72 Geological Society : — 



it was erected by Procopius Divisch, although the suggestion was 

 made by Franklin in 1749. The first observation of chemical de- 

 composition by means of the galvanic current is ascribed to Dr. 

 Asch, of Oxford, in 1795. Humboldt, repeating the experiment, 

 first collected hydrogen from the galvanic decomposition of water ; 

 and Nicholson, in 1800, making the necessary substitution of 

 platinum electrodes for those of brass or copper, first collected 

 oxygen from this source. The first electro-plating was effected by 

 Bitter iu 1800, who deposited copper by means of the galvanic 

 current. The first construction of a secondary battery is assigned 

 to Gautherot, in 1802 ; and the first construction of a dry pile, 

 with which the name of Zamboni is usually associated, is shown to 

 rest with Behrens, who constructed such a pile in 1803, seven 

 years earlier than Zamboni. 



Respecting the rediscovery of Ohm's Law by Pouillet, Dr. 

 Hoppe writes : — " Pouillet does not say whether or not he was pre- 

 viously acquainted with Ohm's law ; the attempt has since been 

 made to claim the priority of the discovery for Pouillet, which is 

 the more absurd since it has not yet been determined that Pouillet 

 was not acquainted with the researches of Ohm and Eechner. 

 For, as I have already had occasion to remark, when Englishmen 

 or Frenchmen do not cite a German work, that is no reason for 

 supposing that they are not acquainted with it. Since Pouillet had 

 been for a long time in scientific correspondence with Poggendorff, 

 as, indeed, appears from the abstracts of his work, which he him- 

 self prepared for Poggendorff's Annalen, it appears to me very 

 probable that Pouillet was acquainted with Ohm's work, and that 

 his excellent experiments therefore, as, indeed, Poggendorff re- 

 marks in a note, were only a confirmation of Ohm's theory." 



The fifth and sixth books, which, of course, occupy the most 

 space, are particularly full and interesting, but space forbids de- 

 tailed reference. We merely mention the account given of the 

 introduction of the idea of " potential " into electrical theory, and 

 the history of the various forms of incandescent lamp. Dr. Hoppe 

 does not seem disposed to credit Edison with quite so much origi- 

 nality as he is generally supposed to have. 



Dr. Hoppe has produced a most valuable and interesting work, 

 which will be cordially welcomed by those interested in the subject 

 who are acquainted with the German language. It is to be hoped 

 that an English version may be produced. 



XL Proceedings of Learned Societies. 



GEOLOGICAL SOCIETY. 

 [Continued from vol. xix. p. 513.] 

 May 13, 1885.— Prof. T. G. Bonney, D.Sc, LL.D., E.P.S., 

 President, in the Chair. 

 HPHE following communications were read : — 

 -^ 1. "On the Ostracoda of the Purbeck Eormation ; with Notes 

 on the Wealden Species." By Prof. T. Eupert Jones, E.E.S., E.G.S. 



