4. Inquiry into the Oriental Sapphire. It is disputable whe ther the modern be the same with the antient sapphire, which had specks of gold embodied in it, and was therefore termed by Theophrastus χρυσόπατος, and by Epiphanius χρυσοςιγής. The antient sapphire differed, however, from the cyanus or lapis lazuli, since Pliny describes the latter as sprinkled with gold points on the surface only. The gem now called sapphire is distinguished by its charming blue colour and its uncommon hardness. Its specific gravity is 3.95. It gave by analysis 98 per cent. of alumine, I of oxyd of iron, and of lime. This extraordinary preponderance of alumine, as observed in the preceding article, deserves most particular attention. Could it be imagined that the pure basis of clay would ever support such obdurate solidity? The scintillation of any stone with steel hence affords but a very weak presumption of its siliceous nature. 5. Inquiry into Cat's-eye. Of this mineral there are two varieties; the one whitish or yellow, from Ceylon; the other, reddish, from the Malabar coast. That from Ceylon had 2.66 of specific gravity, and was found to contain, of silex 95 per cent. of alumine 1, of lime 1, and of oxyd of iron 4. The cat's eye, or astroites, from the coast of Malabar, was composed of 941 per cent. of silex, 2 of alumine, 11⁄2 of lime, and of oxyd of iron. Its specific gravity was 2.625. 6. Analysis of Chryso-beryl. This is not a variety of chrysolite, as commonly supposed; nor is it the same with the chryso-beryl of the antients. It is brought from Brazil, parts of it contain 71' of alumine, 6 of lime, 11⁄2 of oxyd of iron, and 18 of silex. Its specific gravity is 3.71. 100 7. Inquiry into Chrysolite. This gem was really the topaz of the antients, as appears from Pliny. Its external characters and geological affections have been admirably described by the celebrated Werner; and M. KLAPROTH has now deduced its composition from the specimens sent to him by Mr. Hawkins. The specific gravity was 3.34. A rough bit of chrysolite contained 38 per cent. of silex, 19 of exyd of iron, and 391 of magnesia. In a smooth transparent piece, the proportions were, silex 39, oxyd of iron 19, and magnesia 43. It is easy, therefore, to judge that chrysolite is altogether distinct from chrysoberyl. 8. Inquiry into Olivine. This fossil was formerly known by the appellation of basaltic or volcanic chrysolite; but M. Werner was induced, by an oryktognostic investigation, to separate it from the true chrysolite and to give it the name of olivine. It remained that this conclusion, drawn from external characters, should be brought to the test of chemical analysis. Olivine from Unkel yielded, of silex 48 per cent. of magnesia 37, of lime, and of oxyd of iron 121. In another trial, by the effusion of sulphuric acid without the previous roasting with potash, 100 parts were found to contain, of silex 50, of magnesia 38, of lime, and of oxyd of iron 12. The above specimens were fresh and entire: but since, for the most part, the olivines are much affected by corrosion of the weather, other samples were taken from the basalt rock at Karlsberg near Cassel. In these, the proportions were discovered to be, of silex 52, of magnesia 37, of lime, and of the oxyd of iron 10. From all the results, it appears that the olivine is very nearly allied to the chrysolite, and may justly be restored to its former station in the mineralogical systems. 9. Chemical Inquiry into Silver-ores. This learned and excellent dissertation was read before the Academy of Sciences at Berlin in 1793 and 1794. It is distributed into 8 sections, corresponding to the principal genera of silver-ores; and we regret that our limits will not permit us to consider it circumstantially. 1. Horn-ore, Hornerz, Luna Cornea, is one of the richest and least frequent of the silver-ores. It was known, however, to the metallurgists of the sixteenth century, under the name of glass-ore. It is a compound of silver and muriatic acid, with the addition, generally, of some ferruginous or earthy substance. The compact sort was found by resolution to con tain in the proportion of 67% silver, and 21 muriatic acid, joined to 6 oxyd of iron, and 1 clay, with the minute mixture of sulphuric acid. The kind named butter-milk-silver has 24 parts of silver, 3 of muriatic acid, and 67 of clay. Sulphur or sulphuric acid, though often contained in luna cornea, is not essential to its production. M. Proust mentions the case of a Spanish ship wrecked on the coast of Portugal, and soon afterward weighed up, when the dollars that were on board appeared to be crusted over with a scale of real luna cornea; and Dr. Pallas relates that, on the Jaik in Siberia, he found several antient Tartarian coins, which, by lying in those saline. tracts, had been changed, partly superficially and partly through their entire substance, into that mineral. 