Sc'entyic In(elliijence — Mincrahjii and C/uiii'ufiy. 181 



Ly potash. The decomposition proceeded progressively, so that it had 

 ah-eady evidently commenced in the still coherent portion ot the 

 flint, and had formed a white stripe round the mass, having a breadth 

 of 0.3 to 0.4, decimal lines.— fBerzelius' Jahrcs-Bcr'uht, xxi. Jahr- 

 gariij, ii. Heft , p. 187. 



9. Amphodditc. — Breithaupt has found that Amphodclite and Dip- 

 loite (Latrobite, Brooke) not only rcseuible each other in colour and 

 appearance, but also in the angles of their cleavage planes, and m the 

 proportions of their constituent parts. The Diploite, however, con- 

 tains, according- to C. G. Gmelin's analysis, 6i per cent, of potash, 

 while that alkali is entirely awanting in the amphodelite, and is there 

 replaced by a larger amount of lime and magnesia.— /^J^trrfZJMs' 

 Jahres-Bericlit, Jahrgang xxi, p. 202.) 



10. Andcs'mc. — Abich has analysed a mineral to which he has given 

 this name, and which is from the Andes. It was formerly termed 

 Pseudoalbite, from its resembling greatly, in crystalline form, the 

 twin crystals of Albite ; but it presents a less distinct cleavage than 

 that mineral, and its cleavage-surfaces are not so well defined. The 

 Andesine is imbedded in a greyish-Mhite mass, which is termed 

 Andesite, and has a specific gravity of 3.5924 ; and it is mixed with 

 hornblende and quartZ; on which the crystals broken out leave a sliin- 

 iiiof impression. The specific gravity of (he Andesino is 3.7328, 

 therefore greater than that of Albite. In thin splinters it melts 

 before the blow-pipe, and in grains it fuses into a vesicular glag. 

 The analysis with carbonate of Baryta gave — 



O.rygcn, 



Silicic acid, . . . 59.00 



Alumina, .... 24.28 



Oxide of iron, . . l.TiS 



Lime, 5.77 



Magnesia, .... 1.08 



Soda G.53 



Potash, . . ; . 1.08 



It is therefore a Leucite, in which the greater proportion of the 

 potash is replaced by Lime and Soda. — {Bcrzcliug Jahvcs-Bcricht, 

 Jalircjanrj xxi., Jicft ii., p. 167-) 



11. Arqucrite. — In a report made to the French Academy of 

 Sciences by MM. Berthier, Elie de Beaumont and Dufrenoy, on two 

 memoirs by M. Domeyko, on the mineral products of the silver 

 mines of Chili, there is an account given of a new native amal- 

 gam, which constitutes almost exclusively the riches of the silver 

 mines of Arqueros, in the province of Coquimbo, in Chili. This 

 amalgam consists of six atoms of silver, and one atom of mercury, a 

 composition presented by no mineral previously analytcd. Itt ccns- 



