Some extremely beautiful but rather soft gems of various green hues have been extensively sold during the last year or two. They are found in the gold washings of the river Bobrowska, near Poldnewaja, district of Syssersk, in the Urals, and occur in the form of nodular masses, varying in size from a pea to a chestnut. These closely resemble the jelletite from Monte Rosa. All the specimens which I have examined present a roughly radiate structure, are irregularly fissured and veined, and are coated with a talcose mineral, glistening and nearly white. The exposed uninjured surfaces of the nodules are minutely and unevenly striated. The mineral shows no cleavages, but the broken surfaces have a resinous or semi-adamantine lustre, and show a small conchoidal fracture.

During this autumn I had the opportunity of examining several different batches of celestine which had been dug out of the foundations of houses in this neighbourhood. On analysing one specimen which I took to be blue celestine, barium was found to be present in considerable quantities ; I then made a more exact qualitative analysis but failed to detect calcium or any other metal. The mineral then obviously consists of a double sulphate of barium and strontium, and a mineral of that kind has been found by Thomson, and was called by him baryto-celestine. Baryto-celestine, so far as I can ascertain, has not, however, been previously found in the British Isles.

At the General Meeting of the Society held at the rooms of the Royal Microscopical Society, King's College, London, on March 14th, 1877, were exhibited some octahedral crystals of iron, which were procured from a hollow cavity in the middle of a bar of pig iron. The way in which they came into my possession was this.

A friend was walking on the Docks at Liverpool some years ago, watching a vessel being unloaded, which had arrived freighted with pig iron from Gartsherrie. These pigs were lifted by cranes, and one accidentally slipped, and dropped on to its end, and was fractured in two pieces, showing a cavity about the size of a duck's egg, and his attention was drawn to some bright lustrous objects which he saw roll out of the cavity. These he at once picked up, and found they were crystals of the metal, octahedral in shape, and about ⅗ of an inch in size.

My original account of the mineral which I called Mordenite, from having first obtained it in the trap of the bay of Fundy, at Morden, King's Co., N.S., is to be found in the Journal of the Chemical Society, t864. A quotation is made from this to show the peculiarity of the deposit I am about to describe, and a few additions are given respecting opinions expressed on the species, and on its supposed occurrence elsewhere, before taking up the account of the recent observations to which I desire to draw attention.

In the following short paper I propose to describe what I have lately done in improving the method of studying the optical characters of the minerals which I treated at greater length in my address last year at annual meeting at Plymouth.

It is a curious example of how a method may be invented, and then lost sight of, that the determination of the index of refraction in the way there described was proposed by a French savant upwards of a hundred years ago. I have not yet consulted the original publication, but I very strongly suspect that the proposal was more theoretical than practical, and that with the instruments then at disposal the results were found to be so inexact that the whole system became obsolete and practically forgotten.

This lies to the south of Unst ; it is interesting as forming the connecting link which unites the rock masses of Fetlar with those of Unst.

Its western extremity is composed of diallagic rocks, containing crystals of that mineral (Hb) very inferior to those of Balta : its middle portion consists of various rocks of the "chloritic series" ; towards the east there is seen a bed of graphitic slate (H) quite similar to, and doubtless the continuation of one which appears near Trista V oe in Fetlar.

In No. V. of this Magazine (page 149) there appeared a paper on "Some new Minerals in the Collection of the Hunterian Museum, Glasgow," in which I gave a description and analysis of a new Sulphide of Lead, Manganese, Iron, and Zinc, to which I gave the name of "Youngite." In a note to his abstract of the above paper for the Journal of the Chemical Society of January, 1878, Dr. Burghardt, expressed an opinion that the "Youngite" was only a mixture of Galena, Blende, Alabandite (Mn S), and Iron Pyrites; and consequently had no claim to be called a new mineral. Although my analyses agreed closely, and coincided with such a probable formula that there was little reason to doubt their accuracy, I am glad to be able to place the matter beyond dispute.

The following brief notes may be of some interest to students of Cornish Mineralogy.

1 st.—New Localities.

Scheelite.—This occurs as a partial replacement of Wolfram at East Pool Mine, where it was first noticed by Mr. Cornelius Beringer, of Redruth, an Associate Member of this Society. Hitherto it has only been found at Pengelly Croft, Huel Mandlin, and Levant Mine, in Cornwall, and at Huel Friendship, in Devon.

In the course of an examination of such Scottish garnets as were pure enough for analysis, I found that four had a composition which was very similar, but which differed from that of any known, and that to an extent entitling them to be regarded as constituting a well-marked variety.

These garnets, from their purity of colour and transparency, would all be classed as precious garnets–they are, indeed, the most brilliantly coloured which the northern portion of the kingdom affords.