THE TREATMENT OF INFECTED EARS
worm School, Eltham, there appeared to me very great difficulty in exposing contiguous areas of tinea accurately to the x rays. The methods of using circular lead glass tubes or sheet lead invariably left small sections of scalp untreated between the diseased areas. To obviate this it occurred to me to apply to the head a plastic mass, impermeable to the x rays, leaving only that portion of the scalp exposed to the rays which it was desirous to treat. Accordingly, I began to experiment with
... experiment with plasticine, the material with which children model. To this plasticine I added the salts of different metals and even the powdered metal itself in varying proportions, to see if I could make a mass impermeable to the rays ; when I had succeeded in obtaining it the mass was so dry that it had lost all its plasticity and was useless. I found, howevei, a suitable substitute in a lead putty, merely ordinary putty with a fair amount of red lead added ; this, even in a thin layer, was impermeable to the rays, which I was able to prove by covering the free end of a lead glass tube with it and using the fluorescent screen. To use the putty I roll out a sheet of it about 15 inches square and a quarter of an inch thick ; this I place on the patient's head, moulding it smoothly over, then with a blunt spatula I remove a window over the area to be treated and no matter how irregular in shape this space may be the hair epilates uniformly after exposure to the rays and no untreated or overtreated sectors occur.