specting the source from whence
it may probably have arisen, and respecting the causes which he deems
sufficiently powerful to have produced so great a revolution. But I,
having myself had the distemper, and having seen others suffering under
it, will state _what it actually was_, and will indicate in addition
such other matters as will furnish any man, who lays them to heart, with
knowledge and the means of calculation beforehand, in case the same
misfortune should ever occur again."

To record past facts, as a basis for rational prevision in regard to the
future--the same sentiment which Thucydides mentions in his preface, as
having animated him to the composition of his history--was at that time
a duty so little understood that we have reason to admire not less the
manner in which he performs it in practice than the distinctness with
which he conceives it in theory. We infer from his language that
speculation in his day was active respecting the causes of this plague,
according to the vague and fanciful physics, and scanty stock of
ascertained facts, which was all that could then be consulted. By
resisting the itch of theorizing from one of those loose hypotheses
which then appeared plausibly to explain everything, he probably
renounced the point of view from which most credit and interest would be
derivable at the time. But his simple and precise summary of observed
facts carries with it an imperishable value, and even affords grounds
for imagining that he was no stranger to the habits and training of his
contemporary Hippocrates, and the other Asclepiads of Cos.

It is hardly within the province of a historian of Greece to repeat
after Thucydides the painful enumeration of symptoms, violent in the
extreme and pervading every portion of the bodily system, which marked
this fearful disorder. Beginning in Piraeus, it quickly passed into the
city, and both the one and the other was speedily filled with sickness
and suffering, the like of which had never before been known. The
seizures were sudden, and a large proportion of the sufferers perished
after deplorable agonies on the seventh or on the ninth day. Others,
whose strength of constitution carried them over this period, found
themselves the victims of exhausting and incurable diarrhoea afterward;
with others again, after traversing both these stages, the distemper
fixed itself in some particular member, the eyes, the genitals, the
hands, or the feet, which were re