From Chapter 4:
There is a curious entry in Thomas Burton's diary of the proceedings of Cromwell's Parliament, which suggests that there may then have been the luxury of a members' smoking-room. Burton was a member of the Parliaments of Oliver and Richard Cromwell from 1656 to 1659, and made a practice—for which historical students have been and are much his debtors—of taking notes of the debates as he sat in the House. Members sometimes objected to and protested against this note-taking, but Burton quietly went on using his pencil, and though his summaries of speeches are often difficult to follow, argument and sense suffering by compression, he has preserved much very valuable matter. Referring to a debate on January 7, 1656-57, on an attempt to go behind the previously passed Act of Oblivion, the diarist records that "Sir John Reynolds had numbered the House, and said at rising there were 220 at the least, besides tobacconists." This can only mean that there were at least 220 members actually present in the House when it rose, not counting the "tobacconists" or smokers, who were enjoying their pipes, not in the Chamber itself, but in some conveniently adjoining place, which may have been a room for the purpose, or may simply have been the lobby referred to above in the extract from "Mercurius Pragmaticus."

From Chapter 5:
Among the many medicinal virtues attributed to tobacco was its supposed value as a preservative from contagion at times of plague. Hearne, the antiquary, writing early in 1721, said that he had been told that in the Great Plague of London of 1665 none of those who kept tobacconists' shops suffered from it, and this belief no doubt enhanced the medical reputation of the weed. I have also seen it stated that during the cholera epidemics of 1831, 1849, and 1866 not one London tobacconist died from that disease; but good authority for the statement seems to be lacking. Hutton, in his "History of Derby," says that when that town was visited by the plague in 1665, that at the "Headless-cross ... the market-people, having their mouths primed with tobacco as a preservative, brought their provisions.... It was observed, that this cruel affliction never attempted the premises of a tobacconist, a tanner or a shoemaker." Whatever ground there may have been for the belief in the prophylactic effect of smoking, there can be no doubt that in the seventeenth century it was firmly held. Howell in one of his "Familiar Letters" dated January 1, 1646, says that the smoke of tobacco is "one of the wholesomest sents that is against all contagious airs, for it overmasters all other smells, as King James they say found true, when being once a hunting, a showr of rain drave him into a Pigsty for shelter, wher he caus'd a pipe full to Be taken of purpose." But here Mr. Howell is certainly drawing the long-bow. One cannot imagine the author of the "Counterblaste" countenancing the use of tobacco under any circumstances.