170 



Exclusive of these social ideas, they are often equal to the 

 best foreign agates, and bear cutting and polishing equally 

 well. We shall speak of the striped and otherwise marked 

 stones hereafter. 



The agates found on the sea-coast, being rolled and jum- 

 bled together by the force of the waves, are roughened j but 

 being hard, this roughness penetrates but a little way, and 

 the utmost force they experience seems only to make little 

 circular flaws; or, if I may be allowed the expression, more 

 frequently little crescents or semi-circular flaws, from the 

 impulse of the blow coming in a lateral direction. 



The right hand specimen is from the Bill of Portland. Its 

 outer surface is generally as here represented, but sometimes 

 whiter. The left hand top specimen came from Lowestoft, 

 and was, perhaps, formed by aggregation, as most agates 

 seem to be (possibly in. a trap rock, see Tab. 58), as the 

 cloudy appearance within seems to indicate. 



The next figure is of a rougher formation. It was sent 

 by the Rev. H. Davies of North Wales. The smooth one on 

 the right hand, with a little red about it, has been called a 

 carnelian. It was found at Lough Neagh in Ireland : but it 

 must be observed *hat agates, especially British ones, should 

 not be confounded with oriental carnelians, the fracture of 

 the agate not being so shining, and the stone much harder*. 

 TJie next specimen on the left is a rather pellucid fragment 



* This is well known to lapidaries, seal engravers, &c. as it costs them 

 more labour and diamond dust to work them. 



