• 562 8CIE1*TIF1C NEWS. 



alkali, and dried at a temperature below 300', appears as a white 

 powder, so soft as not to scratch glass. When heated to 7009 

 or 800', water is suddenly expelled from it, and, notwithstand- 

 ing the quantity of vapour formed, it becomes at the moment 

 red hot. After the process, it is found harsh to the feel, has 

 gained a tint of gray, its parts cohere together, and is become 

 so hard as to scratch quartz. 



SCIENTIFIC NEWS. 



Geoloaical Society. 

 Geologiffal A T the meeting of this Society. Dec. 4th (the president in 



Society. J\^ the chair) the reading of a paper by William Phillips, 



Esq. M. G. S. " on the views of Cornwall," was begun. 



The regular or metalliferous views of Cornwall are found, 

 with few exceptions, to run east and west. The known length 

 of many of these views is considerable, amounting, in some 

 instances, to two or more miles ; but their actual termination 

 at either extremity has in no case been satisfiictorily ascertained; 

 all that is known being, that they gradually become so poor 

 and narrow, as to make it no longer worth the miner's while 

 to pursue them. 



The dip or descent of the veins varies more or less from 

 perpendicular, inclining towards the north or south, which in- 

 clination is called the underlie of the lode. 



The depth of the veins is still less known than their longitu- 

 dinal extent, not an instance having occurred of a vein being 

 fairly worked out : many veins have indeed been relinquished, 

 but only on account of the expences of working them exceed- 

 ing the produce. The deepest mine now in work in Cornwall, 

 is Dolcoatb, some of the workings of which are 228 fathom* 

 below the surface. 



The usual width of the veins that are worked, varies from 

 one foot to three ; in particular instances^ however, portions of 

 veins occur twenty-four feet, and even thirty feet wide j and, 

 on the other hand, a vein of tii>, not three inches wide, has been 

 followed with profit. 



The 



