148 ABSOLUTE ATOMIC WEIGHT. 



Thus we obtain a determination of the atomic weight of 

 sodium, which we shall credit to Mrs. Aston, who assisted 

 Professor Ramsay in that work. 



Of course, this determination pre-supposes that the 

 " other three elements involved/' namely, Bo, Cl, O, be 

 known as to their exact atomic weights. 



By the general principle just stated, we even need not 

 have actually determined these values. 



It is, I trust, fully understood, that the possible limit of 

 deviation is perfectly fixed for any and all of the elements in 

 any one reaction. 



But as a matter of fact, we have a good determination 

 for boron, independent of the work of Ramsay and Aston, 

 namely, in the boron carbide determination by H. Gautier 

 in the laboratory of H. Moissan, which we shall refer to 

 presently. 



Consequently, the above determination for Naz=r23 

 becomes of undisputable force. 



The Stasian value, Na 1^23.05 is entirely incompatible 

 with the "9 high" of the determinations of Ramsay and 

 Aston ; it would have required a mean about ( i 45 high," as 

 is readily seen. 



Any such "high" is perfectly preposterous in connec- 

 tion with the admirable work of Ramsay and Aston. 



Since sodium has been so completely kept inside the 

 Stasian muddle, this determination here given becomes of 

 very high, value. Strange to say, it is about the only reliable 

 determination we can find. 



Confirmation of Cl = 35.5. 



The Stasian value of 135.45 is utterly inconsistent 

 with the determinations of Ramsay and Aston. 



Evidently, the analytical excess should have been " 45 

 low" instead of "9 high" to warrant the Stasian value. 



Such an analytical excess is absolutely inconsistent with 

 the work of Ramsay and Aston. 



Consequently, this work disproves Stas' value for chlo- 

 rine, and confirms Turner's value. 



