British Association for the Mvancement of Science. 171 



compound. Sir George Cayley remarked that the difficulties on 

 this subject were connected with the speculations on the identity 

 between heat and Hght. 



An interesting discussion now arose on the reading of a paper 

 by Mr. WilUam Hutton of Newcastle, on the great " Whin Sill," 

 or trap dyke of the northern counties of England. This related 

 to the geological age of the intrusive rocks connected with the 

 whin, (a provincial name for trap.) Mr. Hutton had explored 

 and examined this dyke through a line of one hundred miles be- 

 tween the confines of Northumberland and Yorkshire : he ex- 

 hibited a section where beds of limestone and shale were super- 

 incumbent to it, inferring thence, that these last were posterior to 

 the trap, which he considered to be the overflowing of ancient 

 volcanic action. Mr. Murchison, the President of the Geological 

 Society of London, entertained a different opinion as to the re- 

 lative age of these rocks. He had personally examined the dis- 

 trict. He considered Mr. Button's paper to be a very able one ; 

 it was true that the basaltic matter was found in beds between 

 the strata alluded to ; but he had reason to believe there was 

 a connection between the whin dykes of Durham, and those 

 stratified beds, which he considered to be intrusive, and that 

 they had been injected laterally not only into the carboniferous 

 limestone, but into later rocks. He thought it important that 

 further examinations should be made in relation to the general 

 connection of all this basaltic matter. He was entirely of 

 opinion that .all this matter had been laterally injected since 

 the deposit of the rocks which enclosed it. [This is also the 

 opinion of Professor Sedgewick, who has made a profound study of 

 these phenomena. We propose in the plate to our next number to give 

 a figure from Mr. M'Culloch's Western Islands, of the manner in 

 ■which the trap is found in Trotternish, laterally injected, between the 

 strata of sandstone.'^ 



Mr. Johnston now read a paper upon the metal provisionally 

 called vanadium, and exhibited some beautiful crystals formed 

 by gradual cooling. We trust that this gentleman will be in- 

 duced, by our present number, to do perfect justice to this sub- 

 ject. 



Mr. Witham, of Lartington, next gave a very interestmg 

 sketch of the fossil flora. Nothing could happen more fortu- 

 nately for the cause of fossil botany, — which is so much in- 



