lear solution
of sewage, no matter how dilute; but, as a matter of fact, it is
astonishing how long communities may drink sewage-laden water with
comparative impunity, so long as the sewage contains no typhoid
discharges. One case of typhoid fever imported into a watershed will set
a city in a blaze.

The malevolent _Deus_ in the sewage _machina_ is, of course, a germ--the
_Bacillus typhosus_ of Eberth. The astonishing recentness of much of our
most important knowledge is nowhere better illustrated than in the case
of typhoid. Although there had been vague descriptions of a fatal fever,
slow and lingering in its character and accompanied by prolonged stupor
and delirium, which was associated with camps and dirty cities and
famines, from as far back as the age of Caesar, the first description
clear enough to be recognizable was that of Willis, of an epidemic
during the English civil war in 1643, both Royalist and Roundhead armies
being seriously crippled by it. Since that time a smouldering, slowly
spreading fever has been pretty constantly associated with armies in
camps, besieged cities, filthy jails, and famines, to which accordingly
have been given the names, familiar in historical literature, of "famine
fever," "jail fever," and "military fever."

So slowly, however, did accurate knowledge come, that it was actually
not until 1837 that it was clearly and definitely recognized that this
famine fever was, like Mrs. Malaprop's Cerberus, "two gentlemen at
once," one form of it being typhus or "spotted fever," which has now
become almost extinct in civilized communities; the other, the milder,
but more persistent form, which, like the poor, we have always with us,
called, from its resemblance to the former, "typhoid" (typhus-like).

Typhus was a far more virulent, rapid, and fatal fever than its twin
survivor, though as to the relations between the two diseases, if any,
we are quite in the dark, as the former practically disappeared before
the days of bacteriology. The fact of its disappearance is both
significant and interesting, in that it was unquestionably due to the
ranker and viler forms of both municipal and individual filthiness and
unsanitariness, which even our moderate progress in civilization has
now abolished. There can be no question that, with a step higher in the
scale of cleanliness, and further quickening of the biologic conscience,
typhoid will also disappear.

Typhus, the bubonic plague, the sweat