282 NOTE ON THE DISCOVERY 



microscope, proved to consist of spinel, augite, silex, and one very minute 

 emerald 



The specific gravity of the mixed grains at 75.° was 12.17. 

 Fifty grains, dried, were then taken for analysis. 



1 . From this were separated, under the microscope, 0.5 grains of gold, 



2. The magnet removed also 0.4 of small black grains, supposed to 

 be crystalized magnetic oxide of iron. 



3. Theremainder consisted of two portions, which were imperfectly se- 

 parated ; A, shining scaly grains of a silver colour ; & B, dark black grains. 



4. The white metallic scales (A) had a specific gravity of 9.10 — the 

 quantity separated weighed 8.5 grains. The black residue (B) weighed 40.6. 



5. The silvery scales (A) were digested in boiling nitric acid, and 

 caused a slight disengagement of nitrous fumes. The solution was not 

 affected by muriatic acid, and consequently contained no silver; but car- 

 bonate of potash threw down a slight flocculent white precipitate, weighing 

 less than 0.2 grains, which was not examined. It was probably carbonate 

 of iron. The scales were then digested twice in boiling nitromuriatic acid^ 

 which acquired a deep orange colour, but left undissolved a portion of the 

 scales and such of the black grains as had not been thoroughly separated 

 from the rest : the weight of this residue was 3.7 grains. 



6. The separated portion of dark grains (B) was also boiled several 

 times in concentrated nitromuriatic acid, which took up 16.4 grains, and 

 left untouched 24.2 grains, among which were discernible several of the 

 shining scales not separated in the first instance. 



