No. <;.] BRUSH — AMERICAN MINERALOGY. 335 



constituents of the phosphate triphilite, and there are several 

 localities known where this mineral occurs abundantly. Again^ 

 we have the frequent occurrence of some of the rare metals 

 which form metallic acids : Cohnnhium, the first metal, new to 

 science, discovered in America, associated with its twin metal 

 tantalum, is found in Columbite in our granite veins from Maine 

 to Georgia, a range of more than a thousand miles, in a score or 

 more of places, and sometimes is obtained by the hundredweight 

 in a single locality. The American variety of samarsklte, an- 

 other rare columbate has also been found in masses of fifty 

 pounds or more in weight, and these acids occur in still other 

 American species. Moli/bdenuni, both as sulphide and in the 

 oxidized form as native molybdic acid and molybdate of lead, is 

 found in many lucalities, and occasionally in larse quantity. 

 Quite recently vanadium compounds have been discovered in 

 several places, and tnngstates have also been observed over a 

 wide range of country. Titanium has been found iu enormous 

 quantities in extensive deposits of titanic iron as well as in the form 

 of ratele and in shpene. The rare metal tellurium occurs native 

 in Colorado and in one locality where single masses of twenty -five 

 pounds in weight have been taken out, and several new tellurium 

 compounds have been found in our western mines. It is, per- 

 haps, unnecessary to enumerate more fully the many occurrences 

 of other rare elements in American minerals. Enou2;h has al- 

 ready been said to show that important developments have been 

 made in the discovery and investigation of the minerals found 

 in our x\merican rocks during the past eighty years. Neverthe- 

 less it is but a commencement in the work. Only a very small 

 portion of our territory has been explored with any thorough- 

 ness, and none of it exhaustively. The enormous production of 

 the precious metals, and the extensive deposits of ores of the 

 more common metals which have been opened up during the past 

 twenty or thirty years, have placed us in tha front rank as metal 

 producers, but we are still far behind Europe in the variety of 

 minerals obtained from our mines. This may be due, in some in- 

 stances, to the character of the veins or ore deposits, there being, 

 as in many of our gold or silver mines, remarkably few associated 

 minerals. In other cases, however, it is doubtless due to the 

 fact that very few persons connected with our mines have even 

 an elementary knowledge of the rudiments of mineralogy, while 

 in continental Europe almost every mining officer is familiar with 



