3 04 THE POPULAR SCIENCE MONTHLY. 



and the important litigation between the Eureka and Richmond has 

 been decided on geological grounds ; and yet the public has nowhere 

 received the information which it craves as to how it has happened 

 that so many millions have been made from the Comstock mines (by 

 their managers), and so many lost in the White Pine and Emma. The 

 great bonanzas of the California and Consolidated Virginia have no- 

 where been fully described. A few geologists know that they are 

 simply disconnected patches of rich ore, such as lie in most fissure 

 veins ; but the public at large have either no ideas at all about them, 

 or those that are wide of the truth. So we may seai'ch in vain through 

 all mining literature for the simple explanation of the problem involved 

 in the Eureka litigation, and in the ephemeral productiveness of the 

 White Pine and Emma, viz., that these mineral deposits are chambers 

 or galleries formed in limestone beds by atmospheric water carrying 

 carbonic acid, and subsequently occupied with ore deposited from as- 

 cending solutions which filled these cavities, just as elsewhere the sim- 

 ple crevices of fissure veins. 



If any one can imagine the lead-bearing limestones of Missouri or 

 the honeycombed plateau of central Kentucky broken up by volcanic 

 action, the strata set at high angles, and their irregular cavities filled 

 with mineral solutions issuing through fissures from below, he will get 

 a just view of the nature and origin of these mysterious ore deposits, 

 and a ready explanation of their irregular and superficial character. 



If Mr. King could have continued his observations on the Com- 

 stock, and had investigated all the mineral deposits discovered along 

 this rich belt, so freely opened by the active exploitation of the last ten 

 years, in the same thorough way that he did the Comstock, he would 

 have made a contribution to American geological literature which 

 would have been of great scientific interest, and of a pecuniary value 

 to mine-owners and mine-buyers to be reckoned in millions. 



Vol. V. made its appearance in 1871 ; it was devoted to Botany, 

 and was prepared by Mr. Sereno Watson, with the assistance of a num- 

 ber of our best botanists, who have made special studies of particular 

 families of plants ; as Engelmann of the Cactacece, Eaton of the Ferns, 

 Tuckerman of the Lichens, etc. Vol. VI., on Microscopic Petrography, 

 by Professor Ferdinand Zirkel, was published in 1876 ; Vol. IV., on 

 Paleontology and Ornithology, in 1877 ; Vol. II., which embraces de- 

 tailed reports by Messrs. Arnold Hague and S. F. Emmons, on the 

 local geology of the belt of territory surveyed, also appeared in the 

 same year ; and, finally, Vol. I., written by Mr. King himself, forming 

 a comprehensive review of the systematic geology of the country cov- 

 ered by his explorations, has only just now left the binder's hands. 



The magnificent geological atlas intended to accompany and illus- 

 trate the reports of the " Survey of the Fortieth Parallel " was issued 

 in 1876. This will compare favorably with any work of its kind done 

 in the Old World, and at the time of its publication it far excelled 



