After supper I accompanied him to his apartment, and at my request he dictated to me an argument in favour of the negro who was then claiming his liberty, in an action in the Court of Session in Scotland. He had always been very zealous against slavery in every form, in which I, with all deference, thought that he discovered 'a zeal without knowledge.' Upon one occasion, when in company with some very grave men at Oxford, his toast was, 'Here's to the next insurrection of the negroes in the West Indies.' His violent prejudice against our West Indian and American settlers appeared whenever there was an opportunity. Towards the conclusion of his 'Taxation no Tyranny', he says, 'how is it that we hear the loudest YELPS for liberty among the drivers of negroes?'
Boswell's Life of Johnson, eds. Hill & Powell, Vol III, pp. 200-207