IRON. 65 



C. E. Claus : W. M. Watts : 197.6 (O = 16). 

 Watts recalculated two analyses of potassium chloro- 

 iricliate by Claus from the loss in reduction, and for CI = 

 35.457, (Stas.) From one analysis he finds K = 39.87, and 

 Ir = 198.56; from the other K = 39.93, and Ir = 196.62. 

 {Chem. News, 19, 1869, 302.) 



IRON. 



Regnault, Kopp and others have determined the specific 

 heat of this metal. It corresponds to an atomic weight of 

 about 56. [Gmelin-Kraut, I. c.) 



L. J. Thenard : F. H. Wollaston : 55£ (0 = 16) ; 

 345 (O = 100). 



Thenard determined the composition of the oxide at 22.5 

 O and 77.5 Fe, whence Wollaston calculates the value. 

 {Phil Trans., lOJ^, 1814, 21.) 



J. J. Berzelius : 5^37 (O = 16) ; 339.213 (0 = 



100). 



Determined by repeated experiments on the oxidation of 

 iron, such as is used for piano wire, w^ith nitric acid. The 

 carbon was determined and allowed for. Berzelius in his 

 Lehrbuch shows that the error in this determination lay in 

 the unsuspected presence of soluble silica and on reiinalysis 

 he found enough of it to correct the number when taken 

 into account. [Poggend. Ann., 8, 1826, 185.) 



G. Magnus : 54..S5 (0 = 16) ; 339.06 (O = 100). 



Magnus' experiments were made by reducing ferric oxide 

 in a current of hydrogen at about the temperature of boil- 

 ing mercury. He regarded them simply as comfirmatory 

 of Berzelius' number. [Poggend. Ann., 3, 1825, 84.) 



F. Stromeyer : 65.6 (0 = 16). 



Determined by reducing ferric oxide at a red heat by 

 hydrogen. The oxide is reduced only with great difficulty 

 at a lower temperature. The mean of the experiments 

 gave the oxygen contents at 30.15 per cent, [whence I have 

 calculated the value.] {Poggend. Ann., 6, 1826, 475.) 

 6 



