A QUANTITATIVE METHOD FOR THE MEASUREMENT OF THE RATE OF WATER LOSS FROM SMALL AREAS, WITH RESULTS FOR FINGER TIP, TOE TIP AND POSTERO-SUPERIOR PORTION OF THE PINNA OF NORMAL RESTING ADULTS
A method is described for measuring the rate of water loss from small surfaces. The method consists in passing dry O2 through chambers covering the surfaces and then conducting the moisture-containing O2 through cold Al coils. From the difference in wt. of the coils before and after the passage of the O2, the amt. of water lost is learned. The method is accurate to 2.6%. This error can, however, reach 9% when less than 6 mg. of water are measured, but such low values were not encountered. The rate of the elimination of water was studied from the right index finger tip, right 2d toe tip and postero-superior portion of the right pinna of 15 white, normal, resting adult subjects. The mean rate of water loss was 1.86 mg. per square cm. per 15 mins. for the finger tips, 1.18 mg. for the toe tips and 0.48 mg. for the pinnae. The rate of water loss in the toe tips was approx.