probably from the same place, but may be from Whitehall Mine, Spotsylvania county, Va.

Though I was most careful in selecting the material for this investigation, I found invariably from one half to two per cent. of quartz, gold and oxyd of iron mixed with it, which were deducted as impurites.

In making the investigation I have found the method heretofore used for the separation of bismuth from tellurium, by sulphid of ammonium, not to be as correct as is desirable, since there is always a considerable amount of tellurium remaining with the bismuth; I therefore tried to find another mode, which would give more satisfactory results, and succeeded best with the following: The solution containing teroxyd of bismuth and tellurous acid was made acid by hydrochloric acid, and to the hot' solution bisulphite of ammonia was added. It was allowed to stand in a warm place for a day or two until all the tellurium had settled; this was filtered on a weighed filter, washed first with a mixture of diluted hydrochloric and sulphurous acids, then with sulphurous acid alone, and finally with water. The tellurium was completely precipitated and did not contain a weighable quantity of bismuth. The results of the analyses I. and II. were afterwards corrected, and III. and IV. analyzed by this method. B.B. it fuses readily giving out a faint but distinct odor of selenium, leaving on charcoal white incrustations with a yellow centre. The following results were obtained:

These analyses show that neither of the specimens contained a weighable amount of selenium. The small quantity of sulphur (in No. IV,) 0.37 per ct. is equivalent to 1.48 per ct. of tellurium, which if we substitute tellurium for sulphur, would give 47-53 per ct. of tellurium. These analyses show that Tetradymite is tertellurid of bismuth, but that sometimes (as I showed for that from Davidson county) a variable quantity of tellurium may be replaced by sulphur. I have also observed that Tetradymite occurs at several localities in Cabarrus county, N. C., where I have found it in minute lead-colored scales, associated with gold and iron pyrites in quartz at the Phoenix Mine and at the Boger Mine; but, though I had sufficient material to determine the nature of the scales, I could not obtain enough for a quantitative analysis. 6. Bismuthine.

On examining some ores from Gold Hill, Rowan county, N. C., I found that the crevices in specimens from the Barnhardt vein

(from 280 feet below the surface) sometimes contained a steel colored mineral in minute acicular needles, which are apparently rhombic. It was associated with gold, iron and copper pyrites. B.B. it gave the reactions of sulphur, bismuth and copper, and once I observed a faint odor of selenium. Afterwards I found that the chloritic slate of the same vein, in which the copper pyrites occurs, contains also a considerable quantity of almost microscopic specks and stripes of the same color. On extracting some of the slate by aqua regia, the solution contained, besides iron and copper (probably from the copper pyrites), a considerable quantity of bismuth. Neither tellurium nor lead could be found. It is impossible to get a sufficient quantity of this mineral for analysis, or of sufficient purity to ascertain whether the copper, which I found, belongs to the mineral itself, or is owing to an admixture of copper pyrites-or, in other words, whether the mineral is "Cupreous Bismuth," or Bismuthine. I am in favor of the latter opinion.

7. Aciculite.

A mineral between lead and steel-gray in color occurs in small masses imbedded in quartz and associated with copper pyrites and sulphate of baryta. Though it is not found in long acicular needles, like the needle ore from Beresofsk in Siberia, a qualitative analysis showed that it contains the same constituents, viz: bismuth, lead, copper and sulphur.

B.B. it fuses readily, giving off sulphurous acid and covering the charcoal with yellow incrustations; with carbonate of sqda, after the lead and bismuth have been volatilized, a globule of copper remains.

I therefore believe it to be "Aciculite."

8. Barnhardtite, a new mineral.

a. In compact masses; no cleavage could be observed. H. = 35; Sp. grav. (at 25° Cels.) = 4.521; lustre metallic, but somewhat dull; color bronze-yellow; streak grayish black and slightly shining; opaque; fracture conchoidal, uneven; brittle; tarnishes very soon, more readily in presence of moisture, assuming a peculiar brownish, sometimes pinchbeck-brown, sometimes also rose-red and purple colors.

B.B. gives off sulphurous acid and fuses easily to an ironblack magnetic globule; with borax it gives the reactions of copper and iron; with carbonate of soda and borax metallic copper. It was analyzed in my laboratory by Mr. Wm. J. Taylor (I), Mr. Peter Keyser (III) and myself (II), and a copper determination was made by Mr. Chs. A. Kurlbaum (IV).*

* In analyses I. and II. a trace of brown hematite was mixed with the mineral; and in analysis II. some copper was lost. .

SECOND SERIES, Vol. XIX, No. 55.-Jan., 1855.

3

The composition is expressed by the formula: 2C2S+Fe2S3, which is between that of yellow copper pyrites=Cu2S+Fe2S 3 and Erubescite =3Cu2S+Fe2S 3.

I have found this mineral associated with other copper ores at Dan. Barnhardt's land (hence its name) and Pioneer Mills, Cabarrus county; Dr. O. Dieffenbach observed it at the Phoenix and Vanderburg Mines of the same county, and I saw it also amongst copper ores from the neighborhood of Charlotte, Mecklenburg county, N. C. It seems to be abundant in North Carolina, and is of course a very valuable copper ore.

b. I will mention here another copper ore, which also occurs on Dan. Barnhardt's farm.

