2 12' The Scottish Nati(7'aUst. 



sufficient quantity to be visible to the naked eye. In certain 

 other cases the quartz predominates over the gold to such an 

 extent that the specimens represent auriferous quartz instead of 

 quartzy nuggets. Thus, Mr John Laidlaw once found, he told 

 me, a piece of auriferous quartz, of the size of a pea, in a burn 

 that runs into the Mennock. 



This comparative abundance of auriferous quartz in small, 

 rough, little, water-worn pieces, points to the probable existence of 

 auriferous quartz-reefs in the slates of the district. But there is 

 only one authentic instance known to me of the occurrence of 

 such a reef, — viz., that mentioned by the Rev. Dr Porteous, who 

 says, " a gold-bearing vein of quartz, 4 or 5 inches thick, is to 

 be found on the Broad Law." ^ He also goes on to state that 

 quartz from the Longcleuch was analysed in Glasgow in 1858, 

 with the result that it contained 3 dwt. 8 grains of gold to the ton 

 of quartz.- Mr James Aitchison, Leadhills, whose windows con- 

 tain an exhibit of the minerals of the district, is said to have 

 found auriferous quartz in situ, and to have had it analysed. But 

 not succeeding in seeing himself when I visited Leadhills in July 

 last, I am not in possession of details. 



Of auriferous quartz found in the district, but probably not 

 belonging to it, the most famous example is the " Gemmell 

 Quartzite," which I now believe to be Australian. In my 

 account of what I then knew of it in 1875, ^ stated explicitly — 

 " There is a flaw in the evidence as to the said Quartzite belong- 

 ing to the rocks of Wanlockhead, in so far as the mass was found 

 loosely by itself on the side of a public road, and it has been found 

 impossible to trace it to any of the quartz, /;/ sitii, in the sub- 

 jacent or surrounding Silurian slates." Not, however, until last 

 summer (July 1877) was I in a position to study on the spot this 

 " flaw in the evidence." But now, as I have shown elsewhere, I 

 think the specimen in question has been satisfactorily traced, not 

 to the rocks of the district, but to a collection oi Australian gold- 

 quartzes to be found in the possession of Mr Robert Laidlaw, 

 within a stone's-cast of the place where the " Gemmell Quartzite " 

 was discovered the day after the said collection was moved to its 



^ This vein, however, does not appear to be known to the officers of the 

 Geological Survey : for Professor Geikie, who is of opinion tliat the whole Lead- 

 hills district lias l)ccn carefully surveyed and mapped, informed me, in a letter of 

 date 31st December 1874, that "the gold of that region has not been met 

 with in situ, but only in the alluvium." 



'^ ' God's Treasurc-I louse,' p. 57. 



