202 PROCEEDINGS OF THE AMERICAN ACADEMY 



thev were placed under the microscope, which showed the heavier 

 bodies to be quartz, with some facets and fragments of octohedral crys- 

 tals, proved to be magnetic iron-ore. The Hght body was silicic acid, 

 rendered gray by iron oxide. 



" Chlorine was passed into the filtered iron solution, which, after being 

 heated and cooled, was precipitated in a partly closed flask, by gase- 

 ous ammonia passed into it in excess. After being heated by a vapor- 

 bath, the precipitate was separated by fiher and washed. 



" The filtrate and washings evaporated were reduced to a dry mass, 

 which afforded a minute quantity of soda and lime : no other sub- 

 stance was present. 



" Separate parcels of the precipitate by ammonia were used for the 

 detection of Phosphorus, Arsenic and Boron, Alumina, and other earths 

 and oxides : a little silicic acid only was found. 



" 50 grains of the filings of the iron were wet with a few drops of 

 perfectly caustic soda solution, mixed hastily with crystals of pure 

 nitrate of soda and chlorate of potash, and heated in a nearly closed 

 platina crucible rapidly to bright redness twenty minutes : no defla- 

 gration occurred and the fused salts were colorless. 



" The crucible, after cooling, digested in a closed vessel with re- 

 cently boiled pure water, gave its soluble part to the water. After 

 subsidence, the clear fluid was added to a dilute saturated solution 

 of lime in ammonia in one vessel, and to a dilute solution of barvta 

 in another. These vessels were closed, and left twelve hours, and 

 then presented nearly transparent solutions ; no precipitates had fallen, 

 but both showed the presence of silicic acid. The absence of sulphur 

 and carbon was thus proved, and other trials confirmed these results. 



" Analysis. — la the following analysis, and in repetitions, different 

 slabs of the metal were used, so as to obtain an average percentage 

 composition of the mass. 



" A solution in pure water of about one hundred and fifty grains of 

 pure sulphate of copper was used as a medium in which the iron dis- 

 solved replaced by electrolysis the copper deposited on the negative 

 electrode of platinum connected with a small constant battery. 



" 26.30 grs. of iron solved in the fluid and 29.78 grs. of copper 

 were deposited on the platinum, while 0.32 gr. of matter was pre- 

 cipitated. 



" The equivalent of pure iron being 28, the deposit of copper 

 should have weighed 29.71 ; an accordance as near as the experi- 

 ments allow. 