It is massive and resembles copper pyrites, but is somewhat paler. The material for analysis was uniform in appearance and seemed not to be a mixture of two species.

The analyses made by Messrs. Wm. J. Taylor (I) and Charles Froebel (II), gave the following results:

The composition of this mineral may be expressed by the formula: (2Cu 2 S + Fe 2 S 3 ) + (Cu S, + 2Fe S.)

Whether further investigations will prove this to be a distinct species or not, I am not able to say; for the present I only wish to call the attention of mineralogists to this subject.

9. Gray Copper, (Fahlerz.)

In the Am. Journ. of Sc., 2d Ser., vol. xvi, page 83, I have described the first mineral belonging to this group, which has been observed in this country, Since then I have found two new localities, where minerals occur belonging to this group, and a third one (Duchess county, N. Y.) was mentioned to me by Dr. Isaiah Deck.

a. From Eldridge's Gold Mine, Buckingham county, Va.In granular masses; lustre metallic; color between iron-black and lead-gray; streak iron-black; opaque; H.-4. Very brittle; fracture uneven-subconchoidal.

B.B. in an open tube disengages sulphurous acid; and gives a sublimate of arsenious acid. On charcoal it emits fumes of an

alliaceous odor, and fuses with intumescence to an iron black, slightly magnetic globule, covering the charcoal with white incrustations. With fluxes it gives the reactions of copper and iron.

A preliminary analysis, made by dissolving the mineral in aqua regia, gave Mr. Wm. J. Taylor the following results:

It is associated with quartz and auriferous iron pyrites. b. From Geo. Luderick's farm, about 14 miles N. E. of Concord, Cabarrus county, N. C.-The only imperfect crystal which

O 202
2 2

O; it is gen

I found appears to be a combination of erally found massive; its color is between dark lead gray and iron black; streak iron black, somewhat brownish; fracture uneven, subconchoidal; brittle.

B.B. decrepitates slightly; in an open tube disengages sulphurous acid and gives a sublimate of arsenious acid; on charcoal it emits fumes of an alliaceous order, and covers it with white incrustations; it fuses into a magnetic globule and gives with fluxes the reactions of copper and iron. It is found in quartz, associated with copper pyrites, iron pyrites, brown hematite and scorodite.

10. Geokronite. (?)

I received this mineral amongst others from Tinder's Gold Mine, Louisa county, Va.

It occurs in small irregular masses of a crystalline structure, with distinct cleavage in one direction; lustre metallic; color lead gray; opaque; H.-3; Sp. grav. (at 16° Cels.) 6.393.

B.B. upon charcoal gives off sulphurous acid and copious fumes of teroxyd of antimony, covering it with white incrustations, having a yellow centre of oxyd of lead; further reduced yields a small globule of silver; in an open tube it gives off sulphurous acid and a white sublimate of teroxyd of antimony and arsenious acid.

A rough experiment showed that it contains about 16 per cent. of sulphur, 60 per cent. of lead, and 0.25 per cent. of silver. Associated with iron pyrites, galena aud blende.

11. Garnet.

a. From Yonkers, N. Y.-This beautiful massive red garnet, which I have found in many collections labelled "Pyrope," has been examined in my laboratory, by Mr. Wm. J. Taylor.

B.B. it fuses to an iron black, slightly magnetic globule; with borax it gives the reactions of iron, and with carbonate of soda those of manganese. It is acted upon by hydrochloric acid, but not completely decomposed. The analysis gave the following results.

b. From Greene's Creek, Delaware county, Pa.-Under the head "Pyrope," Prof. Dana mentions this beautiful gem, stating his doubts, that it belongs to this species. The following analysis, made by Mr. Chs. A. Kurlbaum will, show the correctness of his view.

B.B. it behaves like a; its composition is:

Though we have already numerous analyses of this mineral, we are not yet arrived to a certainty with regard to its composition. This is owing to various causes, principally, I suppose, to the fact that analysts have in most cases not taken the necessary care to ascertain, whether the iron in allanites is in the form of oxyd (FeO) or in that of sesquioxyd (F2O3), or in both states of oxydation. At my request, Mr. Peter Keyser made a series of analyses of American allanites. The separation of the oxyds of cerium, lanthanum and didymium from iron and alumina in all the analyses (a) was made by sulphate of potash; in analyses (3) by oxalic acid; sesquioxyd of cerium was separated from lanthana and oxyd of didymium by very diluted nitric acid and the oxyd of iron by chlorid of gold and sodium. All the rest of the determinations were made in the usual manner.

a. Allanite from Orange county, N. Y.*-Massive, no cleavage could be detected; H. 55; Sp. gr. (at 17° Cels.)=3782; lustre

This is the mineral of which I spoke in my note in the Am. Journ. of Sc., 2d Ser., vol. xvi, page 86.