New Sulphid of Copper and Lead. 387 
banks of the Cunene. If a friendly intercourse with the people 
of this region be kept up, the colony will here find a new source 
of trade and wealth. ‘his would result in leading that nation 
carry on a direct trade with Mossamedes, after the example 
of the people of Gamba, Huilla, Jau, Humputa, Quillengues, 
Humbe, Kamba, Mulonde, and other places. D.C. G. 
Yale College Library, April, 1859. 
Agr, XLII.—On a new Sulphid of Copper and Lead; by 
FREDERICK FIELD. 
Iy the ‘Mina Grande’ near Coquimbo, Chili, there exists a 
mineral containing sulphur, lead and copper, in certain propor- 
tons which render it highly interesting. From the same mine 
have been obtained the following ores of lead: vanadiate of 
lead, vanadiate of lead and copper, arseno-phosphate of lead, 
sulphate of copper and lead, and carbonate and sulphid of lead, 
ides an intimate mixture of sulphid and sulphate of lead, the 
former mineral evidently undergoing gradual oxydation. = 
The double sulphid of copper and lead has the following prop- 
orl Sp. gr. 6:10. H. from 2°5 to 8, yong lc pon 
4 sight conchoidal fracture, having a deep indigo-blue color, 
quickly tarnishing on exposure to ms atmosphere. Immediately 
‘sociated with carbonate of lead and carbonate of copper. 
The pure mineral is violently acted upon by nitric acid, with 
the formation of sulphate of lead and liberation of free sulphur. 
100 parts yielded— oe 
BBPF  oococtn. ty bo Sooo te cememaa eaeag teen 
Sulphur, ig . J 4 . Fgh ¥700 EBRES 
The only other simple combination of sulphid of copper and 
lead with "whic _ a acquainted is the eupro-plumbite of 
tiner, (also from Chili,) which is a compound of Cu, 25! 
I have proposed the name Alisonile for this mineral, in oe 
of R. E. Alison, who has spent many years in developing t 
muneral wealth of Chili. 
Guayacan, Coquimbo, Jan. 29, 1859. - 
APPENDIX —Tn a letter to one of the editors of the same 
Mtr Field observes, that the mineral described hia be 
the € of Guayacanite (this volume, p. 52), he. : 
“* Tale species Enargi : 
