This mineral occurs in fibrous masses occupying fissures or shrinkage cracks in the serpentine of Duporth, near St. Austell, Cornwall. The thickest veins I have seen are not more than 1 1/2 inches. The fibres are placed transversely across the vein, making generally an angle with the walls of about 70°, so that the crystallization is probably oblique.

The mineral is greenish to brownish gray, has a silky lustre, H about 2 and Sp. Gr. 2.78 : insoluble in HCl, but the iron and magnesia are slowly dissolved out.

Thin fibres are flexible like asbestos. Heated in a matrass the mineral gives off a little water, and becomes lighter coloured ; in forceps thin fibres fuse to a dark glass in the hottest part of the flame. The spectroscope shews the sodium and calcium lines distinctly, but no trace of potassium or lithium.

Mr. Readwin stated that since reading his former paper (Mill Mag., No. 5), he had visited the museums of Copenhagen, Stockholm, Christiania, Kongsberg, and London, in search of corroborative evidences of “Recent Mineral-growth at ordinary temperatures, under ordinary conditions,” and that he was satisfied that mineral “growth under ordinary conditions,” is not of unusual occurrence, .although, hitherto, neither generally observed, nor believed.

Mr. Readwin also stated that several of the specimens referred to in his former paper, some of which he took on his journey, exhibited changes and developments during his absence.

In conclusion, Mr. Readwin submitted an idea of Metal-growth more closely at home.

I have been lately examining in conjunction with Prof. Hull a a large series of lavas from Vesuvius, which were collected by Prof. Ouiscardi, of the University of Naples, with a view of determining whether, in the space of 300 years, any difference had occurred in the composition of the lava flow. In the course of this investigation a much more important question arose, viz. :—What is the proportion of each mineral present in the lava, and why does that proportion exist ?

The rock is composed of unknown quantities of nine minerals, of known composition viz.: Leucite, Plagioclase, Magnetite, Olivine, Augite, Hornblende, Mica, Nephcline, and Sodalite, together with an unknown quantity of a paste of unknown composition; from which it is easy to shew that the unknown quantities exceed the number of equations; and consequently, the discussion of the composition of the rock belongs to a branch of the Indeterminate Analysis.

The origin of the large deposits of Celestine that abound in certain beds of Triassic age has long been a puzzle to Geologists. At Bristol, Celestine is found only on the lowest beds of the Keuper marls resting on the solid red sandstone rock, and may be collected by the ton.

It occurs in large masses, in veins and in geodes, accompanied by Selenite. In many of the concretions the crystals are long and acicular, radiating from the centre. In other places they seem to be a simple aggregation of crystals so loosely bound together that they may be easily rubbed asunder by the slightest pressure of the fingers. The most beautiful forms, however, are those in the interior of the geodes. They are very large tabular prisms with the angles, edges and planes clearly defined. Their colour is white with a delicate bluish tint, and tolerably transparent, having a diameter frequently as much as an inch.

The district to which the following notes refer is contained in sheets 26 and 27 of the one inch Ordnance Survey Maps, and embraces an area of about 985 square miles, the northern boundary being formed by the Bristol channel, and that on the south by a line drawn through the town of Okehampton. The rocks composing this district belong to the Devonian and Carboniferous systems, with the exception of a small portion of new red sandstone and a patch of Greensand, occupying a few acres. The two older systems present a regular sequence of beds from north to south, which, interrupted by the granite of Dartmoor, are represented to a greater or less extent by a similar series in the southern portion of the county.

All minerals are supposed to be either magnetic or diamagnetic, and in a large number, exact measurements have been made of the relative amount of magnetic three in each mineral. As was to be expected, the compounds of Iron and Nickel are, in the great majority of cases, the cause of the magnetism in mineral ; but there exists a large border land of slightly magnetic mineral substances, the cause of whose magnetism has never been very clearly shown. I do not intend, in this paper, to deal with those which are only faintly magnetic, but with those whose magnetism is quite distinct, such as Obsidian, Basalt, &c. The method used for testing the relative amount of magnetism in any specimen was as follows.

