192 AN^^UAL liECORD OF SCIENCE AND INDUSTRY. 



quantities of this salt are found at the foot of the Cordilleras.- 

 1 A, August 30, 1872, 107. 



PITCHBLENDE IX COLORADO. 



Professor Hill announces to the American Journal of Sci- 

 ence the discovery of pitchblende in large quantity near Cen- 

 tral City, Colorado. Several tons of the ore, containing fifty 

 per cent, of uranium oxide, have already been shipped to 

 England. It has, so far, brought a price of one dollar per 

 pound. Another mine in the vicinity has also produced con- 

 siderable quantities of a tellurium ore, containing gold and 

 silver, and also a small percentage of lead. 4 D, May^ 1873, 

 386. ^ 



DOLOMITES OF THE UNITED STATES. 



Dr. Feuchtwanger communicates to the Engineering and 

 Mining Journal a paper upon dolomites in the United States, 

 and calls attention to their very great value in the arts. 

 Chemically considered, these rocks are composed of carbon- 

 ate of lime and carbonate of magnesia, and are not to be con- 

 founded with magnesite, which consists only of magnesia. 

 The American dolomites are used largely in architecture, the 

 favorite white marble of Vermont being composed of it. The 

 Rosenthal cement is said to owe its powerful hydraulic prop- 

 erties to the mixture of clay with the dolomitic material. 

 Engineering and Mining Journal^ December 17, 1872, 72. 



SEEBACIIITE, A NEW MINERAL. 



A new mineral, called seebachite^ from the basalt of Rich- 

 mond, near Melbourne, has lately been described by Bauer. 

 It is closely related to Herschelite in crystallographic char- 

 acter, but differs in having a considerable percentage of lime. 



TAMMITE, A NEW MINERAL. 



Mr. Hugo Tamm has recently described what he considers 

 a new mineral of much interest, under the name of CrooJce- 

 site. The substance, as obtained, was too small to admit of 

 a satisfactory analysis, but it has been determined to contain 

 about 88 per cent, of tungsten, 5.6 of iron, and 0.15 of manga- 

 nese. Mr. Crookes, who has already been honored by having 

 a mineral named for him, suggests that this be called Tarn- 



