From Chapter 8:
The allusion in these verses to a "satiric wipe" refers to a passage in the poem entitled "Conversation," which Cowper had written in the previous year, 1781. In this passage tobacco is abused in terms which Cowper clearly felt to need modification after his personal intercourse with such a smoker as his friend Bull. In describing, in "Conversation," the manner in which a story is sometimes told, the poet says:

The pipe, with solemn interposing puff,
Makes half a sentence at a time enough;
The dozing sages drop the drowsy strain,
Then pause and puff—and speak, and pause again.
Such often, like the tube they so admire,
Important triflers! have more smoke than fire.

From Chapter 6:
There was clearly no prejudice against smoking at Cambridge. Abraham de la Pryme notes in his diary for the year 1694 that when it was rumoured in May of that year that a certain house opposite one of the colleges was haunted, strange noises being heard in it, several scholars of the college said, "Come, fetch us a good pitcher of ale, and tobacco and pipes, and wee'l sit up and see this spirit." The ale was duly provided, the pipes were lit, and the courageous smokers spent the night in the house, sitting "singing and drinking there till morning," but, alas! they neither saw nor heard anything.

From Chapter 5:
General Monk, to whom Charles II owed so much, is said to have indulged in the unpleasant habit of chewing tobacco, and to have been imitated by others; but the practice can never have been common.

From Chapter 10:
Mr. Furniss, in the paragraph quoted on a previous page, says: "No gentleman in those days was seen smoking even a 'weed' in the streets." The nearest approach to this seems to have been smoking on club steps. Thackeray, in the seventeenth chapter of the "Book of Snobs," speaks of dandies smoking their cigars upon the steps of "White's," most fashionable of clubs, and, in an earlier chapter, of young Ensign Famish lounging and smoking on the steps of the "Union Jack Club," with half a dozen other "young rakes of the fourth or fifth order." Two of Thackeray's own drawings in the "Book of Snobs"—in chapters three and nine—show men, one civil the other military, smoking cigars out of doors; but as these were no doubt arrant snobs, the drawings may be accepted as proof of Mr. Furniss's statement.