Mineralogy. 377 



in salt of phosphorus, with the exception of a silica skeleton. When heat- 

 ed with solution of cobalt, it assumes a pale red colour, even when fused, 

 and appears therefore to contain water, silica, and magnesia. 



The cleavahle varieties have been found, accompanied by octahedral Iron- 

 ore and macrotypous Lime-haloide, in a bed in primitive rocks. The only 

 locality hitherto known is the iron mine called Engelsburg near Presnitz 

 in Bohemia. 



It is likely that many varieties of the common Asbestus of Werner, 

 (Jam. Syst, vol. ii. p. 156,) particularly that from Zoblitz in Saxony, 

 should be referred to this species. According to Wiegleb, it consists of 

 silica, -1(3.66; magnesia, 48.45; oxide cf iron, 4.79. 



Various localities are quoted for the common. Asbestus ; but since Asbes- 

 tus contains also varieties of pyroxene and amphibole, they cannot all be 

 supposed exact, and it would, therefore, be very interesting to institute a 

 closer natural-historical examination of all these minerals. Among the 

 localities chiefly quoted are Zoblitz in Saxony, Silesia, the Tyrol, and 

 many other countries along the line of the Alps, the Shetland isles, 

 Portsoy, &c, where it occurs in veins traversing serpentine, in the 

 Taberg and other places in Sweden, where it occurs in beds, along with 

 octahedral Iron-ore, with several species of Pyrites, rhombohedral and ma- 

 crotypous Lime-haloide, &c. 



Picrosmine was proposed us a species of its own by Mr Haiilinger, who 

 has been indebted for the specimens which he examined to Mr Lingke, 

 mathematical and. philosophical instrument maker at Freiberg. The tri- 

 vial name is derived from OT/Cgos, bitter, and oSftri, odour, from the bitter 

 and argillaceous odour the mineral exhales when wetted. — (Mohs, vol. 

 ii. p. 672. Transl. p. 137.) 



32. Brookite, a New Mineral Species. 



Prismatic. P = 135° 46', 101° 37', 94° 44' 



(a : b : c = 1 : ^3.237 : Vl.149.) 



Combination. 1. Pr. — 1 (a). Pr (a 1 ). (I P- 2) 3 (t). (Pr — 

 s {bi). i Pr (e§). P (c- 3 ). (Pr + a>)» (m). Pr + x (A 1 ). Pr + x 

 (g- 1 ). From Snowdon. Fig. 18- 



Inclination of a 2 on a 2 = 148° 56' ; of a' on a' = 124° 52' ; of m on 

 m = 100° 0' ; of /' on i, over «', = 149° 37' ; of 6A on 6^, over a, = 

 135° 41'. 



Lustre metallic adamantine. Colour hair-brown, passing into a deep 

 orange-yellow, and some reddish tints. Streak yellowish-white. Trans- 

 lucent ... opuke, the brighter colours are observed by transmitted light. 



Brittle. Hardness— 5.5 ... 6.0. 



It contains titanium, but has not yet been analysed. This beautiful 

 substance has been described as a particular species by Mr Levy, and 

 named in honour of Mr Brooke. The first varieties had been noticed by 

 Mr Soret among the minerals accompanying pyramidal Titanium-ore from 

 Dauphiny ; but much finer crystals, some of them half an inch in diameter, 

 have lately been found at Snowdon in Wales. In both places they are 

 accompanied by rhombohedral Quartz, in Dauphiny, besides pyramidal 

 Titanium-ore, also by Crichtonite and Albitc— Ann. of Phil. Feb. 1825. 



