XXX Annual Report of the Council. 



By the death of our honorary member, Prof. Willard 

 GiBBs, of New Haven, the world of Science has lost not only 

 one of the most distinguished among mathematicians, but one 

 of that rarer band whose mathematic analysis has profoundly 

 influenced the progress of physics and chemistry. 



In his great memoir " On the Equilibrium of Heterogeneous 

 Substances," published in 1876-78, he systematised the applica- 

 tion of the second law of thermodynamics to the relations 

 between chemical, electrical, and thermal energy and capacity 

 for external work. Gibbs showed in this memoir how the 

 experimental values for the density of nitrogen peroxide obtained 

 by different observers could be interpreted quantitatively by the 

 aid of his fundamental gas equation ; and it fell to the lot of the 

 writer, in 1899, to show how Gibbs' equation accounted for the 

 densities observed when nitrogen peroxide was diluted with 

 indifferent gases, and thus to demonstrate that nitrogen peroxide 

 was capable of uniting with nitric oxide to form an unstable 

 gaseous nitrogen trioxide. This is only one illustration of the 

 aid which chemists derive from Gibbs' work. 



The " Phase-Rule," developed theoretically by Gibbs, is 

 now regarded by the great majority of chemists as governing the 

 general state of complete heterogeneous equilibrium, and its 

 apphcation has been verified in the most varied cases of rever- 

 sible chemical action. Professor Ostwald wrote, in 1892: 

 " The importance of the thermodynamic papers of Willard Gibbs 

 " can be best indicated by the fact that in them is contained, 

 " partly explicitly, partly implicitly, a large part of the discoveries 

 " which have since been made by various experimenters in the 

 " domain of chemical and physical equilibrium." 



Prof Gibbs was born at New Haven in 1839. After 

 graduating at Yale, and studying at Paris, Heidelberg, and 

 Berlin, he was elected Professor of Mathematical Physics in 

 Yale, in 187 1. He was elected an honorary member of this 

 Society in 1892, and received the Copley Medal of the Royal 

 Society in 1901. He died April 28, 1903. H. B. D. 



