326 



DR. W. M. HICKS: A CRITICAL STUDY OF SPECTRAL SERIES. 



The atomic weights are supposed to be those given by BRAUNER,* +x, where x is 

 a number to be added to the fourth significant figure in BRATTNER'S value. BRAUNER 

 gives for Ca 40'124. A, is then divided by (-40124)". 



The result is 



A, = (17336-1 6-22-l'24+ 163^,-8'64a;)ty 2 . 



= 48(361 > 169-13--025+3-4cZ' 1 -'180a;)w a . 



Table I. gives the values for those elements in which the series have been 

 established. The second column contains the atomic weight as given by BRAUNER, 

 except for the few belonging to volumes of ABEGG'S ' Handbuch ' not yet published, 

 with estimated possible error beneath. In the third column the top number gives 

 v and the second 10'A. For triplets there are therefore two sets. The fourth column 

 gives lO^A/MT 1 , and the multiples of which it is composed. In general the 360 ratio 

 is taken, but in several cases it is necessary to take 2x90 or 180 and 1 x 90. The 

 second line of columns 5, 6, 7, 8 gives the coefficient of the error corrections to be 

 applied to this number 360, or 180, &c., as the case may be, and the upper line of 

 figures gives the maximum errors estimated, which have, in general, been less than 

 those permissible by the observations. The last column gives the difference between 

 361 '8 and the factor given in the .fourth column, except that when it is not the 

 4 x 90 term it is brought up to it by multiplying by 2 if it is 180 and 4 if 90. The 

 maximum errors are also attached. 



In many cases it will be seen that the number of significant figures in the 

 calculated numbers is larger than in the data from which they are derived. In these 

 cases the number of significant figures in the data must be supposed to be made up 

 to the proper number by the addition of zeros. This enables new calculated values 

 to be determined when the data are improved without the trouble of recalculation. 



TABLE I. Evaluation of S and of m. 



Notation. W = atomic weight ; qw* = with w = (atomic weight)/ 100 ; error 

 in n,, ; dv, error in v ; x, error in w on the fourth significant figure. 



* ABEGG, ' Handbuch der Anorganischen Chemie.' 





