1835.] 



FARMERS' REGISTER 



199 



Carbonate of lime. — Lime 56.00, carbonic acid 

 44.00. 



Carbonate of magnesia. — Magnesia 48.00, car- 

 bonic acid 49, water 3.00. 



Sulphate of lime. — Lime 32.00, sulphuric acid 

 4G.00, water 22.00. 



Muriate of soda. — Soda 53.44, muriatic acid 

 46.55. 



Oxide of iron. — Iron, oxygen. 



Sulphur ct of iron. — Iron 47.85, Sulphur 52.15. 



Descriptions of the above Minerals. 



Feldspar. — Its colors are various, but it possess- 

 es a peculiar lustre, and a foliated structure, 

 which distinguish it easily i'rom other minerals. 

 Occurs massive, disseminated and crystallized. 

 Its common crystallized form, a broad six-sided 

 prism, with dihsedral summits; an oblique four- 

 sided prism; a six-sided prism, terminated by five 

 unequal faces. Structure foliated; cleavage in 

 two directions; lustre shining, often pearly; trans- 

 lucent or nearly opaque; cross fracture conchoidal; 

 fragments rhomboidal. Scratches glass. Before 

 the blowpipe, on charcoal, in a bright heat, it 

 turns glassy, whitish, semi-transparent, and melts 

 on the edges into a translucent, frothy enamel, 

 with great difficulty. With borax, fuses slowly 

 into a clear glass. With solution of cobalt, gains 

 a blue color on the fused edges. Specific gravity 

 2.54. Abundant in the gneiss rock near Philadel- 

 phia. 



Mica. — Characterized by the readiness with 

 which it splits into extremely thin, smooth, shining 

 plates or scales, which are transparent, flexible, 

 and highly elastic. Occurs abundantly dissemi- 

 nated in grains or spangles, also in masses, and 

 sometimes in regular six-sided tables. Colors 

 various; lustre shining, often pseudo-metallic. It 

 is scratched by the knife, but the edges scratch 

 glass; smooth but not unctuous. Different micas 

 differ in their behavior before the blowpipe; gene- 

 rally they are fusible into a gray enamel, but with 

 difficulty. Specific gravity 2.7. Abundant in 

 the mica slate a few miles up the Schuylkill, also 

 in the rock at Fairmount; beautiful masses occur 

 near Wilmington. 



Hornblende. — Color dark bottle green, passing 

 into black; occurs massive, also sometimes in six- 

 sided prismatic crystals; fracture crystalline, show- 

 ing fibres confusedly aggregated; opaque when 

 black; translucent on the edges when green; lus- 

 tre shininjr, pearly; powder or streak, green; ex- 

 hales a bitter smell when moistened. Before the 

 blowpipe, melts with great ease into a blackish 

 colored glass. Specific gravity 3.15 to 3.38. 

 Found on the Schuylkill, not far from Fairmount. 



Augite. — Prevailing color dark green, some- 

 times blackish or yellowish green; also brownish, 

 gray, or even white. Massive, crystallized, and 

 in grains. When regular, in six or eight-sided 

 prisms, terminated at each extremity by two faces. 

 Structure foliated. Lustre glimmering or splen- 

 dent. Before the blowpipe, melts into a black 

 enamel, with extreme difficulty, and only in mi- 

 nute proportions; this property distinguishes it 

 from hornblende, which it much resembles in ap- 

 pearance. Specific gravity 3.15 to 3.57. Found 

 a few miles from Baltimore. 



Hyper sthene. — Dark greenish brown or black, 

 with pseudo-metallic reflections of a copper red; 



massive; structure lamellar; opaque. Powder 

 dark greenish gray; yields slightly to the knife; 

 scratches glass. Before the blowpipe, on char- 

 coal, fuses easily into a grayish green opaque 

 glass. Melts easily with borax into a dark green 

 glass. Specific gravity 3.4. Found on Brandy- 

 wine creek, Delaware. 



Serpentine. — Common serpentine is usually 

 classed as a simple mineral, though the composi- 

 tion of the rock which receives this name is by no 

 means definite and uniform. Colors green, yel- 

 lowish i^reen, blackish green, brown, bluish gray, 

 or reddish, variegated with stripes, veins and 

 blotches; generally opaque and dull. Massive; 

 fracture uneven, or splintery; hardness extremely 

 variable; often gives out the odor of clay when 

 breathed on. Heated in a flask, it gives off water 

 and turns black. On charcoal, turns white, and 

 in a good heat, melts on the thin edges into an en- 

 amel. With borax, slowly melts into a clear 

 green colored glass. Gives a red color when 

 fused with solution of cobalt. Specific gravity, 

 2.5. Bare Hills, near Baltimore; Hoboken, New 

 Jersey; West Chester and Montgomery county 

 at Easton, Penn. 



Diallage. — Of this mineral there are two species; 

 the metalloidal is however, the commonest as an 

 ingredient in rocks. It is sometimes called Schil- 

 ler spar; its colors are bottle emerald or olive 

 green, yellowish or pinchback brown. Lustre ap- 

 proaching to semi-metallic. In granular concre- 

 tions. Lamellar. Opaque in mass, but transpa- 

 rent in leaves. When turned towards the light, 

 the colors suddenly appear and disappear, as in 

 Labrador felspar. In the flask or matrass, yields 

 water, crackles, and acquires a clearer color. Be- 

 fore the blowpipe, on charcoal, melts slowly on the 

 edges into a gray scoria. With borax, melts with 

 much difficulty into a transparent glass, somewhat 

 tinged. Some variety infusible before the blow- 

 pipe. Specific gravity 3.1. Commonly found in ser- 

 pentine. Found nearHaverstraw Bay, New York. 

 Schorl. — Color velvet, or brownish black. Mas- 

 sive and crystallized in three, six or nine-sided 

 prisms, variously bevelled and striated. Lustre 

 glistening, vitreous; brittle; fracture conchoidal; be- 

 comes elastic when heated. Before the blowpipe, 

 fuses by itself into a frothy mass, and turns white; 

 afterwards melts with difficulty into a translucent 

 grayish yellow bead. With borax, melts readily 

 with effervescence, into a nearly colorless and trans- 

 parent glass. Specific gravity 3. Schorl resem- 

 bles hornblende, but has a vitreous lustre, a con- 

 choidal or uneven fracture and is electric while 

 hornblende has a shining, rather pearly lustre, is 

 softer, has a splintery fracture, a lamillated struc- 

 ture, and is non electric. Found near Baltimore, 

 Rhinebeck, N. Y. In the gneiss rock near Phil- 

 adelphia, at Judge Peters' quarry above the upper 

 bridge — fine specimensS miles on the West Ches- 

 ter road. 



Chlorite. — Green is the prevailing color, vary- 

 ing from dark green to light grayish green, and 

 generally dull; massive, crystallized, in minute 

 hexagonal scales and earth} 7 . Opaque, lustre, 

 shining, pearly, soft, unctious; of a darker green 

 than talc or epidote. Before the blowpipe on 

 charcoal it melts into a black globule, with a dull 

 surface; with boron forms a dark green glass, does 

 not fuse or froth with soda. Specific gravity, 2.6 

 to 2.9. 



