y
may be successful. Some caution must be observed in this treatment, as
symptoms of poisoning have been observed to follow its use. If they
manifest themselves, an injection of warm olive oil should be given; the
oil, left in for twelve hours or so, forms an emulsion with the bismuth,
which can be withdrawn by aspiration. Iodoform suspended in glycerin may
be employed in a similar manner. When these and other non-operative
measures fail, and the whole track of the sinus is accessible, it should
be laid open, scraped, and packed with bismuth or iodoform gauze until
it heals from the bottom.

The _tuberculous ulcer_ is described in the chapter on ulcers.

CHAPTER IX

SYPHILIS

Definition.--Virus.--ACQUIRED SYPHILIS--Primary period:
_Incubation, primary chancre, glandular enlargement_;
_Extra-genital chancres_--Treatment--Secondary period: _General
symptoms, skin affections, mucous patches, affections of bones,
joints, eyes_, etc.--Treatment: _Salvarsan_--_Methods of
administering mercury_--Syphilis and marriage--Intermediate
stage--_Reminders_--Tertiary period: _General symptoms_,
_gummata_, _tertiary ulcers_, _tertiary lesions of skin, mucous
membrane, bones, joints_, etc.--Second attacks.--INHERITED
SYPHILIS--Transmission--_Clinical features in infancy, in later
life_--Contagiousness--Treatment.

Syphilis is an infective disease due to the entrance into the body of a
specific virus. It is nearly always communicated from one individual to
another by contact infection, the discharge from a syphilitic lesion
being the medium through which the virus is transmitted, and the seat of
inoculation is almost invariably a surface covered by squamous
epithelium. The disease was unknown in Europe before the year 1493, when
it was introduced into Spain by Columbus' crew, who were infected in
Haiti, where the disease had been endemic from time immemorial (Bloch).

The granulation tissue which forms as a result of the reaction of the
tissues to the presence of the virus is chiefly composed of lymphocytes
and plasma cells, along with an abundant new formation of capillary
blood vessels. Giant cells are not uncommon, but the endothelioid cells,
which are so marked a feature of tuberculous granulation tissue, are
practically absent.

When syphilis is communicated from one individual to another by contact
infection, the condition is spoken of as _acquired syphilis_, and the
first v