110 W. JOLLY AND J. M. CAMEEON ON A NEW 



1877, at whicli both the authors were present — Mr. Jolly having 

 previously noted it in a preliminary examination of the ground along 

 with Mr. Cran, of Kirkton, and Mr. Cameron having, at the excur- 

 sion first suspected its rarity and subsequently analyzed it. 



(2) MoniacJc Burn. — This passes through a very picturesque 

 gorge called Eeelig Glen, enclosed by high cliffs, finely wooded, and 

 attractive to the geologist and botanist. The stream runs here 

 along a fault, near the synclinal axis, associated with a remarkable 

 conglomerate and with granitic, felspathic veins. A great fall of 

 rock took place last winter from the face of a high precipice in the 

 glen above Reelig House. The fallen debris contained much of the 

 mineral, associated with orthoclastic felspathic rock, interbedded with 

 clay-slate, and mica and chloritic schist, &c., not only in veins but 

 in regular strata some feet in thickness. 



(3) Near South Glunes Farm. — It is also found in situ above this 

 gorge, on the east bank of the stream, at a limestone-quarry, where 

 it occurs in great purity in a felspathic rock in contact and bedded 

 with the limestone. It seems here to be more or less associated 

 with the limestone, which crosses the river from this point near the 

 fallen cliff, and runs to Eebeg farm, where also it is worked. 



(4) Near Dochfour, at the north end of Loch Ness. — It occurs here 

 in rock in situ, on a new road to the Mansion House, about 150 

 yards north of a new bridge over Dochfour Burn. It is also asso- 

 ciated here with felspar in large masses, bright blue at first but 

 gradually losing colour by exposure, and easily disintegrating under 

 water. 



(5) At Lochend, at the north end of Loch Ness. — It was found 

 here, not in situ, but in detached blocks in the burn near Lochend 

 Hotel, by Dr. Aitken and Mr. "Wallace, members of the Inverness 

 Pield Club. The blocks have probably come down the burn, but 

 their source has not yet been discovered. 



II. Its Chemical Analysis. 



The fragmentary blocks of orthoclastic felspar intermingled with 

 quartz and granite found scattered over Englishton Moor contain 

 the blue mineral in very thin veins or laminae. The first portions 

 submitted to analysis were from that locahty, as it was here atten- 

 tion was first directed to it, and, at the time the first analyses were 

 made, this was the only place where it had been noticed in any great 

 quantity. 



As it is unnecessary to dwell on the methods adopted for identi- 

 fying and quantitatively estimating the several substances entering 

 into the composition of this interesting mineral, we shall simply 

 give the following figures, which are the mean of several analyses 

 of specimens from different localities, and constitute the data from 

 which we have calculated the formula. 



