72 Geological Socieiy : — 



Tlicrc could bono doubt regarding the identity of the basic com- 

 pounds thus formed with triethylamine. The base floating on the 

 surface of the satnratcd aqueous solution, possessed in a marked 

 manner the characteristic odour of triethylamine. In order to ex- 

 clude tlie possibility of a mistake, the hydrochloric solution of the 

 compound was mixed with a solution of bichloride of platinum. 

 Only after protracted standing of th.e highly concentrated solution, 

 deep orange-coloured, well-formed crystals of the platinum -salt 

 were deposited, the physical characters of which were still fresh in 

 my memory. 



The determination of platinum furnished results closely agreeing 

 with the formula 



N-^E HCI, PtCI, 

 IE 



I have already applied this reaction in various directions, and 

 shall communicate the results which I have obtained at a future 

 period. On considering how frequently, in the action of hydrated 

 potassa upon organic substances, the hydrogen of the water of 

 liydration is assimilated by the products of dccomjiosition, the sub- 

 stitution of cthylic potassa for the hydrate appears in many cases to 

 promise valual)le results from this mode of ethylation. The facility, 

 however, with which ethylic potassa decomposes at a comparatively 

 low temperature, must always be a serious obstacle to an extensive 

 use of this reaction. 



GEOLOGICAL SOCIETY. 

 [Continued from vol. xiv. p. 156.] 

 November 4, 1857.— Col. Portlock, R.E., President, in the Chair. 

 The following communications were read : — 



1. " On the Correlation of the Triassic and Permian Rocks of the 

 Odenwald in the Vicinity of Heidelberg, and those of Central Eng- 

 land." By E. Hull, Esq., B.A., F.G.S. 



The author first referred to the memoir by Murchison and Morris, 

 in the eleventh volume of the Society's Journal, on the PalBcozoic 

 Rocks of the Thiiringcrwald and the Harz, for the special description 

 of the Permian formation in that jnirt of Germany ; and, as these 

 deposits a])pear to be comjiarable, almost stratum for stratum, with 

 those of England, Mr. Hull sought for a similar correlation at Hei- 

 delberg when on a visit there this autumn. He referred to Dr. Leon- 

 hard's ' Geognostische Skizze von Baden,' 1846, for descriptive details 

 of the geology of this locality. 



Immediately overlying the granite at Heidelberg is a red breccia 

 of porphyry and granite, ujnvards of 200 feet thick, which is the 

 " Uotlic-todt-Liegende" of the Odenwald, l)eing similar to that rock 

 in Thuringia and other parts of Germany, and com])arable with the 



