SECONDARY PRECIPITATION OF GOLD 267 
alkaline sulphide solutions, suggested by Lenher' as a possible 
means for the transportation of gold, as such solutions are not 
formed in the alteration of gold deposits. Their adequacy as a 
means for transportation and primary deposition of gold is beyond 
the scope of this paper. 
In conclusion the writer wishes to express his thanks to Pro- 
fessor W. H. Emmons, who suggested this investigation, and to 
Professor Stieglitz, of the Department of Chemistry; for many 
helpful suggestions, on both theoretical considerations and practical 
experimental methods. 
t Lenher, Econ. Geol., VIII, 744-50 (1912). 
