On the Aerated Barytes. 603 



and Mine-houfe Veins which join it in its progrefs 

 to the Eaft and are nearly of the fame thicknefs. 

 From the Mine-houfe Vein proceeds a fmall one 

 called the String. Vein, which runs parallel to the 

 Sun Vein. To the North of all thefe lies the New 

 Trial Vein, which apparently has alfo its rife in the 

 above-mentioned Chorley road vein and runs in 

 the dire6tion fhewn in the plan, which feems to 

 indicate that it likewife at fome diftance falls into 

 the Sun Vein j it is nearly of the fame dimenfions 

 as the others, but has not been hitherto much 

 worked upon, owing to its lying low, and its being 

 difficult to carry off the water. 



The Matrix of the veins is Aerated and Vitriola- 

 ted Barytes. The former is found in the greateft 

 quantities next the furface, where it is almoft 

 entirely free from any mixture of the latter, but 

 becomes more and more contaminated with it in 

 proportion as the depth increafes, until in the 

 lowermoft ftrata it is fcarcely to be met with at all, 

 the vitriolated having ufurped its place. There is 

 an evident tranfition from the Aerated to the 

 Vitriolated Barytes which may diftindtly be ob- 

 ferved through its different ftages or gradations, in 

 all parts of the mine. Small quantities of Cal- 

 careous Spar are alfo found in the lower part of the 

 Sun Vein. 



The Ores are, the common Galena or Blue Lead 

 Ore, plentifully attended with its ufual fatellites, 

 Plende or Black Jack, and Martial Pyrites. 



The 



