This occurrence of barytes is somewhat remarkable and interesting from several aspects :—The peculiar conditions under which it seems to have been deposited, the limited quantity, and the perfection and richness of the crystallographic development.

It was found some two years ago in one of the shale pits of the Young's Paraffin oil Company, and my friend Mr. J. S. Thomson, to whom I am indebted for two of the four or five existing specimens (of which one, I am happy to say, has been deposited in the Museum of Edinburgh), was so kind as to procure for me from the Mining Engineer of the Company a sketch of the Geological Strata of the neighbourhood, in which the position of the beds containing the crystals is indicated (Plate II.).

In 1885 a trustworthy Persian agent, through whom various antique objects had been already acquired for the British Museum, offered for sale to its authorities a so-called thunderbolt, weighing 131 lbs. (59.4 kilograms), and submitted at the same time the following translation of a Persian letter from his Excellency Hajee Ahmed Khane Sarteep, Ex-Governor- General of Bunder Abbas, Persian Gulf, and Grand Vizier of Muscat:—

The number of localities at which glaucophane has been discovered is still comparatively small, so that it may be of interest to add another and to describe the microscopic structure of a rock in which this interesting variety of hornblende occurs.

The carriage road between Vertex and St. "Vincent in the Val d' Aoste mounts along the left bank of the Dora Baltea, which, in one part, often called the defile of Mont Jovet, is scarped and craggy. The steepest part of the ascent is between the hamlets of Berrioz and Nus (?). I was walking up this, one day in July 1885, in company with my friend the Rev. E. Hill, F.G.S., when my eye fell upon a rock, which I at once reeognised as a variety of eclogite, composed chiefly of small reddish garnets and dull-green hornblende. We secured specimens, though with considerable difficulty, for the rock was very tough ; made a few observations and passed on.

Single fragment of iron, having an estimated weight of eleven pounds, was found about the year 1880 on or near the top of Alleghany Mountain, 3 miles north of White Sulphur Springs, Greenbrier County, not far from the eastern border of West Virginia, U.S.A. ; this corresponds to longitude 80° 20' W. of Greenwich, latitude 37° 51' N. The finder and his official agent, thinking it a piece of rich iron ore, searched unsuccessfully for a vein : the specimen itself was taken to a country smith's shop, heated and cut with a cold chisel; the pieces were distributed as specimens of iron ore. Some time afterwards, two of them, weighing respectively 63 oz. and 31 oz., were given by the agent to Mr. Matthew A. Miller, Civil Engineer, of Richmond, Virginia ; convinced of their meteoric origin, he immediately tried to recover the pieces already distributed, but after travelling several hundred miles was forced to the conclusion that they were irrecoverably lost. From Mr. Miller the two pieces were acquired for the British Museum.

The three varieties of apatite at present known to occur in Cornwall are the sea-green limpid crystals from St. Michael's Mount and other places, the dirty-white, semi-opaque, hexagonal prisms associated with axinite from Botallack Head, and the thin hexagonal plates, described and analysed by Prof. Maskelyne and Dr. Flight as coming from a new locality, now known, however, to have been obtained by the late Mr. Tailing from Fowey Consols, and previously noted from this mine by Greg and Lettsom. To these must now be added a new variety which was lately brought to me as chalybite from the deep workings of Levant Mine, St. Just. The specimens are closely analogous to those analysed by Dr. Flight, but differ slightly in chemical composition and mode of occurrence.

Some Zermatt Guides (Joseph Taugwalder and his brother) made, on a recent excursion up one of the mountains (Pollux ?) in the neighbourhood, the discovery of some very interesting crystals of idocrase and red garnet.

The idocrase crystals are of a dark sherry eolour, and are developed in simple forms, the prism-planes m{110}, a{100}, and the base c{001}, being well developed. The edges [cm] are truncated by narrow planes u{111}, and at the corners small planes i{312} are sometimes found. The prism planes are deeply striated, and at the same time the c plane shows more or less coarse squares, which sometimes seem to belong to independent crystals. The sides of the square are parallel to the a {100} faces. The crystals have, therefore, much the character of a bundle of thin pyramidal crystals united together in parallel positions.

