446 R. G. Drew manner than a lipstick selected by the investigator and hence only one lipstick of each type was tested by the subject. Although a difference was detected between the maximum application forces used in each lipstick range, an investigation of the data showed that this may be due to either the colouring ability of the lipstick, or the age of the subject. The colours applied with the greater force were predominantly pale brown or a clear gloss. The mainly dark colours, of better colouring ability, were applied with a smaller force. The application data implies that lipsticks with relatively low colouring power (usually pale colours) are more likely to fracture during use if the strengths of all lipsticks are equal. Differences in maximum application force were detected between frequent and occasional lipstick users, but not between users and non-users of lipstick. This may be explained by the selection of lipsticks, because non-users of lipstick more frequently selected glossy and paler lipsticks. REFERENCES 1 Elliott, T. J. Present and future trends in make-up. Cosmet. Perrum. 88 35 (1973). 2 Lauffer, P. G.I. Lipsticks. In: Balsam, M. S. and Sagarin, E. Cosmetics, Science and Technology Vol. 1 388 (1972). Wiley-Interscience, New York.

J. $oc. Cosmet. Chem. 29 447 (1978) Oorrigendum Changes in sunburn and mechanisms of protection, by B. E. Johnson. J. $oc. Cosmet. Chem. 29 31-44 (1978). Reference (10) Coblentz, W. Ultraviolet radiation useful for therapeutic purposes: specification of minimum intensity or radiant flux: second communication. J. Am. Med. Assoc. 99 125 (1932) is cited incorrectly for the division of the uv spectrum. Moreover, the wavelength limits for uv-A, uv-B, and uv-C given in the text (p. 32) are not necessarily those universally recognised. It would be better if reference 10 was 'International Lighting Vocabulary, 3rd edn, 4, Publication CIE No. 17 (E-I.1) (1970), Bureau Central de la CIE, Paris'. The spectrum limits would then be uv-A 315-400 nm, uv-B 280-315 nm, uv-C 100-280 nm. 447