Syrovatskii's mechanism of 'dynamic dissipation of magnetic field' is reinvestigated. In order to have this kind of 'dynamic dissipation' at a neutral line the ratio of current density to particle density must exceed a certain critical value. For conditions in the solar atmosphere near sunspots, this value can only be reached by a mechanism which produces a very large compression of the magnetic field as well as an extreme rarefaction of the density. Syrovatskii claims that his mechanism provides both these features. His enormous field compression, however, can only be obtained if one neglects the restoring Lorentz force (e.g. in Syrovatskii's model the compressed field near the neutral line is about one order of magnitude larger than the field of the sunspots which generates it ).The second effect, i.e. the large plasma rarefaction around the neutral line, also is not real. This rarefaction is due to the particular flow field of Syrovatskii's model which allows for a free reconnection of the field lines across the neutral line; the magnetic field is treated like a vacuum field, the effects of the field accumulation near the neutral line being neglected. The aim of the present paper is to show how more realistic models modify Syrovatskii's results. Our numerical calculations lead to a maximum current to density ratio which is a factor of l0 s smaller than the one obtained by Syrovatskii. Therefore one has to conclude that in the solar atmosphere one cannot produce in the way described by Syrovatskii the configurations which are necessary for 'dynamic dissipation'.