296 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS CONCLUSIONS It is clear from the experiments that we have performed that tangling of hair during combing seriously damages the hair surface. In particular it appears that the types of fracture that result from this treatment yield longitudinal splitting. This splitting process occurs far more readily at the tips of hairs than at their roots and we must therefore conclude that the weathering the hair has received has facilitated the ease of splitting. On the other hand it is possible that combing and mechanical atrophy of the hair are essential requirements for splitting and that in the absence of mechanical perturbation splitting will not normally occur. In addition to reaching these conclusions we believe that we have demonstrated the value of the scanning electron microscope as a-diagnostic tool. ACKNOWLEDGMENT We are indebted to Miss Paulene McCarthy for her technical skills in the use of the scanning electron microscope. (Received: 29th April 1974) REFERENCES (1) Split ends--protein diet for a hair problem? Beauty Business Suppl. to Chem. and Drug. 4 15th April 1972. (2) Beyak, R., Kess, G. S. and Meyer C. F. Elasticity and tensile properties of human hair. Part 2. Light radiation effects. J. Soc. Cosmet. Chem. 22 667 (1971). (3) Robbins, C. R. Weathering in human hair. Text. Res. J. 37 337 (1967). (4) Robbins, C. R. and Kelly, C. H. Amino acid composition of human hair. Text. Res. J. 40 891 (1970). (5) Papa, C. M., Mills, O. H. and Hanshaw, W. Seasonal trichorrhexis nodosa: role of cumu- lative damage in frayed hair. AMA Arch. Dermatol. 106 888 (1972). (6) Chernovsky, M. E. and Owens, D. W. Trichorrhexis nodosa: Clinical and investigation studies. Text. Res. J. 94 577 (1966). (7) OwE•qs, D. W. and Chernovsky, M. E. Trichorrhexis nodosa: In Vitro reproduction. Text. Res. J. 94 586 (1966). (8) Swift, J. A. and Brown, A. C. The critical determination of fine changes in the surface architecture of hair due to cosmetic treatment. J. Soc. Cosmet. Chem. 23 695 (1972). (9) Sikorski, J., Moss, J. S., Hepworth, A. and Buckley, T. Specimen preparation for dynamic experiments in the scanning electron microscope. Proc. 2nd Stereoscan Colloquium 25 (1969) (Engis Equipment Co.). (10) McKee, A. N. and Beattie, E. L. Preliminary studies of the fractography of fibres and polymeric materials in the scanning electron microscope. Text. Res. J. 40 1006 (1970).

HAIR BREAKAGE 297 (11) (12) (13) Sparrow, J. T. Application to fibres and polymers. In: The Use of the Scanning Electron Microscope (Ed. by J. W. S. Hearle, J. T. Sparrow and P.M. Cross) 139 (1972) (Pergamon, Oxford). Brown, A. C. and Swift, J. A. New techniques for the scanning electron microscope exami- nation of keratin fibre surfaces. Proc. 5th Eur. Reg. Cong. Electron Microsc., Manchester 386 (1972). Brown, A. C. and Swift, J. A. Low voltage scanning electron microscopy of keratin fibre surfaces. Proc. 7th Ann. S.E.M. Symp. (1974) (IIT Research Institute, Chicago).