Minerals of Organic Origi7i. — Mineral Resins. 89 



possess some resemblance, but their origin must be considered 

 as entirely different. The one occurs in a vast deposit of 

 tertiary clay, the other in a mountain limestone district, and 

 in the centre of an enormous intruding mass of stratiform 

 basalt. 



5*83 grs. gave 5'695 of water and 17'95 of carbonic acid: 

 1'29 grs. left on burning in the air 0'04'2 of brown ash = 

 3'256 per cent. These are equal to 



Carbon 85-133 or 40 atoms. 



Hydrogen... 10-853 or 31-2 atoms. 

 Ashes 3-256—99-242. 



It is therefore doubtful whether this resinoid substance 

 really contains any oxygen or not. It may be only an im- 

 pure carbohydrogen = C4 Hg , agreeing in composition with 

 the hypothetical acetyle, or it may, like petroline, contain the 

 elements in the proportions in which they exist in oil of tur- 

 pentine CjQ Hgg. I regret that my supply of the substance 

 did not permit me to repeat the analysis; and though I have 

 revisited the mine in the hopes of obtaining a fresh supply, I 

 have not been fortunate enough to meet with a single speci- 

 men. 



VIII. Berengelite. 



The specimens of the substance for which I propose the 

 name of Berengelite were given to me by my friend Mr. Frver, 

 of Whitley House, near North Shields, and were obtained by 

 him during his residence in South America. Of the circum- 

 stances under which it occurs Mr. Fryer thus writes to me: 



" Of the resin or asphaltum from South America, I can 

 unfortunately give you but a very imperfect account. I one 

 day found in the yard of the Custom House at Arica a large 

 convoy of llamas loaded with it, and all the information I 

 could obtain from the men having charge of it was that they 

 brought it from the province of St. Juan de Berengela, about 

 100 miles from Arica, that it was found in very large cjuan- 

 lities, and formed, according to their description, something- 

 like a lake resembling the pitch lake of Trinidad. It is ex- 

 tensively used for paying boats and vessels at Arica, and, I 

 believe, on the whole coast of Peru." 



This substance is hard, brittle, may be scratched by the 

 nail, has a resinous fracture and lustre, is of a dark-brown 

 colour with a tinge of green, but gives a yellow powder. The 

 external appearance of the masses as they were brought 

 home appears to indicate that the whole had formerly been 

 in a softer state so as to yield easily to compression. It is in- 

 soluble in water, but dissolves readily and in large quantity in 



