144 ABSOLUTE ATOMIC WEIGHT. 



The Correlation of Ratio and Atomic Weights. 



In the formula, above used, to express the quantitative 

 reaction employed by Ramsay and Aston, we find, in. 

 addition to boron and oxygen, also the symbols of sodium 

 and of chlorine. 



We will here re-print the reaction referred to : 

 2 Na Cl : Naz OT Bo4 = 117 : 202 = 0.57 921. 



This relation is not restricted to boron, but implies a 

 necessary condition for all the atomic weights represented 

 therein. 



We have already, under the head of thallium, practiced 

 the work we shall now explain a little more fully, while 

 using it in its broadest way. 



We determined the exact atomic weight of nitrogen by 

 the reaction devised for the determination of the atomic 

 weight of thallium. However, in that case, we used 

 Lepierre's determination for the value of Tl and then used 

 the syntheses of Crookes for N. 



But it is evident, that we did really not require the work 

 of Lepierre, and still could have -verified both Tl and N from 

 the determinations of Crookes. 



It is this sort of work we want to do now, and for that 

 reason, we better explain the mathematical principle 

 employed. 



The chemical equation, re-printed above, requires nr/7the 

 chemical symbols to possess the values stated as standard 

 atomic weights. 



Hence the numerical values observed, namely, the ana- 

 lytical ratios, will form perfectly binding tests or conditions 

 for any one of the true atomic weights of the elements con- 

 tained in that formula. 



2 Na Cl : Naa OT Bo4 = 117.2 : 202.2 = 0.57 962. 



If we suppose Na to rise by the usual one tenth of a 

 unit (o. i) "while all the others remain constant^ we shall 

 obtain the atomic ratio 0.57 962, which is "41 high," as 

 compared to the above given value for Na = 23. 



2 Na Cl : Naa O? Bo4 = 117.2 : 202 =0.58 020. 



In the same way, for Cl =. 35.6, while all the others remain 



