362 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS MATERIALS AND METHODS 1. Reagents All the chemcial reagents were Certified ACS Grade or higher purity. 2. Hair Sample Acquisition Samples of beard and scalp hair for microscopy and tensile determinations were collected from men (10 Caucasians, 6 Chinese, and 6 Blacks) who were 20 to 50 years old. The fibers were cut very close to the skin line beard hair was taken from the lower chin area and scalp hair from the rear crown of the head. For chemical characterizations the hair fibers of several individuals were pooled beards were contributed by ten Caucasian men and Caucasian scalp hair was purchased from DeMeo Brothers, New York. 3. Hair Sample Preparation a. Purification Specimens for microscopy and tensile work were purified by a half-hour immersion in 1% aqueous Triton © X-100 followed by repeated distilled water rinses and a half-hour immersion in ethanol. The fibers were then air dried at room temperature. Bulk hair samples (50 g batch) were purified via Soxhlet extractions with anhydrous ether (14 hours) and ethanol (7 hours). The hair was then air dried, immersed in 0.001 N HCI (2 hours), and rinsed repeatedly with large volumes of distilled water until the pH of the overnight rinse water was 5.0. b. Mounting of Hair Fibers The fibers were individually mounted either with double-coated transparent tape onto microscope slides or in glycerin on slides under a coverslip. c. Cross Sections of Fibers Cross sections of fibers (6-8 /zm thick) were cut with the Hardy Microtome and mounted in glycerin under a coverslip on microscope slides. 4. Light Microscopy An American Optical Microstar © Series 10 Microscope, equipped with a Polaroid © Land Camera, or Zeiss © Microscope Model 62119 with 10x and 40x polarizing objectives was used in determinations of the diameter, ellipticity, and cross-sectional area of hair fibers. a. Measurement of Fiber Diameter A specially constructed microscope stage was used which would accommodate tabbed single fibers which could be rotated 180 ø along the long axis of the fibers. Five beard and five scalp hair fibers from each of ten individuals were investigated. Fibers were examined at five sites along each sample. At each site, fibers were rotated

COMPARISON OF BEARD AND SCALP HAIR 363 Figure 1. Polarized light photomicrographs of Caucasian scalp hair (top) and beard hair (bottom) cross-sections of the same subject. Magnification 150x. and measurements taken at 0% 45 ø , 90 ø , 135 ø , and 180 ø . The averages of the measurements, taken at all five angles, for all five sites, for each fiber, were then calculated. Data presented are averages for all five fibers for each subject, and the standard deviation from fiber to fiber is reported. b. Determination of Fiber Ellipticity i. Direct Measurement Using the data obtained in 4a. above, ellipticity indices, that is, the ratios of fiber major axes over fiber minor axes, were obtained.