198 



Mr. M. M. Tiittison Muir on 



turc, wliilc that of sulphuric acid varies with the temperature, 

 but iu a. maimer inversely as the binding of that acid by neu- 

 tral sulphate (see Table VL). 



From these results Ostwald concludes that most probably 

 the relative affinity of the acids is a constant number independent 

 of base, and independent of temperature ; he believes that this 

 generalization holds good for all the acids. 



If the absolute affinity of an acid A for a base C be repre- 

 sented as a function of both, the above generalization may be 

 expressed in the form 



/(VC) /(A/oy 



and from this it follows that 



AAiO) _ /(A/C) . 

 /{Afi') /(VC)' 



i. e. the relative affinities of the bases are independent of 'the par- 

 ticular acid used for neutralization. 



From these relations Ostwald deduces the result that the 

 function /(AjC) is a product of two factors, one containing 

 only A x and one only C : 



/(A 1 C) = <^(A).^(C); 



or, the affinity between an acid and a base is a product of the spe- 

 cific affinity -constants of the acid and base. 



If the regularities observed for the special cases now de- 

 scribed be regarded as expressing a true generalization, the 

 affinities which come into play in the formation of salts may 

 be simply expressed in a Table such as that given below. 



The relative affinities of all bases being determined in refe- 

 rence to one acid, and those of all acids in reference to one 

 base, and the affinity of this acid to this base being taken as 

 unit, the values so obtained may be arranged as follows : — 





0(A). 



<P (A')- 



0(A"). 



I 



0(A"'). 



*(C) 



• 



. 





. 



*(C) • 



• 



• 



. 



. 



*(C") ... 



♦ 



• 



. 



. 



*(CP) ... 



• 



• 1 



• 



The product of the expression at the head of one of the 

 horizontal columns, yjr (C), with that at the head of one of the 

 vertical column, (f> (A), gives the magnitude of the affinity 



