452 



A nniversary Meeting. 



.[Nov. 30, 



rated in a given time varies as the resistance multiplied by the square 

 of the current. It was in connexion with magneto-electricity that his 

 first determination was made of the mechanical equivalent of heat, 

 which was confirmed later by its accordance with the equivalent as 

 determined independently altogether of electricity, by measuring 

 on the one hand the work given out by a descending weight, and on 

 the other the heat generated by internal friction in a liquid in which 

 that work was consumed in overcoming resistance. While much may 

 often be done towards discovering the laws of nature by merely qualita- 

 tive experiments, the final testing of theories which we may have been 

 led to form involves almost always accurate quantitative determina- 

 tions. Joule as an experimentalist was accurate in quantitative 

 determinations, and his final number for the mechanical equivalent 

 of heat is accepted as a fundamental constant in thermodynamics. 



On account of the great importance of Joule's labours, both 

 directly, in the advancement of science, and indirectly, through the 

 knowledge thus acquired, in enabling improvements to be made in the 

 practical application of science for industrial purposes, it has been 

 suggested that it might be desirable to raise some public memorial 

 to him, and the Council has appointed a Committee to consider the 

 question. 



Only yesterday our aged Fellow Martin Tupper passed away, who 

 was the author of works which attained a very wide circulation. 



I have referred, and that very briefly, to some only of the Fellows 

 whom we have lost during the past year, but fuller details both of 

 them, of other Fellows whom we have lost, and of our recently 

 deceased foreign members will be found in the obituary notices 

 which appear from time to time in the Proceedings, according as 

 they are received from the Fellows who have kindly undertaken to 

 draw them up. 



Of those who last year were on our list of Foreign Members, we 

 have since lost one who was truly a veteran in science. More than 

 three years have elapsed since the celebration of the centenary of the 

 birth of M. Chevreul, and two more recurrences of his birthday came 

 round before he was called away. He will be known for his researches 

 on the contrast -of colours. But his great work was tfeat by which he 

 cleared up the constitution of the fixed oils and fats, and established 

 the theory of saponification. Few scientific men still surviving were 

 even born when this important research was commenced — a research 

 in the course of which he laid the foundation of the method now 

 universally followed in the study of organic compounds, by showing 

 that an ultimate analysis by itself alone is quite insufficient, and that 

 it is necessary to study the substances obtained by the action of 

 reagents on that primarily presented for investigation. 



Our late Foreign Member Franz Cornelius Donders stood in the first 



