CAPILLARY VISCOMETRY 369 be completely supplanted by any other type or combination of types of viscometry. Other types of viscometry are sometimes accompanied by special complications of their own which do not apply to capillary vis- cometry. For capillary viscometry the reduction of observed results for rheologically complex fluids, though complicated, is explicit and of a closed nature which is not the case for some other types of viscometry. The most serious inadequacies of capillary viscometry probably arise for materials which do not have a unique relation between shearing stress and rate of shear. For such materials the cited method of reduction of observed results is not valid, and no successful modification or replace- ment for it has been developed. The types of materials referred to are illustrated by those exhibiting such effects as thixotropy, work hardening or permanent degradation, and certain types of viscoelastic materials in certain ranges of experimental conditions. For viscometric pursuits which are of an exploratory nature, which do not require high precision, in which great effort is expendable to achieve high precision, or in which interest is centered on complicating processes rather than on fundamental theological quantities, capillary viscometry is likely to continue indefinitely as an important experimental technique. (1) (2) , (3) (4) __. (6) i (7) : (8) (9) (lo) (11) (12) (13) (14) (15) (16) (17) (18) (19) (2o) (21) (22) (23) (24) (25) (26) (27) (28) REFERENCES Barr, G., "A Monograph on Viscometry," l.ondon, Oxford University Press (1931). Merrington, A. C., "Viscometry," London, Edward Arnold and Company (1949). Philippoff, W., "Viskositat der Kolloide," Ann Arbor, J. W. Edwards (1944). Ekman, V. W., Zirkiv. Mat. Zistr. och Fys., 6, No. 12 (1911). Ostwald, W., and Auerbach, R., Kolloid-Z., 38, 261 (1926). Bestul, A. B., and Bryant, C. B., y. Polymer Sci., 19, 255 (1956). Raumann, G., Nixon, I. S., and Denbigh, K. G., Research, 3, 520 (1950). Mooney, M., y. Rheol., 2, 210 (1931). Oldroyd, J. G., "Proc. International Cong. Rheol. Holland 1948," Amsterdam, North Holland Publishing Company (1949), p. 11-130. Garner, F. H., Nissan, A. H., and Wood, G. F., Phil. Trans. Roy. Soc. London, 243A, 34 (1950). Wood, G. F., Nissan, A. H., and Garner, F. H., 7. Inst. Petrol., 33, 71 (1947). Swindells, J. F., Hardy, R. C., and Cottington, R. L., 7. Research NBS 52, 105 (1954). Bashforth, F., and Adams, J. C., "Capillary Action," Cambridge, Universit)' Press (1883). Hersey, M.D., Physics, 7, 403 (1936). Hersey, M.D., and Zimmer, J. C., y. zippi. Physiol., 8, 359 (1937). Brinkman, H. C., zippl. Sci. Research, A2, 120 (1951). Ostwald, W., "Manual of Physico-Chemical Measurements," New York, Macmillan and Company (1894), p. 163. Cannon, M. R., and Fenske, M. R., Ind. Eng. Chem., zinal. Ed., 10, 297 (1938). Cannon, M. R., Ind. Eng. Chem., 16, 708 (1944). Cannon, M. R., and Fenske, M. R., Oil Gas 7, 3:t, 52 (1935) and :t4, 45 (1936). Fox, T. G., Jr., Fox, J. C., and Flory, P. J., 7. Zim. Chem. Soc., 7:t, 1901 (1951). Stabin, J. E., Personal Communication. Ubbelohde, J., 7- Inst. Petrol. Technol., 19, 376 (1933). Bingham, E. C., "Fluidity and Plasticity," New York, McGraw-Hill Book Company, Inc. (1922), p. 76. Tsuda, S., Koll. Z., 45, 325 (1928). Stow, F. S., Jr., Horowitz, K. H., and Elliott, J. H., 7. Colloid8ci., 4, 321 (1949). Willenberg, H., and Fritz, W., Z. Zingew. Chem. B20, 134 (1948). Swindells, J. F., Coe, J. R., Jr., and Godfrey, T. B., 7. Research NBS, 48, 1 (1952).

370 JOURNAL OF THE SOCIETY OF COSMETIC CHEMISTS (29) Maron, S. H., Kreiger, I. M., and Sisko, A. W., 5 e. ./lppL Phys., 25, 971 (1954). (30) Maron, S. H., and Belner, R. J., Ibid., 26, 1457 (1955). (31) McKee, S. A., and White, H. S., ./1STM Bull., No. 153, 90 (1948). (32) McKee, S. A., and White, H. S., 5 e. Rese,a, rch NBS. 46, 18 (1951). (33) Philippoff, W., "Viskositat der Kolloide, Ann Arfior, J. W. Edwards (1944), pp. 44-45. (34) Kreiger, I. M., and Maron, S. H., 5 e. -/lppL Phys., 25, 72 (1954). EXPERIMENTS ON MITOTIC FLARE-UP AND ACANTHOSIS* By Da. ROBERT Bau• University of Geneva Hospital, Geneva, Switzerland L'EXAMEN DE LA POVSS•E mitotique est fait sur la t&ine de cobaye male. On applique une goutte de la solution i tester, puis on injecte au cobaye de la colchicine. Cet alcaloide est un rkvklateur des cellules en division. On kvalue ensuite le nombre des mitoses sur la coupe histologique. Les oestroganes et les produits ayant un effet toxique primaire entre autre provoquent une telle pousske mitotique. Parmi 8 dkrivks du dinitro- chlorobenzane examinks de cette mamiare, les 4 produits connus comme eczkmatoganes provoquarent une forte pousske mitotique tandis que les 4 autres n'en donnarent pas. D'autres produits tels que tkrkbenthine, chrysarobine, cignoline, certains alcools et hydrocarbures, le gkraniol et le farnksol, etc., provoquent kgalement une pousske mitotique. L'examen du pouvoir acanthogane d'un produit est fait sur le fianc du cobaye. Apras avoir appliquk la substance, soit pure, soit diluke dans u'n excipient, pendant plusieurs jours, on prklave un kchantillon du fianc traitk et du fianc non trait& On mesure l'epaisseur de 1%piderme sur les coupes histologiques. On voit ainsi si l'kpiderme s'est kpaissi ou non sous l'infiuence du produit appliqu& Nous avons examink de cette maniare diffkrents onguents ainsi que route une skrie d'alcools et d'acides aliphatiques saturks et non saturks. Tandis que pour les alcools saturks (de C2 & Cls) on ne remarque pas d'effet acanthogane, les alcools avec une double liaison (Cll et C•s) montrent une forte action. Parmi les acides saturks on remarque un maximum avec l'acide laurique quant aux acides avec une double liaison, ils sont net- tement acanthoganes & partir de C•0 et cet effet augmente jusqu'& l'acide krucique (C20. * Risuml of Paper Presented at the August 2, 1957, Meeting, Geneva, Switzerland.