Nickel 345 



8. It is highly probable that nickel exifts 



in fome fpecies of roof flates, and in horn- 



ftones, whofe folution in fpirit of nitre is of 



a green colour. 



CHAP. XV. 



Regulus of Manganefe. 



1. This femi-metal was for the firft time 

 clearly defcribed, and its properties admirably 

 inveftigated and explained by Mr. Scheele in 

 the Memoirs of Stockholm, for the year 1774- 

 It was afterwards exhibited in its metallic 

 form by Mr. Gabn^ and its properties in that 

 ftate, defcribed by Mr. Bergman in the fecond 

 volume of his works; iince that publication 

 it has frequently been produced in France 

 by Meffrs. Morveau and Lafclroufe^ and lately 

 here by Mr. Woulfe. 



2. This regulus is of a dufky White colour, 

 an irregular and uneven furface, arifing from 

 its imperfect fufion ; in its fra&ure it is bright 

 and fhming, but foon tarnifhes by expofure 

 to the air ; it is harder than iron, lefs fufible, 

 and very brittle ; its fpecific gravity is 6,850. 

 When pulverized it is always magnetic, 

 though larger pieces be not fo > if it be ex- 

 pofed to the air, particularly in moift weather, 

 it foon crumbles into a blackifh brown pow- 

 der, 



