Annual Report of the Council. Ivii 



bodies reacting. Thus if A is in presence of B and C, for both 

 of which it has affinity, it divides itself between B and C to form 

 bodies AB and AC in quantities that depend upon the affinities 

 and also on the quantities of the bodies concerned. But 

 Berthollet supposed that when one of the products was precipi- 

 tated or was gaseous it ceased to exercise affinity. Guldberg 

 and Waage saw that the final division of a substance between 

 two others depended upon a number of complex forces, and 

 that the simplest way to determine the resultant force was to 

 study the conditions when the chemical forces were in equilibrium. 

 They showed that solids and gases might take an active part in 

 the change proceeding. 



It had already been shown, especially by the researches of 

 Wilhelmy, of Berthelot and St. Gilles, and of Harcourt and 

 Esson, that Berthollet's Law of Mass action held good in 

 particular cases ; they had shown that the rate of chemical 

 change in liquids and substances in solution varied with the 

 quantities of the reacting substances present at any moment. 

 But Guldberg and Waage pointed out how very general is the 

 reversibility of chemical reactions, and the final slate is usually 

 due to an equilibrium between reciprocal processes. The 

 determination of the conditions of equilibriam in any reversible 

 reaction affords the "affinity-coefficient," by which the whole 

 course of the reaction may be deduced mathematically. 



This work of Guldberg and Waage has had a most widely 

 reaching effect on the study of chemical dynamics 



Besides his great work on Chemical Affinity, Guldberg pub- 

 lished important papers on molecular volumes, on the relation 

 between the coefficients of elasticity and of expansion and the 

 latent heat of fusion of metals, on the thermodynamics of 

 solution and dissociation. 



Guldberg, whose death occurred on January 14th, 1902, was 

 elected an Honorary Member of this Society in 1894. 



Like so many of his countrymen, he was a good English 

 scholar, and was well acquainted with the work of English men 

 of science. He was ever ready to discuss points in physical 



