among crimes. He stood alone among his friends in advocating complete toleration for 'papists,' against the opinion of Lardner and Kippis. With the idea of a national church he had no sympathy, though admitting the utility of existing establishments, and desiring, not their dissolution, but their reform. He advocated the withdrawal of the 'regium donum,' then given to English as well as to Irish dissenters. It was with difficulty that he was persuaded to add his name to the petition (1772) for modifying the Toleration Act, which resulted in the amended act of 1779. 'You have hitherto,' he writes pamphlet of 1773, 'preferred your prayer as Christians; stand forth now in the character of men, and ask at once for the repeal of all the penal laws which respect matters of opinion.' He never qualified under either act, but thought liberty less menaced by the old subscription, practically a dead letter, than by the new and easier subscription, which might be enforced. In the same spirit he advised Theophilus Lindsey [q. v.] not to resign his benefice, but to make his own alterations in the prayer-book (as several clergymen did), and wait till he was ejected. But when Lindsey resigned (1773), Priestley acknowledged his friend's 'better judgment,' and entered heartily into his plans for a new religious movement under the Unitarian name. Till a minister's house was ready for him, he resided in Meadow Lane in the suburbs of Leeds, next door to a brewery. In 1770 he founded the Leeds circulating library. In December 1771 his study of science, to which he had long devoted his leisure (see infra for his scientific work), had brought him sufficient reputation to lead Sir Joseph Banks [q. v.] to offer him the appointment of 'astronomer' (Memoirs, i. 157) to the second expedition of James Cook (1728-79) [q. v.] The Mill Hill congregation agreed to provide an assistant during his absence; but clerical influence intervened, and Priestley's place was filled by Johann Reinhold Forster, who had succeeded him at Warrington [see under Forster, Johann Georg Adam]. A curious story belonging to this period is told of a woman, who imagined herself possessed, applying to him as 'a great philosopher who could perform miracles;' he exorcised the demon by help of an electrical machine.
In December 1772 William Fitzmaurice-Petty, second earl of Shelburne, afterwards first marquis of Lansdowne [q. v.], on the recommendation of Price, appointed Priestley his librarian or 'literary companion.' He was to furnish Shelburne with information on topics arising in parliament, and to superintend the education of Shelburne's sons, with Thomas Jervis [q. v.] under him as tutor. For this he was to have a salary of 250l. with a house at Calne, Wiltshire (near to Bowood), and rooms in Shelburne's London house in Berkeley Square; if the agreement ended by mutual consent, Priestley was to receive an annuity of 150l. He was to preach when he pleased, and pursue his own studies. He resigned Mill Hill on 20 Dec. 1772, preached his farewell sermon on 16 May 1773, and removed to Calne in June. For some years the arrangement worked smoothly. Priestley catalogued Shelburne's books and manuscripts (now the Lansdowne MSS. in the British Museum), and indexed his private papers. Shelburne gave him an addition of 40l. a year towards his scientific experiments; a similar sum was contributed annually (from 1777) by scientific friends through John Fothergill, M.D. [q. v.] In 1774 he spent three months (August-October) abroad with his patron, visiting Brussels (where a 'popish priest' tried to convert him), Holland, with which he was 'much disgusted,' the Rhine, and Paris, where he exhibited some of his experiments on air. Just before starting he had made his capital discovery (1 Aug. 1774) of 'dephlogisticated air' (see below). His winters were spent in London, where he frequented the Whig Club at the London coffee-house, Ludgate Hill, of which Franklin and Canton were members.
By 1778, for some reason unknown to Priestley, but probably owing to his adoption of 'materialism,' his patron's feeling towards him had cooled, and in May 1780 he proposed to transfer him to an establishment on his Irish estate. Priestley at once offered to retire from Shelburne's service. The separation was amicable, and the annuity was punctually paid. Some years later (apparently in 1784) Shelburne made overtures for a renewal of the connection, which Priestley wisely declined.
During Priestley's engagement with Shelburne appeared his 'Examination' (1774) of the Scottish philosophy, written in a tone which he afterwards regretted. It was his first effort in psychology. Up to 1774 he maintained the ordinary distinction of soul and body, as having no common properties; though he had held, with Edmund Law [q. v.], that the soul acts only through an organism. His first hint of the doctrine of the homogeneity of man was given in an essay (1775) introductory to a selection from Hartley. It brought upon him the imputation of atheism. A copy of the work, at the sale of the Abbé Needham's library at Brussels in 1782, was seized by the licensers, and burned along with a copy of Cudworth's 'Intellectual System.' Further study resulted