the face of the
earth. When the only requirement is the destruction of the mosquitoes
and when mosquitoes can be so easily killed as already explained, it is
only a question of time before mosquitoes and the diseases they cause
will be stamped out. In Havana, before 1901, the number of the deaths
yearly was about 750. In the year after the American intervention, when
Colonel Gorgas, by military command, insisted on the thorough cleaning
of the houses and the general use of kerosene in all drains and
cesspools, there was not one single death.

_Hookworm disease._

The third parasitical disease common in some parts of the United States
has received much attention during this last year and is known as the
hookworm disease. It is a new discovery in medical science, and whereas
the physical condition of the victim is usually a clear indication of
the disease, a positive diagnosis is always obtained by the use of the
microscope. Several years ago it was announced in the United States that
the laziness and shiftlessness of the poor whites living in the sand
lands and pine barrens of the South was due, not to any inherent
cussedness but to the presence of a parasite in the intestine, known in
Italy and Germany as the hookworm, the disease being called
Uncinariasis.

The development of the disease is interesting. The worm, which is about
an inch long and looks not unlike a bit of thread, lays eggs by the
thousand in the intestinal tract of a human victim. Afterwards they pass
out in the excreta and, favored by heat and moisture, develop in the
soil in about three days into minute larvae. These larvae have a most
extraordinary power of attaching themselves to and penetrating into the
human skin and body. They may also enter the human body in a drink of
water or on unwashed vegetables. In infected regions the soil becomes
fairly alive with these larvae, and it is hardly possible for a child to
walk barefoot outdoors without becoming infected. When the larvae have
penetrated the hand or foot, they begin a long and circuitous journey
through the body, moving from the extremities through the veins to the
heart and thence to the lungs. From here they are carried through air
cells into the bronchial tubes, thence along the mucous membrane up the
windpipe and down into the stomach and finally, from the stomach, they
pass out into the intestines, the goal of their long journey.

This all takes time, and probably from the time they e