Third Supplement to Dana's Mineralogy. 257 



Hornblende [p. 1*70, and Suppl. i, n]. — Crystallographic and optical relations to 

 pyroxene, W. Haidinger, Sitzungsb. Akad., Wien, xvii, 456. — An important paper. 



Lanthanite [p. 456, and Suppl. i].— Reported by Prof. C. U. Shepard as observed 

 at the Canton Mine, Georgia (Rep. 1856), "at one spot in the 96 feet level, where 

 it was found in very beautiful pink-colord crystals, lining small cavities of botryoidal 

 White iron-pyrites." 



Lead [p. 17].— Native lead and lead ochre are reported as occurring at Zomela- 

 huacan in the state of Vera Cruz, in a communication by M. Noggerath (Zeits. d. 

 geol. Ges, vi, 674). The locality is a valley over 3000 feet deep whose upper rocks 

 are porphyry, melaphyre and basalt, trachyte, with metamorphic limestone and other 

 beds below. The limestone in some parts still retains fossils, as Am nonites Bulk- 

 lundi and Ampullaria angulata. The formation is 900 feet thick, 'i he native lead 

 and ochre occur in a white granular limestone. The lead ochre is somewhat foliated, 

 of a wax or reddish yellow color to reddish where in contact with the native lead. 



The amygdaloid from near Weissig, according to G. Jenzsch, sometimes contains 

 in its cavities native lead, overlying pyrites, weissigite, chalcedony, quartz, galena, 

 hornstone, &c— Jahrb. f. Min. 1855, 805. 



Native lead is stated to occur also in the Altai (v. Hingenau's Oest. Zeits. 1854, in 

 N. Jahrb. f. Min. etc. 1855, 837) seven miles from Mt. Alatau in the gold region. It 

 is described as accompanying limonite, magnetite, and galena, in irregular masses 

 a drachm in weight. Grains of native lead are also found with the gold near Ekath- 

 erinenburg in the Urals. 



Leucite [p. 231].— The leucite of the modern lavas of Vesuvius, according to De- 

 ville (LTnstitut, No. 1173), contains much more soda than that of the old lavas of 

 Somma. The oxygen ratio for the soda and potash in the former is 1 : 2 09 for the 

 crystals from the lava of 1855, and 1 : 8 21 for those from the old lavas of Somma 

 (Fossa Grande). The same for the lavas of 1847, according to Damour, is 1 : 1 67. 



Rammelsberg (Monatsb. Preuss. Akad. March, 1856, 148) has published a short 

 paper on leucite and its pseudomorphs, remarking on the occurrence of a large pro- 

 portion of soda in the altered leucite (2 of soda to 3 of potash). 



Leucopyeite [p. 61, 5 07 J. —Composition by G. A. Behncke (Pogg. xcviii, 187): 



S As Sb Fe 



1. Geyer, G— 6246— 6321, 6 07 58-94 1-37 32 92=99-30 



2. Breitenbrunn, G.=7 282— 7'259, 1*10 69 85 1 05 27 41=99"41 



Regarding the sulphur as being combined with part of the iron and arsenic as mis- 

 picKel, the analyses, this excluded, become — the 1st, arsenic 67 06, iron 32 94=Fe 2 

 As 3 ; the 2nd, arsenic 721 9> iron 27 7l=Fe As 2 . 



Keilhauite [p. 341, and Suppl. i].— D. Forbes and T. Dahll (Nyt. Mag. f. Nat. 

 xiii,) mention the occurrence of masses of Keilhauite weighing 15 to 20 pounds, at 

 Alve in Norway. H.=6 5. G.=3 72. Two perfect cleavages cross at 138°. Color 

 dull brown. Streak pale dirty yellow. B.B infusible and unchanged. Specimen 

 from near Naresto had G.=3 519; and a pale grayish brown, from Alve, G =3 603. 



In the Edinb. N. Ph. J., [2], iii, Jan. 1856, Dr. D. Forbes states that the percentage 

 of titanic acid should read 28 04, instead of 28 84. A comparison of the angles of 

 the crystals with those of sphene, made by Professor Miller of Cambridge, is here 

 given. 



Killinite [p. 170J.— Analyses by Rev. J. A. Galbraith (J. Geol. Soc. Dublin vi 

 165): 



Si £l Fe Ca M"g K N"a H 



1. Dalkey Quarry, Co. Dublin, 50 11 29 37 2-23 0-34 1 03 6 71 0 60 8 03=98 42 



2. Killmey, 5045 30 13 3 53 — 109 481 0 95 7 58=98 54 



The first gives the oxygen ration for R, H, Si and fi. 1 : 5 97 : 11-53 : 3 10 ; and the 

 second, 1 : 6\18j 11 76 : 2 96 ; which Mr. Galbraith takes at 1 : 6 : 12 : 3, arid writes 

 the formula R Si-h^r 2 Si 8 -[-3H The results agree very nearly with those of Lehunt 

 and Blyth, and differ from the analysis of Mallet [see Min. p. 170J. Specific gravity 

 SECOND SERIES, VOL. XXII, NO. 65. SEPT., 1850. 



33 



