FADLiciL] METALLIFEEOUS DEPOSITS GOLD AND SILVEE. 117 



supply of water prevents success in agricultural pursuits. Were it pos- 

 sible to organize an exhaustive collection of rocks and the soils they 

 produce, make analyses of both, and apply the knowledge gained to 

 chemical agriculture, much of importance and value might be learned. 

 For such purposes a region not yet civilized offers the best field. As 

 soon as any crops have been put in and harvested the original compo- 

 sition of the soil is changed, and examination of such character would 

 no longer furnish the same applicable results. Even within the altitude 

 where crops may be raised, soils from many different rocks can be found 

 in Colorado. By paying some attention to the requirements of plants 

 and the capability of the soils, satisfactory results may in most cases 

 be obtained. 



METALLIFEROUS DEPOSITS. 



During the progress of my work in Colorado I have had occasion to 

 visitandexamineanumberoftheminingdistrictsofthatState. Themin- 

 eral resources are of an enormous quantity, and constitute, today, the 

 main wealth of Colorado. Gold, silver, copper, zinc, lead, coal, and iron 

 are mined. Mineral deposits are scattered throughout the entire State, 

 and new discoveries are annually being made. In 1857 and 1858 the 

 Pike's Peak excitement caused a large influx of prospectors, miners, and 

 adventurers. As usual a large number of them left the Territory in dis- 

 gust, but others, more reasonable, set to work to gain gold out of the 

 gulches and placers that in those days yielded very good pay. Most 

 of these, then already worked, are now exhausted, and the miners are 

 obliged to seek the precious metals in veins. The districts which I ex- 

 amined are Gilpin County, Clear Creek County, Boulder County, Cari- 

 bou district, Sunshine district. Gold Hill district, Summit district, the 

 San Juan mines, and the coal mines of Trinidad and Canyon. It is to 

 be regretted that not more time could be spared for each one of these 

 localities, but 1 hope that at some future date more extensive examina- 

 tion may be made. 



GOLD AND SILVER. 



Gilpin County. — N"early all the lodes of this region are auriferous. Cen- 

 tral Nevada and Black Hawk are located in the centre of the metal- 

 liferous region. Thousands of lodes have been located, but there are 

 comparatively few only worked at present. Pyrite, chalcopyrite, and 

 sphalerite are the chief gold-bearing minerals. Of these the last named 

 generally contains a small percentage of silver. By this time the mines 

 have reached an appreciable depth, and the yield therefrom is satisfac- 

 tory. Some of them even furnish an unusually large percentage of gold. 

 Amalgamation and smelting are the means employed in separating the 

 precious metals from the ore. In connection with the auriferous lodes 

 Gilpin County has also some that are worked for silver. In that case 

 the metal is contained mainly in galenite and narrow seams or small 

 particles of fahlerz. These lodes are of secondary importance only, as 

 gold i« the main mineral product of the county. 



Since 1858 the gulches and mines have been worked more or less 

 steadily. Much speculation and mismanagement by incompetent men 

 had temporarily injured the reputation of the mines, but gradually the 

 deeply-rooted mistrust is removed by the proof of their undoubted 

 resources and value. 



Clear Creeli County. — In contradistinction to the preceding, this county 

 contains mainly argentiferous deposits. At and near Georgetown the 

 most remunerative mines are located. Some of them produce an enor- 



