When a layer of Collodion is laid on any surface, a transparent coating is left by the evaporation of the Ether, which possesses in a marked degree the properties of contractility and adhesion, as well as transparency, pliancy, and impermeability. By its powerful contraction, observes Dr. Bigelow, upon evaporation, it places the edges of an incised wound in much more intimate contact than is obtained by sutures and adhesive cloth, unites them by equal pressure throughout the extent of the wound, and maintains them immovably fixed. It preserves the wound perfectly from contact with the air, while its adhesion to the skin is so intimate as to prevent the possibility of air entering beneath the edges. The substance remaining in contact with the skin and wound after the evaporation of the Ether, is inert as far as any irritating property is concerned, and this can hardly be said of any resinous adhesive cloth or preparation. It does away with any necessity for sutures in incised wounds of almost any extent. It is sure to remain in contact with the skin until union is complete, and, being quite impervious to water and presenting a polished surface, it allows the surrounding parts to be washed without regard to the wound or dressing. It is colourless and transparent, thus permitting the surgeon to witness all that goes on beneath, without involving the necessity of removal. No heat is necessary for its application, and the presence of a moderate degree of cold is only objectionable in retarding the evaporation of the Ether. Finally, it is made at a trifling cost, an ounce, intrinsically worth little, being sufficient for a great number of dressings.

If used pure, it has been found that the film left by the evaporation is liable to crack from want of elasticity, and consequently to peel off; to remedy this it should be combined with a small proportion of oil or of glycerine (Glycerine 2 parts, Collodion 100 parts), which does not interfere with its action, and allows of movement in the parts without cracking. A very pliable Collodion may be made of 30 parts of Collodion, 12 of Venice Turpentine, and 6 of Castor Oil. (Squire.)