n the vicinity of swamps, and in one of the Rollo Books, so
much read by the children of the last generation, Uncle George requires
Rollo, on a night journey through the Italian marshes, to stay inside
the coach with the windows closed in order not to breathe the night air
and so contract malarial fever. We know to-day that malarial fever comes
only from mosquitoes, that night air has nothing to do with disease, and
we hear the general advice of doctors that, except where it means the
admission of mosquitoes, we should always sleep with our windows open in
order to breathe as much night air as possible, because the night air is
purer than any other air. These early traditions have not only concerned
themselves with damp cellars and night air, but they have insisted that
even the vicinity of a swamp or pond might lead to disease, and the
State Department of Health of New York is in constant receipt of
complaints because of alleged danger to health on account of some pond
or swamp in the vicinity of houses.

Again, one tradition says that a house should not be located in the
midst of a dense growth of trees, because the shade of the trees,
however welcome in summer, will generate and maintain a condition of
dampness in the house and, therefore, be injurious to the health of the
inmates.

Another tradition is that a house ought not to be located in a valley,
but that a hilltop, or at least a sidehill elevation, is preferable, the
possible dampness of the valley being alleged again as the reason.

To-day, so far as is known, there is no direct evidence of dampness
being primarily responsible for any disease, although, heretofore, such
diseases as typhoid fever, yellow fever, bilious fever, malarial fever,
cholera, and dysentery have all been attributed to miasms springing
from damp soil. To-day we are assured by experts that none of these
diseases are induced by dampness alone. One could spend his days
immersed in water up to his chin and never contract any sickness of the
types mentioned merely through that act. Later on, we shall show how the
presence of swamps in the vicinity of a house is objectionable because
of their providing breeding places for insects, but the dampness itself
never has and never will cause disease. As a concrete example, it may be
noted that the country of Holland, in large part lying below the level
of the sea, with drainage canals and ditches everywhere in evidence, is,
in spite of such manifes