454 Scientific Proceedings, Royal Dublin Society. 



Uranates. 



tiraninite (Saj'da, Saxony) : — possibly softens at about 1220, flows slowly at 

 about 1265, and rapidly at 1380. 



Uraninite (Johanngeorgenstadt, Bobemia) : — softens and melts with loss of 

 body at 1200, flows slowly with iridescence at 1330, and freely at 1440. 



Broggerite (Raade, Norway) : — turns brown at about 1170, yielding a white 

 sublimate with a dull yellow centre. Softens in the neighbourhood of 

 1320, fuses to a brown glass, but does not flow freely up to 1480. 



Qummite (North Carolina) : — reddens litmus paper at high temperatures, 

 turning dark red-brown and partly regaining original colour on cooling. 

 Appears bright upon the hot ribbon. Fuses at 1230, coalesces into 

 drops, and solidifies to a dark brown glass. 



Gummite (Johanngeorgenstadt, Bohemia, 1814) : — small particles lose body 

 and melt at 1300, larger ones fairly rapidly at 1490. 



Uranospliaerite (Sabugal, Portugal) : — reddens blue litmus. Melting difficult 

 to observe. Small particles lose body at 1170 and larger particles melt 

 with iridescence at 1320. 



Thorianite (Lalle, Ceylon) : — infusible below 1660. 



Uranochaloite (Bohemia) : — shows signs of sublimation, and possibly softens 

 at 970; melts at intervals between 1110 and 1170 with decomposition, 

 showing surface-tension effects. The fusion attacks the platinum. 



Zippeite (Schneeberg, Saxony) : — reddens blue litmus, is bright upon the hot 

 ribbon, but, on heating, gradually loses body, and at 1250 partially 

 disappears, leaving a fusion segregated in colourless drops. 



Uraconite (Schneeberg, Saxony) : — gradual rounding of the edges of smaller 

 particles at 1050 ; flowing at 1070. 



Uraconite (Joachimsthal, Boliemia) : — glows on tlie ribbon, yielding a white 



sublimate at 1110, and reddening litmus. Melts to a brown glass, 



presenting incipient crystallization on cooling, and flows with iridescence, 



showing surface-tension effects. 



Recent advances in high-temperature measurement with the accompanying 



improvement in the accuracy of the standard temperatures render inaccurate 



results obtained in relation to old standards. 