In a recently exposed part of a quarry at Bowling, on the Clyde, my friend Mr. John Young, F.G.S., noticed a vein from an inch and half to half an inch in thickness, of a deep green mineral having the hardness and peculiar feeling of stealite, and having secured a good sample he forwarded it to me for analysis. It occurs filling a clean sided fisure on the north side of the quarry. The rock is described by Mr. Samuel Allport, F.G.S., as follows :-

“At Bowling, on the North bank of the Clyde, three miles east of Dumbarton, the rock forming the “Hill of Dun,” is a coarse crystalline dolerite, varying in colour from brownish black to black, with distinct crystals of augite, olivine, and felspar diseminated through it. This porphyritic structure is well seen in thin sections. The base is rather finely crystalline and consists of small crystals or grains of the above mentioned constituents, together with numerous grains of magnetite. The large crystals of plagioclase are clear and beautifully striated, they frequently contain glass cavities, and here and there portions, of the base have been enclosed in them . . . . This rock affords excellent examples of serpentinous pseudomorphs after olivine in various stages of formation; the crystalline forms are unusually perfect, and the gradual encroachmeut of the serpentinous matter on the clear olivine may be very well seen. In one of the sections—microscopic—an old fracture has been filled with serpentine, thus forming a vein which traverses some of the large felspar crystals and the surrounding base. A few cavities are also filled with the same substance.”

In looking over some specimens of chalkosiderite in the possession of Capt. Simmonds, of Liskeard, I noticed a bluish green mineral which was different from the rest, and subsequently on calling the attention of Capt. Hosking of West Phoenix to the mineral I obtained several pieces from him.

In a paper lately communicated to the Chemical Society, I endeavoured to show that an exact examination of the rate at which water was expelled from hydrated substances at any constant temperature, might teach us much as to the constitution of these bodies. One of the bodies examined was the mineral Gypsum, which has been found in three different states—first, in its most usual form as Ca SO4, 2 H2O, or as it should be written 2 Ca SO4, 4 H2O as iu selenite ; second as 2 Ca SO4, H2O in which three of the molecules of water have disappeared, as in certain un-namcd forms of Anhydrite ; and third as Ca SO4 as in Anhydrite. Now these three can also be obtained by artificial means ; the second being found in steam boilers where the water is evaporated under pressure; so I made several attempts to obtain the other two possible hydrates, 2 Ca SO4 3 H2O, and 2 Ca SO4, 2 H2O by evaporating solutions Under different pressures, but I could obtain no satisfactory results.

A defence of Turner’s method seems at first sight to be quite unnecessary, for his test has been used over and over again, for upwards of fifty years, and, as far as I am aware, its usefulness has never been questioned till quite lately. Great was my surprise a few days ago to read a paragraph “On the uselessness of Turner’s flux as applied to the detection of boracic acid.” Professor Chapman speaking of Turner’s method, says:— “This test is much quoted in blowpipe books, and works on chemical analysis generally; but it is altogether superfluous. With borate of soda it fails entirely, or yields very unsatisfactory results ; and although it answers for most other borates, and for borosilicates, it is uselessly applied to them, because these bodies colour the flame equally well per se.” He quotes from Buzengeiger (Annales des Mines, 1829, tome v.p. 36), in support of these statements.

“Plants live, and grow ; Animals live, grow, and move; Minerals, neither live, grow, nor move.”

For so long a time, has this been an article of almost universal belief, that any nonconformity therewith, is looked upon with more or less of grave suspicion.

In what follows, it is proposed to show that there is a rather more natural order in which the aphorism may appropriately run; namely :—

Minerals grow, Plants live and grow, Animals live, grow, and move at will. “The three kingdoms of nature,” as they are not at all inconveniently called, exist in close relationship; so very close, indeed, that some naturalists think they are not really apart from each other.

The Silver-mines, near Kongsberg, in Norway, are said to have been worked unceasingly for the last 200 years or more.

