The custom of exposing old, useless, or sick slaves in an island of the Tiber, there to starve, seems to have been pretty common in Rome, and whoever recovered after having been so exposed had his liberty given him by an edict of the Emperor Claudius, where it was likewise forbid to kill any slave merely for old age or sickness. But supposing that this edict was strictly obeyed, would it better the domestic treatment of slaves or render their lives much more comfortable? We may imagine what others would practise when it was the professed maxim of the elder Cato to sell his superannuated slaves for any price rather than maintain what he esteemed a useless burden. The _ergastula_, or dungeons, where slaves in chains were forced to work, were very common all over Italy. Columella advises that they be always built under ground, and recommends it as the duty of a careful overseer to call over every day the names of these slaves, like the mustering of a regiment or ship’s company, in order to know presently when any of them had deserted. A proof of the frequency of these _ergastula_ and of the great number of slaves usually confined in them. A chained slave for a porter was usual in Rome, as appears from Ovid and other authors. Had not these people shaken off all sense of compassion towards that unhappy part of their species, would they have presented all their friends at the first entrance with such an image of the severity of the master and misery of the slave? Nothing so common in all trials, even of civil causes, as to call for the evidence of slaves, which was always extorted by the most exquisite torments. Demosthenes says that where it was possible to produce for the same fact either freemen or slaves as witnesses, the judges always preferred the torturing of slaves as a more certain and infallible evidence.​[42] Seneca draws a picture of that disorderly luxury which changes day into night and night into day, and inverts every stated hour of every office in life. Among other circumstances, such as displacing the meals and times of bathing, he mentions that regularly about the third hour of the night the neighbours of one who indulges this false refinement hear the noise of whips and lashes, and upon inquiry find that he is then taking an account of the conduct of his servants and giving them due correction and discipline. This is not remarked as an instance of cruelty, but only of disorder, which, even in actions the most usual and methodical, changes the fixed hours that an established custom had assigned them.​[43]