282 Readden — Tung stous .Oxide ^ new Oxide of Tungsten. 







At. eq. 





Cb 



48-56 



51-6 



10-3 



W 



37-64 



20-46 



4-09 



Fe 



3-22 



5"7o 



1-15 



Sn 



0-72 



0-61 



0-12 







10-08 



63-00 



12-60 



14-39 1-14 



12-60 



100-22 



The gain upon ignition amounted to 22-00 per cent of its 

 weight. The formula suggested is the same as in the preced- 

 ing case. 



The third bottom showed, after a portion of it had been 

 dissolved in hydric chloride, the triangular crystals dissemi- 

 nated throughout the mass and particularly abundant at the 

 bottom. The residue in this case was not treated with warm 

 hydric nitrate but was divided into three parts numbered 1, % 

 and 3, beginning with the lightest. 



Paet 1. An analysis showed that this portion was a mixture 

 of oxides and the ratio given for the metals to the oxygen was 

 1:1. When digested with cold hydric chloride, sp. gr.. 1*2, it 

 gave a clear blue solution whose color was discharged upon 

 addition of water. The action of aqua regia upon it pre- 

 sented two phases, the first was very violent, while the second 

 was quite slow ; this was due to the fact that this reagent first 

 dissolved the iron-tin compounds present, and then the tungs- 

 ten or its compounds, which is evident from the following : 

 some of this material was digested with two successive por- 

 tions of aqua regia, each portion was evaporated to dryness 

 after digestion at a gentle heat for about an hour ; the first 

 treatment gave 185-7 ragm Fe 2 3 and 81-0 mgra WO a , the second 

 treatment gave 6-7 mgm Fe 2 3 and 51-0 mgm WO a . The residue 

 from the first treatment consisted of triangular prisms, with a 

 few crystalline grains, that from the second of remnants of 

 such crystals, and after ignition consisted of tungstic acid with 

 a small amount of columbic acid.* 



Pakt 2. This consisted of crystalline grains and crystals. 

 The latter were triangular prisms with an occasional six-sided 

 plate ; these plates which were relatively long and wide, were 

 always pitted and had a much darker color than the prismatic 

 crystals. The analysis of this showed 66'66 per cent of it to 

 be difficultly soluble in aqua regia and emphasized the fact 

 that the iron and tin do not belong to the triangular prisms 

 which make up the larger part of the insoluble portion. 



* In treating this portion with aqua regia containing a large excess of HC1, I 

 obtained a clear yellow solution which gave upon addition of water a precipitate 

 of tungstic acid ; reference will be made to this reaction again. 



