200 Oxide of Manganese found at Neiccastlc-upon-Tyne. [Sept. 



100 square inches, an effect was produced on the needle at a 

 distance of three feet. He also, in this paper, describes the 

 construction of a voltaic combination so light, that being sus^ 

 pended, it moved on the approach of a magnet; the motions 

 were in accordance with what has been said, and may easily be 

 conceived. 



(To be coiitintied.) 



Article VI. 



On Oxide of Manganese found in the Neighbourhood of Newcastle- 

 upon-Tyne. By Mr. N. J . Winch. 



(To the Editor of the Annals of Philosophy.) 



SIR, Nexvcastle-vpon.Tyne, May 3, 1821. 



It may not be uninteresting to such of your readers as pos- 

 sess estates or manorial rights in districts, the geological features 

 of which are similar to those of our coal formation, to be made 

 acquainted with the discovery of the oxide of manganese in this 

 neighbourhood. Flying reports had long been in circulation of 

 the existence of this mineral at Ousten, near Urpeth, situated 

 between three and four miles north-west of Chester-le-street, in 

 the county of Durham, but it was generally surmised that iron 

 slag, of which large quantities occur by the sides of all the 

 Roman roads in the north of England, had been mistaken for it, 

 for no traces of this metal had been previously detected in any 

 of our numerous mines or quarries. However, about a week 

 since, these reports were verified by some large masses of the 

 black oxide being uncovered by the plough, but whether con- 

 nected with a vein, or a bed, is not yet determined. The speci- 

 men now before me is black ; its fracture conchoidal ; and 

 structure cellular ; the interstices partly filled with iron ochre. 

 Manganese seems to pervade the newest as well as the oldest 

 rocks ; Brogniart mentions it in chalk ; the black oxide has been 

 detected in the Orkney Islands, and the gray in the slate moun- 

 tains of Cumberland. The geological position of this coal form- 

 ation is above the encrinal, and below the magnesian limestones. 



While on the subject of localities of rare minerals, it may not 

 be amiss to mention that diallage forming a subordinate bed in 

 mica schist was met with three or four years ago by Dr. Boue, 

 at Craig Cailleich, in the Highlands ; and at Castle Hill, near 

 Keswick, by Mr. Joseph Fryer, who has also noticed veins of 

 beautiful yellow ferruginous quartz in the greywacke at Lang- 

 holm, on the borders of Scotland. 



I have the honour to be, Sir, &c. 



Nat. John Winch. 



