The crystals are of a similar length, though often considerably thicker than those described by Prof. Maskelyne (Phil. Mag. Jan. 1868), and his general description applies to those under consideration.

They are, however, ill-adapted for measurement, as single perfect crystals are rare. As a rule several crystals are longitudinally attached to one another, with slight radial divergence, in such a manner that it becomes difficult or impossible to discriminate between the reflections of their minute faces.

E. D. Clarke was the first mineralogist by whom crystallised graphite was observed and examined. As early as 1821, he described some graphite crystals from the mines at Borrowdale, in Cumberland. Clarke designated graphite by the name of " carburet of iron" or "plumbago," and stated its form to be that of an oblique four sided prism, the obtuse angle of which was found by measurement with the contact goniometer (" the common goniometer ") to be 118°.

My attention was first directed to this rock by Mr. Cruickshank, clerk of works at Beaufort Castle, in July of last year, when, from the description he gave of it, I ventured to pronounce it barytes. Specimens were soon after this put into my hands by Mr. Cruickshank, when I found that my conjecture was a correct one. There was another mineral associated with the barytes, of which we will speak afterwards. The specimens received were so very fine, that I resolved to visit the locality to be able to describe its surroundings and procure specimens for myself. This I did in May last in company with two of my colleagues and Mr. John Ross, one of Lord Lovat's gamekeepers, and who I believe was the first to call attention to this new locality.

The samples to which this note refers were freshly cut from the quarries at Strontian. The mass differs much in quality, but is largely made up of the usual acicular groups. The colour of the mass as received varied, according to the composition, from a slight green shade where Strontianite predominated, to the more pure white of barium and calcium compounds.

The analyses were made from various portions, No. 1 being the selected Strontianite, No. 2 the more white portion of the mass.

In the American Eagle Mine, Utah Territory, occur in intimate association with olivenite and other copper compounds, two copper minerals of an interesting and rare composition.

Covering the surface of often large pieces of more or less friable mixed arseniates, sometimes forming a complete green coating, are numbers of beautiful emerald-green globules. In consequence of the firm adherence of the base of the globules to the underlying gangue matter, it was difficult to obtain material pure enough for analysis, and therefore the results given below lay no claim to great accuracy.

A specimen of crystallised quartz and albite has recently been acquired for the British Museum which has a few isolated crystals of this rare mineral dispersed upon it. Conclusive evidence that the specimen comes from Cornwall is supplied both by the appearance of the quartz and albite and by the presence of the clay-slate with which they are associated.

The mineral monazite or Turnerite has hitherto been discovered in few localities and never in the British Isles. Anatase, however, is mentioned in Greg and Lettsom (Manual of the Mineralogy of Great Britain and Ireland, p. 363) as occurring at Tintagel and near Liskeard in Cornwall ; and it is just possible that crystals of monazite may have been mistaken for anatase.

In dana's System of Mineralogy, 5th Edition, 1883, page 747, the following description of this substance is given :—" Crystallisable in needles; butter-like in consistence; colour, white; melting point of impure native material, 47°, Brazier; but of material after solution in alcohol, 51°, Luck ; 52°-52°· Brazier ; easily soluble in alcohol or ether."

Occurrence. At the Emerald Mines of the Valley of Muso, New Granada, in a gangue composed of anthracitic calcite and pyrites. Lustre, vitreous to resinous ; colour, yellowish brown to honey-yellow. An acute hexagonal pyramid with striations perpendicular to the axis. The crystal measures 84 millim. in length, and 12 millim. in thickness at the base.

The pyramid is perfect and its apex is intact.

All the specimens of Parisite which have been hitherto received, and are found in European Museums, exhibit a truncated hexagonal pyramid. This section is due to a very easy basal cleavage.

During the past few years the study of the minute structure of minerals and rocks has received the attention of so many able geologists, that microscopical mineralogy and petrography may now be regarded as a fairly established means for the identification and diagnosis of inorganic species. As a special instance, I may point to Heddle's researches on Amazonstone, where the discrepancy of its chemical constitution from normal orthoclase, and its aberrant crystalline form, are accounted for under the microscope, with polarised light, by minute structural peculiarities which support the view that it is composed, not of orthoclase and albite, as has been supposed, but of orthoclase and a paragenetic constituent, allied to, if not identical with, oligoclase.

When I submitted my Paper on Enargite (Min. Mag. Vol. vi. p. 49) to this Society, I was unable to give the exact locality of the mineral. As the territory of Montana embraces a considerable extent of land, I was therefore desirous of ascertaining the position of the mines yielding the ore.

Having during the past summer had the opportunity of visiting the locality, I am now able to give some further particulars.

In this Paper the author directs attention to some localities in Scotland where the aetinolite forms of hornblende are to be found.

In Aberdeenshire the actinolite occurs as sheaf-like groups, irregularly distributed through a felspathic base ; also as slender crystals, extending sometimes to the length of eighteen inches, in a dioritic rock. On the hill of Heshgarnich, in Perthshire, this variety of hornblende occurs in nests, also in fan- or sheaf-like bundles of a black colour ; and on the north side of the hill it is found in blade-like forms distributed through a glistening micaceous schist.

The rare occurrence of the primitive rhombohedron r {100} with little or no modification on crystals of calcite has induced me to bring to the notice of the Society some very fine pale lilac crystals exhibiting this unusual habit.

These specimens were raised a few years ago from the Llandeilo flags strata in the Tankerville lead mine, near Shelve, Shropshire.

It does not appear to be at present a matter of fixed precedent whether the Annual Meeting of the Mineralogical Society should or should not be associated with the delivery of a Presidential Address ; and I had hoped, knowing how slightare my claims to the honour which you have conferred upon me, to have escaped until I give place to a worthier successor. But our Honorary Secretary has intimated to me that he would prefer 'a few remarks' and as I feel so strongly the obligations under which he has placed the Society by the free gift of his valuable time, his will is law to me.