sed on a census, because, as will
appear later, even an actual impulse to self-betrayal would not disclose
30 to 40 per cent of the victims of the disease. Approximately this
percentage would either have forgotten the trivial beginnings of it, or
with the germs of it still in their brains or the walls of their
arteries or other out-of-the-way corners of their bodies, would think
themselves free of the disease--long since "cured" and out of danger.

+How Much Syphilis is There?+--Our entire lack of a tangible idea of how
much syphilis there really is among us is, of course, due to the absence
of any form of registration or reporting of the disease to authorities
such as health officers, whose duty it is to collect such statistics,
and forms the principal argument in favor of dealing with syphilis
legally as a contagious disease. Such conceptions of its prevalence as
we have are based on individual opinions and data collected by men of
large experience.

+Earlier Estimates of the Prevalence of Syphilis.+--It is generally
conceded that there is more syphilis among men than women, although it
should not be forgotten that low figures in women may be due to some
extent to the milder and less outspoken course of the disease in them.
Five times more syphilis in men than women conservatively summarizes our
present conceptions. The importance of distinguishing between syphilis
among the sick and among the well is often overlooked. For example,
Landouzy, in the Laennec clinic in Paris, estimated recently that in the
patients of this clinic, which deals with general medicine, 15 to 18 per
cent of the women and 21 to 28 per cent of the men had syphilis. It is
fair to presume, then, that such a percentage would be rather high for
the general run of every-day people. This accords with the estimates,
based on large experience, of such men as Lenoir and Fournier, that 13
to 15 per cent of all adult males in Paris have syphilis. Erb estimated
12 per cent for Berlin, and other estimates give 12 per cent for London.
Collie's survey of British working men gives 9.2 per cent in those who,
in spite of having passed a general health examination, showed the
disease by a blood test. A large body of figures, covering thirty years,
and dating back beyond the time when the most sensitive tests of the
disease came into use, gives about 8 per cent of more than a million
patients in the United States Public Health and Marine Hospital Service
as havin