``Chemical'' Analysis of the Intact Skin by Reflectance Spectrophotometry

IT HAS been said repeatedly that one of the greatest obstacles to progress in dermatology is the lack of practical, quantitative methods for investigation of the skin. It is true, of course, that a number of good functional tests exist: measurement of sweating, sweat sodium, and lipid secretion, for example, is possible on a quantitative basis.¹Skin elasticity can be studied in certain areas in a quantitative manner,²and such tests yield valuable information regarding some functions of the skin. In the main, however, quantitative investigation of the chemical or physical nature of the skin, and in particular investigation which leaves the same area of skin in a condition for further observation, is still a relatively unexplored phase of dermatology. It is the purpose of this paper to present preliminary investigations of a method whereby a "chemical" analysis of the skin may be performed without in any way