SHEET MICA IN BRAIN SURGERY

To the Editor: —Referring to the article on "Repair of Dural and Brain Defects" by Drs. Halstead and Caylor (The Journal, April 26), permit me to call attention to the value of sheet mica (stove isinglass) for this purpose. I once published an article on the subject pointing out the superiority of this (mineral glass) to others as a covering for exposed and damaged brain tissue. Sheet mica can be obtained at any hardware store or, in emergency, removed from the glass windows of heating stoves. It can be split to any amount of thickness from a solid block to that of the thinnest tissue paper. It is smoother than glass; absolutely nonirritant, indestructible, nonadherent to the tissues: a window for observation of the part on which it is applied; is elastic and difficult to break, and can be cut with scissors into whatever size or shape required. Not least