the eye, of which also no physician of the Middle Ages entertained
a doubt, was general among the people; yet in modern times
surgeons have filled volumes with partial controversies on this
subject. The whole language of antiquity has adapted itself to
the notions of the people respecting the contagion of pestilential
diseases; and their terms were, beyond comparison, more expressive
than those in use among the moderns.

Arrangements for the protection of the healthy against contagious
diseases, the necessity of which is shown from these notions, were
regarded by the ancients as useful; and by man, whose
circumstances permitted it, were carried into effect in their
houses. Even a total separation of the sick from the healthy,
that indispensable means of protection against infection by
contact, was proposed by physicians of the second century after
Christ, in order to check the spreading of leprosy. But it was
decidedly opposed, because, as it was alleged, the healing art
ought not to be guilty of such harshness. This mildness of the
ancients, in whose manner of thinking inhumanity was so often and
so undisguisedly conspicuous, might excite surprise if it were
anything more than apparent. The true ground of the neglect of
public protection against pestilential diseases lay in the general
notion and constitution of human society--it lay in the disregard
of human life, of which the great nations of antiquity have given
proofs in every page of their history. Let it not be supposed
that they wanted knowledge respecting the propagation of
contagious diseases. On the contrary, they were as well informed
on this subject as the modern; but this was shown where individual
property, not where human life, on the grand scale was to be
protected. Hence the ancients made a general practice of