if the calf is 
very heavily treated with the vaccinal material. 
We might attribute the phenomena to the virulence of the infect- 
ing organisms, but the same lymph causes the reaction to appear in 
animals primarily vaccinated in the normal period of incubation; 
whereas in those revaccinated there is a hastened reaction. 
A related thought originated with Buttersack * * * * 6 in regard to infec- 
tious diseases who, in a study upon recovery and immunity, asserts 
that recovery is due to a retardation of the development of the cause of 
the infection at the height of the sickness. He believes further that 
the cells of the body, through use in the sense of Darwin’s theory 
of evolution and adaptation, develop the power to combat more 
quickly the multiplication of a new infection. 
Von Pirquet and Schick draw this distinction between Buttersack’s 
theory and their own: Buttersack places this power of the organism 
to prevent a further development of the infection at the climax of 
the disease, while they believe the antibodies are formed at the very 
beginning. Their conception of antibodies does not coincide pre- 
cisely with the generally accepted idea of antibodies, but they use 
this expression in a general sense to comprise the sum of all the spe- 
cific reaction products produced by the organism which are able to 
react upon the antigens introduced. Buttersack's theory does not 
cover the explanation of the serum disease, as serum has no power 
of self-multiplication. 
The sooner the reaction in the organism succeeds, the less time 
has the alien infection to develop. Therefore, its development is 
restricted earlier and, in consequence, the whole organism suffers 
less damage. 
On the contrary, in the case of serum disease we receive the 
impression that it is unfavorable for the organism to react more 
quickly to the reagent. For the quicker the antibodies unite with 
the antigens the more severe will the disease be. 
This contradiction may perhaps be cleared up when we remember 
that the subcutaneous injection of an agent incapable of self-multi- 
plication seldom occurs in nature (insect bites, snake poison) and 
that this to a certain extent represents an artificially produced form 
of disease. The natural way for disease to be produced is, in the 
great majority of cases, by the introduction of minute quantities of 
an irritant capable of self-multiplication. 
r 
a Beclere, Chambon, and Menard: Etude experimentale des accidents postserothera- 
piques. Ann. de 1‘Inst. Pasteur, 1896. Etudes sur l’immunite vaccinale. Ann. de 
l’lnst. Pasteur, 1896 and 1899. 
& Buttersack: Immunitat und Heilung ini Lichte der Physiologie und Biologie. Vir- 
chow’s Arch., Bd. 142, p. 248. 
