382 Scientific Intelligence — Mineralogy. 



in other simple sulphurets, such as magnetic pyrites, yellow nickel 

 pyrites, and Greenockite. 



15. Epidosite, a new species of Mountain Rock. — Under the name 

 of epidosite, Professor Pilla of Pisa has described, in Leonhard and 

 Bronn's Jahrbuch for 1845, p. 63, a rock belonging to the Gabbro 

 series. Savi considered it to be a diorite; but Pilla has ascer- 

 tained that it is composed of pistachio green epidote and quartz. Its 

 colour is green, passing into grey and brown ; and it occasionally 

 contains garnet. The epidosite is sometimes associated with ophio- 

 lite, and passes into it ; and at other times it occurs along with gra- 

 nite. Professor Pilla describes four varieties, viz., the granular, the 

 variolitic, the compact, and the earthy ; all of which are found in 

 various parts of the Island of Elba. 



16. Kersten on the Conversion of Sulphate of Lead into Lead-- 

 Glance^ hy means of Organic Substances. — It is generally supposed 

 that the sulphate of lead, occurring in veins, especially in their upper 

 portions, is the result of a pseudomorphous conversion of lead-glance. 

 It seems, however, that there are also examples of lead-glance, in which 

 it is very probable that that substance has been reproduced from 

 sulphate of lead. Fournet remarks, that the older mineralogists 

 speak of wood covered with lead-glance, and also of human bones 

 encrusted with the same substance ; and he suggests the idea, that 

 perhaps these encrustations are to be explained by assuming a re- 

 duction of sulphate of lead by the agency of organic substances. In 

 order to ascertain what takes place when sulphate of lead is in con- 

 tact for a long time with organic substances and with water, the 

 author undertook experiments, from which it resulted, that small 

 quantities of sulphuret of lead were obtained from sulphate of lead 

 by means of contact of the latter with organic substances ; and that 

 this effect was greatest when fresh leaves of plants were employed, 

 and smallest when rotten wood was the agent. Nevertheless, it is 

 not improbable, that, in nature, cases occur where regenerated lead- 

 glance has been produced by the action of sulphuretted hydrogen gas 

 on the phosphate, carbonate, and sulphate of lead ; because, according 

 to Haidinger's experiments, that gas easily reduces, at the ordinary 

 temperature, the salts of lead just mentioned to sulphuret of lead. 

 — (^Leonhard and Bronn's Jahrbuch, 1845, p. 202. From Erdm. 

 und March. Journ. xxxi., p. 491.) 



17. Vanadium detected in an Ore of Iron. — Kersten (Erdm. 

 und March. Journ. xxxi., p. 106) states, that the iron-ore of Maxen, 

 near Pirna, which is an oxide of iron, penetrating clay-slate, contains 

 vanadium ; and that the latter is easily separated by smelting the 

 ore with saltpetre and potash, &c. — {Leonhard and Bronn's Jahr- 

 buch, Jahrgang 1845, p. 323.) 



18. Chrome in Serpentine. — Z. F. Suersen has detected a consi- 

 derable quantity of the green oxide of chrome in the black serpen- 

 tine of Zoblitz.— (i^idf., p. 326.) 



