The twin sisters Agnes Lewis (1843–1926) and Margaret Gibson (1843–1920) were pioneering biblical scholars who became experts in a number of ancient languages. Travelling widely in the Middle East, they made several significant discoveries, including one of the earliest manuscripts of the four gospels in Syriac, the language believed to have been spoken by Jesus himself. Previously published in the Horae Semitica series, this second fascicule contains Gibson's English translation of the Didascalia Apostolorum. Traditionally attributed to the apostles, the text is a treatise on Church law and doctrine, and the volume includes additional material supplied by Gibson from a variety of sources. Covering topics including church organisation, charity and forgiveness, Gibson described the Didascalia as a 'potent instrument' used to gain the 'unquestioning obedience of the Christian people'. An early precursor to the Apostolic Constitutions, this text is of considerable significance to ecclesiastical history.