Q]g sci£Nrrric news. 



Quartz per- jecture, that quartz might prove to be an older formation 



haps older ^jjj^^j cjranite, because the oldest eranite contains much 

 tlungnuiue. n » i , , 



quartz, but Httle mica, and less feldspar than the newer ra- 



rieties. He pointed out several observations to be made, 

 with the view of verifying or of refuting this conjecture* 

 In his description <JT gneiss, he alluded to the veins of gra- 

 nitic gneiss which traverse it, and which, when the gneiss 

 and granite are in contact, have been represented as veins 

 of granite shooting from the subjacent into the superin- 

 cumbent rocks. The red sandstone the professor appear- 

 ed inclined to refer to the first or old red sandstone of Wer-. 

 ner. When describing its stratification and structure, he 

 pointed out the appearances that ought to be attended to 



Direction and in endeavouring to ascertain the dip and direction of strata, 

 '^ ' and particularly cautioned observers against confounding 



the structure of individual strata or beds with the direction 

 and dip of the strata. The numerous fissures that traverse 

 the sandstone of Arran, and which exhibit every variety of 

 magnitude, direction and dip, afforded apt illustrations of 

 Werner*s theory of veins. The porphyry-slate the Profes- 

 sor described as appearing in the form. of overlying oonicalj 

 or irregular tabular-shaped masses, resting on the red sand- 

 stone, also in veins traversing granite, sandstone, greenstone, 

 and other rocks. He gave a description of some tabular 

 masses of this rock, accompanied with pitchstone and 

 claystone, contained between strata of sandstone, and which 

 might be confounded with beds ; but which he was inclined 

 to consider merely as lateral branches of veins, or as slightly 

 inclined veins. 



Geagnosyof At the next meeting, on the 2d of February, Professor 



Arranconti- Jameson read the continuation of his mineraloijical observa- 

 nued. 



tions on Arran. He first detailed the geognostic relations 



of the floetz greenstone of that island. From this account 

 it appeared to occur in overlying masses resting on aand- 

 stotie, in beds in sandstone, and in veins that traverse sand- 

 stone and other rocks. He next described the various kinds 

 of pitchstone that occur in Arran, and seemed to think 

 «ne of the varieties was so well marked, that it might con- 

 stitute a distinct subspecies of the pitchstone. The account 

 •f its ^ognostic relations afforded a detail of many curious 



geognostic 



