744 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS •s y qnpbob½ ' Figure 27.--Graphical determination of dilatometric curve. the intercept of the line parallel to the abscissa drawn through P and Mm. •O is found next since NM = N. R. The line through • parallel to the ab- scissa is the asymptote sought. The ends of the experimental graphs are not always absolutely hyper- bolic. However, the difference between the experimental asymptote and the theoretical asymptote is only slightly in error.

5 t. Soc. Cosmetic Chemists, 15, 745-760 (1964) THE EFFECTS OF AFTER-SHAVE LOTIONS ON SKIN FLORA By FR•.D C. TsEIL•., B. So., and D^Ni•.L C. P•.As•, JR., B.A., M.S.* Presented yune 22-26, 1964, Third Congress International Federation of Societies of Cosmetic Chemists, New York City ABSTRACT Methods for rapidly and conveniently estimating the number of colonies on the skin have been developed. The activities of various lotions immediately after application and several hours later are compared using in vivo and in vitro techniques. The new in vivo method utilizing the Rodac plate is convenient, rapid and reproducible. Correlation of the in vivo procedure with in vitro tests shows that the perfume plays an important part in inhibiting the growth of many or- ganisms. The ingredients of after-shave lotion, individually and in various combinations, as well as commercial after-shave lotions have been tested. The effect that these have on the skin flora and their antifungal and antibacterial activities are shown. INTRODUCTION Fragrant materials were recognized almost from the very beginnings of civilization as having strange and mysterious properties. Initially, perfumes were concocted by heathen priests as offerings to their Gods. The occult powers of these Holy Men extended into the healing profession, and they continued to use fragrant balsams and ointments as curative agents. In almost every land from China to Egypt, odorous incense was burned in the temples, and shrines were considered to be areas of purity. Recent investigations have given credence to the effects which were noted but not understood by these ancients. The pleasing and soothing effects that fragrant oils had upon the senses were coupled with very real and measur- able antimicrobial activities. * Shulton, Inc., Clifton, N.J. 07015. 745