CHEMISTRY. 



497 



and not 9.1, as liad been <jenerally admitted. Lothar INFeyer attempted 

 to show that their results are capable of a diflerent iuteri)retation, quite 

 in harmonj' with the atomic weight 9.1. Afterward Nilsou replied to 

 ;Me.ver, and, takiufj into account the specific heats of tlie oxide and sul- 

 phate of jjhuinum, found continuation of his view that the atomic weight 

 is equal to 13.65. If this figure be correct, the periodic law receives a 

 serious blow, for with the larger atomic weight gluciiuun does not fit 

 into the scheme based ou the law. In the article under review the 

 authors named give the results of the determination of the specific 

 gravity of gaseous glucinum chloride, and find that the correct formula 

 is BeCl2, in which the atomic weight is equal to 9.1. In view of this re- 

 sult, they add, and of the fact that Avogadro's law is, without exception 

 in the whole field of chemistry, the basis for the conception of the 

 molecule, we must give up the idea formerly held by us that gluci- 

 miin is a trivaleut element, to which we were led by the agreement 

 of the atomic heat (Be "' = 13.65) with the law of Dulong, and the 

 mimerous analogies between the physical constants (molecular heat 

 and volume) of the compounds of glucinum, on the one hand, and of 

 the rare metals scandium, erbium, yttrium, &c., on the other. While 

 recognizing in this important case the validity of the periodic law, 

 we at the same time call special attention to the lingular fact that 

 the laws of Dulong and of Avogadro lead to exactly opposite conclu- 

 sions regarding the atomic weight and value of the element of gluci- 

 num, a fact which is unique in the field of metallic elements. {Ber. d. 

 chon. Ges.y xvil, 987.) 



Redetermination of the Atomic Weight of Cerium, by Henry Robinson. — 

 The author details the precautions taken in prepaiing the cerous chloride 

 and in conducting the experiments. The mean of seven determinations 

 of the chlorine (made by titration with silver nitrate) gives 139.8584 as 

 the atomic weight of cerium if H=l, or 140.2154 if = 1(5. [Chem. 

 N'eicSy L, 251.) 



Redetermination of the Atomic Wei (jht of Platinum ,hy W. Ilalberstadt.- 

 As a result of 97 analyses of no less than five different compounds of 

 platinum, conducted in two distinct series, the author finds for the 

 atomic weight of platinum the value 194.57592. {Berichtc d. chem. Gcs., 

 XVII, 2902.) 



Additional determinations of atomic weights. 



S. Mis. 33 32 



