self. But as the remarks in my last communication (p. 266) require some explanation, I here publish my results, and an account of the processes employed. M. Kopp has also shown that the nitric ether (nitrate of oxyd of ethyle of Liebig) is decomposed in a similar manner by hydrosulphuret of ammonia with the production of ammonia and sulphur-alcohol or mercaptan. Montreal, July, 1847.

ART. XXIX.-Description of a Meteoric Stone which fell in Concord, New Hampshire, in October, 1846; by Prof. B. SILLIMAN, Jr.

My attention was called to this remarkable body by Mr. Abiel Chandler of Concord, N. H., who, in October, 1846, sent me some small fragments of it in a letter, requesting an opinion on its character, and stating the fact that J. S. Noyes, Esq. of that place, was witness to its fall and had retained the meteorite in his possession up to that time. The fragments sent by Mr. Chandler so little resembled, in physical character, any meteoric body which I had before seen, that a letter of particular inquiry was addressed to Mr. Noyes through Mr. Chandler, calling for all the circumstances of the fall and asking the privilege of examining the specimen in his possession. I received in reply, a letter from Mr. Noyes, from which I will make some extracts. The letter is dated Concord, New Hampshire, Oct. 19, 1846. After describing the isolated position of his house on a sandy plain, he goes on to say: "Some time in the month of October, 1840, about two hours after sunset on a bright starry evening, I stood in the road, south of my house some six rods, with my arm resting upon the fence, and facing the southwest, gazing at the stars. Whilst looking up almost perpendicularly, I saw a star, or fireball, fall a considerable distance and then become extinct. Some little time after, I heard a noise in the air, such as a falling body would make, and immediately after I saw a small body strike upon the top board of the fence, about fifteen feet before me, and glance into the road some six feet, then bounding and rolling along several feet farther. I immediately commenced a search, stooping down and feeling in the grass around where I last saw it. After some little search, I picked up the substance in my possession and carried it into the house and examined it. Its appearance being different from what I expected, caused me to make sure by visiting the spot early on the following morning and giving it a further search, the result of which was I found not the least movable substance in the place of its fall. From the circumstance here narrated, I came to the conclusion that I had obtained the body which fell, and that it had a connection with the star SECOND SERIES, Vol. IV, No. 12.-Nov., 1847.

45

described above. I am well aware that it is an easy thing to be deceived, but sure I am that if mistaken in this instance, no man will be able to undeceive me. The pieces which broke out by the fall I gave to Rev. William H. Ryder, now of Nashua, N. H., about three years since. I have often exhibited the stone and related the manner by which I became possessed of it. There has never been any published account of it." ****

Accompanying this letter, I received the specimen in question, which if a meteorite, (as I have now no doubt,) can claim the distinction of be

ing one of the smallest of these celestial fragments, which has yet reached our earth. The accompanying figure is a correct delineation and of the exact size. Some small fragments have been detached but the main portion weighs only 370 grains.

Physical Description.-Its external surface is every where glazed with a brilliant enamel of a grayish white, with occasional patches of deep brown metallic stains. The glazing is found also on the cracked and broken surfaces which penetrate deeply into the mass. The interior is scoriaceous like the frit produced by the partial fusion of feldspar, blown up with extremely minute vesicles and occasional larger bubbles. The porous character of the mass rendered it impossible to procure a satisfactory determination of its density. Its hardness is about 6.5, and it easily scratches feldspar. The larger part of this stone is quite white in color and the fracture has a vitreous lustre. It has no dark colored crust, similar to that which is so characteristic of most meteoric stones, which is owing to the absence of metallic oxyds in its composition, the surface enamel which has been already mentioned, being for this reason without color, excepting in a few spots. The whole stone bears every mark of having been intensely heated. The portions which have the iron stain, are small, and the most careful search with a powerful eye-glass detected no metallic points; nor did the magnet attract the minutest particles.

The blowpipe indicated the presence of silica, soda and magnesia. It dissolved in carbonate of soda with effervescence, forming a glass which was nearly opake on cooling. Alone in platinum forceps it fused on the edges, and emitted a phosphorescent light, while the flame beyond the mineral was colored of a clear soda yellow. In a close tube no escape of water or empу. reumatic odor was perceived, and the mineral was unchanged by heat. The bead produced by its fusion alone in the platinum forceps, was a clear and bubbly one, which had no metallic stain.

Chemical Composition.-So little of the mineral was at my disposition without breaking the principal mass, that no other qualitative examination was made than that with the blowpipe, and this was the less important from the fact, that the pyrognostic characters were so decisive as to the absence of all metallic oxyds. All the fragments which could be found were carefully ground in the diamond mortar and then in agate, and 390 millegrammes of this powder were attacked by hydrofluoric acid, after the manner recommended by Bunsen. When it was judged that all the silica had been removed as hydrofluo-silicic acid, the residue was dissolved in hydrochloric acid in the same platinum vessel in which the attack was made by hydrofluoric acid. The absence of alumina, iron, phosphoric acid, lime, &c., was easily ascertained by the want of any reaction with ammonia and oxalate of ammonia, which failed to produce any troubling in the solution after addition of a sufficient quantity of chlorid of ammonium.

