344 BUTTERWORTH AND CHURCHILL. bably the most profitable medical book ever written (but not to the author, as he sold the copyright for five pounds), after being re-written by Smellie was issued in 1770, by the ordinary booksellers. During the author's lifetime, nineteen editions, each of five thousand, were published, and the volume was trans- lated into all the modern languages. If Mr. Churchill's catalogue can show no book with a popularity like this, it displays many which, appeal- ing only to a class audience, and necessarily obliged to keep pace with the discoveries of the day, have at once retained their high price and yet reached the honour of numerous editions. It is probably owing chiefly to this fact of an inces- sant demand by a large section of, at all events, one branch of students, that technical publishing has proved so remunerative, and has escaped, in a great degree, the risk attached to other departments of the trade. I- At the close of the year 1870, Mr. Churchill resolved to give up the active management of his large busi- ness, and issued a farewell circular to the trade: " After fifty-five years' active and immediate associa- tion with your profession, I see it my duty to retire into private life. Be my future days few or many, I shall ever retain a lively sense of the many friendships I have formed, and of the unvarying proofs of confi- dence and regard shown to me through so long a series of years. My pathway of life has been a happy one, bringing me into daily correspondence with the elite of the profession, and united with them in promoting the interests of science and literature, while the success of my many publications has both gratified and amply
