186 Scientific Intelligence. 



21. New Localities of Rare Minerals. Levyne — Professor Zippe, of 

 Prague, has discovered this mineral in the cavities of an amygdaloidal rock, 

 forming part of a collection of minerals from Greenland, sent to the Museum 

 at Prague by Sir Charles Giesecke. The locality atached to the specimen 

 is Kognersoak, near Godhavn, in the island of Disco. It is in every re- 

 spect similar to the variety from Dalsnypen in Faroe, established as a new 

 species by Dr Brewster.* As at Dalsnypen, it is accompanied by Heulandite. 

 Another variety was discovered by Mr Haidinger in the cavities of a rock of 

 the same description, said to be from the Vicentine. Here it also occurs 

 in twin crystals similar to those represented in Mohs" Treatise, (vol. ii. 

 Fig. 194;) but it is associated chiefly with chabasite. It would be inte- 

 resting to inquire into the chemical difference of two species which are so 

 very like each other in the whole disposition and physical quality of their 

 faces of crystallization, while they differ in their angles, which are 

 =94° 46' in chabasie, and 79° 89' in Levyne. The mineral analyzed by 

 Berzelius, under the name of Levyne, and mentioned in his last Account 

 of the Progress of Chemistry, $c. t is, in fact, chabasie, with the other va- 

 rieties of which it agrees also in its chemical composition. The form of 

 Levyne has been likewise met with among the products of Hartfield-moss, 

 near Glasgow. A twin crystal of considerable size, having this form, is 

 preserved in the cabinet of Mr Allan. The plane perpendicular to the 

 axis is, however, much smaller in comparison to the other faces, than in 

 any of the other varieties. It is of a reddish colour, compact in its frac- 

 ture, and opaque. This peculiar appearance, very different from the fresh- 

 ness of the rest, is owing, perhaps, to some particular decomposition, or to 

 the pseudomorphous formation of another mineral in the shape of Levyne. 

 It is to be hoped that we shall soon become acquainted with the specific gra- 

 vity and other important characters, as well as the chemical composition of 

 Levyne, which appears not to be such an exceedingly rare substance as 

 was first supposed. 



88. Comptonite. — The neighbourhood of Aussig, in Bohemia, is very rich 

 in varieties of this mineral, established as a new species by Dr Brewster, 

 and which was hitherto believed to be confined to mount Vesuvius. At 

 Aussig, it is generally found as a thin coating on the surface of reniform 

 masses of a kind of mesotype. More rarely it is met with in small but very 

 distinct single crystals, disposed within the cavities of the grey rock, well 

 known as the matrix of the chabasites. Mr Haidinger found the same spe- 

 cies in nearly transparent crystals, exactly similar to those from Vesuvius, 

 and approaching to them also in size, in the cavities of a perfectly compact 

 basalt from the Pflasterkaute, near Marksuhl, in Thuringia, a classical spot 

 in the early history of the disputes concerning the igneous or aqueous origin 

 of basalt. The Compontite is accompanied with small crystals of harmotome, 

 and nearly opaque white crystals, having the shape of obtuse isosceles four- 

 sided pyramids, of a mineral not yet sufficiently examined. 



23. Brewslerite. — Mr Bcrgemann of Berlin found a variety of this; 

 * Sec this Journal, vol. ii. p. 332. + Sec our last Number, p. 316. 



