TRAVELS BRAZIL 



NOTES TO CHAPTER III. 



Mr. Von Eschwege gave the first account of the occur- 

 rence of the chromate of lead in Brazil, in Baron Von 

 Moll's Annals of Mining, vol. iii. No. 3. Mr. Zinken 

 gave more particulars respecting it in Eschwege's Account 

 of Portugal and its Colonies. Mr. Eschwege lately men- 

 tioned this fossil in his Geognostisches Gemdlde von Bra- 

 silien. Referring, for the sake of brevity, to the works 

 just mentioned, we add the following observations ; — 



The numerous specimens lying before us show the chro- 

 mate of lead of aurora and hyacinth red of different shades. 

 It is generally crystallised, and that in small, and very small, 

 four-sided rather oblique prisms, which, for the most part, 

 are indiscriminately heaped and grown together. This 

 chromate of lead is found on a fine-grained greenish white 

 quartz, to which the oxyde of chromium has not unfre- 

 quently imparted a reddish, yellowish, and greenish colour. 

 Next to the crystals of red lead there is an earthy covering 

 of a lemon and orange colour, passing into siskin-green, 

 which appears to have originated in decomposed red lead- 

 ore. Besides this green lead-ore, we found, particularly on 

 the debris of the mine of Cujabeira, a lead-ore in detached 

 pieces, from a quarter to an inch in diameter, botryoidal 

 and small reniform, diverging from siskin into olive green, 

 and sometimes into blackish green. Externally, this fossil 

 is dull, occasionally soils ; internally, it is of a faint, but 

 almost metallic lustre. Most of the pieces show curved- 



VOL. II. u 



