During the whole time that Priestley was at Bowood his literary activity never ceased. Oratory, Criticism, Metaphysics, Moral Philosophy, and Theology, all successively engaged his active pen. It being probable that the Disquisitions relating to Matter and Spirit would be unpopular, and might be a means of bringing odium on Lord Shelburne, "several attempts," he says, "were made by his friends, though none by himself, to dissuade me from persisting in it. But being as I thought engaged in the cause of important truth, I proceeded without regard to any consequences, assuring them that this publication should not be injurious."[1] The result was a friendly controversy with Dr. Price, but none with Lord Shelburne. While however busy with theological controversy, Priestley also continued those scientific researches which have given him an enduring fame. It was while at Calne that he made the discovery of oxygen, although he himself never recognized the full importance of his own discovery in its bearing on the phenomena of combustion. "Lord Shelburne," he writes, "encouraged me in my philosophical inquiries, and allowed me 40l. per annum for expenses of that kind, and was pleased to see me make experiments to entertain his guests and especially foreigners. The greatest part of the time that I spent with him I passed with much satisfaction, his Lordship always behaving to me with uniform politeness and his guests with respect."[2]
It has been seen that in 1779 Lord Shelburne had married a second time. The intimate position occupied by Priestley in what since 1771 was a bachelor household, became difficult of adjustment in altered circumstances, especially as his occupation as tutor was at an end. Priestley himself began at this time to think that he observed marks of dissatisfaction on the part of Lord Shelburne, who finally intimated to Dr. Price that he wished to give his friend an establishment in Ireland. "This," says he, "gave me an opportunity of acquainting him that if he chose to dissolve the connection, it should