Oxyd of mercury was next added to the boiling and concentrated solution, which was subsequently evaporated to dryness, ignited to expel the mercury, treated with pure hot water, and the magnesia, separated in this manner, from the double chlorid of magnesium and mercury, was collected on a filter and weighed 0471 millegrammes.

The filtrate from the magnesia, which contained nothing but alkaline chlorids, was evaporated in a platinum vessel of known weight, and their quantity determined by the increase of weight observed on repeated trials, with a constant result. The alkaline residue had the taste only of chlorid of sodium, it was dissolved and treated with bichlorid of platinum, evaporated on a water-bath to dryness, and treated with alcohol. No double chlorid of potassium and platinum was obtained, and the consequent purity of the chlorid of sodium was inferred. The amount of chlorid of sodium obtained was equivalent to 0106 mm. of soda.

The weight of the meteorite employed = 390 grms. We

have found,

Magnesia,
Soda,

Now the known composition of tersilicate of magnesia Mg 3Si, is, magnesia 12.98, and silica 87-02 per cent. = 100. And the composition of simple silicate of soda, Na +2Si, is, of soda 40.37, and of silica 59.63 per cent. = 100.

=

Then 12.98 87-02::12-076: 80-959 the silica requisite to form a tersilicate with the magnesia:

And 40-37 59-63::2-718 4.014 the silica needed to form a simple silicate with the soda.

Or stating the analysis in the usual form we have

This gives as the formula, Mg Si3+Na Si, which is unlike that of any known mineral of terrestrial origin, but which approaches the composition assigned by Prof. C. U. Shepard to a mineral first observed by him in the meteoric stone from Bishopville in South Carolina, and which he states, "is a tersilicate of magnesia." For this mineral Prof. Shepard has proposed the name of Chladnite. It is believed that the mineral now under consideration is identical with that in the Bishopville stone, and should therefore be called by the same name. The analysis above given was commenced by myself, but being called away from home before its completion, I entrusted it to my friend and pupil, Mr. B. W. Bull of Hartford, to carry through, which he did in a very satisfactory manner.

In conclusion I would say that the chemical constitution of the body under consideration, in connection with the very satisfactory testimony of Mr. Noyes as to its falling from the atmosphere, as already described in the introduction to this article, leaves no doubt in the mind of the writer, that it is a meteorite. Yale College Laboratory, July 24, 1847.

* This Journal, ii Ser., vol. i, p. 381.

ART. XXX.-Remarks on the Characters of several Species of Tertiary Corals from the United States, in reply to Mr. Dana.* (Extracted from a letter from W. LONSDALE, Esq. to C. LYELL, Esq.)

Kynsham near Bath, June 21st, 1847.

My Dear Lyell,—I am much indebted to you for sending me additional specimens of Endopachys Maclurii. They have been carefully considered; but they have not led to a change in the printed opinion; which is perhaps too briefly expressed. It states that, "the Alabama coral was progressively altered in aspect, by the development of tubercles, secreted through foramina connected with the internal structure." (Geol. Journ., Vol i, p. 514.) This remark refers especially to a difference between Endopachys and typical species of Turbinolia, in which no foramina had been noticed in the walls, nor any external changes: but in the generic characters of Endopachys, the boundary wall is said to be "progressively thickened by papillæ secreted from within," (515,) and in a note the generic name is shown to have been proposed in allusion to a "thickening from within." If you will kindly examine the specimens marked 1 and 2 from Claiborne, Alabama, the uppermost portions will be found to be externally imperfect, and in parts, least liable to abrasion, being protected by the bold ridges. The structure in those portions of No. 1, is highly reticulated and there is apparently a perfect connection throughout by means of circular openings or foramina. These cancelli were evidently occupied with animal matter, which was intimately connected with the soft internal living structures; and which, it is believed, secreted the solid calcareous reticulations. In No. 2, the analogous portions are in a more advanced state externally, that condition having, it is inferred, been effected by secretions from the same animal tissues as built up the inner part of the fabric-the foramina, which are now distinct, having been the channels through which nourishment and calcareous matter were supplied from within. The beautiful sections of No. 2, are supposed to support the original inference. In the upper part, the channels leading from the interior outwards, are very numerous: but in the lower, they are less abundant, the exterior having been perfected and the want of such passages diminished.

Certain structural agreements between Endopachys and Dendrophyllia are alluded to in the notice,‡ though from the manner

* Silliman's Journal, ii ser., vol. i, p. 220.

↑ Consult also wood-cut, fig. a, p. 514, and specific characters. Geological Journal, vol. i, p. 514, 515.