44.6 Koenig — Mohawkite, Stibio-domeykite, Domeykite, 



an equal amount. Some showed more, some less than the type 

 specimen. I selected the one with the heaviest sediment and 

 determined the antimony as trisnlphide. It gave Sb = 1/29. 

 This must be taken as the maximum until other tests show 

 greater amounts. The Houghton domeykites show no trace 

 of antimony. 



3. Mohawk Whitney ite. 



With this name I shall designate not a species, nor even a 

 variety but simply a most intimate mixture of the two species 

 Whitneyite and Mohawkite, of which considerable masses are 

 at present encountered in the Mohawk mine. This material is 

 distinguishable at once to the lay man. even. It is very tough 

 and approaches Whitneyite in that respect. Ordinary blows 

 with the hammer fail to break the masses, the chisel is often 

 required and the hammer leaves a dent as in soft metal. The 

 fresh fracture is gray, fine granular, even hackly. These 

 fractures assume a dull brown or olive-green tarnish, much 

 like algodonite and Whitneyite. There are, of course, all 

 gradations, from nearly pure Mohawkite to nearly pure Whit- 

 neyite. The material looks homogenous, but is not, as the 

 following analyses show. The samples were broken with the 

 chisel in close proximity to one another. 



No. 1. No. 2. No. 3. No. 4. 



Cu 85-36 [ R „ fll Cu *7936 Cu 84-86 



(NiCo) 0-32 j btibi Co.... 0-82 (Ni + Co).. 0-64 



(bydiff.) As.. 13-59 Ni 0-61 As 13-06 



CaCO 3 0-73 Fe 0-36 (CaMg)Co 3 0-71 



Cu 



79-36 



Co .... 



0-82 



Ni .... 



0-61 



Fe . . . . 



0-36 



As .... 



15-07 



CaCO 3 . 



2-41 



MgCO 3 



0-60 



100-00 CaCO 3 . 2-41 99-27 



99-23 



A notable fact is that in No. 3 the cobalt exceeds the nickel. 

 Calcite is the gangue of this material. All manner of atomic 

 ratios can be calculated from these analyses. 



No. 1 has the ratio Cu 7 - 5 As 



No. 2 " Cu 6 - 7 As 



No. 3 " Cu 6 - 45 As 



No. 4 " Cu 7 - 7 :As 



In connection with these results, attention may be called to 

 a communication made by Mr. J. Stanton, Secretary of the 

 Mohawk Mg. Co., to the Engineering and Mining Journal of 

 April 7, 1900. Mr. Stanton here gives Dr. Ledoiix's report 

 upon some of the Mohawk mineral. Dr. Ledoux figures from 



