er
against them, for in no known civil epidemic has the number of those who
caught the disease exceeded ten per cent of the total number drinking
the infected water or milk. In one or two camps in time of war the
percentage has risen as high as eighteen or twenty per cent of those
exposed, but this is exceptional. However, now that we know that
intestinal symptoms do not constitute the entire disease, and may even
be entirely absent, we strongly suspect that many cases of slight
depression, with feverishness, loss of appetite, and disturbances of the
digestion, which occur during an epidemic, may really have been very
mild cases of the disease.

One of the singular features of the disease is that, unlike many other
infections, we are entirely unable to say what conditions or influences
seem either to protect against it or to predispose toward it. In the
days when we believed it to be an exclusively intestinal disease it was
naturally supposed that chronic digestive disturbances, and especially
acute attacks of bowel trouble or dysentery, would predispose to it, but
this has been entirely disproved. Soldiers in barracks with chronic
digestive disturbances, and even with dysentery, have shown no higher
percentage of typhoid during an epidemic than others. Nor does it seem
much more likely to occur in those who are constitutionally weak, or run
down, or overworked, as some of the most violent and unmanageable cases
occur in vigorous men and women, who were previously in perfect health.
So that, although we have unquestionably a high degree of resistance
against it, since not more than one in ten exposed contracts it, and
only one in ten of those who contract it dies, we have not the least
idea in what direction, so to speak, to build up our resisting powers in
order to increase them.

The best remedy is to destroy the disease altogether, and this could be
done in five years by intelligent concerted effort. It was at one time
supposed that typhoid fever was a disease exclusively confined to adult
life; but it is now known to occur frequently in children, though often
in such a mild and irregular form as to escape recognition. Something
like seventy per cent of all cases occur between the fifteenth and the
fortieth year, and it is, for some reason, though rarer, peculiarly
serious and more often fatal after the fiftieth year.

When once the outer wall has been pierced, the sack of the city rapidly
proceeds. The bacilli mu