He next laboured in Perth for a few years, where he was joined by Robert Sandeman (see Glasites), who became his son-in-law, and eventually was recognized as the leader and principal exponent of Glas's views; these he developed in a direction which laid them open to the charge of antinomianism.
He laboured for the attainment of a united Nonconformist body, which should retain the cultured element without alienating the uneducated.
He laboured for some time as a missionary priest in Staffordshire, held several positions as tutor to young Roman Catholic noblemen, and was finally appointed president of the English seminary at St Omer, where he remained till his death on the 15th of May 1773.
But besides the vocation he had freely selected and assiduously laboured to fulfil, two more external influences helped to shape Martineau's mind and define his problem and his work; the awakening of English thought to the problems which underlie both philosophy and religion, and the new and higher opportunities offered for their discussion in the periodical press.
From that time he gave up all worldly learning and laboured solely to expound spiritual things.
Though a man of great personal strength, Arkwright never enjoyed good health, and throughout his career of invention and discovery he laboured under a severe asthmatic affection.
He also laboured to improve his English style by translation, particularly from the French.
But this they could not do; and since the version, owing to the limitations of the translators, departs widely from the sense of the original, Christian scholars were on the whole kept much farther from the original meaning than their Jewish contemporaries, who used the Hebrew text; and later, after Jewish grammatical and philological study had been stimulated by intercourse with the Arabs, the relative disadvantages under which Christian scholarship laboured increased.
Although there was much in the official life of Lord Palmerston which inspired distrust and alarm to men of a less ardent and contentious temperament, he had a lofty conception of the strength and the duties of England, he was the irreconcilable enemy of slavery, injustice and oppression, and he laboured with inexhaustible energy for the dignity and security of the Empire.
The individuals among the American Quakers who laboured most earnestly and indefatigably on behalf of the Africans were John Woolman (1720-1773) and Anthony Benezet (1713-1784), the latter a son of a French Huguenot driven from France by the revocation of the edict of Nantes.