1865.] Mining, Mineralogy, and Metallurgy. 309 



of the means by which the source of danger may be removed. One 

 thing should be steadily borne in mind. Men who will tamper with a 

 safety lamp are not to be trusted with delicate apparatus, or with 

 observing it, if placed beyond the danger of their handling. This 

 tube and its balloon cannot be seen without the use of a lamp, and 

 the flame of the lamp is a far more delicate indicator of fire-damp 

 than any other at present known. 



Amongst the numerous safety-chairs exhibited at the International 

 Exhibition of 1862, none attracted so much attention as that of Mr. 

 J. T. Calow, of Staveley. It has been thought so highly of by prac- 

 tical men, that a company, ' The Patent Safety Chair Company,' is 

 formed for bringing it into more general use. 



Miner alogv. 



From some interesting papers " On the Mineralogy of South 

 America," by Mr. David Forbes, F.R.S., we take a few notes.* 



Bismuth. — This metal occms in the native state as well as in com- 

 bination with oxygen, sulphur, and tellurium, in a small vein in the 

 Lower Silurian clay slates of the mountain Illampur, in Bolivia. The 

 mine of San Baldomero opened upon this vein, is situated but little 

 under the line of perpetual snow, and has an elevation of between 

 14,000 and 15,000 feet above the level of the sea. The analysis of 

 the native bismuth gave Bismuth 94*46, Tellurium 5*09, Gold a trace, 

 Arsenic 0-38, Sulphur 0-07. The ore Bismuthine gave Bismuth 80-93, 

 Sulphur 19-61. 



Mispickel was found in the same mine, as was also Banaite. Nickel- 

 iferous Mispickel is found in a vein in the Lower Silurian slates in the 

 Corderillas, between La Paz and Yongas, in Bolivia. 



Antimonial Galena. — Of this ore considerable veins are worked 

 near La Paz, and are worked chiefly for the amount of silver contained 

 in them. 



Gold was discovered by Mr. Forbes in several places in Bolivia ; 

 amongst others, at Ancota, Playa Gritada, Romanplaya, and the valley 

 of Tipuani. 



The composition of the specimens was as follows : — 





Tipuani. 



Romanplaya. 



Playagritada. 



Ancota. 



Gold . 



91-96 



94-189 



93-51 



94-73 



Silver . . 



7-47 



5-811 



6-49 



5-23 



Iron . 



Trace 





. . 



0-04 



Matrix 



0-57 





. , 





Tin. — The discovery of metallic tin may be regarded as amongst the 

 most carious fact recorded. It has been stated by others that tin has 

 been found in the metallic state, but the correctness of this has been 

 doubted. Mr. David Forbes appears to have taken every precaution 

 to avoid being deceived, and he assures us of the discovery of a piece 



* 'Philosophical Magazine,' vol. xxix., Nos. 193 and 194. 



