This section is from the book "Dental Medicine. A Manual Of Dental Materia Medica And Therapeutics", by Ferdinand J. S. Gorgas. Also available from Amazon: Dental Medicine.
Coryl is a mixture of chloride of methyl and chloride of ethyl. It is kept liquid under a pressure of three atmospheres in a recipient called a "Coryleur," which is a small nickel-plated metallic tube, easily managed with a stop-cock, which allows the regulation of the escape of the vapor of the compound. In using it, the tube must be kept in a horizontal position. It is a colorless liquid of an ethereal odor and taste, and is obtained by a methylation of chloride of ethyl.
Coryl is a refrigerating local anaesthetic, less powerful than chloride of methyl, and not so liable to cause 24 an eschar; it is, however, more powerful than chloride of ethyl, and produces a deeper state of insensibility. It is as inflammable as chloride of ethyl, and boils at 320 F. Coryl will produce complete anaesthesia in 15 to 20 seconds; and to apply it the patient is directed to breathe by the nose, and not by the mouth; he must then rinse his mouth with water at the temperature of the room ; the gum must be dried and the jet of coryl applied to the mucous membrane below the crown of the tooth to be extracted. Beginning at the apex of the root and carrying the jet upward toward the neck of the tooth, then over the crown, and down on the inner side of the alveolus up to the end of the root, then coming back again over the same parts, and repeating this for 15 or 20 seconds, when the anaesthesia will be found complete. To obtain a deeper and more prolonged state of insensibility, as soon as a first application of the coryl is made, the mouth must be quickly rinsed with water; then another application is made, followed by another rinsing of the mouth, and finally a third application, when the anaesthesia will be found to last over 40 minutes.