Professor Reich on the Electrical Currents 



of a slight difference of temperature, probably induced by the 

 forcible driving up of the strut at the point a, whilst the disc 

 at h had been in position for some time. 



Other cases, in which probably uninteri'upted metallic con- 

 nection between two points had place, were, — In Friscli Gliick, 

 on the 6th drift, with an interval of 20'" without any visible 

 interruption in the continuity of the galena, and where a devia- 

 tion of 12'^ was obtained. The heating of that point towards 

 which the (Current in the wire went, produced a reversion of 

 the same, causing a deviation of 10° in the opposite direction. 

 In the same vein, two galena points, one 12™ above the 

 other, — when a deviation of 7° was observed. The tempera- 

 ture, however, was not noted. 



In the same vein, on the 5th drift, with 8'" interval of ga- 

 lena interspersed in the gangue, when all action failed, al- 

 though the current from a zinc-copper element introduced, 

 caused a deviation of 10°, and a zinc-plate having been sub- 

 stituted for the copper one at one point, caused a deviation of 

 2°. 



In the same vein, with 56'^ interval of massive and inter- 

 spersed galena, without an}^ action, although the zinc-copper 

 element gave a deviation of 15^, 



In the same vein, with SB"" interval of massive galena and 

 massive blende, without any action, although the zinc-copper 

 element gave 30° deviation, — ^at the same time, the heating of 

 the one or the other disc produced a current which, strangely 

 enough, in both cases, went from galena towards blende, indi- 

 cating opposite thermo-electric properties of galena and blende 

 . in reference to copper. 



It deserves also to be mentioned, that, in the above cited 

 case, where in Gottlob, E. and W. vein, two galena points 

 at 10™ apart, and disunited by a rent throwing the vein, 

 gave a cm'rent through the wire connecting them, causing a 

 deviation of 23°, — the heating of the point from v/hence the 

 current proceeded increased the deviation ; and that the heat- 

 ing of the other point above it, not only decreased it, but even 

 occasioned a reversion of the current to the opposite direction. 

 This strong action of heat must have been a consequence of 

 the short interval, and of the good conducting power of the 



