THORIUM. 121 



855.29, S = 200.75, K = 488.856. {Poggeiid. Ann., 16, 1829, 

 398, and Lehrbuch, S, 1224.) 



J. J. Chydenius : 236.64 (O = 16). 



This chemist analysed the sulphate, the double sulphate 

 of potassium and thorium, the oxalate, the acetate and the 

 formate, getting results which vary from 228.52 to 243.76. 

 He averages with his own results analyses made by Ber- 

 zelius and by Berlin, which, however, alter the result in- 

 appreciably. According to Delafontaine, the methods 

 employed for purification are ineffectual. Chydenius 

 assumes a single atom of oxygen in the oxide. {Poggend. 

 Ann., 119, 1863, 55.) 



K J. Berlin: 231.64 (O = 16). 



Chydenius reports two analyses of the oxalate by Berlin 

 which gave for thorium 57.87 and 57.95, or 231.48 and 

 231.80. {Poggend. Ann., 119, 1863, 56.) 



M. Delafontaine : 231.5 (0 = 16). 



Determined from analyses of the sulphate. Fourteen 

 experiments on the decomposition of this salt, by the heat 

 of a strong double-draught lamp, gave a mean of 52.51 per 

 cent, oxide ; extreme difference, 0.83. In three experiments 

 the sulphur contents of the salt was determined by precipi- 

 tation with barium chloride after the sulphate had been 

 decomposed with ammonium oxalate. The mean amount 

 of sulphuric anhydride so found was 31.92 per cent.; ex- 

 treme difference, 0.78. Three experiments on the water 

 contents gave 15.68 per cent ; extreme difference, 0.21. 

 The sum of these means is 100.11. The value of thorium 

 was calculated from the relation of the oxide to the sul- 

 phuric anhydride for S = 32, Ba = 137. The salt was pre- 

 pared from thorite and from orangite by decomposition 

 with sulphuric acid and recrystallization of the sulphate 

 with the help of heat. The purification was continued 

 until the crystals and the mother liquor had exactly the 

 same composition. Marignac assisted at this investigation. 

 [Liebig's Ann., 131, 1864, 100.) 



P. T. Cleve : 233.88 (O = 16). 



Cleve made six analyses of the anhydrous sulphate, get- 

 ting in mean Th = 233.8 ; extreme difference, 1.36. From 



