The Scale Substance of Wool

Abstract

The scaly outer layer of wool fibers is commonly believed to protect them from injury and to assist in the felting process. Little is known about the composition of this layer because no ready means of separating it from the rest of the fiber has been available. Earlier work in this laboratory has shown that wool that has been reduced with thioglycolic acid and then alky lated with ethyl bromide is attacked by pepsin in such a, way that the scale material remains intact while the in terior of the fiber is completely dis solved. The composition of the scale material so obtained has now been studied. It has been found that it is essentially protein in nature and, al though it contains the same amino acids as the whole wool, the proportions of these in the two materials differ.