METALS. 89. Zincum. 2gi 



gravity 3,434 : combined with copper it forms feveral ufeful 

 alloys : when the zinc does not exceed a fourth part of the 

 copper it makes Br<7/j, and becomes malleable and duflile: 

 when three parts of zinc are combined with four of copper it 

 then forms Pinchheck or Prince's metaU of a deeper orange- 

 colour than brafs and not {o malleable. 



PseuJoga" With a femiaietalHc luftre, of a lamellar texture, emitting 

 Isna, fulphurous flame and vapour before the blowpipe, 



Black-jachk 

 Blende. Kirnvan miner. 2. ^ 237. 

 Sulphurized zinc. Schmeifser miner. 2. p 197, 

 Sulphuret of zinc. Thomjon chem. ^.p. 9^^, 



1. Sulphur yellow with often a (hade of olive-green or brownifh- 



red, with a yellowifh ftreak and pale yellow powder. 

 Yel 1 o w Me n d e . Kiri.i:an miner . 2 p. 238. 

 Yellow blende. Schmeijfer mineral, 2. p. \(^()^ 

 YeUow blende. Thomfon chem. 4. /, 84. 



2. Brown in difFeient fhades, with a yellowifla-grey ftreak and 



brown ifh- grey powder. 

 Brown blende. KiriMan mln. 2./. 239. 

 Brown blende. SchmeiJJer mineral, 1, p. 200. 

 Bown blende. 7homjbnchems 4. p. 85. 



^. Black or browniih black ofren palfing into the blood-red, with 

 a reddiflj-grey ftreak and brownifti-black powder. 

 Black blende. Kir<vj an miner . 2. p 241. 

 Black blende. Schmeifser mhier. 2. p, 201. 

 Black blende. Thomfon chem. 4. p. 85. 



4. In a ftateof cryftallization, with the cryftals varioufly modified, 

 moftly confufed, and often blood-red at their tips. 

 Sulphuret of zinc. Soiverhy Dr. min. tah, y^,y^. 

 Found in various parts of Great -Britaint 'Sibtria, Nornvay, 

 S<zvedent Germany ^ Hungary, Sec, in various ftiapcs and mix- 

 tures, with frequently an internal luftre: texture lamellar, 

 the foliations of which mav be eafily feparated : when heated 

 it decrepiutcs and becomes whiter, and fojiietimes emits a 

 phofphorefcent light when fcraped in the dark: when mixed 

 with lead it forms the metal called Tutenagj and combined 

 with tin it is an in^rcdieat in Peivter, 



Op 2 



