4. Houghite, (ibid, p. 314.)-Occurs near Oxbow, St. Lawrence Co., N. Y., and also in Rossie, associated with spinel, from which region specimens were received by Prof. Shepard from Dr. Franklin B. Hough of Somerville. It presents oblong flattened reniform concretions, rarely above ths of an inch long, with botryoidal surfaces, whitish externally and bluish or reddish white within; lustre faintly pearly, glimmering. Sometimes has a spinel crystal as a nucleus. H. 2.5. G.-2-02-2-03. It decrepitates and emits water before the blowpipe, losing 33 p. c. by ignition. Appears to be a hydrate of alumina and magnesia.

[Houghite has been studied recently by Mr. S. W. Johnson, of the Yale Analytical Laboratory, who finds that it is a pseudomorph, often of spinel and probably also at times of scapolite; some of his specimens are spinel crystals (octahedral) in one part, and true Houghite in another, and all conditions of change are well illustrated by them. Mr. Johnson is still engaged in his investigations on the subject.]

5. Marasmolite, (ibid, p. 315.)-From the feldspar quarry near Middletown, Ct., along with columbite, pitchblende and albite. Monometric, with cubic cleavage; color brownish black, and streak reddish brown; brittle; H.-3.5; G.=373-3-74. Composition, according to Prof. Shepard :

Sulphur 38-65

Zinc 49-19

Iron 12.16

affording the ratio 5:3: 1, and the formula 3Zn S + FeS2. The name is from uapaouos, decaying.-[The marasmolite, according to the writer's examinations of Prof. Shepard's specimen, is a brittle, partially decomposed blende, containing free sulphur in minute points throughout it, as seen with a glass. This free sulphur accounts for the excess in the analysis; allowing thus for a small excess, the composition will become 3Zn S+Fe S, which is the formula of the marmatite variety of blende.]

6. Calyptolite, (ibid, p. 316.)—From Haddam, with chrysoberyl, garnet and beryl; also from the feldspar quarry near Middletown. Crystals minute, and usually square prisms with pyra midal terminations; surfaces not smooth and often somewhat concave; color dark brown; lustre adamantine; opake. H.-6.5. G.=4.34. B.B. in an open tube, yields moisture, having an acid reaction, and becomes pale yellowish white; alone, whitens but does not fuse; does not fuse readily with soda; with borax dissolves slowly into a glass which is yellow while hot, but colorless on cooling. When heated in powder with sulphuric acid for some time, it appears to be completely decomposed, and the glass tube exhibits corrosion. "The quantity of the mineral was too small for a satisfactory examination; but the absence of silica, lime, magnesia and alumina was ascertained; and the probability that the substance is a fluo-columbate of some of the less com

mon earths and oxyds, established." [We may mention that the most common form closely resembles that of garnet, and the mineral had been referred to this species, which it externally resembles. The angle of the pyramid is given at 122° to 124°; but the surfaces are so irregular that the measurements are uncertain.]

0

7. Eumanite, (ibid, p. 317).-From Chesterfield, Mass., at the albite locality. Only a single minute crystal less than a grain in weight is known. Form trimetric; M: M=123°. M: e'= 136°; e': e' 151° 30'; e': e"=159° 30'; ě: a=127° 40'; M: -118°-118° 30'; e': a=127°30'; a:o=144° 20'; ě: 0 =128° 20'; e': o= =156° 30′; surface M rather imperfect and not very lustrous; the other faces brilliant. Color blackish-brown, resembling certain crystals of tin ore. Translucent; color by transmitted light deep red, like almandine garnet. H. above 6.

M

ē M

Eumanite.

[The crystal of eumanite has closely the form of topaz, even to the general character and position of the planes on the summit, and is near figure 393 in Dufrenoy's Mineralogy; the angles also are nearly identical. Topaz gives M: M=124° 19'; and if M on ĕ in eumanite is 118°, it will give 124° for M: M in eumanite-M, M, it should be noted, are the least lustrous faces of the crystal; M: e'=135° 59′ (136° in eumanite.) The mineral must therefore be closely isomorphous with topaz, if not identical with it, and some other characters are needed to show that the latter supposition is not true, although so peculiar in its color. In the figure, the edge o': e" on the right is parallel to the edge e": e", but not so that on the left; we cannot say which is right.]

