re, more
readily controlled than that of tuberculosis. It is impossible for a
syphilitic to leave a room or a house infected for the next occupants,
and it is not necessary to do more than disinfect objects that come in
contact with open lesions or their secretions, to prevent its spread by
indirect means. Such details will be considered more fully under the
transmission and hygiene of the disease.

+Mode of Entry of the Germ.+--The germ of the disease probably gains
entrance to the body through a break or abrasion in the skin or the
moist red mucous surfaces of the body, such as those which line the
mouth and the genital tract. The break in the surface need not be
visible as a chafe or scratch, but may be microscopic in size, so that
the first sore seems to develop on what is, to all appearances, healthy
surface. It should not be forgotten that this surface need not be
confined to the genital organs, since syphilis may and often does begin
at any part of the body where the germ finds favorable conditions for
growth.

+Incubation or Quiescent Period.+--Almost all germ diseases have what is
called a period of incubation, in which the germ, after it has gained
entrance to the body, multiplies with varying rapidity until the
conditions are such that the body begins to show signs of the injury
which their presence is causing. The germ of syphilis is no exception to
this rule. Its entry into the body is followed by a period in which
there is no external sign of its presence to warn the infected person
of what is coming. This period of quiescence between the moment of
infection with syphilis and the appearance of the first signs of the
disease in the form of the chancre may vary from a week to six weeks or
even two months or more, with an average of about two or three weeks.

In the length of the incubation period and the comparatively trifling
character of the early signs, the germ of syphilis betrays one of its
most dangerous characteristics. The germ of pneumonia, for example, may
be present on the surface of the body, in the mouth or elsewhere, for a
long time, but the moment it gets a real foothold, there is an immediate
and severe reaction, the body puts up a fight, and in ten days or so has
either lost or won. The germ of syphilis, on the other hand, secures its
place in the body without exciting very strenuous or wide-spread
opposition. The body does not come to its own defense so well as with a
more active enemy.