The temperature of liquid air is 312° F. below zero. It is applied in the form of spray. Liquid air has received attention from a surgical standpoint in regard to its efficacy as a local anaesthetic, in the treatment of ulcers, opening abscesses, for relief of facial and other forms of neuralgia, sciatica, herpes zoster, erysipelas, etc. Dr. A. C. White states, after experimenting with liquid air, "I first began the use of liquid air in the local treatment of ulcers of the leg chiefly varicose, many chaucroids and some specific ulcers. So many of these cases have now been treated with liquid air that it can be said with positiveness that we have nothing at our disposal today which will so quickly, thoroughly, and with so little pain clear up the edges and stimulate the surface of an ulcer to granulations as liquid air does when properly applied. The application should not be made so frequently as to break down the new granulations as they form. After the first two applications to an ulcer, one application a week is usually sufficient. All ulcerations treated with liquid air seem to do better when followed by a dry dressing, such as aristol, subgallate of bismuth, or stearate of zinc instead of any unguent. An abscess, boil, or carbuncle, in the early stage is aborted absolutely in one thorough freezing. If it is more advanced, several applications at intervals of twenty-four hours are necessary. Whenever pus has formed in large quantity it is advisable to anaesthetize with liquid air, incise and evacuate. In case of carbuncle and bubo well advanced, it is unnecessary to curette if the liquid air is applied generously to the base of the abscess after incision. No sloughing follows except in the case of fairly well advanced carbuncles, and in some of the abscesses, when the overlying skin has become devitalized from tension and inflammation." In applying liquid air it is better to apply it intermittently while the operator is working than to try to freeze the part so that it will remain senseless for any length of time. This intermittent use of the spray would not be necessary when a simple incision was required as in the case of opening an abscess. In all such cases it is applied in the form of spray.

Dental Uses

As a local anaesthetic to relieve the pain of all inflammatory and ulcerated conditions, such as periodontitis, alveolar abscess, ulcers, pulpitis, etc.; also to abort periodontitis, and alveolar abscesses in their incipient stages; also for opening abscesses, and in the treatment of ulcers.