In general the electrical resistivity of metal specimens does not depend on their size. At low temperatures, however, the mean free path of the electrons can be comparable with the geometric dimensions of the specimens. In this paper the theory of K. Fuchs and R.B. Dingle is discussed in detail, and it is shown that there is a discrepancy between their formulae and the experimental results of van den Berg and hitherto unpublished own measurements for gold at liquid helium temperatures. On the assumption of Rutherford-scattering in a semiconductor one can see that in first approximation the mechanism of electron scattering has only little influence on the formulae derived by Fuchs for thin films.
In agreement with similar observations on the anomalous skin-effect the authors propose to explain· the discrepancy by the increase of residual resistivity with cold working of the surface layer and therefore by the enlargement of the effective surface-area. As to thin wires the assumption of a "surface-resistivity" yields some approximated results in good agreement with those of Dingle.
In conclusion, the authors give a report of the above discussed resistivity measurements on cylindrical specimens of Mylius-gold, perhaps the purest metal ever obtained
