310 . THE ATOMIC WEIGHTS. * 



From (14) Ni = 58.456, ±-.0316 



From (15) " =58.551, d=. 0231 , 



From (9) " = 58.587, ± .0179 



From (10) " = 58. 594, ± .0141 



From(ii) , "= 58.607, rh .0128 



From (12) " =58994,^.0248 



General mean Ni ^ 58.243, ± .0019 



If = 16, this becomes Ni = 58.687. 



It is quite evident here that ratio (8), which inckides the marvelously 

 concordant determinations of Zimmermann, far outweighs all the other 

 data. Whether so excessive a weiglit can justifiably be assigned to one 

 set of measurements is questionable, but the general mean thus reached 

 is not fur from midway between the highest and lowest of the values, and 

 hence it may fairly be entitled to provisional acceptance. No one of the 

 individual values rests upon absolutely conclusive evidence, so that no 

 one can be arbitrarily chosen to the exclusion of the others. Further 

 investigation is evidently necessary. 



For cobalt we have sixteen ratios, as follows : 



(i.) Per cent, of Co in CoC20^.2H20, 32.5555, ±z .0149 



(2.) Per cent, of CO.^ from CoC20^.2H20, 47.7475, =i= .0213 



(3.) Per cent, of Co in CoO, 78.633, ± .0002 



(4.) Per cent, of Co in purpureocobalt chloride, 23.6045, ± .0018 



(5.) Per cent, of Co in phenylammonium cobalticyanide, 11.8665, ± .0124 



(6.) Per cent, of Co in ammonium cobalticyanide, 21.943, ± .029 



(7.) Per cent, of Co in brucia cobalticyanide, 3.7437, zj= .0036 



(8.) Per cent, of Co in strychnia cobalticyanide, 4.5705, ± .005 



(9.) Per cent, of CoO in CoSO^, 48.287, i .0135 



(10.) Agj : C0CI2 : : lOO : 60.200, dz .0095 



(11.) 2AgCl : Co : : lOO : 20.687, ± -0033 



(12.) Ag2 : Co : : 100 : 27.705, ± .0050 



(13.) Au., : C03 : : 100 : 45-151, ± -025 



(14.) Co : H2 : : lOO : 3.41 10, dr .0009 



(15.) I2 : Co : : 100 : 23.462, ± .0027 



(l6.) CI2 : Co : : lOO : 82.873, ± .0241 



From these, using the atomic weights already cited under nickel, and 

 combining ratios (1) and (2), we get — 



From (16) Co = 58.308, ±: .0187 



From (9) " = 58.321, zh .0288 



From (3) " = 58.437, ± -OOH 



From (10) "= 58.600, ± .0228 



From (14) " = 58-630, rt .0286 



From (5) "=58.639,^.0619 



From (8) " = 58.696, i .0642 



From (6) "=58.736,^.0808 



From (4) " =- 58.774, =fc .0071 



From (7) " = 58.791, ± -0566 



