180 Scientific Intelligence. 



veins in the greenstone, which contains in other countries of the Harz 

 mountain axinite, which through the boracic acid is allied to the datholite. 

 Professors Hausmann aud Stromeyer of Gottingen have examined the 

 datholite from Andreasberg. (Gottinger gelehrte Anzeigen, 1828, No. 9.) 

 It occurs in beautiful aggregated crystals, like Figs. 67 and 68 of the se- 

 cond volume of Moh's Treatise on Mineralogy, from half an inch in dia- 

 meter, and massive with granular composition. The surface of most of 

 the faces is even, the lustre vitreous, the colour white, inclining to green 

 and red. The crystals are translucent. The specific gravity found by 

 Professor Stromeyer of this and a variety from Arendal, in Norway, is 

 = 3.3541, and therefore they differ from other crystals. According to 

 Stromeyer, the datholite from Andreasberg consists of 



Lime, 35.67 Boracic acid, 21.26 



Silica, 37.36 Water, 5.71 



From Professor Hausmann's " Treatise on Mineralogy." — A second edi- 

 tion of this valuable work is in the press, and will appear in the course of 

 this year. The first edition appeared in the year 1813. 



26. Protherite. — According to Professor Breithaupt of Freiberg the 

 protherite of the Count Razumoosky, in Petersburgh, (Fe'russac, Bulletin des 

 Sciences Natur. 1827, No. 5, p. 42,) is a variety of the paratomous augite- 

 spar or augite. 



27. Diatomous Schiller Spar. — The diatomous, or common schiller spar, 

 from the Baste, near Harzburgh, in the Harz mountain, a mineral little 

 known, has been examined with great exactness by Dr Kohler of Cassel. 

 (PoggendorfFs Annalen der Ph. u. Chem. vol. xi. p. 192, &c.) The mine- 

 ral has a cleavage in two directions, with different distinctness. The one of 

 them called P being highly perfect, and easily obtained, has a great exten- 

 sion, while the other, M, appears only in slight traces. The inclination 

 between M and P is 130°, measured with the common goniometer of Haiiy. 

 The perfect faces of cleavage P have an eminent metallic pearly lustre, the 

 others, M, a silky glimmer, and are striated. The colour upon P is deep 

 leek-green, and in the light, brass-yellow or bluish-green. The directions 

 in which these change of colours appear are constant in connection with 

 the crystalline structure. The German name schillerspath or schillerstein 

 is derived from this property. In the fracture the mineral is dull, or a 

 little glimmering ; in thin laminae translucent. The hardness is = 3.5. 

 The spec. gr. = 2.652. 



Dr Kohler has marked the analysis of the mineral 1, with carbonate of 

 potassium, and 2, with fluoric acid. The results are the following : 



