410 A Chemical Analyfis of Three Species of IVhinJlone, and Two of L&tmi . 



' cryftals of alum *. I dilTolved thefe cryftals in water, and precipitated the argil by carbo 

 nate of ammonia. After being carefully waflied, dried, and heated red hot a -quarter of 

 an hour, it weighed 12 grains. 



8. The brownifli matter, No. 6. infoluble in cauftic pot-afli, feemed to be oxyde of 

 iron ; and after having been heated red hot, weighed 24J grains. I powdered this mafs, 

 and poured on it fcrme acetous acid, in order to deleft magnefia ; but nothing was dif- 

 folved. It was next treated with nitric acid, which diflblved the Iron, but left 4 grains of 

 files. The iron being precipitated, dried, and heated red hot, weighed 20 grains, and 

 was magnetic. Sufpefting that fome iirgil might ftill be mixed with it, from having efcaped 

 the a£tion of the cauftic pot-afh, I diflblved 5 grains in muriatic acid, and precipitated the 

 iron by Pruflfian alkali. Having fcparated the blue precipitate, I boiled the folution with 

 carbonate of foda, and obtained i grain of argil. Thefe 20 grains confided, therefore, of 

 16 grains of iron, and 4 grains of argil. 



The remaining part of the iron was melted for an hour, with ten times its weight of 

 nitre, in order to dete£l manganefe. The mixture, however, when cold, was not greenifh; 

 and water made a colourlefs folution of the faline matter, vrhich did not become turbid> 

 when expofed fome days to the aftion of the air f- 



9. The two portions of white earth above mentioned, which feemed to be carbonate of 

 lime, weighed together 16 grains. To feparate magnefia, if any were mixed with this 

 earth, I put it into a little water, and added fulphuric acid till flightlyin excefs. Sulphate 

 of lime was produced. Having poured fome alcohol into this mixture, I filtered it, and 

 wafhed the fulphate of lime with more alcohol diluted with water. The filtered liquor 

 was then boiled with carbonate of foda, but no magnefia was precipitated. 



Thefe 16 grains were therefore carbonate of lime, of which, according to Mr. Klaproth'i 

 talculation, about 9 grains were pure lime. 



One hundred parts of the bafalt of StafFa contain, according to the above analyfis : 



4& 



- 16 



9 



Moifture, and other vol. matter, . - - - 5 



The fum is 94 parts ; confequently there is a lofs of 6 per cent. 



94 



* It therefore contained none of the earth which Vauquelin lately difcovered, and to which he has gire* 

 the name of glucine. • 



■f I think, however, it is probable, that this bafalt contained a fmall quantity of manganefe, both from 

 the brownifh colour of the folution. No. !• and from the green colour which the undiflblved refiduum gave, 

 ky fufion, with cauftic pot-alh. 



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