84 
Here we come to speak of hypersensitiveness in infectious processes. 
Arloing, in 1888, stated as his opinion that the pathogenic organisms, 
above all the tubercle bacilli, excrete soluble substances that influence 
the organism in such a way that the animal at a later infection with 
the same bacilli dies more quickly. 
Courmont a studied this question in relation to the tubercle bacillus. 
He found that bacilli obtained in pure culture from tuberculous 
pleurisy caused in rabbits general tuberculosis and kill guinea pigs 
without microscopic lesions. He injected animals with the filtered 
soluble products of young cultures of this bacillus. 
Guinea pigs and rabbits never react to these injections. However, 
if the animals so prepared were immediately afterwards inoculated 
with pure cultures then they reacted, as did the untreated animals; 
but if the inoculation follows several days after the introduction of 
the soluble products, then the results were very different. Animals 
which twenty days previous^ had been injected with the filtrate, as 
a result of which they showed no reaction, were then inoculated with 
a tubercule from a guinea pig; then the guinea pigs died in fifteen 
and the rabbits in about twenty-three hours. The animals died six- 
teen times more quickly than the control animals. This predisposi- 
tion seems to be at its height from four to twenty days after the first 
injection of the soluble extract. Courmont believes that the organ- 
ism, as a result of the previous treatment, becomes a better culture 
medium for the infection. The gist of his explanation lies in the fact 
that the organism possesses for itself protective substances which 
are eliminated or neutralized by means of the soluble products of the 
first injection. This explanation is called, for short, the ’“ absorption 
theory 7 7 (Ausschaltungs Theorie) . Why several days are necessary for 
this action Courmont does not explain. 
The school at Lyons developed this observation in relation to 
other micro-organisms, as the staphylococcus, streptococcus, bacillus 
pyocyaneus, etc. Rist made similar observations with the diph- 
theria bacillus. 
Strauss and Gamaleia 6 report that animals, after repeated injec- 
tions with dead tubercle bacilli, die acutely. They bear the first 
injection of large quantities without reaction. 
Babes and Proca c confirmed this observation. 
Against the “addition 77 theory of Koch, to which most of the Ger- 
man authorities adhere, and against the “absorption 77 theory of the 
a Courmont: Etudes sur les substances solubles predisposantes a Faction pathogene de 
leurs microbes producteurs. Rev. de med., 1891. Centbl. f. Bakt., Bd. 13, p. 714. 
b Strauss, L., and N. Gamaleia: Recherches experimentales sur la tuberculose. Arch, 
de med. experiment., Ill, 1899. 
c Babes and Proca: Untersuchungen iiber die Wirkung der Tuberkelbacillen und liber 
gegenwirkende Substanzen. Zeit. f. hyg., v. 23, p. 331. 
