In intrameatal operations the head should be wrapped in a sterilized towel, and a square of sterilized lint, having an aperture in the centre so as to expose only the auricle and meatus, should be placed over the side of the head and face. In operations on the mastoid process, and in those involving a post-auricular incision, the head should also be shaved for at least two or three inches beyond the region of the ear. =Anæsthesia.= Both local and general anæsthesia are used. Unless contra-indicated for some special reason, and unless the operation is a very trivial one, it is wiser to give a _general anæsthetic_. Of these, chloroform is the most suitable in adults and infants, and the A. C. E. mixture in children. Ether, although it may be safer, is frequently a source of annoyance to the operator, as it tends to increase the hæmorrhage. In order to produce _local anæsthesia_ two methods may be employed: (1) The instillation of fluids into the meatus; (2) subcutaneous injection of fluids beneath the lining membrane of the meatus and into the surrounding parts of the auricle. The solution usually employed is a sterilized aqueous solution of cocaine hydrochloride in varying strengths up to 20%, to which may be added equal parts of 1 in 1,000 adrenalin chloride solution; the latter not only increases its analgesic properties, but also acts as a powerful hæmostatic. _Instillation._ As the auditory canal and the tympanic membrane are lined with epithelium which is very resistant to the absorption of fluids, complete anæsthesia is almost impossible to obtain. This method, therefore, is practically limited to such trivial operations as the curetting away or snaring off of granulations or polypi from the external or middle ear. To render anæsthesia more complete, the affected part may be finally rubbed over with a crystal of solid cocaine hydrochloride just before the operation--is begun. On the other hand, if the raw surface is large--for example, the wound left after a recently performed complete mastoid operation--the cocaine employed should not be stronger than a 5% solution in order to minimize the risk of poisoning. Gray of Glasgow has suggested, as a more penetrating anodyne solution, a mixture consisting of a 10% solution of cocaine hydrochloride in equal parts of aniline oil and absolute alcohol, a solution which he especially advocates in order to produce anæsthesia of the tympanic membrane before doing paracentesis.