g of the brain, early apoplexy,
blindness and deafness, paralysis, chronic fatal kidney and liver
disease, heart failure, hardening of the blood-vessels early in life,
with sudden or lingering death from any of these causes, are among the
ways in which syphilis destroys innocent and guilty alike. And yet, for
all its destructive power, it is one of the easiest of diseases to hold
in check, and if intelligently treated at almost any but the last
stages, can, in the great majority of cases, be kept from endangering
life.

Chapter VI

The Blood Test for Syphilis

It seems desirable at this point, while we are trying to fix in mind the
great value of recognizing syphilis in a person in order to treat it and
thus prevent dangerous complications, to say something about the blood
test for syphilis, the second great advance in our means of recognizing
doubtful or hidden forms of the disease. The first, it will be recalled,
is the identification of the germ in the secretions from the early
sores.

+Antibodies in the Blood in Disease.+--It is part of the new
understanding we have of many diseases that we are able to recognize
them by finding in the blood of the sick person substances which the
body makes to neutralize or destroy the poisons made by the invading
germs, even when we cannot find the germs themselves. These substances
are called antibodies, and the search for antibodies in different
diseases has been an enthusiastic one. If we can by any scheme teach the
body to make antibodies for a germ, we can teach it to cure for itself
the disease caused by that germ. So, for example, by injecting dead
germs as a vaccine in typhoid fever and certain other diseases, we are
able to teach the body to form protective substances which will kill any
of the living germs of that particular kind which gain entrance to the
body. Conversely, if the body is invaded by a particular kind of germ,
and we are in doubt as to just which one it is, we can identify it by
finding in the blood of the sick person the antibody which we know by
certain tests will kill or injure a certain germ. This sort of medical
detective work was first applied to syphilis successfully by Wassermann,
Neisser, and Bruck in 1904, and for that reason the test for these
antibodies in the blood in syphilis is called the Wassermann reaction.
To be sure, it is now known that in syphilis it is not a true antibody
for the poisons of the Spirochaeta pallida for whi