From Chapter 1:
Who first smoked a pipe of tobacco in England? The honour is divided among several claimants. It has often been stated that Captain William Middleton or Myddelton (son of Richard Middleton, Governor of Denbigh Castle), a Captain Price and a Captain Koet were the first who smoked publicly in London, and that folk flocked from all parts to see them; and it is usually added that pipes were not then invented, so they smoked the twisted leaf, or cigars. This account first appeared in one of the volumes of Pennant's "Tour in Wales." But the late Professor Arber long ago pointed out that the remark as to the mode of smoking by cigars and not by pipes was simply Pennant's speculation. The authority for the rest of the story is a paper in the Sebright MSS., which, in an account of William Middleton, has the remark: "It is sayed, that he, with Captain Thomas Price of Plâsyollin and one Captain Koet, were the first who smoked, or (as they called it) drank tobacco publickly in London; and that the Londoners flocked from all parts to see them." No date is named, and no further particulars are available.

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.