have fallen from the Heavens, 349 



- F, The amnioniacal liquor, from which the magnefia had 

 been feparated by means of cauliic .potafh, was mixed with a 

 fohition of fulphurated liydrogen. By this mixture there was 

 formed a very voluminous black precipitate, which vvhea 

 wafhed and dried weighed feven parts. This part beinc 

 united with the three parts obtained alfo by fulphate of 

 magnefia, and kept at a red heat for fome minutes, exhaled 

 the odour of fulphureous acid, and acquired a very dark green 

 colour inclining to brown : the whole then weighed fcarcely 

 three parts. 



A fmall quantity of this matter fufed with borax gave glafs 

 of a hyacinth colour; put into fulphuric acid diluted with 

 water, it dilfolved only in part, and a fniail quantity which 

 had a metallic appearance refufed to combine witlV it ; but 

 the addition of a few drops of nitric acid, by oxidating it, 

 favoured its folution : by fpontaneous evaporation it furnifhed 

 elongated cryftalsof a very beautiful green colour. 



By the properties which this matter exhibited it is evident 

 that it was nothing elfe bat oxide of nickel ; for it is the 

 only one among the metals which potrefTes the property of 

 colouring borax of a hyacinth red colour by fufiun, of giving 

 to ammonia a purplifii blue colour, of forming with fulphurip 

 acid a prifmatic fait of a green colour, and of producing by 

 its conibinalion with acids and ammonia triple falts which 

 are not precipitated by fi.ved alkalies. 



An examination of the principles fucceffively obtained by 

 the different means employed for analyfing ihe Itone of Be- 

 nares, proves that it is compofed of filex, magnefia, and iron, 

 a part of which appears to be oxidated, nickel and fulphur. 

 Iron, nickel, and fulphur^ according to every appearance, 

 form a particular triple combination, which feems only to be 

 interpofed between the earthy parts, fam, however, in- 

 clined to believe, that one part at leaft of thcfe fubltances is 

 really in combination with, the earths; for at the moment 

 when the ftone is attacked by the acids, the filex (hows itfelf 

 in a Itaie of very great divifion, and like a kind of jellv. 

 The proportions m which thefe matters are found in the 

 ftone of Benares are nearly as follows : : 



Silex - - - 48 



Oxidated iron - - oy 



Magnefia - - 10 



Nit'kel - - - 3 



Sulphur an indeterminate quantity 



If 



