MINERALOGY. 213 



*. Of coarfe, wedge-like lcales, from 

 Kongruben, at Geilebeck in Norway*. 



SECT. CCXXVI. 



Observations on Bismuth. 



Although Mr. Pott has, in a feparate treatife 

 en bifmuth, fhewn, that it is diffoived without 

 giving any colour to the folution, and that it is 

 precipitated with pure water; and, though the 

 mine-mafter Mr. Brandt has likewiie, in the 

 Acla UpfaUenfia for the year 1735, given an ac- 

 curate hiftory of the cobalt, we rind nevertheless 

 in fome new authors fuch a defin'tion of bifmuth, 

 as includes at the fame time the principal cha- 

 racters of the cobalt, viz that of giving to glafs a 

 blue colour, and to tinrre folution s red. This 

 confufion proceeds from the bifmuth being com- 

 monly found among cobalt ores, and that it can- 

 not be ieparated from it but by the way of eliqua- 

 tion ; during which the cobalt, as being lefs fufi- 

 ble, remains, and is by the workmen called Vif- 

 mut graupe, or Bifmuth grains. 



This error is excufable in thofe who do not prer 

 tend to maintain and vindicate their ignorance, it 

 having been the fate of the femi-metals to be but 

 very little examined. It the alchemifts had not 

 thought the quickfilver, antimony, and zink, fit 

 for their purpofes, we fhouid very likely have Hill 

 wanted many of thofe advantages which they af- 



* This mineralifed bifmuth ere yields a fine radiated regu- 

 las ; fcr which reafon it has been ranked among the antlrno- 

 nial ores, by thofe who have not taken proper care to rneit a 

 pure regaloi or deftitute cf fulphur from it; uhilc cihers, 

 vho m?.ke no difference between regules and pure metals, 

 have ftill more pofitively affcrted it to be only an antimonial 

 ore. 



P 3 ford 



