J. C. Branner — Hydrocarbon Found in Brazil. 25 



Art. II. — A Hydrocarbon Found in the Diamond and Car- 

 bonado District of Bahia, Brazil / by J. C. Branner. 



Among the minerals obtained by me in the diamond wash- 

 ings of Bahia was one known among the miners as "gelo" — 

 ice. The only specimen I have seen was originally about the 

 size of a man's fist, but upon drying it crumbled into angular 

 lumps about as large as peas. It is jet black and opaque; it 

 has a conchoidal fracture, a hardness of -2*2, a specific gravity 

 of 1*51, and is very friable. 



The following note was sent me by my Brazilian friend Dr. 

 Alencar Lima of Bahia in regard to this hydrocarbon : " This 

 specimen is from the Caetano Martins diamond washings at 

 Chique-Chiqne, State of Bahia. The diamond miners call it 

 'gelo' (ice). It is found in the beds below the diamond-bear- 

 ing gravels, and it occurs in big pieces, sometimes nearly as 

 large as a man's head. It is solid only so long as it retains its 

 natural moisture, for as soon as it dries it becomes friable in 

 proportion as it dries out. While it is moist it yields a black 

 inky substance, but once dry it does not absorb moisture again." 



I have had an analysis made of this material with the fol- 

 lowing results : 



Analysis of a Hydrocarbon from the Diamond-bearing Gravels 

 at Chique- Chique, State of Bahia, Brazil. 



L. R. Lenox, analyst. 



Water _ 19'43$ 



Volatile combustible matter .. 35*4 7 



Fixed carbon _ 40*06 



Ash 5*07 



100-03$ 



The ash is mainly alumina with a little silica, calcium, and 

 magnesium. 



Tested for solubility it was found to be : 



Insoluble in Soluble in 



Cold water Concentrated sulphuric acid 



Hot water (to a dark brown liquid) 



Alcohol Nitric acid 



Ether (to a dark brown liquid) 



Petroleum ether Strong potassium hydroxide 



Chloroform (to a dark brown solution) 



Benzene 



Carbon disulphide 



Hydrochloric acid 



