^{page 7 note *} While confounding these bands with “contemporaneous veins,” Jameson saw clearly their marked features. He writes—“These veins do not present the slaty structure which is one of the discriminating characters of gneiss when it occurs in strata ; hence contemporaneous veins, filled with common granular, or what may be called granitic gneiss, have been confounded with true granite.” Thereby meaning common or eruptive granite.

^{page 8 note *} The alkali-charged waters are, however, potent, even at low temperatures, to change clay slates and argillaceous gneiss into granite, and so to extend the sphere of the metamorphism.

^{page 22 note *} My assistant, Mr Dalziel, finds it advisable to use a mixture of potassium fluoride and calcium fluoride—the former being in excess. Less calcium sulphate is thus formed, and the platinum crucible is more speedily emptied of its contents.

^{page 26 note *} Something very close to this is given by Cotta as his description of typical porphyritic gneiss,—“ In the otherwise uniform schistose mass there occur at intervals large egg-shaped crystals of orthoclase (sometimes amorphous), round which the foliated texture bends itself with a wavy sweep.” Ruskin, in treating of the rock-structure of the Alps, gives an admirable drawing of such gneiss.

^{page 34 note *} Hebenstreit. From gneiss, with axial angle small.

^{page 34 note †} Hebenstreit. From the granite of the Tyrberger water-fall; specific gravity, 3 07. Zeitschrift für Krystallographie und Mineralogie, Zweiter Bund, erstis heft.

^{page 34 note ‡} One or two of the Haughtonites were not included in calculating the average, their analysis having been very lately executed; as they agreed with the others, their exclusion does not effect the result.

^{page 37 note *} This peculiar granitiform belt I have seen cutting limestone strata elsewhere in Scotland,—as at Laggan near Dulnan Bridge, Inverness-shire; and Boultshoch, in Aberdeenshire. This belt always carries Biotite, and the felspar in two of these cases has upon analysis proved to be Andesine.

^{page 41 note *} Localities in which it is doubtful whether the black mica is this species or Biotite are the following:—

At Badnagauch on. the Deskery there is a rotting syenite, which is riddled with exfiltration veins composed of large crystals of labradorite and hornblende, with a hydrated Biotite (?), menaccanite, sphene, and Allanite as accessories.

In the hyperite of Scuir na Gillean in the Cuchullins, and of Halival in Rum, a black mica is rarely seen, which is most probably Biotite.

Scales of a dark brown uniaxial mica, which occur in tufa at Kinkell and Kincraig in Fife, I also set down as Biotite. Haughtonite probably is the brown mica which, in somewhat small quantity, is found in the andalusite layers of the gneiss of Clashnaree, Glendarff, and other hills of the Clova district. The associates here being andalusite, quartz, fibrolite, and labradorite. The composition of the mineral from this locality does not altogether accord with that of the generality of specimens, and its occurrence in gneiss is somewhat exceptional.