Cotton was a physician, remarkable for his success and humanity in the treatment of mental disorders. He kept an asylum for insane patients in the town of St. Albans, and called it the College. Cowper was for some time under his care. Few particulars of his life have been preserved, but there are many testimonies to the excellence of his character. Among these is the following affectionate tribute to his memory from one of the letters of Cowper. "I reckon it one instance of the Providence that has attended me throughout this whole event, that instead of being delivered into the hands of one of the London physicians, who were so much nearer that I wonder I was not, I was carried to Dr. Cotton. I was not only treated by him with the greatest tenderness while I was ill, and with the utmost diligence, but when my reason was restored to me, and I had so much need of a religious friend to converse with, to whom I could open my mind upon the subject without reserve, I could hardly have found a fitter person for the purpose. My eagerness and anxiety to settle my opinions on that long neglected point made it necessary that while my mind was yet weak, and my spirits uncertain, I should have some assistance. The Doctor was as ready to administer relief to me in this article likewise, and as well qualified to do it, as in that which was more immediately his province. How many physicians would have thought this an irregular appetite and a symptom of remaining madness! But if it were so, my friend was as mad as myself, and it is well for me that he was so."
Mr. Hayley observes of Dr. Cotton, that he was "a scholar and a poet, who to many accomplishments added a peculiar sweetness of manners in very advanced life."
His writings do not display an original genius, but are full of good sense, benevolence and piety. The Fireside is a beautiful domestic picture.