GEOLOGY IN" NATIONAL MUSEUM MERRILL. 295 



including Virginia, North Carolina, South Dakota, and California. 



Of historical interest is a small bar of metallic tin smelted in 1840 



from tin ore in Jackson, N. H., and a mass of block tin, weighing 



70 pounds, smelted from the San Jacinto ores in California. This 



bears the following legend, which is of historical interest : 



For Hon. Thos. S. Wilson, 



Commissioner of the General Land Office. 



Tin from the mines of the San Jacinto Tin Co., 



San Bernardino Co., California, U. S. A. 



Office of Company, San Francisco, Mch., 1870. 



The collection is particularly rich in the newly exploited Bolivian 

 ores, including the somewhat rare form cylindrite, which have been 

 secured for the Museum through the cooperation of Mr. F. L. Hess, 

 of the U. S. Geological Survey. 



The commercially workable copper ores are mainly in the form of 

 chalcopyrite, bornite, chalcocite, and covellite, or their numerous 

 alteration products — malachite and azurite. As with the other series 

 these collections contain masses selected to show the pure mineral as 

 well as in the gangue as ordinarily mined. 



The ores of antimony are primarily the sulphide stibnite, though 

 occurring sometimes native, as in the mass from Kern County, 

 Calif. Of particular interest is the crystallized stibnite from Japan. 

 Ores of mercury are nearly altogether of the sulphide type cinna- 

 bar. The collection is particulaly rich in samples from the Pacific 

 coast, but contains also specimens from all important regions of 

 the world. 



The ores of aluminum are primarily beauxite, the hydrous impure 

 oxide. This mineral is shown by samples from Georgia and Arkansas 

 in the United States, as well as from the original locality Beaux, in 

 France, and also from British Guiana. Cryolite, the fluoride of 

 aluminum and calcium from Greenland, is shown in its typical forms. 

 Corundum, the oxide of aluminum, is included, although not 

 ordinarily considered an ore of the metal. 



Nickel and cobalt, although widespread, rarely occur in quantities 

 sufficient to be of economic importance. The main bodies of work- 

 able ore to-day are Canadian, where the nickel mineral is polydymite 

 associated with pyrrhotite, and New Caledonia, in which the ores are 

 a secondary product known under the names of garnierite and 

 noumeite. There are shown also as of historical interest examples 

 of the sulphide ore from the now abandoned mines at Lancaster 

 County, Pa., the cobalt ore chathamite from the original locality at 

 Chatham, Conn., and the rarer forms of ore, such as smaltite, niccolite 

 and their oxidation products from other sources. An adjunct to this 

 collection is shown in the desk-top case against the window. This 

 includes a selected series of the nickel-copper ores and their associ- 



