Hoy al Irish Academy. 135 



by floating icebergs liberated from ancient glaciers in Scandinavia 

 and Lapland, at a period when Russia in Europe was submerged. 

 The examination of the Ural has in the meantime convinced them 

 of the utter inapplicability of a terrestrial glacial theory even to all 

 mountainous tracts of the earth ; for these mountains, the peaks of 

 which rise to upwards of 5000 feet above the sea, though situated 

 in so cold a climate as to be now covered with snow during eight 

 months in the year (and some peaks are never uncovered), show 

 none of those signs insisted on by glacialists, of their having been 

 at any period the residence of permanent glaciers. With the total 

 absence of such proofs, so it is a striking confirmation of the con- 

 nexion between glaciers and the blocks which in Russia in Europe 

 are supposed to have been floated from Scandinavia and Lapland, 

 that the flanks of the Ural chain and the adjacent plains are entirely 

 void of all such far-transported detritus*. 



XIX. Proceedings of Learned Societies. 



ROYAL IRISH ACADEMY. 

 [Continued from vol. xxii. p. 495.] 

 Nov. 30, ''l^HE following communication " On the Compound Na- 

 1841 . * ture of Nitrogen," by George J. Knox, Esq., was read. 



Soon after the discovery of the bases of the alkalies and earths 

 by Sir Humphry Davy, the compound nature of nitrogen began to 

 be a subject of discussion amongst chemists ; but the arguments in 

 favour of this supposition, deduced principally from the nature of the 

 ammoniacal amalgam, led to no satisfactory physical results. 



The experiments of Sir Humphry Davy on the ammoniacal nitruret 

 of potassium, and those of Despretz and Grove f on the compounds 

 of nitrogen with iron, copper, &c, have shown that the metals 

 singly (even when aided by the most powerful electrical induction) 

 have not the power of decomposing nitrogen. There is one experi- 

 ment, however, by Sir Humphry Davy, from which one might de- 

 duce its compound nature. 



Upon heating ammonia-nitruret of potassium in an iron tube, he 

 obtained more hydrogen, and less nitrogen, than the ammonia ought 

 to have given. 



Again : on mixing this substance with a greater proportion of 

 potassium, he obtained still more hydrogen, and less nitrogen ; 

 whereas, on heating the same substance in a tube of platinum, the 

 potassium alloyed with the platinum, and the ammonia was given 

 off almost entirely undecomposed. 



How can these experiments be explained except upon the suppo- 



* The authors announced that the geological map of Russia and the 

 Ural, as taken from their larger documents, would be published in a short 

 time, and that their work descriptive of all the phaenomena alluded to in 

 these notices would be prepared in the ensuing [1842-43] winter. 



[f Prof. Grove's paper here referred to will be found in Phil. Mag. S. 3. 

 vol. xix. p. 97 ; and a notice of M. Despretz's experiments in Phil. Mag. 

 S. 2. vol. vi. p. 147.— Edit.] 



