THYROID IN INFECTIOUS DISEASES 83 
patients with a primary induration are very satisfac- 
tory for this kind of work. When, however, in a sus- 
picious ulcer spirochaeta pallida is found we have no 
right to wait with the abortive treatment till infection 
is generalized. 
Now, I have treated five patients in whom no Spiro- 
chetes were found and where later the Wassermann 
test became positive and secondary symptoms devel- 
oped, with the oral administration of thyroid extract 
(50 milligrams of the dried gland, 3 times daily). Of 
course there are other patients who have never devel- 
oped secondary symptoms or a positive Wassermann 
treated in the same way. They are not mentioned here, 
as it never can be proved that they have been infected 
with syphilis. Asa control, I have used six only locally- 
treated ulcers, which proved later on to be of syphilitic 
origin. 
The Wassermann reaction is a modification of a test 
invented by Bordet & Gengou. This reaction of Bor- 
det & Gengou is a real reaction between antigen and 
antibody. In the beginning, Wassermann and his co- 
operators believed that the syphilis test was based on 
the same principle. Though we cannot yet understand 
the physicochemical process of the Wassermann test, 
one thing is very probable: 
This test is not a simple reaction between antigen 
and antibody, but rather is a test on a colloid-chemical 
change in the serum [Walker (35), Holker (35) ]. 
The positive test may be considered as the first proof 
of the generalization of the pathological process. It is, 
however, of the highest importance to diagnose the 
syphilis before the Wassermann test is positive. Was- 
sermann himself (37), has divided syphilis into two 
periods: a pre- and a post-Wassermann period. In the 
first period an abortive treatment is sufficient. In the 
second period, treatment may take many years. Was- 
