lo Proceedings. 



with the section is the occurrence of numerous blocks of 

 the limestone mingled with the overlying clay on the 

 eastern side of the section, none being found to the west. 

 A careful search was made for fragments of Permian or 

 New Red Sandstone rocks which may have been carried in 

 the same direction, but none were noticed. 



Dr. HODGKINSON made a communication on *^ Micro- 

 scopical examination by mono-chromatic light, polarized 

 light, etc." 



Ordinary Meeting, October 2ist, 1890. 



Professor OSBORNE REYNOLDS, M.A., LL.D., F.R.S., 

 Vice-President, in the Chair. 



The thanks of the Society were voted to the donors of 

 the books upon the table. 



Professor H. B. DixoN, F.R.S., exhibited some of the 

 nickel carbonic oxide recently described by Mr. Ludwig 

 Mond, Dr. Langer, and Dr. Quincke, referred to at the 

 previous meeting. The liquid is extremely volatile, and 

 Mr. Dixon showed the effect of the vapour on a Bunsen- 

 burner flame ; he also exhibited nickel deposited from the 

 vapour on a glass tube. It was pointed out that the dis- 

 covery may lead to both new methods of research and more 

 accurate determinations of the physical constants of nickel 

 and cobalt. • 



Professor W. C. WILLIAMSON, RR.S., referred to a 

 communication which he had received from the Berg- 

 Akademie of Berlin, giving details of the discorvery of four 

 Stigmarian trees similar to the huge specimen in the Owens 



