I am just now entering upon my fifth decade as a practitioner of medicine, and though it is a humiliating reflection, yet it is a fact, that what I learned of therapeutics during one of these epochs, I had to unlearn in the next, and that with all my delving among the resources of the materia medica, I can now count upon the fingers of both hands, nearly all the remedial agents that have stood with me the test of forty years. Among the few ideas, the few firm convictions that have become thoroughly implanted in my mind in the use of drugs, the superiority of ether as an anesthetic has become with me a confession of faith, firmly rooted and immovably fixed. It is now over thirty years since I made my first professional tour of Europe, and since then I have repeated the journey four times, and among