The Apostolic Period began on the day of Pentecost when the disciples who were gathered together were a hundred and twenty in number (Acts i. 15), but were only a section of the 500 brethren who had seen the Lord after His resurrection (I. Cor. xv. 6). On the same day, as the result of St. Peter's first missionary sermon, "there were added unto them about three thousand souls" (Acts ii. 41). A short time afterwards "the number of the disciples multiplied in Jerusalem greatly; and a great company of the priests were obedient to the faith" (Acts vi. 7). This progress continued to such a degree that St. James, after hearing the interesting missionary report of St. Paul, "about the things which God had wrought among the Gentiles by his ministry," said to him, "Thou seest, brother, how many thousands of Jews there are which believe" (Acts xxi. 20). How glad we should have been if we had some account of, at least, the more prominent converts of that period, and knew something of the sufferings that they had to endure for the sake of Christ. Nevertheless, the Acts of the Apostles, though containing much in relation to the progress of the Gospel among Jews and Gentiles, gives but little information with regard to Jewish individual conversions, and mentions only two Jewish Christian martyrs--namely, St. Stephen and James the Elder--and is even silent about the exclusion of Jewish converts from the Temple, which we gather only from the Epistle to the Hebrews. This fact is to us an evidence that St. Luke, the first ecclesiastical historian, had no design to shew to the world the inherent power of the Gospel exemplified by the conversion of many of the very people who had rejected Christ, and it proves the genuineness and authenticity of the Acts of the Apostles and the date commonly assigned, for had it been written later, as some critics maintain, the author would surely have taken the trouble to give his readers some detailed information concerning at least one per cent. of that vast multitude of Jewish converts mentioned by St. James. Such is the method of the ecclesiastical historian in modern as well as in ancient times, as the following two examples will shew: Pastor de le Roi, Jewish missionary historian, has for years not only collected statistics of Jewish converts in various churches, and summed up the whole number as being 224,000 in the nineteenth century, but he has also furnished us with a great deal of information concerning the history of many of these converts. For, as the Rev. W. T. Gidney rightly says, "Jewish converts must be weighed as well as counted." The second example is Hegesippus, who, according to Eusebius, was a Palestinian Hebrew Christian, and lived in Rome about 150 A.D. He is the father of Church history, and wrote a book under the title "Hyponeymata Pente," with the special design to answer the question of the Pharisees, "Have any of the rulers believed in Him?" and to shew that the Gospel made rapid progress among