ADDENDA. 285 



fortified by examples from all parts of the world; the other en- 

 deavors to be a judicial statement with a complete description of 

 the ore bodies of the United States alone. 



II. An extended treatise on the useful minerals, earthy as well 

 as metallic, by M. M. E. Fuchs and L. De Launay, has recently 

 appeared (Traite des Gites Min&raux et M&talliferes, Paris, 1893). 

 The book is based on the lectures in economic geology delivered 

 in the Ecole Superieure des Mines, at Paris, in the last fifteen years 

 by the two authors. (Professor Fuchs died in 1889, and was suc- 

 ceeded by Professor De Launay.) A vast amount of valuable in- 

 formation is brought together and discussed from various points 

 of view, useful applications and methods of treatment being set 

 forth as well as geological occurrence. So far, however, as the ore 

 deposits and other useful minerals of the United States are con- 

 cerned, the authors have suffered from the unavoidable limitations 

 of those not native and conversant in a discriminating way with 

 our literature. In many cases, if not in most, the descriptions used 

 by them are from German or other foreign sources,' and are often 

 antiquated and curiously mixed. While placing at command much 

 that is not easily accessible on foreign ore deposits and those in 

 outlying parts of the world, and also much that is valuable in the 

 way of general discussion, nevertheless the book cannot be con- 

 sidered in its American relations as adding much to our literature. 



