d indolent, and attended with bullet-buboes in
the groin, the diagnosis of primary syphilis is not difficult. Owing,
however, to the great importance of instituting treatment at the
earliest possible stage of the infection, an effort should be made to
establish the diagnosis without delay by demonstrating the spirochaete.
Before any antiseptic is applied, the margin of the suspected sore is
rubbed with gauze, and the serum that exudes on pressure is collected
in a capillary tube and sent to a pathologist for microscopical
examination. A better specimen can sometimes be obtained by puncturing
an enlarged lymph gland with a hypodermic needle, injecting a few minims
of sterile saline solution and then aspirating the blood-stained fluid.

The Wassermann test must not be relied upon for diagnosis in the early
stage, as it does not appear until the disease has become generalised
and the secondary manifestations are about to begin. The practice of
waiting in doubtful cases before making a diagnosis until secondary
manifestations appear is to be condemned.

Extra-genital chancres, _e.g._ sores on the fingers of doctors or
nurses, are specially liable to be overlooked, if the possibility of
syphilis is not kept in mind.

It is important to bear in mind _the possibility of a patient having
acquired a mixed infection_ with the virus of soft chancre, which will
manifest itself a few days after infection, and the virus of syphilis,
which shows itself after an interval of several weeks. This occurrence
was formerly the source of much confusion in diagnosis, and it was
believed at one time that syphilis might result from soft sores, but it
is now established that syphilis does not follow upon soft sores unless
the virus of syphilis has been introduced at the same time. The
practitioner must be on his guard, therefore, when a patient asks his
advice concerning a venereal sore which has appeared within a few days
of exposure to infection. Such a patient is naturally anxious to know
whether he has contracted syphilis or not, but neither a positive nor a
negative answer can be given--unless the spirochaete can be identified.

Syphilis is also to be diagnosed from _epithelioma_, the common form of
cancer of the penis. It is especially in elderly patients with a tight
prepuce that the induration of syphilis is liable to be mistaken for
that associated with epithelioma. In difficult cases the prepuce must be
slit open.

Difficulty may o