Koenig — New Species Melanochalcite and Keiceenawite 40T 



Material "B." 0*5658 gr. The tenacity for water at in- 

 creasing temperature was tested by exposing the powder, for 

 two hours each, at the following temperatures : 



0-0092 loss at 88 C. 

 0-0142 *' HOC. 

 0-0082 " 160 C. 

 0-0128 " 210 C. 



0-0444 



0-0451 loss at red heat. 



0-0895 total loss. 



CO2 was not separately determined in this sample ; but from 

 the determinations in " C," when H^O and CO, are nearly 

 alike, the inference may be drawn that all the water is expelled 

 at 210 C. 



0-0500 SiO,; 0-3415 Cu+0-0082 CuO from electrolyte by 

 H,S, 0-0008 Fe.O,. 



CuO = 76-46 

 SiO, = 8-83 



S5i- — 



Fe 0„ = 0-14 



99-63 



Material '' C " — This having been proved irreproachable 

 material, the analysis was made with great care. CO, and 

 water were determined as follows : 0-5260 gr. of the fine 

 powder was placed in a porcelain boat and the latter heated 

 in a combustion tube to redness, whilst a slow current of per- 

 fectly dried and purified air passed through the tube. An 

 "IT" calcium chloride tube received the water and a Geissler 

 Potash bulb received the CO^. The increase of weight in the 

 former ^as 0-0407 gr.; in the latter, 0-0378 gr., a total of 

 0-0785 gram. At the same time the weight in the boat 

 decreased by 0766 gram. Hence there is here an error of 

 0-0019 gr., which may be evenly distributed between H,0 and 

 CO,, or may even be neglected altogether without affecting 

 the result sensibly. The copper was precipitated electrolyti- 

 cally, and in this case H2S found no residue of copper in the 

 electrolyte. The latter being thereupon rendered ammoniacal, 

 a flocculent precipitate fell, which, after filtering and ignition, 

 showed by its color that it did not consist of iron oxide alone. 

 It was found to be ZnO-fFCjOg. I had overlooked the zinc in 

 the other analyses. 



