254 



SMITHSONIAN MISCELLANEOUS COLLECTIONS 



VOL. 54 



In the filtrate from the merciir}^ the chlorine was precipitated as silver 

 chloride and so weighed. The results were as follows, with vacuum 

 weights : 



Mean, 94.7177, ± .0023 



Hence Hg= 200.617. 



We now have seven ratios involving the atomic weight of mercury, 



follows : 



(1). Per cent, of Hg in HgO, 92.595, ± .0003 

 (2). Per cent, of Hg in HgS, 86.2127, ± .0027 

 (3). Per cent, of Hg in HgCU, 73.8459, ± .0008 

 (4). Per cent, of Hg in HgBr^, 55.556, ± .0012 

 (5). Per cent, of Hg in HgC^N,, 79.339, ±: .0004 

 (6). 2Ag:Hg:: 100: 92.660, ±.0051 

 (7). 2AgCl:HgCl2: : 100: 94.7177, ± .0023 



as 



The antecedent atomic weights are — 



Ag = 107.880, ± .00029 S = 32.0667, ± .00075 



CI = 35.4584, ± .0002 N = 14.0101, ± .0001 



Br = 79.9197, ± .0003 C = 12.0038, it .0002 



Hence, 



From ratio 4 Hg = 199.803, ± .0069 



" 5 199.835, ± .0045 



" 6 199.923, ± .0110 



" 1 200.070, ± .0081 



" 3 200.233, ± .0066 



" 2 200.520, ± .0394 



" 7 200.617, ±: .0067 



General mean, Hg = 200.054, ± .0027 



Mathematically, Hardin's determinations seem to outweigh the others. 

 They are, moreover, comparatively concordant and by four methods. But 

 it is quite possible that Easley's much higher figures may prove to be 

 more correct. His work is to be continued; but, until it is finished, it 

 would be unwise to adopt his results exclusively. The atomic weight of 

 mercury is still much in doubt. 



