The mean of three trials gave 11.691 of CO2. A trace of magnesia in the specimen examined was disregarded, as being accidental. The mineral rests on a basis of carbonate of magnesia, which is difficult to separate entirely.

The constitution resulting from the analysis is

This gives the empirical formula, 3Ni+C+6H=Ni C+2Ni 6H,

or NiC+2(Ni H ̧).

When we remember the isomorphism of magnesia and oxyd of nickel, it will be agreed by all who attach any value to this agency in modifying minerals, that we may have many cases in which these two oxyds are mutually interchanged. Hence we find at the Texas locality, dolomitic carbonates with a faint tint of green derived from a small trace of oxyd of nickel present in them-others of green color several shades deeper, and others which closely approach the high color and other properties of the pure hydrous carbonate of nickel described in this paper. In some specimens, unquestionable emerald nickel is found mechanically mingled with and coating whitish dolomite. I cannot agree with the opinion expressed by Prof. Shepard, at page 250 of this volume, that these varieties are distinct species. Certainly we must demand analyses to show that the MgO and Ni O are in fixed atomic proportions with water, before the "hydrated carbonate of magnesia and nickel" can be regarded as a true species. Analytical Laboratory, August, 1848.

ART. XXVI.-On new Minerals from Texas, Lancaster Co., Penn.; by CHARLES UPHAM SHEPARD, M.D.

Williamsite.

MASSIVE: Composition lamellar, individuals of considerable size. Lamellæ straight, rather difficultly separable. Faces of composition not very even. Fracture even. Surface nearly dull.

Lustre feebly shining, pearly to resinous. Color apple-green. Streak white. Translucent.

Hardness =

4.5. Sp. gr. = = 2·59...2·64.

Before the blowpipe, it phosphoresces, turns white, and hardens so as to scratch glass, but does not fuse. It dissolves with much difficulty in borax, without imparting any color or opacity to the bead. In powder, it dissolves slowly in hot hydrochloric acid.

It approaches therefore the following: three atoms sesquisilicate of magnesia, one of silicate of alumina, + three atoms of water.

3Mg O, Si O 13+ Al2 O3, Si O3 +3HO.

This mineral was sent to me by L. White Williams, Esq., (for whom it is named,) of West Chester, Chester Co., Penn. It had been designated as nephrite. It occurs in irregularly shaped seams, sometines above an inch in thickness, between chrome iron ore and serpentine. It belongs to the order Mica, and has affinities with schiller spar (metalloidal diallage).*

New Haven, July 12, 1848.

*

Hydrated carbonate of magnesia and iron, and hydrated carbonate of magnesia and nickel (hydro-nickel magnesite).-These two new compounds occur at the same locality with the foregoing species, but in quantities so minute as to render the most of their natural properties indeterminable. I refrain therefore for the present, from attempting any formal description of them. They are very closely associated together, and mingled up also with minute granular crystals of white dolomite,-the three substances forming together, thin, drusy incrustations upon the joints of serpentine rock, and presenting an apple green color. Examined under a microscope however, the niixture resolves itself into three distinct substances,-the first consisting of pearly white, thin lamin which form the basis of the coating, next to the serpentine, and which are arranged perpendicularly to its surface. This is the hydrated carbonate of magnesia and iron. Upon the top of these laminæ, are scattered little particles of a lively colored apple-green mineral, mixed with minute granules of a grayish white substance, the former is the hydrated carbonate of magnesia and nickel, the latter is dolomite. These three minerals become much more readily distinguishable if heated for a few minutes in a glass tube over a spirit-lamp. Abundance of moisture, attended with a peculiar odor, is evolved, while the foliated mineral first mentioned exfoliates and turns reddish-brown, the green mineral turns bluish black, and the little crystals of dolomite are left of a characteristic white color.

Hitherto I have been unable to separate these minerals from each other so as to enable me to make a quantitative analysis of the two which are new; but my examinations have been carried far enough to satisfy me that the foliated, pearly mineral is a hydrated carbonate of magnesia and iron, and the green one, a hydrated carbonate of magnesia and nickel, which for the present may be called hydronickel magnesite.

ART. XXVII.—An Account of the Meteorite of Castine, Maine, May 20, 1848; by CHARLES UPHAM SHEPARD, M.D.

THE following abstracts of letters, and description of the lately fallen meteoric stone in Maine, in the absence of fuller accounts, will no doubt prove interesting to meteorologists.

The only stone thus far found, together with the principal facts in the case, fell into the hands of Prof. P. Cleaveland of Bowdoin College, from whose letter (of August 5th) it seems proper to make the following quotation as my apology for not leaving this communication to be made by himself. "I have written to Castine, proposing certain queries, with a view of obtaining more facts. When I receive them, I will prepare a notice, if in season for the next number of the Journal. The notice ought to appear in the next number, and as you have all the facts which I now possess, if you hear nothing from me before the printing of the last pages, you had better put the facts in due form, and insert the notice yourself."

On observing a paragraph in a newspaper respecting the fall of a meteoric stone in Maine, I addressed a letter to my friend, Rev. Ray Palmer, of Bath, (Me.,) requesting his aid in procuring a reliable account of the occurrence. This drew forth the following excellent description from Rev. Daniel Sewall, of Castine, in a letter dated June 12th, to Mr. Palmer. "I received your note on Friday evening, and on the day following, I rode out to the place (which is one mile distant) where the stone fell. I made what inquiries and search I could, but without being able to procure a specimen. The only stone that has been found as yet, is now in the possession of Prof. Cleaveland of Brunswick. Mr. Lemuel Atherton, a member of College from Bowdoin, took it with him thither a few days since. I saw the stone, the morning it was picked up. It was not larger than a hen's egg.

