FALLEN ON THE EARTH. 93 



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

 the ufual lofs be added to the 16| grains of iron, and deducted 

 from the nickel, may not be very remote from the truth. 



I fhall next examine the globular bodies, alfo irregularly The globular bo- 

 difperfed throughout the ftone. A number of them were re- t h e r o U g h pe t r h g 

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

 rated by the magnet. As a preliminary experiment, I fought "° thins ^' A 'i nt ' 

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

 fmell was in the leaft perceivable, nor was white carbonate of 

 lead at all altered by being held over the mixture. I therefore 

 conclude thefe globular bodies do not envelope either iron or 

 pyrites. By way of analyfis, I treated 100 grains with pot- Analytic 

 afh, in a filver crucible ; and, after the ufual application of a 

 red heat, feparated as much filica as poflible, by muriatic acid 

 and evaporation. The filica being collected on a filtre, car- 

 bonate of potafti was added to the filtrated liquor ; by which^ 

 a precipitate, almoft wholly ferruginous, was produced. This 

 precipitate was colle&ed in the common way ; then boiled 

 with potafh, to extract alumina ; and, by fuperfaturating the 

 alkaline liquor with muriatic acid,, and precipitating by car- 

 bonate of ammonia, an earth was gathered, which I after- 

 wards found to be partly, if not intirely, filiceous. After re- 

 dirlblving, in muriatic acid, the portion of the ferruginous 

 matter reje&ed by the potafh, I precipitated by ammonia, 

 what I took to be intirely oxide of iron ; but, after igniting it, 

 and again attempting to rediflblve the whole in muriatic acid, 

 more filica was left. The non-exiflence 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 fub- 

 j eel of my analyfis, 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 firft 

 inltance, thrown down by carbonate of potath - x and the latter 

 >vas found in the laft named muriate of ammonia. I difengaged 

 the magnefia, by the affiftance of potath, and by evaporating 

 to drynefs. The oxide of nickel was precipitated by hidroge- 

 nized fulphuret of ammonia. 



Under all circum fiances I am induced to ilate the propor- Conftituerit 

 tions of conflituent part^ thus : . F art8 « 



Silica 



