RAMBLES OF A GEOLOGIST. 431 



embedded in a matrix of barytes, stromnite, and other kin- 

 dred minerals, and the thickness of the entire vein is not 

 veiy considerable. I have since learned, from the " Statisti- 

 cal Account of the Parish of Sandwick," that the workings 

 of the mine penetrate into the rock for about a hundred yards, 

 but that it has been long abandoned, " as a speculation which 

 would not pay." 



I observed scattered over the beach, in the neighbourhood 

 of the lead mine, considerable quantities of the hard chalk 

 of England ; and, judging there could be no deposits of the 

 hard chalk in this neighbourhood, I addressed myself, on my 

 way back, to a kelp-burner engaged in wrapping up his fire 

 for the night with a thick covering of weed, to ascertain how 

 it had come there. " Ah, master," he replied, " that chalk 

 is all that remains of a fine large English vessel, that was 

 knocked to pieces here a few years ago. She was ballasted 

 with the chalk and as it is a light sort of stone, the surf 

 has washed it ashore from that low reef in the middle of the 

 tideway where she struck and broke up. Most of the sailors, 

 poor fellows, lie in the old churchyard, beside the broken 

 ruin yonder. It is a deadly shore this to seafaring-men." 

 I had understood that the kelp-trade was wholly at an end 

 in Orkney ; and, remarking that the sea-weed which he em- 

 ployed was chiefly of one kind, the long brown fronds of 

 tang dried in the sun, I inquired of him to what purpose 

 the substance was now employed, seeing that barilla and the 

 carbonate of soda had supplanted it in the manufacture of 

 soap and glass, and why he was so particular in selecting his 

 weed. " It's some valuable medicine," he said, " that's made 

 of the kelp now : I forget its name ; but it's used for bad 

 sores and cancer ; and we must be particular in our weed, 

 for it's not every kind of weed that has the medicine in't 

 There's most of it, we're told, in the leaves of the tang." " Is 

 the name of the drug," I asked, " iodine?" " Ay, that must 