This iron was found on January 5th, 1884, by Alfred Eaton, a mounted police constable, when on duty in the sub-district of Youndegin, at a spot distant about 60 chains (three-quarters of a mile) in a north-west direction from the top of Penkarring Rock, and roughly estimated by him as 70 miles east of York, Western Australia; this must be about longitude 117°30', E. of Greenwich, latitude 31°30' S. Only one of four observed fragments having been brought in by Mr. Eaton, the late Captain Smith, Commissioner of the Police at Perth, sent him out to Penkarring with a native assistant with instructions to bring in the other three, at the instance of the Rev. Charles G. Nicolay, Curator of the Geological Museum, Fremantle, to whomthe late Mr. Edward T. Hardman, F.C.S., the Government Geologist, had expressed his belief in the meteoric origin of the iron.

The coins referred to in this paper were received through Professor J. W. Judd, F.R.S., to whom they had been sent by Mr. George W. Shrubsole, F.G.S., Honorary Curator of the Museum belonging to the Chester Society of Natural Science.

According to Mr. Shrubsole the Roman coins of Chester are generally found in soil consisting more or less of disintegrated red sandstone and clay : the coins of the find now under consideration must have been buried for fifteen centuries, for such as have been deciphered belong to what is called the Roman Third Brass, and range from Philippus, A.D. 244, to Constantine, A.D. 887. Mr. Shrubsole further remarks that crystals are not found to result from the alteration of isolated coins ; when met with they line cavities between adjacent coins of a pile.

Professor Bonney has described, in the British Association Report for 1885, the rock specimens brought from Kilima-njaro by Mr. H. Johnston, and has called attention to the peculiar form of the felspar crystals which are porphyritieally developed in a rock referred by him to augite-andesite. It is at his suggestion that a more detailed account of these crystals is here attempted.

They are of a brown to yellowish-brown colour, full of cavities, and considerably weathered, and are so much rounded that it is impossible to determine their nature with certainty by means of the hand goniometer. They sometimes attain a length of 85 mm.

A Chemical analysis of this felspar, to which our attention was directed by Professor Bonney, and which was subsequently described on crystallographic and optical grounds as orthoclase, shows it to be a sodapotash felspar of somewhat peculiar composition.

In the following table, the first two columns give the results obtained on analysis (Fletcher) of two loose crystals, of which the second was a twincrystal of lighter eolour than the first; the next two columns represent the same analyses if the oxide of iron (present as visible enclosures) and the loss on ignition are neglected; the numbers in the fifth column are obtained by taking the means of the numbers in the two preceding columns.

The three varieties of apatite at present known to occur in Cornwall are the sea-green limpid crystals from St. Michael's Mount and other places, the dirty-white, semi-opaque, hexagonal prisms associated with axinite from Botallack Head, and the thin hexagonal plates, described and analysed by Prof. Maskelyne and Dr. Flight as coming from a new locality, now known, however, to have been obtained by the late Mr. Tailing from Fowey Consols, and previously noted from this mine by Greg and Lettsom. To these must now be added a new variety which was lately brought to me as chalybite from the deep workings of Levant Mine, St. Just. The specimens are closely analogous to those analysed by Dr. Flight, but differ slightly in chemical composition and mode of occurrence.

Since many of the minerals grouped as hydrocarbon compounds in Dana's Mineralogy have become extensively exploited for their commercial uses, allied questions in chemical geology and in their classification have bulked largely in scientific discussion. Thus their place as rocks or minerals in petrology has been mooted; for it is difficult to make out definite chemical composition or crystallographic form in many of the materials of the group now used for heating, lighting or paving. Notably the question, What is coal ? has not been authoritatively removed from the range of scientific controversy―though the supply of the mineral which occasioned the great trial Gillespie v. Russel, nearly thirty years ago, was, until last year, considered exhausted. Diligently bored for to its exact position inthe Scottish carboniferous series of rocks, no trace of it has been found except in its limited basin of four miles area or so around Torbanehill, Linlithgowshire.

