CHEMISTKY. 



G41 



With the aid of a second table, in which calculations 'are made on 

 the two suppositions that 0=1G, and O =15-90, the authors show that 

 according to the former a given analysis would lead to the formula 

 C25H52, but according to the latter the formula would be C27H56. Of 

 course in such a case no one would determine the formula b^^ analysis 

 alone. In conclusion, the authors say : '' We are all convinced that the 

 relation under consideration (and thereby every other atomic weight re- 

 ferred toH = l) is not accurate to the thousandth i^art of its value. 

 Let us accept it without artificial interpretations and wait till the future 

 for its further proof and confirmation by experimental methods." {Ber. 

 <i. cliem. Ges., xviii, 1089, and Am. Chem. J., vii, 90.) 



Proufs Hypothesis and the Atomic Weight of Silver (by Lothar Meyer 

 and K. Seubert). — The calculation of the atomic weights of many of the 

 elements depends, as is well known, upon that of silver, so that the 

 sharpest possible determination of this is desirable in order to obtain 

 accurate results, without which a discussion of Front's hyi)othesis, as 

 far as this is concerned with facts, is unprofitable. For this reason J. 

 S. Stas, in his masterly investigations, used the utmost care in determin- 

 ing the stoichiometrical relations between silver and oxygen. Dumas, 

 in 1878, showed that oxygen was contained in pure silver which had 

 been fused with borax and saltpeter. The authors have studied the in- 

 tiuence which the slight percentage of oxygen may have exerted on 

 Stas' silver determinations, and conclude that the latter were not ap- 

 l)reciably influenced by the occluded oxygen. The authors maintain 

 that the most accurate determinations of atomic weights of the elements 

 all contradict Front's hypothesis in its characteristic original concep- 

 tion; it must therefore be looked upon as having been disproved by 

 experiment. {Ber. d. chem. Ges. xviii, 1098, andAm. Chem. J., vii, 104.) 



Re-determinations of Atomic Weights. 



Element. 



Cerium 



Lanthanum 



Carbon [0=16] .... 

 Phosphorus [0=16] 



Tiu [0=16] 



Zinc [0=16] 



Titanium 



Bismuth 



Glucinum 



Samarium 



Didymium 



Cerium [0=16].... 



Atomic 

 weight. 



141-1 



i:W-3 



1-2-0 



31-0 



118-07 



05-17 



48-01 



208-16 



9-1 

 150-02 

 142-3 

 140-22 



Authority. 



Crookes 



....do 



van der Plaats. .. 



....do 



....do 



.-..do 



T. E.Thorpe 



R. Schneider 



Humpidge 



Cleve 



...-do 



Brauner 



Reference. 



Chem. News, Ln, 302. 



Do. 

 Comptes rendus, c, 5-i. 



Do. 



Do. 



Do. 

 Chem. News, Li, 46. 

 J. prakt. Chem., xxx. 

 Chem. News, i.i, 121. 

 Chem. News, li, 145. 

 Chem. News, lii, 227. 

 J. Chem. Soc, 1885, 879. 



H. Mis. 15- 



-41 



