A. H. wilson To conclude, one further gaffe is perhaps worth mentioning. For many years cuprous oxide was the most interesting semiconductor as an object both of academic study and for commercial applications. When I first discussed it in 1931(a, b)it was deemed to be anexcess conductor in which the current is carried by electrons derived from excess donor copper atoms. In 1935 it was discovered by Schottky Waibel that in all previous measurements the Hall coefficient had been given the wrong sign, and that the current is in fact carried by holes produced by excess acceptor oxygen atoms REFERENCES Bloch,F.1928Z.Phy8.52,555 Borelius, G. 1935 Handbuch der Metallphysik, vol 1, p. 353 Dehlinger, U. 1935 Handbuch der Metallphysil, vol 1, p. 79 Dirac, P. A M. 1926 Proc. R, Soc. Lond. A. 112, 161 Drude, P, Igoo Annin Phys.(4)1, 566 Fermi, E. 1926 Z. Phys. 36, 902 Floquet, G. 1883 Annls Ec norm. sup.(2)12, 47 Fowler, R. H. I926 Mon. Not, R. astr. Soc. 87, 114 Gruneisen, E. I928 Handb. Phys. 13, 61-64 Gudden, B. 1930 Sber. phys med. Soz. Erlangen 62, 289 Houston, W. V. 1928 Z. Phys. 48, 449 Kapitza, P. 1929 Proc. R Soc. Lond. A 123, 292. Lorentz, H. A, 1904-5 Proc. Acad. Sci. Amst. 7, 438, 585, 684. Pauli, W. 1925 Z. Phys, 31,765 Peierls, R. 1930 AnnIn Phys.(5)4, 121 Schottky, w.& Waibel, F, 1935 Phys. Z. 36, 912. Schulze, A. 1931 Z. Metall, 23, 261 n.H. J. Sommerfeld, A. 1928 Z, Phys. 47, 1 wilson, A H. 193Ia Proe. R Soc. Lond. A 133, 458. Wilson, A. H. 1931b Proc. R Soc. Lond. A 134, 277 Conductibility electrique des meaux et problemes connects Conseil de Physique, tenu a Bruxelles du 24 au I'Institut International de Physique Solvay(Paris ga pport Villars, 1927)48 A. H. Wilson To conclude, one fur er ga.ffe Îs pc worth mentioning. For many ycars cuprOU8 oxide was thc most intere tin co ndu cto as an object both of academic study and fOf commcrcial applications. When 1 firs disc ssed it in 19 忡，的 was deemed to be an • exccss ndu r' in hi currcnt is carried byelcctrons derivcd from ex 盹s8 pper atoms. In 1935 it was d iscovered by Schottky & Wa ibel that in aU previous mCa.<!urements the H a.U cocffi cient had becn given the wrong sign, nd mt thc currcn in fact carried by holes produ byex accep oxygen atoma REFEREN CES Ji'rom 1m ~. 1928 Z. Phy,. 52, 555 Borolius, G. 1935 H (J'‘dbuch d~r Maallphy8ik . vol. 1, p. 353 Dohlinger. U. 1935 nd.buch MttaU内时， vol. 1, p. 79 Dirac, P. A. M. 1926 Proo. R. SQc. Lond. A 111, 161 Drudo. P. 1900 A 饰州，、 ν8 (4) 1, 566 Formi, E. 1926 Z. Phν.，. 36, 902 F1oquet, G. 1883 Annlø Gc. norm 'p. (2) 47 Fowler, R. H. 1926 Mot~. Not. R. aøtr. Soc. 87, 114 ，也 ae E. 1928 Handb. Phy" 13, 61- 64 Gudden, B. 1930 SlMr. 'P ，.-med. So:. 也呻剧 89 OU8 W. :;: Z. Phy 咽， 44 a. pi a.， P. 1929 肉:JC. R. Soc. J.nn4. A 123, 292 Lorontz, H. A 吨。 PrOC. Awd. Sci. f7 438, 585, 684 a. uli ，飞，V. 1925 Z. Phy', 31, 765 a. uli ，飞 1927 Z. Phν.，. 41 , 81 Peierlø, R. 1929 Z. Phy,. 53, 255 PeierJs, R. 1930 An Phy'. (5) 4, 121 S< 。‘吐:y ，飞鸟，. l< 飞， a. ibel F. 1935 Phy'. Z. 36, 912 Sehulw, A. 1931 Z. Mttallk. 23, 261 Seema.nn , H . J. 1927 Phy,. Z. 28, 765 Sommerfeld, A. 1928 Z . Phy', 47, I Wil A. H. 1931 a Proo. R. Soc. Lmd. A 133, 458 Wil80n, A. H. 1931 b Proe. R. Lond. A 134, 277 Oenual 。衍Klua liu éledriq~ m/阳回 et problbnt 阳出:u. a. ppor也矶 diøcu 8II Îonø du qua.trième Conøeil de Phyøique, tenu à. Bruxellee du 24 a.u 29 A vri1 t 924 ØOU8 les a.uøpices de Inøt阳也 Inωma. ti on a. de Phyøique Solva.y (Pa.riø: Ga.utier Villa.rø, 19