Systematic observations of the administration and mode of action of general anaesthetics have been much practised since. the days of Sir J. Y. Simpson. Many papers bearing on the subject have appeared from time to time in the Medical papers, and many treatises by Specialists have been issue. In spite, however, of all this activity, the anaesthetics in present use are not without danger even in skilled hands. Considerable importance is now given to the teaching of this subject in all Schools of Medi- cine. The Royal College of Surgeons England re- quire a certificate of Efficiency from their candi- dates for Membership. To most of the large hos- pitals Specialists are now attached, a provision which will greatly tend to improve the capabilities of the average practitioner. Having been on the Resident Staff of a very active general Hospital for the last 22 years, I have had exceptional opportunities for observing the action of general anaesthetics. During this time I have held two surgical appointments, One ophthalmic and one medical, the latter involving the practical teaching of anaesthetics. Alto- (1) gether I roughly estimate that I must have given 1500 administrations. By far the greater part of these have been chloroform and ether, next in frequency nitrous oxide and a comparatively small number of the more recent anaesthetics such as Ethyl Chloride and mixtures containing that preparation. In endeavouring to make this a clinical treatise I have thought fit to exclude all refer- ence to the discovery and history of the above mentioned Drugs, also the experimental and physiological details, and have taken accurate notes of a considerable number of cases, especially of those which have presented features somewhat out of the common. The following is a short summary of the arrangement and contents of the following pages: - | Selection of .Anaesthetic: - State of the Patient - Nature of the operation; | Preparation of the Patient: - Chloroform - Ether - Soemnoform; | Difficulties and Remedies: -. After Effects; | Selection of Anaesthetic.