Under all these influences many laws were promulgated which profoundly altered the legal position of the slaves, and opened what may be termed the third period of Roman slavery. The Petronian law, which was issued by Augustus, or, more probably, by Nero, forbade the master to condemn his slave to combat with wild beasts without a sentence from a judge.(584) Under Claudius, some citizens exposed their sick slaves on the island of Æsculapius in the Tiber, to avoid the trouble of tending them, and the emperor decreed that if the slave so exposed recovered from his sickness he should become free, and also, that masters who killed their slaves instead of exposing them should be punished as murderers.(585) It is possible that succour was afforded to the abandoned slave in the temple of Æsculapius,(586) and it would appear from these laws that the wanton slaughter of a slave was already illegal. About this time the statue of the emperor had become an asylum for slaves.(587) Under Nero, a judge was appointed to hear their complaints, and was instructed to punish masters who treated them with barbarity, made them the instruments of lust, or withheld from them a sufficient quantity of the necessaries of life.(588) A considerable pause appears to have ensued; but Domitian made a law, which was afterwards reiterated, forbidding the Oriental custom of mutilating slaves for sensual purposes, and the reforms were renewed with great energy in the period of the Antonines. Hadrian and his two successors formally deprived masters of the right of killing their slaves; forbade them to sell slaves to the lanistæ, or speculators in gladiators; destroyed the ergastula, or private prisons; ordered that, when a master was murdered, those slaves only should be tortured who were within hearing;(589) appointed officers through all the provinces to hear the complaints of slaves; enjoined that no master should treat his slaves with excessive severity; and commanded that, when such severity was proved, the master should be compelled to sell the slave he had ill-treated.(590) When we add to these laws the broad maxims of equity asserting the essential equality of the human race, which the jurists had borrowed from the Stoics, and which supplied the principles to guide the judges in their decisions, it must be admitted that the slave code of Imperial Rome compares not unfavourably with those of some Christian nations.