OF A METEORIC STONE. 545 



in a platinum crucible, the oxid of mercury was decomposed, 

 and its elements expelled, and a small portion of a green oxid 

 remained in the crucible. In several repetitions of the process 

 this, invariably, occurred. I had been led to suspect that this 

 was the oxid of nickel, because the alkaline solution, from 

 which it had been obtained, gave a black precipitate, with the 

 hidro-sulphuret of ammonia; accordingly, on fusing a portion 

 of this oxid, with borax, under the blow-pipe, it produced a 

 glass of a hyacinth red; the same fact took place with a por- 

 tion of a substance, known to be the oxid of nickel, which was 

 fused with borax, for the sake of comparison. On fusing a 

 portion of the chromat of lead, or Siberian red lead ore, with 

 borax, and afterwards with vitreous phosphoric acid, glasses of 

 an emerald green colour were produced. 



Hence it was concluded, that the meteoric stones of Weston 

 do not contain chrome, but that the green oxid obtained, was 

 the oxid of nickel. 



No. LII. 



Observations of the Comet which appeared in September 1 807, in 

 the Island of Cuba, by J. J. de Ferrer. 



Read August 19th, 1808- 



The longitudes and latitudes of the preceding table, have 

 been deduced from angular distances observed of Arcturus, 

 Vega, Altair, «, (3 and > in the Swan, with the circle of re- 

 flection, described in page SJ65 of this volume. 



The observations from the 1st Octr. till the 7th Novr. were 

 made in the city of Havanna, the others at the plantation of 



