Arrangements for the protection of the healthy against contagious diseases, the necessity of which is shewn from these notions, were regarded by the ancients as useful; and by many, 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 2nd 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[167]. This mildness of the ancients, in whose manner of thinking inhumanity was so often and so undisguisedly conspicuous, might excite surprise, if it were any thing 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 moderns; but this was shewn where individual property, not where human life, on the grand scale, was to be protected. Hence the ancients made a general practice of arresting the progress of murrains among cattle, by a separation of the diseased from the healthy. Their herds alone enjoyed that protection which they held it impracticable to extend to human society, because they had no wish to do so[168]. That the governments in the 14th century, were not yet so far advanced, as to put into practice general regulations for checking the plague, needs no especial proof. Physicians could, therefore, only advise public purifications of the air by means of large fires, as had often been practised in ancient times; and they were obliged to leave it to individual families, either to seek safety in flight, or to shut themselves up in their dwellings[169], a method which answers in common plagues, but which here afforded no complete security, because such was the fury of the disease when it was at its height, that the atmosphere of whole cities was penetrated by the infection.