Chemical Society. 71 



The authors adhere to the opinion previously expressed by them, 

 that such blocks were transported to their present positions by huge 

 floating icebergs, arrested, in some instances, by rising grounds and 

 hills at the bottom of the then sea, and in others permitted to ad- 

 vance further south by longitudinal depressions, which are traceable 

 in the present configuration of the land. Proofs are given that in 

 many instances blocks of trap and quartz rock advance to quite as 

 southerly latitudes as those of granite, and that all these blocks can 

 be traced back to their parent rocks in Russian Lapland and the 

 northern parts of Russia in a north-north-westerly direction, the 

 currents by which they were transported having therefore been di- 

 rected to the south-south-east. The black earth or Tchornoi Zem, 

 which forms the highest deposit of the central and southern regions 

 of the empire, has been described in a previous memoir (See ante, 

 vol. xxii. p. 71). 



A large geological map of Russia in Europe, coloured by the 

 authors, and numerous sections and collections of fossils, illustrated 

 this communication, and it was announced that other conclusions 

 respecting the structure of Russia would follow the description of 

 the Ural Mountains*. 



CHEMICAL SOCIETY. 



(Continued from vol. xxii. p. 323.) 

 March 7, 1843. — The following communications were read: — 



71. " On the Astringent Substances " (continued), by John S ten- 

 house, Ph. D.t 



72. " On ^Ethogen and the ^Ethonides," by William H. Bal- 

 main, Esq. 



On the 6th of December, 1842, I communicated to the Society 

 the discovery of a new compound of nitrogen and boron which was 

 named " JEthogen," and which, like cyanogen, combined with the 

 metals J. At that time hopes were held out that I should be able to 

 furnish the Society with an analysis of sethogen and the results of 

 further experiments, but I am still without the means of doing the 

 former, and have been prevented by illness from working much at 

 the latter. However, some experiments which I have been able to 

 make have brought out very easy processes for preparing sethogen 

 and the sethonides, which may be interesting to chemists, and will 

 place at their disposal a ready means of obtaining these very stable 

 compounds which may prove powerful agents. 



./Ethogen was originally obtained by heating together a mixture 

 of boracic acid and melon, and the principal difficulty attendant upon 

 the process was the previous preparation of the melon. An attempt 



* On the Geology of Russia, see also Mr. Murchison's recent Address 

 to the Geological Society, inserted in our Supplement to vol. xxii. pub- 

 lished with the present Number. — Edit. 



T This paper, together with all those read before the Chemical Society, 

 of which abstracts do not appear in these Proceedings, or which are not 

 otherwise referred to, will be given entire in future Numbers of the Philo- 

 sophical Magazine. — Edit. 



t Mr. Balmain's former communication was given in our last volume, 

 p. 467.— Edit. 



