366 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Figure 4. Transmission electron micrographs of Chinese beard and scalp hair cross-sections of the same subject. Magnification 915 x. M: Medula CO: Cortex C: Cuticle. Table I Diameters of Caucasian Beard and Scalp Hair Diameter a (tim) Subject Beard Hair Scalp Hair Beard/Scalp CMT 143.7 _+ 6.9 72.0 _+ 2.9 2.00 DLS 124.6 _+ 8.7 79.9 -+ 1.1 1.56 GHS 131.3 _+ 3.2 72.9 _+ 1.7 1.80 JGY 123.3 _+ 5.7 71.4 _+ 15.1 1.73 LHE 107.0 _+ 3.3 64.3 _+ 4.6 1.66 MDG 126.9 _+ 11.3 58.7 _+ 7.6 2.16 NHS 120.8 _+ 11.3 55.7 _+ 2.9 2.17 PHY 113.4 _+ 5.6 68.9 _+ 8.9 1.65 PKA 139.1 _+ 20.8 86.6 + 4.5 1.61 SDN 125.6 _+ 13.1 65.3 +- 11.0 1.92 Average 125.6 _+ 10.9 69.6 + 9.3 1.83 aFive beard and five scalp hairs from each subject were measured at five locations along the fiber. At each location the fiber was rotated and measurements taken at 0% 45% 90% 135% and 180 ø axial rotation. Diameter values for the five fibers were averaged and reported here along with standard deviations from fiber to fiber.

COMPARISON OF BEARD AND SCALP HAIR 367 either cross or longitudinal sectioning, beginning at the proximal end. Serial sections, 600 • thick, were cut with a diamond knife in a Sorvall © Porter Blum MT-2 ultramicrotome. The sections were placed on carbon-backed nitrocellulose-covered single slot copper grids and stained with lead citrate/uranyl acetate for image enhancement. The TEM studies were performed on aJ.E.O.L. Model 100 B at 80 kV. 6. Scanning Electron Microscopy (SEM ) Small segments of hair fibers, 5-8 mm in length, were mounted with double-coated transparent tape onto SEM specimen holders. The mounted samples were coated with approximately 30 nm gold in a Polaron Instruments E5100 Sputter Coater and examined at 60 ø tilt in a J.E.O.L. Model JSM-U2 Scanning Electron Microscope, operated at 6, 9, 15, or 24 kV. Micrographs of each fiber were made at 300x to 10,000x magnifications. 7. Tensile Measurements Tensile properties were determined on an Instron Tension Compression Tester Model TT-D, extending 5 cm long fiber specimens, of 70-90 #m diameter, in water at 1 cm/min. A Perkin Elmer Autobalance © Model AD-2 was used to establish the linear density of the fibers. For each sample 20 fibers (ten fibers each from two subjects) were tested. 8. Amino Acid Analysis Acid hydrolysates of the hair samples were analyzed on a Beckman © Model 119 Automatic Amino Acid Analyzer. 9. Urea- Bisulfite Solubility Test Standard test method I.W.T.O.-11-54 (18) was used to determine urea-bisulfite solubility. Triplicate analyses were performed. Table II Ellipticity Indices of Caucasian Beard and Scalp Fibers Ellipticity Index a Subject Beard Hair b Scalp Hair b CMT 2.08 _+ 0.18 1.42 _+ 0.21 DLS 1.72 _ 0.50 1.58 _ 0.20 GHS 1.55 _+ 0.27 1.41 _+ 0.05 JGY 1.81 + 0.32 1.35 + 0.19 LHE 1.55 _+ 0.18 1.48 _+ 0.12 MDG 1.97 + 0.23 1.44 + 0.07 NHS 1.58 + 0.27 1.20 + 0.11 PHY 1.83 + 0.13 1.27 + 0.17 PKA 1.80 _+ 0.15 1.74 + 0.22 SDN 1.35 + 0.24 1.46 + 0.22 Average 1.72 + 0.20 1.44 + 0.15 aRatio of the major axis to the minor axis. bDiameters of five beard and five scalp fibers were measured at five locations along the fiber and five axial rotations at each location. Average values and standard deviations are reported.