8. Corundophilite, (ibid, p. 318).—Occurs with corundum near Asheville in Buncombe county, N. Carolina, in imperfectly stellate groups, and also spreading out in lamina between layers of corundum. A single crystal, exceedingly minute and less than th of a grain in weight, was monoclinic and gave the angles M: M about 120°; P: M=97° 30′ and 82° 30′; P(0P): ∞P' =88° to 890; P(OP): mP' =122°30′. Cleavage basal, perfect; also in traces parallel with M and the shorter diagonal of P. Lustre of cleavage faces commonly pearly. Color dark leek-green, passing into gray and greenish black; streak like the color. Thin laminæ flexible, but less so than talc. B.B. affords a little moisture in a glass tube; alone instantly turns black, and without phosphorescence. Melts at the extremity to a shining black globule; with borax, forms readily with effervescence a clear bottle green

glass. On analysis it afforded Prof. Shepard, Silica 34-75, protoxyd of iron 31-25, alumina 8.55, water 547, making a loss of nearly 20 p. c., a portion of which he attributes to the alkalies. 0.146 gramme was used in the analysis. Neither lime nor magnesia were detected. The name is from Corundum and quos, friend.

[This mineral, as observed by the writer, is usually thin foliated or micaceous. It closely resembles chloritoid in appearance, which, as stated by J. Lawrence Smith, who analyzed a specimen, occurs frequently with the Corundum of Asia Minor; but it divides into much thinner laminæ than is usual in that species and is less brittle. The angles are nearly those of common mica.]

2. Described Species.

On some Canadian Minerals, by T. S. HUNT, (Phil. Mag., [4], i, 322.) 1. Perthite, of Thomson.-This feldspathic mineral is from Bathurst, and forms part of a eurite rock, being sometimes in large cleavable masses. Form apparently monoclinic. H. 6. G. 2-576-2-579; a darker colored fragment 2-583. Lustre vitreous, inclining to pearly; color a light flesh red, in alternating bands, with reddish or pinchbeck brown, the bands half a line or a line wide, coincident with one of the planes T; the darker bands on the cleavage surface T give a golden reflexion. when viewed perpendicularly, like aventurine feldspar. Analysis by Mr. Hunt.

The composition is that of orthoclase, to which species, as he observes, the mineral had been referred by Shepard, Dana and himself.

2. Peristerite, Thomson.-The specimens furnished Mr. Hunt by Dr. Wilson, as duplicates of those sent to Dr. Thomson, were a feldspar containing disseminated quartz grains; and others from the locality were fine cleavable masses often free from the quartz. Form triclinic, near albite in cleavage, being perfect parallel to P and M, less distinct with T, a fine play of colors on P, as in labradorite, a delicate cerulean blue prevailing which occasionally passes into light green and yellow. H.-6. G.-2-625-2-627. Composition according to Mr. Hunt:

Si

Fe Na K Ča Mg

I. 66.80 21.80 0:30 7:00 0.58 2.52 0.20 ign. 0-60-99-80

IL 67.25

whence the mineral is albite.

3. Bytownite. The specimen analyzed was from Dr. Holmes and was taken from a specimen pronounced by Dr. Thomson to

Massive,

be this mineral. H. about 6.5. G.=2732-2-733. granular, strongly coherent; grains with one perfect cleavage and indications of another oblique to it. Lustre vitreous, approaching to pearly upon the cleavage faces; translucent; color greenish white. The smoky blue mineral from Perth generally circulated among mineralogists as bytownite, is a mixture apparently of the true bytownite with what appears to be a black hornblende. Composition of the bytownite according to Mr. Hunt, Mg Fe Na K

Si

47:40 47:30

ΑΙ Ča Ĥ 30-45 14.24 0.87 0.80 2.82 0.38 2.00 98.96 1.80

Mr. Hunt deduces from these results and the characteristics of the species, that it is anorthite. [The oxygen ratio for the protoxyds, peroxyds and silica is 1: 2-66: 4.62, which is wide from 1:34, the ratio for anorthite; and therefore, it must be, if this species, an impure variety of it. The mineral thiorsauite of Genth, has nearly the same composition according to Genth's analysis; but this Iceland feldspar is considered impure anorthite by Rammelsberg.]

