(Not Official)

C5H10=69.85. Synonym. - Trimethylethylene.


It is obtained from Amylic Alcohol by digestion with Zinc Chloride for twenty-four hours, and fractional distillation.


A colorless liquid, very volatile, insoluble in water, but miscible in all proportions with Alcohol, Ether, and Chloroform; highly inflammable. Sp. gr., 0.620.

Action and Uses of Pental

Pental is an anaesthetic, the equal of nitrous oxide in rapidity of action and perhaps safety, but superior to it in its more prolonged action and in having no unpleasant after-effects. Even when insensibility to pain is reached, consciousness is retained sufficiently to respond to commands. The stage of exhilaration is seldom present; it does not lose its effect by repeated inhalations. It differs from chloroform in that it acts more promptly, and has no evil after-effects; from ethyl bromide, in that it is somewhat slower in its action, but is more lasting in its effects, and can be prolonged as may be necessary; from nitrous oxide, in its freedom from unpleasant effects.

Two substances used to produce local anaesthesia should be considered. These are ethyl chloride {synonym, hydrochloric ether) and methyl chloride (neither official).

Ethyl chloride is an inflammable liquid of a low boiling-point and produces intense cold by its evaporation. It is sold in glass capsules terminating in a fine tube with a screw-capped point. When the capsule is held in the hand about eight inches from the part to be anaesthetized, the warmth of the hand volatilizes the ethyl chloride, and the vapor falling on the skin of the patient, by its evaporation produces enough local anaesthesia for the performance of small operations, such as the removal of warts, etc. All fat must be removed from the skin by soap and washing with ether. The same objections apply to this, and the following as to ether, for the production of local anaesthesia. {See p. 300).

Methyl chloride is used in the same way to produce local anaesthesia and to relieve the pain of neuralgia, etc. The vapor is allowed to play obliquely on the skin for four or five seconds.