These crystals of anglesite were given to me by Dr. Gadow, the Strickland Curator to the University of Cambridge, who obtained them while on a zoological expedition to Portugal.

They were given to him by the agents at the San Domingos copper mines near the Guadiana river in the province of Algarve, South Portugal, as crystals strange and unknown to them.

The only Portuguese localities recorded at present for anglesite are far north of these mines.

The San Domingos mines are worked in a portion of the great metallic lode or bed which stretches from the S.W. of Portugal, across the southern portion of Spain, in the province of Huelva, in an E.S.E. direction, and appearing again in a similar manner and direction on the other side of the Mediterranean in Algeria. The age of the surrounding strata is a matter of dispute.

Some small crystals of a substance, supposed at the time to be an allotropic modification of Creatinine (C4H7N3O), were submitted to me for crystallographic determination. The crystals of which the angles were to be measured were thin elongated plates nearly of an inch long, of an inch broad, and of an inch thick.

More than a year ago I obtained a number of minerals in Boylestone quarry, which lies about a quarter of a mile north-west of Barrhead, near Glasgow.

Upon breaking up at home the very unwieldly druses which alone seem to occur at this locality, I found one which contained Greenockite.

A single bright yellow crystal only occurs, and it lies so deep in the specimen, between two mammillations of prehnite, that its form cannot be deciphered.

I was induced by the urgent solicitations of a local collector, to whom I mentioned the find, to refrain for a time from announcing it. His argument was that the mineral collectors of the neighbourhood should have the earliest chance of being supplied.

As I have myself fruitlessly visited the quarry since, and as even the occurrence of the ordinary zeolites is only very occasional therein, I conclude that time must elapse before more crystals are turned out.

The ores which I have the honour to submit for your inspection were collected by me in Chili. They consist of numerous compounds of copper, silver, gold, &c., and represent the very varied minerals obtained in that country.

Besides the primary metal there is usually at least one secondary body of value present.

The proportion in which this secondary metal—I mean secondary as regards quantity—is present in metallic ores does not seem to be a mere chance affair, but seems to follow some law. My attention was directed to this matter by the silver ores from the district of “Lomas Bayas” near Copiapó. These ores contain gold in a certain proportion, not in relation to the gross weight of the ore but to the contents in silver.

As I was descending the Val Chisone from the Col de Sestriéres last summer, my eye was attracted by the peculiar colour of an erratic, which was lying on the hillside very near the road. The violet-blue tint, generally indicating the presence of giaucophane, was perceptible, especially in certain lights, but, as it was much less strongly marked than in rocks in which I had previously observed the mineral, I felt doubtful. However, I secured a good specimen, and now find on microscopic examination that glaucophane is present, though it is a pale coloured variety, differing from those which I have hitherto examined.

The block was a fairly large one, perhaps more than a square yard in area, and a couple of feet thick. I did not, however, take measurements, as the exact size was unimportant.

This mineral, lead dioxide, does not seem to have been examined since it was first noticed by Breithaupt and Plattner in 1837 (Journ. pr. Chem. x. 508). This specimen, named "Schwerbleierz," is said to be probably from Leadhills, and the mineral is called, in the manuals of Dana and others, a doubtful species. It was named Plattnerite by Haidinger and subsequent authors.

A short time ago my friend Mr. Thos. Davies, F.G.S., of the British Museum, asked me to analyse a mineral from Leadhills, Lanarkshire, which he had had in his possession for some years, but the examination of which he had, from various causes, frequently postponed. On examination it was found to be lead dioxide—Plattnerite.