on certain Stony and Metalline Sub/lances, 223 



and ignited, it weighed 24 grains ; whereas, according to 

 my experiments, 33 - : grains fhould have been produced from 

 the folution, had it contained nothing but iron. I examined 

 tfie fal'me liquor, when free from ferruginous particles, and 

 difcovered it to be the triple fait of nickel. Hence, allowing 

 for lofs, the quantity of nickel may be eftimated, by calculat- 

 ing the quantity of iron contained in 24 grains of cxide. 

 Thus, if 145 grains of oxide contain 100 of iron, about 16 J 

 are contained in 24 of oxide. This would fuppofe the 23 

 grains of alloy to confift of 16^ iron and 6\ nickel ; which, 

 if the ufual lofs be added to the \6\ grains of iron, and de- 

 ducted from the nickel, may not be very remote from the 

 truth. 



I mail next examine the globular bodies, alfo irregularly di- 

 fperfed throughout the (tone. A number of them were re- 

 duced to fine powder; but nothing metallic could be fepa- 

 rated by the magnet. As a preliminary experiment, I fought 

 for pyrites, by digeftion with muriatic acid ; but no hepatic* 

 fmell was in the lealt perceivable, nor was white carbonate 

 of lead at all altered by being held over the mixture. I there- 

 fore conclude thefe globular bodies do not envelope either 

 iron or pyrites. By way of analyfls, I treated 100 grains 

 with potafh, in afilver crucible ; and, after the ufual applica- 

 tion of a red heat, feparated as much filica as poffible, by 

 muriatic acid and evaporation. The filica being collected on 

 a filter, carbonate of potafh was added to the filtrated liquor ; 

 by which a precipitate almofl wholly ferruginous was pro- 

 duced. This precipitate was collected in the common way ; 

 then boiled with potafh, to extract alumina; and, by fuper- 

 faturating the alkaline liquor with muriatic acid, and preci- 

 pitating by carbonate of ammonia, an earth was gathered, 

 which I afterwards found to be partly, if not entirely, fili- 

 ceous. After rediflblving, in muriatic acid, the portion of the 

 ferruginous matter rejected by the potafh, I precipitated by am- 

 monia, what I took to be entirely oxide of iron ; but, aTter 

 igniting ii, and again attempting to rediflolve the whole in 

 muriatic acid, more filica was left. The non-exiftence of* 

 lime was proved, by the addition of carbonate of ammonia, 

 immediately after the fame alkali, pure, had thrown down 

 what I took wholly for oxide of iron. I had now obtained 

 every thing in the.fubjec~t of my analyfls, except magnefia 

 and nickel. The former, and a trace of the latter, were held 

 by carbonic acid in the liquor, from which the ferruginous 

 precipitate was, in the fir ft inflance, thrown down by carbo- 

 nate of potafh ; and the laUer was found in the laft-named 

 muriate of ammonia, 1 difengaged the magnefia. by the af- 



fiftance 



