iIO ABSOLUTE ATOMIC WEIGHT. 



different from the standard atomic weight 24 within the 

 limits of precision, which may be taken at 0.02. 



Richards' Determinations. 



Several other methods have been tried ; but the alphabet- 

 ical record in Part IV, shows that these methods were 

 defective, either in the starting material, the final product 

 or even in both, when dry way processes, or they had some 

 of these defects and were made by some much less reliable 

 wet way process. 



It is not necessary here to give any of these except, per- 

 haps, the volumetric process, rejuvenated by Richards, of 

 Harvard. 



Mg Ch : Agz =95 : 216 = 0.43 982. Change 46 high. 

 Dumas, 1860: 



i 4 gr. Det. u, Extr. 380 154; 226. Mean 279 high. 

 Richards and Parker, 1896: 



Series II, Det. 3, Extr. 152 130; 22. Mean 160 high. 



" III, Det. 6, Extr, 144 131; 13. " 156 high. 



" IV, Det. 6, Extr. 138 = 136; 2. " 155 high. 



Evidently the entire object of the work of Richards is to 



obtain concordance and with it the praise of our olla podrida 



maker in Washington. 



Richards Excels Dumas 4,000 Times. 



This praise Professor Richards has received (p. 144) in 

 the following words : 



(< Here the first two values " (Dumas and Series II of 

 Richards and Parker) " practically vanish, and the third and 

 {C fourth series of Richards and Parker appear atone." 



The reason of this high praise rests upon the " weight" 

 of the determinations always measured by the inverse square 

 of the probable error of the mean by Clarke, in his u Con- 

 stants of Nature." 



These probable errors are given in units of the fourth 

 place of the per cent, that is, in units of the sixth place the 

 millionths of the unit of weight according to our tables. 