"The appearance of the meteor and the attendant circumstances, so far as I have been able to gather them, may be described as follows: On Saturday morning, May 20th, about half past four in the morning, Mr. Charles Blaisdell, a mechanic, who lives about a mile from the village, being out of the house at the time, noticed dark clouds, apparently gathering from different quarters of the heavens. Soon, he saw what he supposed to be a flash of lightning. Presently, however, upon looking at that portion of the cloud which came from the northwest, he saw what appeared like the moon in a cloud, not as at the horizon, but when high in the heavens. A sudden, sharp report like a cannon was heard, followed by a quick succession of reports not so loud as the first, but which resembled a running fire of musketry; and after these a whistling sound in the air, as of a body passing through it with

great rapidity. Something was seen and heard to strike the ground in the road, but a little distance from the place where he was standing, which proved to be the stone in question. Mr. Giles Gardiner also saw the stone strike the ground, but he did not notice the meteor. I could not learn from Mr. Blaisdell that the meteor had any apparent motion, except with the cloud, before the explosion. He stated that he was looking at it from eight to ten minutes. The report was heard by great numbers in the village and elsewhere. Some saw a streak of light.”

Prof. Cleaveland's account of the stone and the attending phenomena is the following. "It fell at Castine, Maine, May 20, (4h. 15m. A.M.,) 1848. The fall was accompanied by a noise similar to thunder, but quicker and more like that of a gun. The report was distinctly heard at a distance of thirty or forty miles from Castine. A second report, resembling the discharge of muskets, was also heard.

"The stone came from the southeast, and by its fall penetrated to the depth of two inches into a dry, hard road. No flash of light was observed by the person who witnessed the fall, although the stone struck the earth within a few feet of him. Others assert that they saw a flash.

"Its whole weight when entire was 1 oz. avoir. The finder broke off a piece to examine the inside, and threw the fragment away. It was farther diminished by the portion sent to you. Its present weight is 1oz. 3pwts. 5grs. The whole was invested by a black crust. Its shape was somewhat wedge-shaped, one surface being nearly plane, and the other irregular or slightly waved. This stone is now in the mineralogical cabinet of Bowdoin College, to which it was presented by Mr. Lemuel W. Atherton, of Castine, who received it from the person who observed its fall."

To the foregoing, I have the following observations to make, derived from an examination of the fragment so obligingly presented to me for the purpose by Prof. Cleaveland.

Sp. Gr. 3.456.

In general appearance, it resembles the Poltawa stone (of March 12, 1811); but is distinguishable from that, by possessing a much lighter color, a more pearly lustre, and in being destitute of specks of iron-rust. The nickeliferous iron is in smaller points, and possessed of an unusually brilliant silver-white lustre. The magnetic iron pyrites is easily distinguishable in little points, though less abundant than the malleable iron. A few, very fine black points are also discernible, which give before the blowpipe the reaction of chromium: they are probably chrome-iron.

The malleable iron was separated by means of the magnet, and equalled in weight 11 22 p. c. of the entire stone. It proved uncommonly rich in nickel, being identical in composition with the Green Co., Tenn., meteoric iron; i. e., having

Iron,.
Nickel,

85.3

14.7

100.

The earthy constituent of this stone, like that of the Iowa meteorite, is decomposed by concentrated hydrochloric acid, and like it, appears to be a tersilicate of the protoxyd of iron and magnesia, a mineral which though frequent in meteoric stones, has never yet been distinctly recognized, and which in a future paper on American Meteorites, I shall more particularly describe under the name of Howardite, after the Hon. Mr. Howard, that celebrated chemist, who was the first British writer whose labors contributed to elucidate the history of these extra-terrestrial bodies. New Haven, Aug. 16, 1848.

SCIENTIFIC INTELLIGENCE.

I. CHEMISTRY AND PHYSICS.

1. Ice, a Conductor of Galvanism.-In experimenting with a Grove's battery of eighteen cups, I left the whole standing over night the poles not being connected, or the circuit not being closed. There was no action going on, or at least, no hydrogen was evolved in the cups. Owing to a sudden change of weather, the liquid in the cups was found frozen in the cups next morning. In each of the cups the local action was evolving hydrogen, which continued till, by a knife, I had separated the ice from the platinum, when, in each instance, it immediately ceased. C. DEWEY.

2. Grove's Battery with only Water used with the Zinc cup.— Having seen in some of the papers that the telegraph was made to operate by means of water alone with the zinc, I charged a new Grove's battery of eighteen cups in the usual way, only using water instead of diluted sulphuric acid. The whole was quickly put in operation and the poles connected.

(1.) In the first minute there was the indication of only the feeblest action, either in evolving hydrogen, or making iron filings magnetic. (2.) In two or three minutes the action had sensibly increased, as shown in both these results, and in thirty to sixty minutes the action was quite powerful. With a large helix the large dancing iron was made to play finely. The action had now attained its maximum power.

(3.) In two or three hours the power was manifestly less, and ere long it was exhausted. The strength of the nitric acid was nearly gone. It is evident, that the action of the battery was dependent upon the passing of the nitric acid through the porous cup into the water so as to operate on the zinc; that the power increased with the exosmosis of the acid, and decreased as this diminished; that the acid was rapidly used up. As amalgamated zinc was used, nitrate of mercury was formed, for the crystals yielded red oxyd of mercury. C. D.

Vermont Medical College, March, 1848.

SECOND SERIES, Vol. VI, No. 17.-Sept., 1848.

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