STUDIES ON PERSPIRATION 71 The ball thus prepared is dressed in a square-shaped piece of gauze and placed in the armpit in the same manner as a thermometer for ten minutes. The gauze is then unfolded and the size of the blue stain produced by the perspiration is evaluated (2, 5) (Fig. 1). Scores: 0 Figure 1, 2, 3.--Standard Scales, Axilla, Palm, Sole.

72 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS PAPER TESTS ENABLING THE EVALUATION OF SMALL QUANTITIES OF PERSPIRATION (PRussIAN BLUE TEST) A strip of Scotch tape is sprinkled with the following mixture (finely ground): Fe2(SO4)• anhydrous ......................... 35% K4(FeCN6) anhydrous .................................... 65% The test paper, light gray before application, becomes colored in contact with water. Very fine drops of sweat are thus detected, each spot repre- senting the lumen of a sweat gland. This test has the advantage over that of Minor's in that it does not necessitate the painting of the skin with iodine which could modify the terrain. The Prussian blue test paper is rapidly saturated and is not adequate for the evaluation of abun- dant sweating (3, 6) (Fig. 4). Scores: ! Figure 4.--Standard Scale, Prussian blue test paper. PAPER TEST FOR HANDS AND FEET We have elaborated a test paper which permits the evaluation of abun- dant sweat secretion. A Whatman filter paper is impregnated with a 1 per cent bromophenol blue solution in anhydrous ether. In the absence of humidity, this paper becomes yellow by the action of water it changes to dark blue. Our principal objective in elaborating this test was to find a method permitting the evaluation of plantar and palmar sweating (5, 7) (Figs. 2 and 3). STUDY OF THE ACTION OF VARIOUS DRUGS ON THE SWEAT G•,AND (6, 8) A series of d•ugs influencing the autonomic nervous system were in- troduced in the skin by means of iontophoresis. By applying the Prussian blue paper tests at regular intervals on the treated site, the duration of action, and intensity of effect of a drug can be estimated (see Table 1). Drugs which inhibit sweating by their action on the autonomic nervous