32 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS Biocenosis. Normal skin care, therefore, would appear in our non-tropical latitudes to be not only sufficient but also appropriate. (Received: 15th June 1960) REFERENCES Gaul, L. E., and Underwood, G.B. Geriatricts 7 198 (1952) Epstein, S. Arch. Derrnatol and Syphilol. 71 692 (1953) Burckhardt, W. Derrnatologica 113 255 (1956) Kimmig, J. Arch. Derrnatol u. Syphilis 200 68 (1955) Ross, P. Brit. Med. J. 4572 369 (1948) Sidi, E. and Dobkevitch-Morill, S. J. Invest. Derrnatol. 16 299 (1951) Ippen, H. Berufsderrnatosen 4 235 (1956) Sidi, E., Hincky, M. and Gervais, A. J. Invest. Dermatol. 24 345 (1955) Monocorps, C. Arch. exp. Pathol. Pharrnakol. 141 Vonkennel, J. Augsburger Friihjahrstagung far iirtzliche Fortbildung (1959) c. Czetsch-Lindenwald, H. and Schmidt-La Baume, F. Salben-Puder-Externa (1956) (Springer Verlag, Heidelberg.) Sulzberger, M. B., Zak, F. G. and Herrmann, F. Arch. Derrnatol and Syphilol. 60 404 (1949) Sabalitschka, T. Pharrnazeutische Industrie 9 2 (1942) Therapeutische Gegenwart 89 297 (1950) Chem. Z. 4 108 (1953) Gottron, H.A. Personal Communication Jacobi, O. KolloidZ. 114 88 (1949) Schneider, W. and Schuleit, H. Arch. Dermatol u. Syphilis 193 434 (1951) Miinzel, K. and Ammann, R. Pharrn. Acta. Helv. 30 1 (1955) Weidmann, A. Wien. rned. Wochschr. 102 243 (1952) Schmitz, R. and Cropper, H. Derrnatol. Wochschr. 129 385 (1954) Emmerson, B.T. Med. J. Australia 11 837 (1951) v. Bormann, F. and Blatz, E. Fette, Seifen, Anstrichrnittel 57 605 (1955) DISCUSSION MR. G. E. NEU: 1. What is the effect of sunlight on dry and greasy skin ? If there is an effect, what is the cause of this ? 2. Does perspiration affect greasy or dry skin, i.e. would a person who perspires normally have greasy skin ? Is it possible for somebody who perspires a lot to have dry skin ? 3. Why is it that some parts of our body are dry and others are greasy ? I can understand that the exposed parts of the body, i.e. face, arms, etc., are greasy and that the covered area is dry, but how is it possible that the exposed part is dry and the covered part is greasy under similar atmospheric conditions ? 4. What is dry, normal and greasy skin ? THE LECTURER: 1. You have no doubt noticed that the face feels greasier after exposure to the sun. This is due to stimulation of the secretory

CARE OF THE SKIN, WITH REFERENCE TO CLIMATE AND SEASON 33 glands. Exposure to sun also causes cell multiplication and this causes a person with a weak, thin and sickly skin to have a firmer and more resistant skin after exposure. It is also necessary to differentiate between short term and long term effects. The former is indicated by an increase in the fat and moisture content. On the other hand, excessive and extensive exposure can cause drying of the skin and could lead to cancer, particularly in the presence of tar and other carcinogens. 2. We differentiate between a person with a greasy skin (seborrhoeic) and one with a dry skin (ichtyotic). There are, however, many mixed types, but an ichtyotic does generally perspire less. Basically, a seborrhoeic should have a greasy skin and an ichtyotic a dry skin, but there are excep- tions, because one also finds persons who have seborrhoeic characteristics on the head, and bear signs of ichtyosis on the rest of their body. Such persons perspire to a lesser extent. 3. We know and have observed this phenomenon and this occurs because people are not usually of one or the other type. As the body is covered with clothing the rate of perspiration is reduced, whereas the exposed face perspires freely and becomes dry. 4. A normal skin is never extremely dry or extremely wet. A normal skin is one which is intermediate between a seborrhoeic and an ichtyotic type, which exhibits a certain clamminess without being too wet or too greasy, and which functions properly in the temperature regulation of the body. It is indeed a difficult question to answer. After all, is anything normal ? MR. A. HERZi•A: 1. In your experiments with sunscreen preparations, did you find any advantage in working with the pressurized packs ? 2. Did you utilise surface sprays or foam packs in your experiments ? ThE LECT•RER: 1. The pressurized packs were far superior to the other preparations, and I achieved very good distribution on the skin. Quite honestly, as a dermatologist I was always in favour of ointments and I always thought that they were superior to any other mode of application. My experiments did, however, indicate that pressurized packs were better. 2. The experiments were carried out with spray packs, not with foams. MR. S. C. ELVIN: Were your pressurized surface sprays based on alcohol or on oil ? ThE LECTURER: I used both, without significant difference between either.