On June 6th, last, I was fortunate in being allowed to visit these celebrated mines, and also the silver-works at Kongsberg. More fortunate still, in obtaining the present beautiful specimens of native silver and Argentitc. They had very recently been taken from the mines, and I was told that my visit was opportune, because such specimens were not of every day occurrence. Be this, as it may, they are of especial interest just now, as illustrating the theory of “metal-growth,” and the more particularly so, as two of them have most obligingly, since they came into my possession, thrown out sundry hints of bodily activity. In fact, have “grown”; and, as they have a direct bearing upon a previous paper, I propose to describe them as well as I can.

A Ms. Catalogue of Minerals by the Comte de Bournon has lately come into my possession. From internal evidence the date of the volume may be fixed at 1811—three years after the publication of the Count's Traité de Minéralogié. The collection of minerals described in this catalogue was made for the Government of Brazil ; if the collection still exists, a careful comparison of some of the specimens in it with their descriptions in the catalogue would clear up some obscure points and lead to useful results. Without this aid to a clear understanding of Bournon's descriptions, many interesting facts may be gathered from the manuscript in question. It is, however, a voluminous work extending over 356 pages, and illustrated with a large number of careful drawings of crystalline forms. The author was a very laborious compiler of catalogues. One of these, known to the present writer, is still in existence in the Town Hall of Devonport, along with the magnificent collection of minerals (the St. Aubya collection) to which it refers. A few notes on the Brazilian catalogue may not be without interest.

At the last meeting of the British Association, Dr. A. yon Lasaulx, who has recently been appointed Professor of Mineralogy in Breslau in succession to Professor Websky, exhibited two new minerals which he has described in the Neues Jahrbuch. A brief notice of these minerals may fitly find a place in the Mineralogical Magazine, although the original descriptions are too lengthy to be translated in extenso.

The Mineral from West Phoenix occurs in globular masses of a Turquoise blue or bluish green color upon Limonite. The interior of each spherule is composed of Limonite within which is sometimes a minute quartz crystal; the exterior surface usually shews indistinct crystalline facets. Fragments examined with a hand-lens shew a conchoidal fracture, but a thin section exhibits faint indications of radiated and concentric structure.

The first specimen which came under my notice was given to me by Mr. Simmonds of Liskeard, in October 1875 as a variety of Chalcosiderite or Andrewsite. These minerals had recently been described by Professor N. S. Maskelyne and Dr. Flight, and as there is occasionally a certain resemblance between them and the new mineral, and they all occur together, it was supposed to be the same as one of them. As the specimen was small I placed it in my cabinet, being unwilling to destroy it by making an analysis.

About two years ago, while working at the crystalline form of a number of chemical substances of which I could obtain only small quantities, and in consequence minute crystals, I found that a great deal of time and trouble were lost in consequence of having the use of only one goniometer. When a crystal was fixed in its place by canada balsam and carefully centred,—a tedious operation when carried on under the microscope, as I had generally to do,— its angles measured and description noted, I found I often wanted to keep it for comparison, but before another could be examined, the first had to be taken off and half an hour spent before the second could be got into a satisfactory position, the first being very often spoilt in being removed, or even if still entire, much time must be lost before it can again be referred to. Now the possession of half a dozen instruments would obviate all this, but few chemists can afford the luxury of such a number of goniometers, and unfortunately so few possess one at all that it is seldom that such a thing can be borrowed.

To the geologist, the mineralogist and the chemist, two of the observations made during the voyage of the Challenger are of especial interest. One of these observations is the occurrence over vast areas of the deep sea bottom of a peculiar red clay, containing silica, peroxide of iron, and alumina. The other discovery to which I refer has been described by Sir Wyville Thomson as the occurrence throughout this red clay of nodules of “nearly pure peroxide of manganese.” To these nodules, as well us to the red clay, an organic origin has been assigned. But the immediate source of so much manganese is hard to find, for this element is by no means an abundant constituent of animal or vegetable organisms. The difficulty is, however, somewhat lessened when the manganese nodules are submitted to a more minute chemical examination. From two correspondents I have received an ample supply of these curious concretions, accompanied by a suggestion that they should be submitted to chemical analysis.