IRON. SVAXBERG. 93 



We would like to enter upon some of the more interest- 

 ing chemical points, but space forbids. We shall have to 

 confine ourselves to the systematic statement of the results 

 obtained, using the form already familiar to the reader. 



The results obtained by other chemists will also be stated 

 in the same form. Erdmann and Marchand are thorough 

 representatives of the method of Berzelius. 



Fe2 : Fe2 Oa =r 112 : 160^1:0.70 ooo. Change 19 high. 



Berzelius, 1809, Mean 66 low. 



Magnus, . , . , . . : . " 68 low. 



Stromeyer, 1826, . V . . -.".'... " 15 low. 

 Wackenroder, 1843, < . . Results from 38 to i low. 

 Svanberg and Norlin, 1844: 



Oxidation, 7 Det., 977 928; 49. Mean 47 low. 



Reduction, 7 Det., 072 014; 58. " 35 high. 



Mean, 14 Det., 072 928; 144. " 6 low. 



Erdmann and Marchand, 1844. Reduction only: 



Substance A, 5 Det., 030 962; 68. Mean Slow. 



Substance B, 3 Det., 055 015; 40. " 38 high. 



Mean, 8 Det., " 9 high. 



Berzelius, 1844, 2 Det., 022 018; 4. " 20 high. 

 Maumene", 1850, 6 Det., oio 990; 20. ff i high. 

 The last two series were made by wet way synthesis 

 dissolving pure iron in nitric acid with final ignition. 



We notice that the earlier determinations were low. 

 Berzelius over 60 low in 1809, Stromeyer only 15 low in 1826, 

 while Wackenroder in 1843, almost reached the standard as 

 a limit. 



The most complete work of Svanberg and Norlin gave 

 constantly low results by oxidation, high results '. y reduc- 

 tion; indicating minute constant errors acting in opposite 

 directions, and giving the more reliable mean only 6 low. 

 This makes their mean doubly valuable, according to the old 

 rule of Berzelius. Sebelien p. 13; True Atomic Weights p. 

 16 p. 3, Supra. 



The determinations of Erdmann and Marchand were all 

 made by reduction only, but the substance operated upon 

 was obtained from ferrous oxalate prepared in two different 

 ways. 



