In 1776, Arne was engaged to compose music for the Rev. William Mason's drama, "Caractacus." The original libretto was written in 1759; but considerably revised, altered, and adapted for stage purposes in 1776 by the author, and this amended version, with Arne's incidental music, was produced at Covent Garden Theatre on the 6th of December. That it was a complete success is evident; the _New Morning Post, or General Advertiser_, on the day following the performance, congratulated the town "on the acquisition of so fine an entertainment as 'Caractacus' where poetry and music unite their fascinating powers." Dr. Samuel Arnold, the composer, who was attached to Covent Garden Theatre when "Caractacus" was produced, spoke in the highest terms of Arne's music. Unfortunately every vestige of this has disappeared; according to the testimony of Dr. Arnold and of Dr. Thomas Busby, "One of the latest and finest of Dr. Arne's theatrical compositions, was an Opera called 'Caractacus,' founded on a piece of that name written by Mason. Every portion of the music, as the late Dr. Arnold, who had seen it, informed the compilor of this work, evinced a vigour and warmth of imagination worthy of the flower of early manhood. At Dr. Arne's decease, this production came into the possession of his son, Mr. Michael Arne, who unfortunately sold the manuscript to one Harrison, a bookseller in Paternoster-row, who becoming a bankrupt before the piece was published, it was publicly sold together with his other effects, to whom it is not now known, and never has been heard of since." Six years after Dr. Arne's death, in 1784, _The Universal Magazine_ announced that Mr. Michael Arne was intending to publish his father's "Death of Abel, Caractacus, and a Set of Concertos for the Harpsichord or Pianoforte with the Choruses in Judith." Michael Arne died in 1786, without having accomplished his desire; in 1793 the Concertos appeared, having been edited by Mr. Groombridge, and from the interesting preface to the volume we learn that this was the only piece which had been published. Quite recently an anonymous publication of music for Mason's "Caractacus" has been attributed to Dr. Arne, but the composition is so faulty and puerile that, even if other evidence were wanting, it would be impossible to suppose it the work of an experienced and accomplished musician like Arne. The book in question has a water-mark in the paper, 1794, which was sixteen years after Dr. Arne's death. The author's preface to the publication was evidently written by some one alive at that date; it is therefore not necessary to waste more space in discussing it.