inferior and anterior walls of the auditory canal. Finally, a pledget of cotton-wool soaked in a 20% solution of cocaine is pushed into the tympanic cavity. In the case of simple opening of the mastoid, subcutaneous injections into the auditory canal are not necessary. On the other hand, if the operation is limited to the auditory canal and tympanic cavity, the injections into the mastoid process are not required, but a primary injection of a small quantity of eucaine solution into the auriculo-mastoid fold considerably diminishes the pain produced during the act of injection into the auditory canal. Fifteen minutes should be allowed to elapse before the operation is begun. The anæsthesia lasts about half an hour. _Difficulties._ It is by no means easy to inject fluid beneath the periosteum of the auditory canal, owing to its close adherence to the bone. The needle by mistake may repierce the skin at a point farther in, so that the fluid, instead of being injected beneath the periosteum, is injected into the auditory canal itself. In these cases anæsthesia will not be obtained, and the operator may possibly blame the principle of subcutaneous injection, rather than his own faulty technique. In favour of subcutaneous injection it is urged that most of the minor operations within the tympanic cavity, including ossiculectomy, may be performed with the patient sitting up in the chair in the consulting room, and further, that the patient can afterwards go home; that the operation is rendered more easy owing to there being practically no bleeding; and that in the case of the more severe operations, such as opening of the mastoid antrum, the surgeon, in a case of emergency, may make use of this method if he cannot possibly obtain the services of an anæsthetist. Against subcutaneous injection is the pain of the injection, which may be so great that the patient will not submit to it, and in consequence the proposed operation may have to be postponed. In the case of the mastoid operation, it is difficult to believe that local anæsthesia, however efficient, will be looked upon with favour either by the surgeon or by the patient, except when a general anæsthetic is absolutely contra-indicated. The discomfort produced by retraction of the parts, the jarring caused by chiselling, and the consciousness of what is taking place, are far more unpleasant and more of a shock to the patient, than a general anæsthetic carefully given. Further, it is not always possible to foretell the extent of the operation, and if repeated injections become necessary, there is danger of eucaine or cocaine poisoning being produced. =Position of the patient and the surgeon=