From Chapter 4:
But to turn from this worthy Exeter citizen to more famous names: I do not know of any good evidence as to whether or not Cromwell smoked, although he is said to have taken an occasional pipe while considering the offer of the crown, but John Milton certainly did. The account of how the blind poet passed his days, after his retirement from public office, was first told by his contemporary Richardson, and has since been repeated by all his biographers. His placid day ended early. The poet took his frugal supper at eight o'clock, and at nine, having smoked a pipe and drunk a glass of water, he went to bed. Apparently this modest allowance of a daily evening pipe was the extent of Milton's indulgence in tobacco. He knew nothing of what most smokers regard as the best pipe of the day—the after-breakfast pipe.

From Chapter 8:
Notwithstanding the unfashionableness of tobacco, there were still some noteworthy smokers to be found among the clergy. Dr. Sumner, head master of Harrow, who died in 1771, was devoted to his pipe. The greatest of clerical "tobacconists" of late eighteenth century and early nineteenth century date was the once famous Dr. Parr. It was from him that Dr. Sumner learned to smoke. When he and Parr got together Sumner was in the habit of refilling his pipe again and again in such a way as to be unobserved, at the same time begging Parr not to depart till he had finished his pipe, in order that he might detain him, we are told, in the evening as long as possible.