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.
Rhigolene is a product of the distillation of petroleum. In its composition it is a hydrocarbon, and is destitute of oxygen, being extremely volatile and inflammable, and is the lightest of all liquids, with a specific gravity of 0.625. It is a petroleum naphtha, and boils at 7000 F., and when perfectly pure should be almost odorless; but it is difficult to procure any specimen that does not have the unpleasant odor of petroleum. It is colorless, and on account of its great volatility and inflammability requires to be kept tightly stoppered, in a cool place. The storage of large quantities, except in very secure places, is attended with considerable risk, and on this account it is somewhat difficult to procure it outside of the manufactories. It is dangerous to use it at night near a light.
Rhigolene is employed, like absolute ether, to produce local anaesthesia, by dispersing it in the form of spray, with the spray apparatus, being the most rapid in its congealing effects, and also the most easily controlled and convenient of all of the freezing mixtures. As a local anaesthetic it is employed in the operation of extracting teeth, by applying it, in the form of spray, to the parts about the tooth to be removed until a blanched surface of gum is produced. The spray of rhigolene is also applied to the gum over the root of a tooth affected with incipient periodontitis.