||P.55 bottom paragraph: "Although research in the area of fractionation and peptide analysis of human hair is considerably behind that of wool fiber, the following research in this area has been described. Fractionation of human hair into keratosis by the method of Alexander and Earland [ref 84] as modified by Corfield et al. [ref 85] has been reported by Menkart et al. [ref 24] (see Table 2-8). This procedure consists of oxidation of the fibers with aqueous peracetic acid and solubilization in dilute alkali. The insoluble fraction is called beta keratose and is believed to consist of proteins derived primarily from cell membranes and similar matter. Acidification of the solution to pH 4.0 produces a precipitate called alpha keratose which is believed to originate primarily in the crystalline or fibrillar regions of the cortex. The material remaining in solution has been labeled gamma keratose, which is the fraction containing the largest percentage of sulfur (see Table 2-8) and is believed to consist of proteins derived primarily from the amorphous regions of the fibers (primarily from the matrix). Of special interest is the significantly larger gamma keratose fraction from human hair compared to merino wool (see Table 2-8). This is consistent with the higher cystine content in human hair."