STUDIES ON PERSPIRATION 75 alcohol and on a symmetrical site which has not been cleaned, by the action of aluminum chloride on the sweat gland, it can be observed whether the sebum has prevented the penetration of the solution or not. For this, a locally induced perspiration by ionophoresis of pilocarpine and a Prussian blue test paper is applied on each of the sites treated. In a group of ten men and ten women of twenty to thirty years (the age group where the sebaceous layer is high), a significant difference between the formerly cleaned and noncleaned sites is noted (see Fig. 5). Thus, it can be seen that the sebaceous layer protects the skin against the action of an aluminum chloride solution. Figure 6. INFLUENCE OF AGE AND SEX ON PERSPIRATION Figure 7. INFLUENCE OF AGE AND SEX ON PERSPIRATION I significant S 0 [ e (• di[[ePence

JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Figure 8. INFLUENCE OF AGE AND SEX ON PERSPIRATION difference PHYSIOLOGY OF PALMAR, PLANTAR AND AXILLARY PERSPIRATION (5, 7) The tests described have also permitted the authors to study systemat- ically the influence of age and sex on the intensity of the palmar, plantar and axillacy perspiration in the normal subject. The study of approximately 200 persons has given the following results. Palmar and plantar perspiration decreases with age. Abundant in children and adolescents it decreases little by little to become scanty in old people (see Figs. 6 and 7). On the other hand, the statistical analysis shows a correlation between the intensity of the "hand" and "feet" tests, even if the influence of age is excluded. This means that it is very probable that persons who perspire abundantly on the hands also show strong perspiration of the feet. The axillacy perspiration shows a different curve in that it is at first nonexistent or slight until puberty, abundant in young adults and then diminishes in function according to age from thirty years onwards in men and from fifty years onwards in women (Fig. 8). CONCLUSION In order to investigate the physiology of perspiration or the action of •tntiperspirants, it is indispensable to elaborate methods of investigation (tests). Only objective tests will give some value to the results obtained. The clinical observations, if possible, should always be controlled by a test. The results of the tests, on the other hand, should be controlled clinically.