1 1 6 Annals of the Philosophical Club 



had come to the conclusion that there both the chalk and 

 the Pleistocene Tertiaries were affected by disturbances, 

 which had occurred between the deposition of the Glacial 

 or Pleistocene drift and the last boulder period. 1 



Colonel Sykes gave an account of a number of mud 

 craters, small and large, extending for 25 miles along the 

 coast of Lus, to the N.W. of Cutch and the mouth of the 

 Indus. 2 They emit gas (the nature of it undescribed) 

 together with mud. 



At the 36th meeting (Feb. 27th) Dr. Faraday said, in 

 reference to Mr. Grove's communication at the previous 

 meeting, that Professor Schonbein writing to him on Dec. 

 28th, 1850, mentioned his discovery that oil of turpentine 

 and essence of lemon, if exposed for some time to the joint 

 action of pure oxygen (or atmospheric air) and light, can 

 become ' most energetic oxydizing agents/ changing the 

 colour of indigo solutions, and turning with the utmost 

 facility the metallic sulphides into sulphates. Experiments 

 which he had made fully confirmed Professor Schonbein's 

 conclusions. 



Dr. Lyon Playfair remarked that artists would give a 

 large price for turpentine which had been long exposed to 

 sunlight in half-empty bottles, because it possessed peculiar 

 properties in dissolving cobalt. 



Mr. Gassiot described at the 37th meeting (March 27th) 

 an apparatus, recently obtained by the Kew Observatory, 

 for graduating with great accuracy thermometer and 

 barometer tubes, after which Sir R. Murchison spoke of a 

 new war-steamer on the wave principle, the outcome of 

 some experiments undertaken for the British Association, 

 and built for the King of Prussia. It was 550 tons burden, 

 and had engines of 160 horse-power, making, on the average, 



1 See Lyell, Antiquity oj Man, ch. xvii., for a fuller account. In the 

 Quart. Jour. Geol. Soc. vol. Iv. (1899), pages 305-311, reasons are given 

 by myself and Canon E. Hill why vie were unable to accept the above- 

 named explanation, or that which attributed the disturbance to the thrust 

 of an ice-sheet. 



8 See Lyell, Principles oj Geology, for a fuller account (ed. u, vol. ii. 

 pages 76-7). 



