SPECIAL BACTERIOLOGY 
185 
A year later Ehrlich discovered the famous Salvarsan 
(606) which, combined with mercury, insures the cure 
in practically all cases. Truly, this has been a wonder¬ 
ful age! 
Syphilis may be transmitted from the parents to the 
offspring. 
The Wassermann Test. —The exact technic will not 
be given here, as the test should be learned in a sero¬ 
logical laboratory by actual work under a careful super¬ 
vision of some competent instructor; but the beginner 
should be acquainted with the general principles of 
the text. Read the chapters on Immunity before you 
read the following. 
If a person has syphilis, he must have the syphilitic 
antibody (amboceptor) ; that is what we wish to deter¬ 
mine in the Wassermann test. We know that ordinarily 
in the body the antigen (the infecting bacterium), the 
amboceptor (the antibody) and the complement (the 
substances always found in the blood) unite together; 
if, therefore, we would take in a test tube, the comple¬ 
ment (for this we use a guinea pig’s blood), the antigen 
(the preparation from the bacteria causing the given 
disease—in this case spirocheta pallida), and the pa¬ 
tient’s blood serum, then, the antigen and the comple¬ 
ment would unite with the amboceptor if the patient has 
syphilis and his blood serum had the amboceptor; but 
even if it were so how would we know it? Such a 
union of the three substances in a test tube would show 
no change visible to the naked eye. 
For this reason, Wassermann, Neisser, and Bruck 
took advantage of the following: they injected the rab¬ 
bit with a sheep’s blood until the rabbit’s serum con¬ 
tained the amboceptor against the sheep’s red blood 
cells; now if into a test tube we place the sheep’s red 
