+Strength of Solutions.+ In the eye, it is customary to employ a 4 per cent. solution. For work in the nose, 2 per cent. is generally considered sufficient. In the latter connection, it is often combined with adrenalin solution in small amounts to mitigate its depressing effects as well as to control bleeding. The latter effect is but transient and is omitted by many as unsatisfactory because of the more profuse subsequent hemorrhage. In this respect cocaine and adrenalin are similar. They both cause constriction of the minute superficial vessels and immediate blanching of the membrane; work in the nose is hence greatly facilitated, the field of operation being clear and enlarged by the shrinkage of the encroaching membrane, but it is incumbent upon the operator to keep his patient under observation at least an hour after the completion of the operation that he may be certain of the degree of hemorrhage after the effects of the drugs have passed away. For the above reason many operators prefer a general anesthetic or one of the local anesthetic drugs which exert no constrictor action so that they may know, _ab initio_, the exact degree of bleeding. Whatever drug is used, strong solutions are seldom necessary for application to the mucous membranes but the necessary time for its absorption is a prime requisite. To secure anesthesia of the conjunctiva and cornea, the solution is dropped into the eye at the outer canthus and as it flows off with the tears, it must be replenished three or four times until anesthesia is accomplished. In the nose, a spray over the site of incision or a pledget of cotton saturated with the anesthetic solution and allowed to rest in contact with that locality, will suffice. The flow of mucus from the nasal mucosa is stimulated by the presence of the cotton pledget and it soon becomes entirely coated with a thick mucus which no longer is able to impart to the membrane its anesthetic solution and must therefore be renewed several times before complete insensibility of the part is assured. The topical application of a strong solution on a cotton wound applicator to a limited area or spot is also efficient. +Application by Injection.+ In order to bring the anesthetic in contact with the nerves, it is necessary, where a skin surface is to be incised, to inject the solution as already described. The technic, previously detailed, applies here, and any of the methods may be employed for the injection of solutions of cocaine, some preferring a single method to the exclusion of all others. The locality to be treated will also influence the operator as to method.