mentary on the Acts,’ Bede writes to Acca: ‘Accepi creberrimas beatitudinis tuæ literas, quibus me commonere dignatus es, ne mentis acumen inerti otio torpere et obdormire permittam.’ One only of these letters of Acca has come down to us (Bedæ Op. ed. 1563, v. 175; also Raine's Priory of Hexham, i. 33). In this letter Acca beseeches Bede to write a commentary on St. Luke's Gospel; he combats the plea that the work has been sufficiently done by St. Ambrose; he urges the need of a simpler commentary, and humorously exclaims, ‘Beatum Lucam luculento sermone expone.’
The end of Acca's life is obscure. In 732 he was driven from the see of Hexham. We do not know the reason; probably it was some cause connected with the still uncertain organisation of the Northumbrian dioceses. It cannot have been for any reason disgraceful to him, since he was revered by the monks of Hexham as a saint. Richard of Hexham (p. 35) records a story that Acca spent the years of his exile in organising the new diocese of Whithern, in Galloway. However this may be, Acca returned to Hexham before his death in 740. He was buried outside the east wall of the church, and two stone crosses of elaborate workmanship were erected over his grave (Simeon, in Twysden, 101). One of these crosses has been identified by Raine, and is engraved in the ‘Priory of Hexham’ (i. p. xxxiv). The remains of Acca were twice translated, once in the eleventh century and again in 1154. He is commemorated in the Calendar on 19 Feb. His miracles are recorded by Simeon of Durham, s. a. 740, and by Aelred, abbot of Rievaux (Raine, i. 184).
ACCUM, FRIEDRICH CHRISTIAN (1769–1838), chemist, was born in Buckebourg, in Westphalia, in 1769. In 1793 he came to London, and engaged in some science work, which led to the delivery of a course of lectures on chemistry and physics in 1803 at the Surrey Institute, and to the publication in that and the following years of several treatises on chemistry and mineralogy, including a ‘System of Chemistry’ in 1803, an ‘Essay on the Analysis of Minerals’ in 1804, and a ‘Manual of Analytical Mineralogy’ in 1808. He afterwards associated himself with Ackermann, the art publisher, in order to introduce into England the lighting of towns by gas; and in 1810, when the London Chartered Gaslight and Coke Company was formed, Accum was nominated one of its engineers. It is said that the prompt adoption of this mode of lighting in London and other large cities was greatly due to his ‘Practical Treatise on Gas Light,’ which was published in London in 1815 (3rd edit. 1816), and speedily translated into German, French, and Italian. A second work by Accum on the same subject, entitled ‘Description of the Process of manufacturing Coal Gas,’ appeared in 1819 (2nd edit. 1820). He was made librarian of the Royal Institution in Albemarle Street, but a charge of embezzlement was brought against him shortly afterwards, and he was dismissed. On being brought to trial, he was acquitted; but he immediately left England for Berlin. There, in 1822, he obtained a professorship at the Technical Institute, which he retained till his death on 28 June 1838. Accum published ‘Chemical Amusement’ (London, 1817, 4th edit. 1819), which was translated into German in 1824, and into French in 1827; and ‘Adulterations of Food and Culinary Poisons’ (London, 1820, 2nd edit. 1820), which was translated into German in 1822. In 1826 he published a work in two volumes at Berlin on the physical and chemical qualities of building materials (Physische und chemische Beschaffenheit der Baumaterialen). He also wrote on ‘Crystallography’ (London, 1813); on ‘Chemical Reagents’ (London, 1816), translated into Italian in 1819; on the ‘Chalybeate Spring at Thetford’ (1819); on ‘Brewing’ (London, 1820); on the ‘Art of making Wine’ (London, 1820), translated into French in 1821; on ‘Culinary Chemistry’ (London, 1821); and on the ‘Art of making wholesome Bread’ (London, 1821).
ACHERLEY, ROGER (1665?–1740), lawyer, constitutional writer, and politician, was the son and heir of John Acherley of Stanwardine, or Stottesden, Shropshire, where he was the representative of a long-established family. Roger was admitted a student of the Inner Temple on 6 March 1685, and called to the bar on 24 May 1691 (Inner Temple Register). He married Elizabeth, only daughter of Richard Vernon, Esq., of Hanbury, Worcestershire, and sister of Thomas Vernon, Esq., a celebrated lawyer, known especially for his ‘Reports,’ posthu-