972 



SCIENCE 



[N. S. Vol. XXX. No. 783 



" The Magnetic Properties of the Heusler Al- 

 loys," by E. B. Stephenson. 



" The Effect of Temperature on the Magnetic 

 Properties of Electrolytic Iron," by Earle M. 

 Terry. 



" The Point Discharge in Air for Pressures 

 Greater than Atmospheric," by O. A. Gage. 



" On the Mechanical Equivalent of Heat by a 

 Porous Plug Method," by J. R. Koebuck. (Read 

 by title.) 



" The Elastic Properties of Platiuum-iridium 

 Wire," by Karl E. Guthe. 



" An Apparatus for Measuring Sound," by F. 

 R. Watson. 



" Polarization of Cadmium Cells," by R. R. 



" A Method for Determining the Optical Con- 

 stants of Metals Applicable to Measurements in 

 the Infra-red," by L. R. Ingersoll. 



" The Absolute Values of the Moments of Ele- 

 mentary Magnets," by Jakob Kunz. 



" An Apparatus for Studying Moment of In- 

 ertia," by C. M. Smith. (Read by title.) 



" Some Curious Phenomena Observed in Connec- 

 tion with Melde's Experiment," by J. S. Stokes. 



" ' Porous Plug ' and ' Free Expansion ' Effects 

 under Varying Pressure," by A. G. Worthing. 



" The Absorption of X-rays an Additative Prop- 

 perty," by R. A. Millikan and E. J. Moore. 



" A Comparison of the Echelon and Diffraction 

 Gratings," by H. B. Lemon. 



" The Value of e by Wilson's Method," by 

 A. Begeman. 



" The Flow of Energy in an Interference Field," 

 by Max Mason. 



" The Stark Effect with Canal Rays," by G. S. 

 Fulcher. Ebnest Mebbitt, 



Secretary 



THE GEOLOGICAL SOCIETY OF WASHINGTON 



At the 222d meeting of the society, held at the 

 George Washington University, on Wednesdaj' 

 evening, November 10, 1909, Mr. Waldemar Lind- 

 gren offered an informal communication regarding 

 the discovery of a selenium mineral in the gold- 

 quartz ores of the Republic district, Washington 

 State. The veins, which have yielded several mil- 

 lion dollars in gold, are contained in Tertiary 

 andesitic rocks and tuffs. The vein matter is 

 quartz, chalcedony and opal deposited in concen- 

 tric crusts. " Adularia, in considerable amount, 

 also occurs in the gangue." Ore minerals and 

 particularly native gold are rarely visible in the 

 gangue and the ores have proved very difficult to 



treat. In rich ores slight, black streaks indicate 

 the presence of metallic minerals and in a few 

 places, in the Republic mine, a well-defined black 

 or dark gray mineral forms crusts a few milli- 

 meters in thickness. This material is exceed- 

 ingly rich in gold, but contains no free metal. 

 It consists mainly of an antimonial tetrahedrite 

 associated with specks of chalcopyrite. A partial 

 analysis by Dr. Palmer, of the U. S. Geological 

 Survey, showed no tellurium, but the presence of 

 about one per cent, of selenium, which in all proba- 

 bility is combined with the gold. This interesting 

 result places the Republic veins in the rare class 

 of Tertiary selenide veins, of which Tonopah is the 

 only known representative in the United States. 

 ■' From descriptions, one of the few deposits of 

 this kind, outside of the United States, is that of 

 Radjang Lebong in Sumatra." No doubt the diffi- 

 culties which have been experienced in the treat- 

 ment of these ores are attributable to the presence 

 of selenium compounds. Further metallographic 

 investigations are now in progress to determine 

 the exact character of the selenide. 



Regular Program 

 Characteristics of some Ore Deposits of Southern 



Eumboldt County, Nevada: F. h. Ransome. 



A large proportion of the deposits of southern 

 Humboldt County consist of silver ores carrying 

 varying minor quantities of gold. These ores are 

 prevailingly antimonial, the silver being combined 

 chiefly in tetrahedrite or jamesonite. They gen- 

 erally contain in addition a little galena (prob- 

 ably argentiferous) and sphalerite, with of course 

 some pyrite. The gangue is quartz, and as a rule 

 the sulphides are subordinate to the gangue and 

 are rather finely disseminated through it. Argen- 

 tite and other rich silver-bearing minerals may 

 occur in the upper parts of some of these deposits. 



The deposits that owe their value chiefly to 

 gold are those at Seven Troughs and at Chafey. 

 Those at Seven Troughs are in Tertiary volcanic 

 rocks; those at Chafey are in Mesozoic volcanic 

 and sedimentary rocks, probably Triassic. 



Like the gold deposits, the copper deposits of 

 the region fall into two classes. One of these is 

 exemplified oy the deposits southwest of Boyer's 

 ranch in Tertiary andesite, and by those at Red 

 Butte, which are in igneous rocks doubtfullj' 

 regarded as of Tertiary age. The deposits at Cop- 

 pereid and Adelaide, on the other hand, are in 

 calcareous sedimentary rocks, probably belonging 

 to the Triassic. They have the mineralogic char- 

 acteristics of contact metamorphie deposits. Gar- 



