194 Scientific Intelligence — Mineralogy. 



Silica, 24-1 



Alumina, 43'2 



Protoxide of Iron, . . . 23'8 



Oxide of Titanium^ . . . trace. 



Water, 7-6 



98-7 

 — Ann. de Ch. et de Phys. ix. 385 ; and Berzclhis'' Bericht, xxiv. 

 p. 281. 



20. Spadaite, a New JMincral. — Von KoLell has examined and 

 described a new mineral iVom Capo di Bove, vvlucli he has named 

 Spadaite in honour of Monsigie. de Medici Spada, from whom he ob- 

 tained it. This substance forms small compact masses, which arc 

 intermixed with Wollastonite. Its fracture is imperfectly con- 

 choidal and sjjlintery ; the colour reddish or flesli-ix'd ; streak 

 white ; it is transparent ; the lustre is glistening or glimmering, 

 and resinous ; hardness = 2"5. It is soluble in muriatic acid, with 

 a residuum of gelatinous silica ; and it is composed of silica, mag- 

 nesia, protoxide of iron, alumina, and water. The formula is 

 M Aq* + 4 M S^. The following is an interesting comparison, given 

 by Von Kobell, of the combinations of silicate of magnesia and hyd- 

 rate of masnesia :— 



— From Jjcr-el'iKs' Jcdires-Bcricht, 24^A Jcdirgang, p. 281. 



21. Snlpho-Arsenhiret of Lead, a New Sfineral Sp>ecies. — On 

 the 14th April 1845, M. Dufrenoy read to the Academy of Sciences 

 of Paris a notice by M. A. Damour, on the crystallized sulpho- 

 arseniuret of lead from Saint-Gothard, a new mineral species, which 

 seems to have been hitherto confounded with grey copper. It is 

 found in granular dolomite, and is principally composed of sulphur, 

 arsenic, and lead, but also contains slight traces of copper and silver. 

 The followino; is its chemical constitution : — 



* Or Schiller-asbestus from Reichenstein, a substance which, as it 

 does not beloiig to what is generally understood under the name of as- 

 bestus, has been termed chrysotile, from xi""' gold, and Tikm wire. 



