Notices of Memoirs — Short Notices of Scientific Papers. 119 



The assay of selected samples produced sixty-nine per cent, of lead, 

 with fourteen ounces of silver to the ton of lead worked. 



These mines of iron, though exceedingly rich in metal, labour 

 under the disadvantage of want of mineral fuel. Wood certainly 

 exists, and in fair quantities, but in the present day the competition 

 with coke-made iron is too serious to induce large operations in 

 them, Eailways and good roads may some day make these valuable 

 deposits available. At present their superabundance is excessive in 

 comparison with the means of treating them. 



The first part of Vol. viii. contains the Annual Eeport of the 

 Council for the past year, etc. 



Shokt Notices of Scientific Papeks. 



I. Enakgite from California. — Mr. E. W. Eoot gives us the 

 following account of this mineral : — ^ 



It occurs both massive and crystallized in small rhombic prisms 

 whose planes are much striated. The crystals possess a brilliant 

 metallic lustre, are of a greyish-black colour, and about a millimetre 

 in length. In the massive state it is somewhat coppery in colour 

 when fresh fractured ; exposed surfaces have a dark-bluish tarnish. 

 It is very brittle. Streak black. Hardness about 4. Sp. grav. 4-34:. 

 B.B. decrepitates with violence, and fuses readily to a globule giving 

 off arsenical and sulphurous fumes, and forming a coating of anti- 

 monous acid. 



With fluxes it gives the copper reactions. It fuses readily at a 

 gentle heat in a closed tube, giving off a yellow sublimate of sul- 

 phur, and at an increased heat a reddish sublimate of tersulphide of 

 arsenic. It is insoluble in hydrochloric acid. Soluble in nitric acid 

 with a residue of sulphur and antimonous acid. Associated with 

 the specimen was a little iron pyrites and quartz, and a few small 

 shining particles which, before the blowpipe, gave the reactions for 

 iron and titanic acid. 



In two analyses the following results were obtained : — 



No. 1. No. 2. Mean. 



S, 31-81 31-51 31-66 



Cu, 45-94 45-95 45-95 



As, 13-65 13-74 13-70 



Sb, 6-03 2 6-03 



Fe, 0-81 0-64 0-72 



Si02 1-03 1-13 1-08 



99-27 99-14 



If the iron present is considered as iron pyrites, and this, together 

 with the silica deducted, the following mean is obtained : — 



S. Cu. As. Sb. 



31-68 47-21 14-06 6-19=99-14. 



This Californian Enargite differs from those heretofore described 



in having a much larger proportion of the arsenic replaced by 



^ For a Ml account, see Silliman's Journal, No. 137, vol. xlvi. pp. 201-203. 

 2 In analysis No. 2, owing to accident, a part of the antimony -was lost, but still 

 some 5 per cent, remained. 



