Proceedings of the Royal Socu'ty. 203 



own era, and is probably still undergoing a sensible diminution. 

 His views are founded partly on speculative considerations, of 

 which it is not possible to give a sufficiently circumstantial abridg- 

 ment, and partly on the evidence of various operations going on at 

 or near the surface of the earth, the tendency of which must, on the 

 whole, apparently be to diminish the quantity and proportion of 

 the oxygen in the atmosphere. In addition to the ordinary and 

 well-known causes of deterioration, the author points out a new 

 source of diminution to which his attention has been lately drawn. 

 From experiments made upon the aeriform fluid discharged from 

 the earth during an inundation, and obviously expelled by the 

 water penetrating to a considerable depth, and displacing the gases 

 contained in the soil, he found that this gaseous matter consists of 

 2.5 per cent, carbonic acid, 12.764 oxygen, and 84.736 nitrogen. 

 Taking this observation in conjunction with many others pi-eviously 

 made on the composition of the gaseous discharges in volcanic dis- 

 tricts, and the gaseous contents of mineral waters, he infers that a 

 process of oxidation is constantly going on at various depths below 

 the earth's surface, the oxygen for which is, in all probability, de- 

 rived by absorption of the atmospheric gases at the surface. 



2. An Account of a New Species of British Bream, and a 



Species of Skate new to Science ; with a List of, and 

 Observations on, the Fishes of the Frith of Forth and 

 Neighbourhood. By Richard Parnell, M.D., F.K.S.E. 



3. Notice on the Composition of the Right Prismatic Ba- 



ryto-Calcite, the Bicalcareo-carbonate of Baryta of Dr 

 Thomson. By Professor Johnston, Durham. 



4. An Explanation of the Aristotelian Expression Msra ra 



4>uff/xa, with some inferences from the Explanation. By 

 the Venerable Archdeacon WiUiams. 



Proceedings of the Wernerian Natural History Society. 

 {^Continued from vol. xxi. p. 163.) 

 Sessiok 1836-7. 

 The Thirtieth Session of this Society commenced on the 3d De- 

 cember 1836, Professor .Jameson, President, in the Chair. 



A Report from the Joint Prize Committees, dated 26th Novem- 

 ber 1836, was read, approved of, and sanctioned. It was of the 

 following tenor : — 



