It should be remembered that, in all cases where the contrary is not explicitly announced, the slave is of the same colour and race as the master. At this era of the world, slaves were too common, and their value too little, to warrant the expense of a distant importation. The negro slave, from his exhibiting an extreme variety of the human species, was regarded more as an article of curiosity and pride than usefulness; and therefore was seldom or never found in Europe, except near the royal palaces, or in the trains of emperors. As early as the days of Polycarp and St. Ignatius, who were disciples of the apostles, Christians had, from motives of mercy, charity, and affection, manumitted many of their slaves in presence of the bishops, and this was more or less extensively practised through the succeeding period. In several churches, it was agreed that if a slave became a Christian, he should be manumitted on receiving baptism. In Rome, the slave was frequently manumitted by the form called _vindicta_, with the prætor’s rod. Constantine, in the year 317, Sozomen relates, lib. i. c. 9, transferred this authority to the bishops, who were empowered to use the rod in the church, and have the manumission testified in the presence of the congregation. A rescript of that emperor to this effect is found in the Theodosian code, 1. i. c. _De his qui in eccl. manumitt_. The master, who consented to manumit the slave, presented him to the bishop, in presence of the congregation, and the bishop pronounced him free, and became the guardian of his freedom. The rescript was directed to Protogenas, bishop of Sardica, and was in the consulship of Sabinus and Ruffinus. In book ii. of the same code, is a rescript to Osius, bishop of Cordova, in which the emperor empowers the bishops to grant the privilege of Roman citizenship to such freedmen as they may judge worthy. In the consulship of Crispus and Constantine, a grant was given to the clergy of manumitting their own slaves when they pleased, by any form they should think proper. About a century later, St. Augustine, bishop of Hippo, informs us (_Sermo. de diversis_, 50) that this form was established in Africa. “The deacon of Hippo is a poor man: he has nothing to give to any person: but, before he was a clergyman, he, by the fruit of his labour and industry, bought some little servants, and is to-day, by the episcopal act, about to manumit them in your sight.”