^ BorrodaU^ Ayrshire^ and Glenstratlifarrar. 13S 
the glen, as far up as we examined it, is gneiss^ which is every 
where stratified, and varies in colour from red to grey and white, 
Tlie strata range from north-east to south- West, dip to the east 
under various angles, and are frequently very tortuous in their 
direction. The gneiss is traversed by veins of granite, and also 
of quartz, and beds of these rocks are to be observed alternat- 
ing with it. The most frequent imbedded mineral is precious 
garnet. Mica-slate, which in other parts of Scotland is so 
abundant, occurs here in comparatively small quantity, and is 
to be considered as subordinate to the gneiss. Quartz-rock is 
more frequent than the mica-slate, but like it occurs in beds 
subordinate to the gneiss. All the varieties of this rock contain 
scales of mica, and sometimes in such quantity, that they pass 
into mica-slate. 
The rock in which the graphite is situated is gneiss, and im- 
mediately beside the workings, the strata run north-east and 
south-west, and dip under an angle of 80'" to the west. The 
gneiss in some parts is very micaceous, and is intersected by small 
veins of red granite. The graphite is not in veins or in regular 
beds, but in irregular masses imbedded in the gneiss. The first 
mass is about three feet thick where broadest, and several yards in 
extent. It is not throughout pure graphite, but is much mixed 
with gneiss, and we observed not only apparent fragments of 
gneiss, but also the different ingredients of the rock, viz. 
felspar, quartz and mica, disseminated through it. Pre- 
cious garnet, which occurs so often in the gneiss, is also very 
abundantly disseminated through the graphite, a circumstance 
which materially deteriorates it. The second mass is nine inches 
wide ; and a third mass is about the same dimensions. Besides 
these masses, we observed others in different parts of the gneiss 
strata, and we were told that others of considerable magnitude 
had been discovered, even at the summit of the neighbouring 
mountains. 
The graphite is scaly, and sometimes undulating curved 
foliated, and occasionally runs into compact. Some of the 
masses we saw were of good quality. 
This mine was discovered by accident in the year 1816, and the 
proprietor, Fraser of Lovat, immediately determined on its being 
