Reflexions on Cobalt , &c. 367 



forgot that cobalt and bifmuth will not unite, 

 nor will cobalt and filver, or cobalt and lead, 

 whereas nickel will unite to any of them 

 when well purified from cobalt, and with bif- 

 muthj even without fuch purification 



10. 5 tK1 y- Becaufe according to Cronjled 

 himfelf, nickel will give a blue colour to 

 borax. But Mr. Bergman has {hewn, that 

 when it is well purified from cobalt, it will give 

 a hyacinthine, and not a blue tinge to borax. 

 Mr. Monnet adds, that cobalt, melted with 

 quartz and alkali, gives %greeni/h brown glafs 

 in ibme circumftances, and quotes Brandt, but 

 Brandt fays the colour was rtddtfh brown, 

 and in effecl: this colour fhould be expefted 

 from the fpecies of cobaltic ore he examined, 

 which was loaded with iron, and from the 

 manner in which the experiment was con- 

 ducted, the cobalt being too much dephlo- 

 gifticated. 



1 1. Laftly, he obferves that the cobalt is al- 

 ways magnetic ; but it is to be obferved, that 

 this magnetifm conftantly decreafes in propor- 

 tion as it is freed from iron, and yet the cobalt 

 remains in full pofleffion of all its proper- 

 ties, therefore its properties do not depend on 

 the prefenceof iron, and if it were perfectly free 

 from iron (a ftate of purity to which Mr. Monch 

 fays he has reduced it, 3 Crdl. p, 164) it would 



not 



