more than one type of eruption--papules and pustules, for
example--are present at the same time; there is little itching; they are
at first a dull-red colour, but later present a brown pigmentation which
has been likened to the colour of raw ham; they exhibit a predilection
for those parts of the forehead and neck which are close to the roots of
the hair; they tend to pass off spontaneously; and they disappear
rapidly under treatment.

#Serum Diagnosis--Wassermann Reaction.#--Wassermann found that if an
extract of syphilitic liver rich in spirochaetes is mixed with the serum
from a syphilitic patient, a large amount of complement is fixed. The
application of the test is highly complicated and can only be carried
out by an expert pathologist. For the purpose he is supplied with from 5
c.c. to 10 c.c. of the patient's blood, withdrawn under aseptic
conditions from the median basilic vein by means of a serum syringe, and
transferred to a clean and dry glass tube. There is abundant evidence
that the Wassermann test is a reliable means of establishing a diagnosis
of syphilis.

A definitely positive reaction can usually be obtained between the
fifteenth and thirtieth day after the appearance of the primary lesion,
and as time goes on it becomes more marked. During the secondary period
the reaction is practically always positive. In the tertiary stage also
it is positive except in so far as it is modified by the results of
treatment. In para-syphilitic lesions such as general paralysis and
tabes a positive reaction is almost always present. In inherited
syphilis the reaction is positive in every case. A positive reaction may
be present in other diseases, for example, frambesia, trypanosomiasis,
and leprosy.

As the presence of the reaction is an evidence of the activity of the
spirochaetes, repeated applications of the test furnish a valuable means
of estimating the efficacy of treatment. The object aimed at is to
change a persistently positive reaction to a permanently negative one.

#Treatment of Syphilis.#--In the treatment of syphilis the two main
objects are to maintain the general health at the highest possible
standard, and to introduce into the system therapeutic agents which will
inhibit or destroy the invading parasite.

The second of these objects has been achieved by the researches of
Ehrlich, who, in conjunction with his pupil, Hata, has built up a
compound, the dihydrochloride of dioxydiamido-arseno-benzol,