2. Red-productiveore, Rothgültigerz. This beautiful ore, distinguished into many varieties by its colour, its form, and its consistence, is commonly regarded, and even by Bergman himself, as a compound of silver with sulphur and arsenic-but this opinion is fully disproved by M. KLAPROTH's accurate analysis, which likewise *Do not these curious facts prove that silver has a greater attraction to the muriatic acid than to soda, the basis of common salt? shews that arsenic is by no means such an active mineralizer as ít has been hitherto supposed. A specimen of fine crystallized red ore, from Andreasberg, gave 60 per cent. of silver, 20 of antimony, 11 of sulphur, and 8 of deaqueous sulphuric acid. Another, from Freiberg, was found to contain of silver 62 parts, of antimony 18, of sulphur 11, and deaqueous sulphuric acid. It thus appears that arsenic has been made, by theorists, to usurp the place of antimony. 3. Silver Galena, Silber glanzerz, the richest of all the silver ores. It is silver mineralized with sulphur, and in the proportion of 85 to 15, according to our author. 4. Brittle Silver Galena. This afforded by analysis 66 per cent. of silver, 12 of sulphur, 100f antimony, and a very small admixture of copper, arsenic, and earthy matter. 5. White-Productive-Ore, Weissgültigerz. The composition of this ore was imperfectly known. It is indeed very complex, and the ingredients present themselves in various proportions. The light coloured sort yields 201⁄2 silver, 48 lead, 8 antimony, 12 sulphur, 7 alumine, e iron, and silex. The dark coloured variety contains only 9 silver, with 41 lead, 214 antimony, 22 sulphur, I alumine, iron, and silex. 6. Grey-ProductiveOre, Graugultigerz. The specimens of this ore were obtained from Kremnitz in Hungary. It is brittle, with a square fracture, and contains a large admixture of clay. The proportions of its ingredients are, silver 15, copper 311, antimony 34, iron sulphur 11 and alumine. 7. Silver-Amalgam. This was found to be composed of 36 parts of silver and 64 of mercury. 8. The last genus of silver ores is arsenic-silver. A specimen from Andreasberg contained 121 per cent. of silver, 444 iron, 35 arsenic, and 4 antimony. 10. Inquiry into the Oriental Lapis Lazuli. The result of this analysis was that 100 parts of the mineral contained 46 of silex, 14 of alumine, 28 of carbonated lime, 6 of gypse, 3 of the oxyd of iron, and 2 of water. Bergman conjectures that the potters of China and Japan give the fine blue tints to their porcelain by means of the lapis lazuli: but M. KLAPROTH found that, in the enamel furnace, the colour changed into a bluish ash-grey. 11. Examination of a Smalt-Blue Fossil from Vorau. This fossil, lately discovered in the territory of Austria, has been successively reckoned a natural smalt, a Prussic blue, and finally a mountain blue. That it is neither of the first two of these, M. KLAPROTH satisfactorily demonstrates. It contains silex, alu ́mine, and the calx of iron; and it ought, therefore, to be considered as a variety of the lapis lazuli. M. Stutz accordingly calls it bastard lapis lazuli. 12. Chemical 1 12. Chemical Inquiry into Zirkon. This is a crude sort of gem brought from Ceylon, and but little esteemed. By Romé de l'Isle it was regarded as a distinct species, under the name of Jargon. Other mineralogists have variously reckoned it a sapphire, a topaz, a. ruby, a diamond, or a hyacinth. Its specific gra vity is 4.615, and it suffers scarcely any loss in the fire. From the experiments which he instituted, M. KLAPROTH concludes that it contains a new, independent, and simple earth. By one analysis, the ingredients were discovered to be silex 31, oxyd of iron, and zirkon earth 68; and by another mode, silex 264, oxyd of iron, and zirkon earth 69. That earth seems the nearest related to the siliceous. 13. Chemical Inquiry into Hyacinth. This precious stone is most intimately connected with the preceding. It comes likewise from Ceylon, and has a specific gravity between 4.545 and 4.620. One hundred parts of it were found to contain 25 of silex, of the oxyd of iron, and 70 of zirkon earth. 