85 
Lyons school, Kohler and Westpfal a in 1891 announced a third theory 
to explain the action of tuberculin. The last-named authors believed 
that, through the union of tuberculin with the products of the tuber- 
cle bacilli in the tuberculous lesions, a third and new body results 
which causes the clinical manifestations of the tubercle reaction. 
A similar explanation is used by Marmorek to account for the 
elevation of temperature. He believes that the tubercle bacilli, 
under the influence of tuberculin, secretes a pathogenic substance. 
Bail, based upon the work of Detre-Deutsch, has taken up anew 
the work of Courmont and studied more precisely the hypersensi- 
bility in tuberculosis. To explain this hypersensibility in tubercu- 
lous guinea pigs he advances another theory, based upon the power 
to transmit the hypersensibility. For example, if we inject an 
animal, into the peritoneal cavity, at a certain stage of tuberculosis 
the animal dies rapidly. At the site of the injection an exudate is 
produced. If this exudate is added to tubercle bacilli and injected 
into normal animals it produces sudden death. 5 
Bail believes that the tubercle bacillus secretes a soluble substance 
in the infected organism which substance exerts a paralytic action 
upon the leucocytes. This substance he has called “ aggressing’ He 
believes that the exudate obtained by this reaction contains this 
aggressin and, when carried over, has the power of destroying the 
power of the leucocytes — that is, the protecting power of the new 
organism — and therefore the poisonous substance in the tubercle 
bacillus is able to develop its power quickly. 
This explanation seems to be in line with Arloing and Courmont’ s. 
In recent years Wolff c has also worked up the question of hyper- 
sensibility, proceeding upon the work of Pfeiffer upon the endotoxins. 
The endotoxin only possesses power when the bacterial capsules are 
dissolved by means of bacteriolysins that are freed by means of anti- 
bodies. As soon as the endotoxin is set free it exerts its power and, 
without a period of incubation, is a powerful poison. 
The results of Pfeiffer and Wolff’s observations upon the method 
of operation of the endotoxin are very closely related to von Pirquet 
and Schick’s explanation of the production of the serum disease. 
Wolff also experimented upon the question of hypersensibility 
caused by the reinjection of dissolved albuminous substances and 
his observations coincided with those of Arthus, Pirquet, and Schick. 
The endotoxic theory, in the sense of bacteriolysis, naturally can not 
“Kohler and Westphal: Eine neue Theorie zur Erklarung der Wirkung des Koch’sch en 
Heilmittels auf den tuberculosen Menscken. Dent. med. \rock., 1891, p. 839. 
& Bail: Ueber Empfindliehkeit bei tuberculosen Thieren. Weiner klin. woch., 1904. 
Der acute Tod von Meerschweinchen an Tuberculose. Loc. cit., 1905. 
c Wolff, A.: Uber grundgesetze der immunitat. Centblt. f. bakt., bd. 37, 1904, pp . 390, 
566, and 684. _ 
