REED — RELATION BETWEEN VALENCE & ATOMIC WEIGHT. 649 



TJiR Graphical Representation of the Relation 

 between Valence and Atomic Weight. 



By C. J. Reed. 



I>A.R,T I. 



Valence as a Measure of Electro-Polabity. 

 The following discussion is an attempt to determine what relation, 

 if any, exists between atomic weight and valence. 



Whatever data could be obtained from reliable sources re- 

 specting- atomic weights and valences was collected and tabulated 

 for convenience. An interpretation of the data capable of a gra- 

 phical representation was then sought. The interpretation finally 

 adopted rests upon the following hypotheses :* 



Hypoth. I. — T/ie valence of an atom is its capacity for electro- 

 polarity. 



Hypoth. II. — The polarity of an integrant /nolecule is always zero. 



Hypoth. III. — Positive and negative changes of polarity are always 

 contemporaneous and equal. 



Cor. I. — The sum of the positive polarities in any molecule is 

 equal to the sum of the negative. 



This follows directly from Hypoth. II. 



All the atoms existing in a molecule are to be considered as po- 

 larized, one-half the atoms (measured in valence, not in numbers) 

 positively, the other half negatively ; but an isolated atom, like a 

 molecule, has no polarity toward any external atom or system. 

 When an atom is in the " nascent state" it cannot be considered 

 isolated. 



An atom is neutralized when it is united with one or several 

 atoms having the same degree of polarity, but of opposite sign. 

 By neutralized we do not mean that the polarity is destroyed, but 

 opposed by an equal and contrary polarity. 



When a molecule is decomposed, the work done in separating 



* These hypotheses were first announced in a different form by Mr. O. C. Johnson. See 

 Chem. News, vol. 42, p. 51 ; also Pkarm. Record, vol. 3, p. 394. 



