cruder
tricks of those who make a corrupt use of statistics for advertizing
purposes. There is, for example, the percentage dodge. In some hamlet,
barely large enough to have a name, two people are attacked during a
smallpox epidemic. One dies: the other recovers. One has vaccination
marks: the other has none. Immediately either the vaccinists or the
antivaccinists publish the triumphant news that at such and such a place
not a single vaccinated person died of smallpox whilst 100 per cent of
the unvaccinated perished miserably; or, as the case may be, that 100
per cent of the unvaccinated recovered whilst the vaccinated succumbed
to the last man. Or, to take another common instance, comparisons
which are really comparisons between two social classes with different
standards of nutrition and education are palmed off as comparisons
between the results of a certain medical treatment and its neglect. Thus
it is easy to prove that the wearing of tall hats and the carrying of
umbrellas enlarges the chest, prolongs life, and confers comparative
immunity from disease; for the statistics show that the classes which
use these articles are bigger, healthier, and live longer than the class
which never dreams of possessing such things. It does not take much
perspicacity to see that what really makes this difference is not the
tall hat and the umbrella, but the wealth and nourishment of which they
are evidence, and that a gold watch or membership of a club in Pall Mall
might be proved in the same way to have the like sovereign virtues. A
university degree, a daily bath, the owning of thirty pairs of trousers,
a knowledge of Wagner's music, a pew in church, anything, in short, that
implies more means and better nurture than the mass of laborers enjoy,
can be statistically palmed off as a magic-spell conferring all sorts of
privileges.

In the case of a prophylactic enforced by law, this illusion is
intensified grotesquely, because only vagrants can evade it. Now
vagrants have little power of resisting any disease: their death rate
and their case-mortality rate is always high relatively to that of
respectable folk. Nothing is easier, therefore, than to prove that
compliance with any public regulation produces the most gratifying
results. It would be equally easy even if the regulation actually raised
the death-rate, provided it did not raise it sufficiently to make the
average householder, who cannot evade regulations, die as early as