When they were apart, they questioned and instructed each other minutely on the state of their health. “How is it my darling,” Mill inquired, “that you say you have broken the habit of expectoration? When you cough are you not obliged to swallow something if you do not spit it up?” “I cannot but think,” replied Harriet with her characteristic note of self-righteousness, “that if you tried as earnestly as I have done since October to avoid any expectoration that you would lose the habit altogether as I have done.” It was her idea that Mill was bothered by phlegm because he was in the habit of spitting, not that he was forced to spit because he was bothered by phlegm. Perhaps she was right.

John Stuart Mill and Harriet Taylor recalled in Parallel Lives : Five Victorian Marriages by Phyllis Rose (1984)