309 



siders as other memorials of the operation in question. The nature 

 of the rocks is unfavourable for the preservation of smoothed and 

 striated surfaces ; but Mr Chambers had found one such on the 

 border of St Mary's Loch in Selkirkshire, 800 feet above the sea. 

 On the assumption that the hills had been shorn and rounded by 

 moving ice, it appeared from the high inclination of the strata, as 

 exhibited in a copy of Professor Nicol's section of the district, that 

 the amount of denudation fully equalled the remarkable examples 

 adduced by Professor Ramsay in regard to South Wales and the 

 Mendip hills. Finally, Mr Chambers described an example of the 

 later and limited operations of ordinary glaciers, in the elevated 

 moor of Loch Skene, a tarn formed and retained by a moraine. 



3. Preliminary Notice on the Decompositions of the Platinum 

 Salts of the Organic Alkalies. By Thomas Anderson, 

 - M.D., Regius Professor of Chemistry in the University 

 of Glasgow. 



The following pages are intended merely as a preliminary notice 

 of an investigation, which has occupied me for some time past, and 

 which, though still too incomplete for publication in full, is suffi- 

 ciently advanced to render obvious the general character of the 

 results, although, from the extensive and elaborate nature of the 

 inquiry, a very considerable time must elapse before it is complete 

 in a!l tlie requisite details. 



It has been known for some years that the platinum salts of the 

 organic alkalies are decomposed when boiled with excess of bichloride 

 of platinum ; and with narcotine, the only one as yet examined, the 

 action is a true process of oxidation, yielding results similar to those 

 obtained by treating the base with peroxide of manganese or nitric acid. 

 The present investigation refers to the pure platinum salts, which 

 undergo an entirely different decomposition, the nature of which is 

 materially dependent on the stability of the base. Having observed 

 that the decomposition was more precise and definite when the less 

 decomposable bases were employed, and apparently calculated to af- 

 ford the key to the more complex changes, which occur in other 

 cases, I have hitherto directed my attention more particularly to 

 pyridine and picoline, which are so remarkable for their stability 



VOL. III. 2 u 



