270 JOURNAL OF COSMETIC SCIENCE / j Figure 4. Hair fiber pretreated with aqueous silver nitrate, then made alkaline with sodium hydroxide. Intense staining of the sulphur-rich domains (D) shows penetration of silver and hydroxide throughout the cuticle and cortex. Deposits of silver are present in the cuticle cell membrane complex (4-,•). Scale bar = 0.5 !•m. sion in aqueous silver nitrate (two minutes), and then exposed to light, fine deposits were observed within the cell membrane complex of some, but not all, cuticle cells. Adjacent to these deposits and within the a-layer and exocuticle were "cascade-like" deposits of silver (Figures 6, 7). Fine, disperse deposits were ob-

PENETRATION INTO HAIR FIBER 271 Figure 5. Hair fiber pretreated with aqueous silver nitrate, then made alkaline with sodium hydroxide. Extensive large and fine deposits of silver are evident in the cell membrane complex of the cuticle (•--•). Scale bar = 0.5 lam. served throughout the cortex and on pigment granules. The microfibril/matrix composite was not evident. In some sections the inter-macrofibrillar material contained obvious silver deposits outlining the macrofibrils. Silver deposits were seen at the cuticle cortex boundary, but no cascades were observed.

Purchased for the exclusive use of nofirst nolast (unknown)
From: SCC Media Library & Resource Center (library.scconline.org)