94 ABSOLUTE ATOMIC WEIGHT. 



In their results we have quite an indication of the effect 

 of the manner of preparation of apparently the same oxide. 

 The mean of all is only 9 high. 



Berzelius himself (1. c.) accepts the results of Svanberg 

 and Norlin with the distinct statement that his own deter- 

 minations last given are not to be considered. 



The final mean of the determinations of Svanberg and 

 Norlin would lower the atomic weight about 0.03. 



The mean of Erdmann and Marchand would raise it 

 about 0.05. 



But both combined would give a final mean % low, which 

 would lower the atomic weight only 0.002. 



Evidently, all such calculations are based upon assuming 

 an accuracy of the mean higher than the facts substantiate. 



All we can conclude is that the determinations made do 

 not establish any deviation from the standard value 56. 



Therefore, the only statement that expresses the actual 

 experimental determinations made is that the true atomic 

 weight of iron is 56 exactly, no positive evidence having 

 been obtained to establish any deviation however slight, 

 from this standard number, not even to the extent of one 

 thousandth of a ttnit. 



Before closing this subject we may mention the deter- 

 minations by Richards and Baxter, recently made by reduc- 

 tion with electrolytic hydrogen. 



The ferric oxide was, for the first series, obtained by 

 calcining the hydrate; for the second series by ignition of 

 the nitrate. The results are : 



Richards and Baxter, 1900* : 



Series I, 2 Det., 968 955; 13 Mean, 39 low. 



" 11,5 " 959 95i; " 44 low. 



Mean 7 " 968 951517 " 42 low. 



The weighings are, of course, stated to the hundredth of 

 the milligramme. 



I do not see that these new determinations add anything 

 to the stock of our knowledge. 



They do not conflict with the reductions of Svanberg 

 (mean 35 high) or Erdmann (B, 38 high). 



* Report Chemical News, 1901, April 4; vol. 83, pp. 161 162. 



