tin. 599 



times. . Possibly these furnaces may have given rise to the traditions rife 

 among the people and referred to by Dr. Roemer, to the effect "that on the 

 San Saba River silver mines have been worked formerly by the Spaniards," 

 etc.* 



At the time of my visit (November 2, 1890) nearly all traces of the fur- 

 nace itself had been removed, but there are still evidences of its former ex- 

 istence in the shape of roughly hewn stones, fragments of ore, slag, and cin- 

 ders. Such pieces of ore as could be reasonably regarded as of the raw ma- 

 terial used in the furnace are chiefly identical with the glistening iron ore 

 which abounds in Shaft Mountain, south of the locality, where Mr. Durst also 

 showed me an old shaft. This excavation was made in a ledge of feldspar 

 carrying the bright iron ore in plates irregularly distributed. Adjoining it 

 are the quartz and sandy hematite layers already referred to. The slag and 

 matte are extremely interesting. The general color of well fused portions is 

 reddish-brown exteriorly, with glassy portions brown to black, the vesicular 

 portions being gray to greenish, and surfaces of fracture greenish-black to 

 jet black and nearly adamantine in lustre. The specific gravity varies from 

 3.37 to 5.24, the latter probably a matte or partially fused ore. Some pieces 

 have small globules of metallic tin adhering or imbedded, and nearly all con- 

 tain a very noticeable amount of this metal, which has usually been reported 

 as silver by those who have found it heretofore. The following are the re- 

 sults of a qualitative analysis by the writer: 



Small fragments were broken from different pieces of the lighter slags to 

 make a rough average, carefully rejecting all lumps which showed metallic 

 globules to the unaided eye. None of the heavier, less fused pieces were 

 taken. The powder of the whole was dark greenish gray. With borax and 

 cupric oxide in the lower reducing flame a decided reaction for tin was ob- 

 served. With boiling dilute hydrochloric acid a partial solution was obtained 

 of a dark brownish yellow color, with the separation of a copious slime of 

 silica and a slight evolution of chlorine, thus showing traces of manganese. 

 Dilute nitric acid gave a partial greenish yellow solution, with barely per- 

 ceptible precipitation of a white powder, indicating the presence of tin. 

 Strong aqua regia, after long boiling, with successive additions, left a black 

 residue, with much silica. Further reactions were obtained in the systematic 

 analysis, as below: 



Tin, present in very evident traces. 



Iron, abundant. 



Manganese, traces. 



* American Journal of Science (2d Ser.), Vol. II, 1846, p. 364. (Willow Creek flows 

 southward into the Llano River, but the locality in point is near the divide between the 

 waters of. the Llano and the San Saba rivers. T. B. C.) 



