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LXI. A Reply to a criticism of the Unit-Stere Theory. 

 By G-ervaise Le Bas, B.Sc. (Lond.)* 



THE following is a reply to the criticism of the Unit-Stere 

 theory by Ernest Vanstone which appears above. 

 The relation 



S — X^ — ^ n ^ a 

 W"~ W ' 



where S is the volume of a unit (combined hydrogen) or its 

 equivalent, W is the sum of the valencies, or a larger number 

 which may be integral, or a whole number and a fraction 

 (see Trans. Chem. Soc. 1907, xci. p. 112, § 1). W is thus 

 the sum of numbers, which are made up from certain 

 numbers given to the atoms, referred to combined hydrogen 

 as the unit. By the additive rule we see that the whole 

 volume is made up from the sum of the individual atomic 

 volumes, and by means of the additional assumption referred 

 to above we are able to state the volume in terms of the 

 normal volume of the combined hydrogen (3'7 c.c). 

 Vanstone assumes the following relation : — 



M being the molecular mass and v the specific volume or 

 the volume of one gramme. W is invariably the valency 

 number. 



It would appear from this that S is made up of two factors, 



M 

 (1) v^j and (2) v, both of which vary, but in opposite 



directions. The values of S are thus dependent on the 

 variations of the two factors, and consequently conclusions 

 drawn from a consideration of the values of S (the unit-store) 

 may be unreliable. 

 In considering Vanstone's criticism we may state — 



(a) It is nowhere stated that W invariably represents the 

 sum of the valencies. The definition has already been given. 

 Thus C = 4H, = 2H and 3H, 01 = 6H, 1= 10H, Br = 7-6H,&c. 



(6) A careful study will show that although algebraically 



M 



S is made up from the numbers ™, and v, they are not factors 



* Communicated by the Author. 



