268 Visit to the Graphite or Bluck-Lead Mine 



Besides the gneiss, quartz- rock also occurs, and, in some 

 places, in considerable quantity. It always contains mica, and 

 hence frequently passes into mica- slate. 



We did not reach the Black-Lead Mine until 12 o''clock, the 

 distance being greater from Beauly than we had calculated on, 

 it proving to be twenty or twenty-two miles. The excessive heat 

 of the day, and the torment of the midges, was intolerable. My 

 face, lips, and eyes were speedily distorted by them, and one of 

 my eyes fairly closed up. Since a similar attack, during a very 

 hot season in Sutherland, I had experienced nothing like this. 

 The rock in which the graphite or black-lead occurs is gneiss, 

 in which the direction is a little to the E. of N. and dip W. 80°. 

 The gneiss in some places is very micaceous, contains garnets, 

 and here and there is traversed by veins of granite. The gra- 

 phite is not in beds or veins, but in tnasses imbedded in the 

 gneiss. The Jirst mass, or bed, as it is called, is fully three 

 feet thick where broadest. The whole mass appeared to be 

 scaly foliated •, no regular crystals were observed, although, judg- 

 ing from the crystalline nature of the deposit, I think it pro- 

 bable that in cavities, varieties of its regular form, which is 

 rhomboidal, will be met with. It is not throughout pure, but 

 is occasionally mixed with the gneiss, which occurs either in ap- 

 parent fragments, or its ingredients, especially felspar, are dis- 

 seminated in grains or crystals. The precious garnets, already 

 mentioned as imbedded in the gneiss, also occurs abundantly in 

 some kinds of the black-lead, and thus deteriorates it. The 

 second mass (according to the manager of the mine, John 

 Young of Beauly, who first made the locality known in the month 

 of March of the year preceding that of our visit in 1817), is 

 about a foot wide : the third mass the same width. Besides 

 these masses, which were observed extending several yards, we 

 noticed several smaller masses imbedded in other parts of the 

 gneiss near to the mine, and indeed more or less interruptedly 

 to the summit of the gneiss mountain, which rises from the 

 mine. The working we found carried on in a very paltry and 

 slovenly way : three or four men only were employed digging 

 out the graphite, in the style of an open quarry. This district, 

 I doubt not, if thoroughly examined, will be found to afford 

 larger and pure masses of this valuable mineral, than those al- 



