GIBBS. — COMPLEX INORGANIC ACIDS. 273 



tungstate acts in the same manner upon the uranious salt, giving also 

 an olive-green crystalline salt and a brown-red solution. Similar 

 results were obtained with acid ammonic tungstate. After drying for 

 some days upon paper, the sodium salt was analyzed by Dr. Loeb: 



0.4436 gram lost with WO4NO0 0.0331 gram = 7.46%. 



( 0.9861 gram gave 0.3954 gram WO. = 40.09%. 



\ 0.9861 gram gave 0.3360 gram UOo and KMnO^ = 34.08%. 



The analyses lead to this formula, 



4676 100.00 



The water determination was made by heating with sodic tungstate 

 and determining the loss of weight. In the fusion the UO, is com- 

 pletely reoxidized to UO3. Hence a correction must be applied to the 

 water, which in the above case amounts to 2.01% to be added. As the 

 salt could not be recrystallized, it was doubtless not perfectly pure. 



The olive-green potassium salt is also insoluble in hot water and in 

 chlorhydric acid. It reduces silver and mercury from their nitrates, 

 and appears to undergo double decomposition with baric and calcic 

 chlorides. This salt was also analyzed by Dr. Loeb: 



( 1.3260 grams gave 0.4997 gram WO3 = 37.69%. 

 1 1.32G0 grams gave with KMn04 gram UO2 = 33.21%. 

 0.9275 gram lost on ignition with WO^Nag 0.0833 gram = 8.98%. 



The analyses lead to the formula, 



8 WO3 . 6 UO2 . 9 K2O H- 34 aq. 



Calculated. Found, 



37-^n 70.50 S^-^n 70.90 

 32.92) 33.21) 



17.12 16.60 (diff.) 



12.38 12.50 



4940 100.00 



The potassic salt corresponds in constitution to the sodic salt if we 

 write it : 



8 WO3 . 6 UO2 . 9 K2O . 3 H2O + 31 aq. 



VOL. XXX. (n. S. XXII.) 18 