4. Labradorite.-Common in boulders from Labrador to Canada West, but has not been observed in place. A specimen from Drummond, C. W., of a lavender blue color and pearl-gray opalescence, had the sp. gr. 2.697, and consisted as follows:

Mr. Hunt observes with regard to the water in this and other feldspars, that he agrees with Delesse and Laurent, in considering it as belonging to the constitution of the mineral and not hygroscopic.

5. Raphilite of Thomson.-This mineral from Lanarck, C. W., is tremolite. H.-5.5. G. (in powder) =2.845. Lustre vitreous silky; color grayish or greenish-white, becoming reddish on weathered surfaces. Composition:

Si Al Ča Mg Fe Mn Na K

0.21 0:04

55-30 040 13.36 22.50 6.30 traces 0.80 0.25 ign. 0.30=90-31 Oxygen 28-72 0.19 3.80 8.72 140 6. Relinalite and Serpentine.-The retinalite of Thomson was founded on a serpentine from near Grenville, sent him by Dr. Holmes, and a portion of the same specimen he gave Mr. Hunt for analysis; other specimens were procured at the locality. It fills seams or penetrates granular limestone near a trap dyke. H. 35. G. 2-494-2-525-2-476. Lustre resinous; streak white; color honey yellow passing into oil green and olive green; translucent; fracture conchoidal. Composition:

Another serpentine of similar character, from Grand Calumet Island, having a pale wax color and sp. gr. 2-362-2-381, afforded

Si 41.20

Fe 0.80

Mg 43.52

15:40100.92

Mr. Hunt observes that the mineral has the composition of marmolite of Hermann, but is not foliated; and he inclines to consider the species as not distinct from serpentine.

7. Zircon.-Crystals half an inch thick and an inch or more long occur at Grenville, along with tabular spar, calc spar, sphene, pyroxene and plumbago. G.=4-602-4-625. Color brownish red, passing into flesh-red and cherry-red. Analysis afforded Mr. Hunt:

Silica 33.7

Zirconia 67.3=101.0

The zirconia contained a trace of iron which was not separated.

Celestine. The crystallization of celestine has been studied with much labor by M. Hugard, and some new crystalline forms are described by him (Ann. des Mines, [4], xviii, 3.) Mr. Hugard adopts as the mean of his measurements, for M: M, 104°, the angle varying between 103° 30' and 104° 30'; he observes that the crystals which vary most from this are chemically impure. A neat crystal from Lake Erie gave him constantly less than 104° (mean, 103° 30'); but the Lake Erie celestine contains a considerable proportion of sulphate of barytes. The paper is illustrated by twenty-seven figures.

Limestone of Predazzo.-This mineral, called Predazzite by Petzholdt, is a carbonate of lime and magnesia containing water. This chemist deduced the formula 2Ca C+MgCH. J. Roth, by his analysis (J. f. pr. Chem. lii, 346,) makes the composition of a white variety, 2Ĉa C+ Mg = carbonic acid 34-11, lime 43-41, magnesia 15.50, water 6.98=100. He obtained

Ča

Mg

I. 33.35

44.67

14:54

II. 33.98

42.63

14:05

6.96 Si, Al, Fe 0:48 =10000; G 1:868 7:00 Si 0-29 A1, Fe 0·49 9844; G-1018

For another variety of a gray color he obtained, excluding the alumina, silica and oxyd of iron, which amount to 6 per cent.

I.

II.

Ĉ 29.23

28.10

Whence he has the formula Ca C+ Mg = carbonic acid, 27.85, lime 35-44, magnesia 25-32, water 11:39=100. Brucite occurs in the marble of Predazzo, and also a variety of serpentine.

Composition of Apatite from Snarum; G. Rose (Monatsb. Akad. zu Berlin, March, 1851, 173.)-Analyses by M. Weber in the laboratory of H. Rose :