GEOLOGICAL PAPERS. 



135 



Kansas shale from Trego county, Kansas. Assays of fourteen mill-runs, by 

 Dr. Ernest Fahrig, August 12, 1902. 



All the shale contains more or less zinc and asphaltum petroleum. 



the question of cost of extracT;ion, and this of course is the crucial 

 point of the whole investigation. 



Doctor Fahrig's process is electrical and its principles are well 

 known to metallurgists, though he has devised appliances which ex- 

 hibit uncommon mechanical skill in handling the ore. 



For an electrolytic fluid Doctor Fahrig makes use of a substance 

 discovered by himself, and named bauxogen. He has found this sub- 

 stance possessed of very unusual and useful properties, aside from its 

 utility as an electrolyte. The exact constitution and mode of manu- 

 facture of bauxogen is his secret, and he is confident that if made on 

 a large scale its cost will not be prohibitive. Since a compound such 

 as this cannot be protected by patent, his only chance to profit by 

 his discovery seems to be to keep the mode of making bauxogen to 

 himself. 



Among the shale experimenters during the past year, I may men- 

 tion Waldemar Lingren, sent out from the government chemical de- 

 partment, at Washington. He visited the Smoky valley last June, 

 and took back to Washington specimens of shale from several locali- 

 ties. His report indicated that the shale was subjected, at Washington, 

 to the usual fire tests, and with the usual results, viz.: Many blanks, 

 some small values of gold, and a few that were encouraging. Lingren 

 discovered no trace of zinc, and concludes that, while the shales may 

 contain some gold, the amount does not justify the expectation that 

 it will be found in paying quantities. A report from a government 

 expert doubtless carries much weight, though I am not aware that 

 Lingren employed any methods or used any skill that may not be re- 

 produced by many less known chemists. 



Fire assays, at best, are but crude processes, and are liable to many 

 errors. One common source of inaccuracy is the presence of sub- 



