1832.] Miscellaneous Intelligeiice. 423 



At p. 102 lie repeats Lis erroneous theory of the artificial formation of ice in 

 India, — "by evaporation and a current of air;" while the former circumstance 

 is unnecessary to the process, and the latter always fatal to it. Radiation is the 

 principle. D. B. 



10. Silver Mines discovered in Cuba. By Don Ramon de la Sagra, Supeiintendent of 

 the Botanic Garden at the Havannah. 



(From the " Anales de Ciencias, Agricultura, Comercia o Artes" of May, 1828.) 

 When towards the end of 1826, I began a course of lectures on mineralogy and 

 geology, it was my object to induce attention to the mineral productions of the 

 Island of Cuba, and they had the effect of procuring me numerous contributions of 

 specimens from various districts. About the same time Don Jose de Escalante, 

 an inhabitant of Villa Clara, being well acquainted with the mines of Peru and 

 Mexico, employed himself in exploring and examining the minerals of that neigh- 

 bourhood, and he succeeded in discovering, first, several veins of copper, and after- 

 wards a mine of silver, which he has claimed (denunciado) in the usual form. The 

 specimens of minerals submitted by him, were sent to me for analysis by His Ex- 

 cellency the Intendent ; and the following is the result ; the silver being separated 

 by amalgamation. 



Iron, 67.84 



Silver, — _, , , 0.48 



Silex and Alumina, ~„ ~~„„~„^ ~ ^ „ „ 9-7 



Loss in gases and water, ~~~^^~~,.~ ~~~„„~^.~^~ 21.98 



100 

 The mineral is found in mass ; of an earthy ferruginous appearance ; friable 

 on the surface, but compact within ; of a grey metallic colour ; texture granular, 

 sometimes Iaminous ; fracture irregular and rough, with a few bright specks ; 

 fluate of lime makes no impression ; but the ore is easily scratched by rock crystal ; 

 yields a reddish powder, — not magnetic : its specific gravity is 2.25 ; easily dis- 

 solved by nitric and hydrochloric acid ; and also by weak sulphuric acid, which 

 disengages much hydrogen gas. When dissolved, prussian-blue may be precipitated 

 abundantly with hydroferrocyanate of potash. Infusible with the blowpipe, which 

 converts the ore into black scoria. Hence I class the mineral among the ochreous 

 iron-stone, or the Ochriger roth Eisenstein, of the Germans. 



According to Geological reports of the mines in Peru, most of the silver from 

 that country is extracted from ore of iron clay. In Mexico also, there are 

 mines worked in the province of Oajaon the ore of which has a similar appear- 

 ance, being composed of grey iron with native silver disseminated in the mass, 

 not perceptible to the eye. Humboldt remarks, that, both in Mexico and in 

 Peru the masses of oxide of iron which contain silver are found in the upper 

 part of the veins near the surface of the earth ; which is a good sign as regards 

 Senor Escalante's discovery. 



According to the report of the discoverer, the mine occupies a great extent of 

 ground on the slope of a hill ; but he is ignorant of the width and depth of the 

 vein. A mine which yields 1\ ounces of silver to the quintal of ore, if the ore 

 be abundant and of easy access and separation, is a treasure worthy the attention 

 of government and of enterprising individuals. Should the mass of mineral prove 

 as considerable as Senor Escalante asserts, the mine of Villa Clara will be one of 

 the most valuable in America, on account of the proportion of metal which it 

 contains, and the very simple process required to extract it. 



2 H 



