ABSOLUTE ATOMIC WEIGHT. 



In his Annual Report presented to the Swedish Academy 

 of Sciences on the last of March, 1844, he gives an interesting 

 summary of the work done by him and his school up to that 

 time, including the final work of Svanberg. 



I possess only the 8 volumes of these famous yearly 

 reports of Berzelius, translated by Plantamour. The above 

 historic sketch is found on pages 64 to 67 of the 5th volume 

 of this French series, corresponding to the 24th volume of 

 the German edition. 



The earliest determination of Berzelius dates back to 

 1809, when he found 69.34 per cent of iron in ferric oxide by 

 preparing ferric oxide from purest iron nails, in which he 

 had determined the trace of carbon. 



He admits, in this report, that at the time he could not 

 suspect the effect of a small amount of silicon present in that 

 iron. 



Magnus of the school of Berzelius confirmed this 

 result by reduction of this oxide in a current of hydrogen. 

 He obtained 69.329 per cent of iron. 



Stromeyer, the discoverer of the metal cadmium, showed 

 that these results were considerably too low; but his value 

 69.85 found no immediate acceptance. 



Hence Stromeyer, in 1843, caused the work to be care- 

 fully extended in his laboratory by Wackenroder who found, 

 in five determinations, from 69.62 to 69.99 P er cent f iron 

 by reduction in a current of hydrogen. See also Sebelien, 

 p* 184. 



These determinations running up to within one hun- 

 dredth of one per cent to the full seventy (which we here 

 shall find to be the true value), influenced Berzelius to 

 resume the work. 



He induced Lars F. Svanberg to undertake a fundamen- 

 tal revision of the atomic weight of iron in his laboratory. 

 This was done with the assistance of Norlin and " proved 

 " that the results of Stromeyer came nearer the truth than 

 {c had been supposed." 



Svanberg- and Norlin, in the laboratory of Berzelius, 

 and under his direction and with his assistance, produced a 

 work that is worthy of the master himself. 



