430 Scientific Intelligence. 



and heating to incipient white heat only 1*63 per cent could be 

 obtained, regard being paid to the oxidation of the ferrous iron 



present. The water being considered as basic the analysis 



in 

 showed the mineral composed of a mixture of RSi0 3 and R.,Si0 6 

 silicates and as a result of his work the writer urges that more 

 attention should be paid to the determination of water in horn- 

 blende analyses, since small quantities escaping determination 

 may cause great differences in the molecular formulas, on account 

 of its low molecular weight. l. v. p. 



9. Danalite from Cornwall. — The occurrence of the rare min- 

 eral danalite at Redruth, Cornwall, has been recently described 

 by Miers and Prior {Min. Mag., vol. x, p. 10). The only speci- 

 men thus far known was obtained in 1864 ; it shows a group of 

 large reddish crystals of tetrahedral aspect which were formerly 

 supposed to be pseudomorphs of garnet after tetrahedrite. The 

 danalite is associated with quartz, small crystals of arsenopyrite 

 and sphalerite. The hardness of translucent crystalline frag- 

 ments of a columbine-red color is 5*5 ; the specific gravity is 

 3*350. An analysis gave the results in 1, while a new analysis of 

 the Schwarzenberg helvite gave the numbers in 2 ; from the 

 latter a little fluorite has been deducted. 





Si0 2 



FeO 



MnO 



ZnO 



BeO 



CaO. 



S 







1. 



29-48 



37-53 



11-53 



4-S7 



14-17 



tr. 



5-04 = 



102-62 





2. 



33-33 



4-45 



44-43 





14-92 





5-03 



A1 2 3 0-77 = 



= 102-93 



A new occurrence of danalite from Colorado is described with 

 analysis by Genth and Penfield on p. 385 of this number. 



10. Mineral Resources of the United States, Calendar years 

 1889, 1890. David T. Day, Editor, 671 pp. Washington, 1892 

 (U. S. Geol. Survey, J. W. Powell, Director). — The seventh vol- 

 ume of this valuable series has recently been issued and like its 

 predecessors gives a careful review by competent writers of the 

 mineral industries of this country ; the period embraced by the 

 report covers the years 1889 and 1890. It is announced that the 

 volume for 1891 is also well under way. 



Temperature of the Gircumpolar region. — A short paper on 

 the temperature of the Circumpolar regions, by Jules Girard, 

 along with a map, is contained in the Bulletin of the Societe de 

 Geographie of Paris, for the 2nd trimester of 1892. It is based 

 on the International observations during the year August 1882 

 to August 1883, and the reports furnished by the expeditions. 

 There were 15 stations occupied by the several nations — the 

 United States, England, Germany, Denmark, Austria, Sweden, 

 Norway, Holland and Russia — which took part in the observa- 

 tions. 



