quietener

A man doesn't get delirium tremens even if he smokes more than is good for him; he doesn't become a debased mortal; there is nothing about tobacco which makes a man beat his wife or assault his mother-in-law -- rather the reverse, in fact, for tobacco is a soother and a quietener of the passions, and many a man, I daresay, has been prevented from doing rash things in the way of retaliation, when he has lit his pipe and had a good think over his affairs.

The Social History of Smoking George Latimer Apperson 1897