FALLEN ON THE EARTH. 89 



of this cruft had been detached with a knife or a file, and finely was digefted in 



pulverized, I feparated the particles attractable by a magnet, mtnc aci » 



and digefted the unattractuble portion with nitric acid, which wh j c , h if dccom - 



. poled, 



was prcfently decompofed ; but, owing to a ftrong adherence 



of fome of the interior and earthy parts of the ftone, it did not 

 difentangle tlie coating or metalline part without fome diffi- 

 culty. The acid being fuihciently neutralized, the folution was I 

 palled through a filter, and faturated to excels with ammonia. 

 An abundant precipitate of oxide of iron was produced ; and, The iron folu- 



when this oxide was feparated, I obferved the faline liquor to 11 . " *as preci- 

 r * t^ M pi tated by am- 



have a greenifli colour. I evaporated it to drynefs, and re- monia. 



difiolved the dry fait in diftilled water. No precipitate was 

 formed during the evaporation, nor was the colour of the 

 folution entirely deftroyed. It appeared to me like a triple Ammohiacal ni- 

 fait, defcribed by Mr. Hermftadt * as an ammoniacal ni- trate °* nicke 

 trate of nickel. By examination with pruffiate of ammo- 

 nia, it yielded a whitifli precipitate, inclining to a violet 

 colour; and, by various properties, 1 was foon confirmed 

 in the opinion, that nickel was prefent. Since I (hall have 

 occafion more than once to treat of the triple compound, 

 and fince it has been only mentioned by Mr. Hermftadt, 

 it is neceflary now to detail fome of its distinctive charac- 

 ters. The fame chemift informs us, that the three mineral Diftinftivc cha- 

 acids, with ammonia, enter into fimilar combinations with tr ] p ] e f a °] t# /f 

 nickel ; and- 1 have obferved, that oxide of nickel can be 

 difiolved by nitrate and muriate of ammonia. The muriate 

 feems to take up the largeft quantity. The colour of this i 

 fait is by no means uniform : it is fometimes grafs green, 

 violet, rofe colour, inclining to purple, and I have feen it 

 almoft colourlefs. It feems to be purple, and to incline to 

 rofe colour and violet, when all the oxide of nickel is not 

 united to both acid and alkali, but, from the deficiency 

 of fait, is held in folution by an excefs of ammonia. In this 

 cafe, evaporation, of courfe, precipitates the nickel in the 

 /late of oxide, which is of a whitifli green colour. 



The nickel cannot be precipitated from a perfectly formed The nickel is 

 triple fait, by any reagent I have tried, except by a pruffiate, ^j^"' an * 

 or a hidrogenized fulphuret of ammonia. Potafh and lime, as hidrogeaized ' 



fulphuret of 



* Annales de Chimie, Tom. XXII. p. 108. ' ammonia * 



weil 



