RHEOLOGY OF STRATUM CORNEUM--II 21 (3) A mechanism of the effect of (2) on the stratum corneum is outlined. It is suggested that reduction of the water-retaining capacity of the stratum corneum, after extraction with the above solvents, is due to increased protein-protein interactions which reduce water binding, in the absence of hygroscopic substances, by creating a more compact structure. (4) It is suggested that the cell membrane protein might be more im- portant than the keratin in controlling the mechanical properties of the corneum. (Received: 26th July 1971) REFERENCES (1) Blank, I.H. Factors which influence the water content of the stratum corneum. J. Invest. Dermatol. 18, 433 (1952). (2) Blank, I.H. Further observations on factors which influence the water content of the stratum corneum. J. Invest. Dermatol. 21, 259 (1953). (3) Blank, I.H. and Shappirio, E.B. The water content of the stratum corneum. III. Effect of previous contact with aqueous solutions of soaps and detergents. J. Invest. Derrnatol. 25, 391 (December, 1955). (4) Singer, E.J. and Vinson, L.J. The water binding properties of skin. Proc. Sci. Sect. Toilet Goods Ass. 46, 29 (December, 1966). (5) Flesch, P. Chemical basis of emollient function in horny layers. Proc. Sci. Sect. Toilet Goods Ass. 40, 12 (December, 1963). (6) Jelenko, III, C. Purification of the water-holding lipid of intact skin and burn eschar. Arner. Surg. 35, 864 (December, 1969). (7) Middleton, J.D. The mechanism of water binding in stratum corneum. Brit. J. Derrnatol. 80, 437 (July, 1968). (8) Laden, K. and Morrow, R. Torsional measurements on skin. J. Soc. Cosmet. Chern. 21, 417 (1970). (9) Park, A.C. and Baddiel, C.B. Rheology of stratum corneum. Part I. A molecular inter- pretation of the stress-strain curve. J. Soc. Cosrnet. Chern. 23, 3 (1972). (10) Bulgin, J.J. and Vinson, L.J. The use of differential thermal analysis to study the bound water in stratum corneum membranes. Biochirn. Biophys. Acta. 136, 551 (April, 1967). (11) Bendit, E.G. Infra-red absorption spectrum of keratin. 1. Spectra of e-, 13-, and super- contracted keratin. Biopolyrners, 4, 539 (June, 1966). (12) Susi, H. Infra-red spectra of biological macromolecules and related systems. In: Timasheff, S.N. and Fasman, G.D. Structure and stability of biological macromolecules, 575-663 (1949) (Dekker, New York). (13) Krimm, S. Infra-red spectra and chain conformation of proteins. J. Mol. Biol. 4, 528 (1962). (14) Chapman, D. The structure oflipids, 52-128 (1965) (Methuen, London). (15) Alexander, P. and Hudson, R.F. Wool, its chemistry and physics, 2nd edn, 63 (1963) (Chapman and Hall, London). (16) Matoltsy, A.G. and Matoltsy, M.N.J. Invest. Derrnatol. 46, 127 (January, 1966). (17) Crounse, R.G. Nature (London), 200, 539 (November, 1963).

J. Soc. Cosmet. Chem. 23 23-43 (1972) ¸ 1972 Society of Cosmetic Chemists of Great Britain Measurement and perspiration control of MARGARET UTTLEY* Presented on 9th March 1971 in Eastbourne, Sussex, at the Symposium on 'Appendages of the Skin', organised by the Society of Cosmetic Chemists of Great Britain. Synopsis--A short description of the ECCRINE and APOCRINE SWEAT GLANDS is given. Methods available for visualizing sweat on the SKIN, and for collecting and measuring the quantity produced, are reviewed. Brief mention is made of factors which can influence sweating, materials which have been used to inhibit sweating and the MECHANISMS by which they function. INTRODUCTION Under conditions of extreme emotional, sensory, or thermal stress the response of the human body is strikingly evident in the form of beads of moisture which appear on the skin surface. This moisture, or perspir- ation, is the product of the two to three million skin structures which collectively are referred to as the 'sweat glands', but individually are identified as either eccrine or apocrine glands. Eccrine sweat glands The eccrine glands are tubular, coiled structures 0.4 mm in diameter (1) extending into the subdermal fat and opening on to the skin surface via *Beecham Products (U.K.), Brentford, Middlesex. 23