128 Scientific Intelligence. 



Chimie, 1848, 145.)— This mineral is a red powder from the mercury 

 mines of Chili. It consists of antimonious acid 21*2 to 238 oxyd of 

 mercury, with peroxyd of iron, silica and water. 



34. Arsenical Nickel from Oelsnitz; by M. H. WACKENRODER,(Arch. 

 f. Pharm., xcvii, 288; Annuaire de Chem., 1847, 211.)— This mineral 

 was found in the green sand, in a gangue looking like spathic iron. The 

 fresh fracture has a lead gray color which soon changes to brownish 

 gray, with spots of oxyd of nickel. An analysis obtained : — Nickel 

 20-937, arsenic 35-258, sulphur 8903, lead 0-299, protoxyd of iron 

 8-26, protoxyd of manganese 1-023, lime 12-578=87-248, the loss be- 

 ing carbonic acid ; carbonic acid and oxyd of iron and manganese 

 belong to the gangue. The lead is undoubtedly an unessential ingredi- 

 ent and exists as a sulphuret. Omitting these, the author considers the 

 species as having the formula Ni S 2 -f-2Ni Ar 2 , which would give for 

 its composition nickel 32*700, arsenic 54*440, sulphur 11*860, the 

 analysis affording (after separating the impurities) nickel 32*185, ar- 

 senic 54*198, sulphur 13-617. 



35. On an Arsenio-sulphuret of Nickel ; by MM. Wackenroder and 

 Ludwig, (Jour. f. Prakt. Ch., xl, 318.) — This ore of nickel occurs mas- 

 sive with spathic iron in graywacke. Analysis afforded the formula 

 NiS 2 -f2(Ni,As.) 



36. On Polymerous isomorphism; by M. Naumann, (Jour. f. Prakt. 

 Ch., xxxix, 196, and xl, 1; Annuaire' de Ch., 1848, 142.)— M. Nau- 

 mann admits that Scheerer's theory explains well the relations of 

 the serpentine of Snarum and chrysolite. But as regards cordierite 

 (iolite) and aspasiolite, it is unsatisfactory ; for the constitution of these 

 two minerals requires rather the isomorphism of 1 equivalent of mag- 

 nesia and 4 of water; and even admitling 5 of water to be isomorph- 

 ous with 1 of magnesia, there is little diwscrepancy with the analytical 

 results. 



Naumann also shows that the minerals fahlunite, praseolite, chloro- 

 phyllite, esmarkite and bonsdorffite do not sustain Scheerer's theory; 

 and to account for their forms, we must admit that they are derived 

 from iolite. 



37. Analysis of California Gold, (Ann. des Mines, torn, xiv, p. 67 ; 

 Phil. Mag., May, 1849.) — M. Rivot, mining engineer, has analyzed a 

 specimen of California gold sent by Mr. Peabody to the Ecole des 

 Mines. The specimen contained — small flattened grains, of a fine yel- 

 low color, and extremely small and smooth grains, attracted by the 

 magnet, which appeared to be titaniferous iron. A rather large, yel- 

 low and irregularly rounded grain, weighing 0*628 grs., the density of 

 which was only 14*60, was fused on a small cupel in a muffle, and 

 gave a button of alloy, the density of which was 17*48. 



The analysis of the grains of gold, performed on one gramme, gave 

 the following results : 



Gold, 90*70 



Silver, 8*80 



Iron, 0*38 



99*88 