14. Chemical Inquiry into the supposed Red Schorl of Hungary. The specific gravity of this fossil is 4.18. Many, judging from its bar-like form, have reckoned it a schorl; while others, deceived by its colour and fracture, have esteemed it a garnet. A series of well-conducted experiments, however, has enabled M. KLAPROTH to conclude that it does not at all belong to the class of earths, but is really the oxyd of a peculiar metal, to which he appropriates the significant name of Titanium. 15. Inquiry into a new fossil from Passau. This consists of small shining crystals, interspersed in a coarse rock. Its specific gravity is 3.51. By a very delicate analysis, it was found to contain of silex 35 per cent. of lime 33, and of the oxyd of titanium 33. This fossil might, therefore, be aptly denominated Titanite 16. Examination of the supposed Molybdenic-Silver. This ore was discovered at Deutsch-Pilsen in Hungary, and was decribed by Born as a compound of silver with sulphurated molybdena: but M. KLAPROTH's experiments establish that it contains neither silver nor molybdena, and is only bismuthgalena or Sulphurated bismuth. The components are in the proportion of 95 parts of bismuth to 5 of sulphur. 17. Examination of the natural Alumine from Schemnitz. This substance, being light, of a snowy white, and very easily broken, is generally reckoned to be a pure aluminous earth, without admixture of silex. That opinion, however, must be qualified; for, by resolution, the fosil appears to contain 45 Dr. Girtanner terms it Hard earth. It will not melt with alkalies. See his Anfangsgrunde derantiphlogistischen Chemie, second edit. p. 260. APP. REV. VOL. XXII. Rr parts parts of alumine, with 14 of silex, and 42 of water. The most unaccountable circumstance is, that such a notable excess of alumine should not produce hardness of structure. 18. Chemical Inquiry into Strontianite in comparison with Witherite. The subject of this valuable memoir, which first appeared in Crell's Chemical Annals, about the year 1793, has of late very much engaged the curiosity of mineralogists. It once was believed to be the same as Witherite, or the natural carbonated barytes: but the subsequent observations of different experimenters have completely overturned that opinion. Several discriminating circumstances, indeed, had induced M. KLAPROTH to call in question the supposed identity. Witherite has not the property, like Strontianite, of giving a red tinge to flame; its specific gravity is superior, being 4.300 instead of 3.675; it proves a mortal poison, and is therefore called, by the people in the neighbourhood of Anglezark in Lancashire, where it is found, rat's stone; whereas Strontianite, from the trials made on animals by Professor Blumenlach, seems not to have any noxious quality. The sus picions of our experienced analyst were confirmed by a chemical research, which shewed decidedly that Strontianite contains an original and simple earth; joined, however, to the same acid of carbone. He diligently pursues the comparison between those two fossils. Both of them are remarkable for the extreme obstinacy with which they retain their gaseous acid in the fire but the Strontianite is distinguished by those physical attributes, by the different proportion of carbonic acid which it contains, and by the differently figured crystals which it forms with the nitric, the acetic, and still more with the muriatic acid. It is conspicuous, too, by its property of chrystallizing when quenched in water after having been burnt. One hundred parts of Witherite were found to hold 78 of barytes and 22 of carbonic acid. The Strontianite contained 691⁄2 per cent. of Strontian earth, and 30 of carbonic acid, with of water. This fossil derives its name from Strontian in the western Highlands of Scotland, where it occurs in a vein of lead ore in a mountain of gneiss or stratified granite. It is of a light green, somewhat transparent, shining, and moderately hard. It dissolves in nitric acid *. 19. Chemical Inquiry into the Lepidolite. The first public notice of this fossil, from Rosena, is due to Counsellor Born, who described it by the name of Lilalite † in the Chemical Annals + * See our Review of the last Vol. of the Irish Transactions, p. 182. vol. xviii. An hybridous compound, formed out of our lilac, a word of Arabic original, and the Greek as which signifies a stone. for |