London Eleclrical Society, 409 



From these facts the authors conclude, that the older rocks of the 

 Hartz are chiefly Silurian and Devonian, with a few traces of the 

 lower carboniferous. 



If the great contortions and strike of the Rhenish provinces were 

 produced contemporaneously with tiiose of the Hartz, then must 

 the great derangements of the Hartz have taken place after the de- 

 posit of the Belgian and Westphalian coal-fields. But the principal 

 dislocations of the Hartz must have taken place before the deposit 

 of the red conglomerates, sandstones, coal-beds and trappean masses, 

 which rest on its eastern flank. Hence the authors conclude, that 

 none of these red conglomerates are of the date of the old red sand- 

 stone ; and that the coal-beds belong to the highest part of the car- 

 boniferous series, where it passes into the base of the new red sand- 

 stone. 



Lastly, The authors describe a hasty traverse, made from the 

 Thuringerwald through the forest of Upper Franconia, and thence 

 to the north flank of the Fichtelgebirge. On the northern limits of 

 the section (the strike and many accidents of position remaining as 

 before) were rocks with a true slaty cleavage, which might (at least 

 mineralogically) be compared with the upper slates of the Ardennes ; 

 and further south, the analogy was confirmed by bands of limestone, 

 Avith stems of Encrinites, but with very few other fossils. Still further 

 south occur a few impressions of plants, and the whole system ap- 

 pears to be at length overlaid by a series of limestones and schists, 

 some of which are very rich in fossils. One of these zones of lime- 

 stone (the lowest according to Count Munster) rests on calcareous 

 slates, containing a cardiola of the upper Ludlow rock. It is in this 

 zone that the Clymenia is most abundant. Goniatites, Orthocera- 

 tites, &c., are abundant in a higher zone ; and the series is overlaid 

 by a limestone with many species of true carboniferous productae, 

 &c., and identified with the mountain limestone. From these facts 

 the authors conclude, that the fossiliferous region near Hoff (south 

 of the Fichtelgebirge) belongs to the Devonian system, with the 

 exception of the highest beds, which are carboniferous. 



Such are the results arrived at by the authors, which seem to 

 be in general accordance with one another, and to bear out the clas- 

 sification they proposed for the older British formations. 



LONDON ELECTRICAL SOCIETY. 

 April 20, 1 84 1 . — The Society held their firstmeeting of this Session. 

 After the election of members had been announced, the Chairman 

 stated that Walter Hawkins, Esq. had presented the Society with 

 a dried specimen of the Gymnotus Electricus. The Secretary read 

 a letter he had received from J. P. Gassiot, Esq., F.R.S., in which 

 was a description of a voltameter containing live pairs of electrodes, so 

 arranged as to enable the experimenter to use one or more pairs at 

 plea.surc. A communication was received from George Mackrell, Esq., 

 detailing experiments wherein the fi\e terminal wires of a voltaic 

 battery were ignited at the surface of acid water, forming a part of 

 the circuit. 'I'he negative wire was lieatcd to a greater degree than 



