186 Scientific Intelligence. 



(silicate of zinc), idocrase, garnet, phenakite, emerald, euclase, and zircon 

 are obtained. By making a mixture corresponding to the constituents of 

 magnesia, tourmaline, and iron, and magnesia tourmaline, adding excess 

 of lime or magnesia, and exposing the whole to the chloride of silicium, 

 in addition to rock crystal, very distinct hexagonal prisms with all the 

 properties of tourmaline were obtained. 



By passing chloride of aluminium over red-hot lime, crystals of alumina, 

 corresponding to the two well-known forms of corundum, were obtained. 

 When magnesia is used, the silicic acid unites with the* excess, and crys- 

 tals of spinelle are produced. A mixture of chloride of zinc and aluminium, 

 brought in contact with lime, produces gahnite. 



Chloride of titanium, acting on lime, produces titanic acid in the form 

 of Brookite. Chloride of tin gives the crystallized oxide. Chloride of iron 

 gives specular iron ore, and if mixed with chloride of zinc, Franklinite is 

 produced. Chloride of magnesium gives crystallized magnesia, exactly 

 similar to the periclase of Monte Somma. 



The results of these experiments lead to many interesting conclusions, 

 They shew us how such minerals, as augite, garnet, epidote, axinite, and 

 many other minerals, which certainly cannot have been produced by fusion, 

 may be formed. Indeed, the production of a large number of minerals 

 may, with great probability, be attributed to the action of volatile chlorides 

 and fluorides, and the penetration of those into the fissures of limestone; 

 and the very powerful action of lime on these compounds, may explain 

 the abundance of silicates which exist disseminated through many lime- 

 stones. Minerals, such as spinelle, chondrodite, mica, augite, amphibole, 

 serpentine, &c, are frequently found in limestones which contain no mag- 

 nesia, and this hitherto unexplained fact may be due to the difference in 

 the chemical affinities of lime and magnesia; for it is observable that in 

 all these experiments chloride of magnesium is decomposed by lime. Many 

 other obscure facts may also be explained by reference to these researches, 

 which are of very great mineralogical interest. — Comptes Rendus, vol. 

 xxxix., p. 135. 



Meteoric Iron from Greenland.* — Forchammer describes a meteoric 

 stone discovered by Rinck, in possession of the Esquimaux at Niakoruak, 

 Lat. 69° 25', by whom it had been found at a short distance from their 

 hut, on a stony flat through which the river Annorritok flows into the 

 sea. It weighed 21 lbs. The specific gravity of the whole mass was 7*00, 

 that of small fragments varied from 7*02 to 7'073. It was so hard that 

 it could neither be filed nor sawed, but was very brittle. Its fracture was 

 granular ; it took a high polish, and showed beautiful Widmannstatt's 

 figures when acted on by nitric acid. By treatment with acids it evolves 

 sulphuretted hydrogen, and hydrogen of bad odour exactly like inferior 

 cast iron. At first iron alone is dissolved, and a black matter consisting 

 of minute crystals is left behind, which eventually dissolves, and a black 

 powder, which proved to be carbon, floats through the fluid, while, in place 

 of the fragment of the iron, a gray porous mass amounting to 1 or 2 per 

 cent, of the stone is left. It contained — 



Iron 93-39 



Nickel 1-56 



Cobalt 0-25 



Copper , 45 



Sulphur 0-67 



Phosphorus 018 



Carbon V69 



Silicon 0-38 



98-57 



