244 Prof. W. A. Tilden. On the Specific Heat of Metals 



in producing superior offspring. It is shotvn, for example, that if an 

 individual who possesses a degree of character only found in one in 

 twenty be considered "exceptional," then eighteen times as many 

 exceptional men will be born of non-exceptional parents as of excep- 

 tional parents ; but on the other hand, exceptional parents produce 

 exceptional offspring at a rate ten times as great as non-exceptional 

 parents, the greater gross product of the latter being due to their 

 much greater numbers. In other words, distinguished parents are 

 more likely to have distinguished offspring than undistinguished — ten 

 times as likely — and yet only one distinguished man in nineteen will 

 be born of distinguished parents. The importance of such conceptions 

 for both natural and artificial breeding can hardly be over-estimated. 



March 8, 1900. 



The LORD LISTER, F.R.C.S., D.CL., President, in the Chair. 



A List of the Presents received was laid on the table, and thanks 

 ordered for them. 



The Bakerian Lecture, " The Specific Heat of Metals and the 

 Relation of Specific Heat to Atomic Weight," was delivered by Pro- 

 fessor W. A. Tilden, F.R.S. 



Bakeeian Lecture. — "On the Specific Heat of Metals and the 

 Relation of Specific Heat to Atomic Weight." By W. A. 

 Tilden, D.Sc, P.R.S., Professor of Chemistry in the Royal 

 College of Science, London. With an Appendix by Professor 

 John Perry, P.R.S. Received February 9, — Read March 8, 

 1900. 



(Abstract.) 



The experiments described in this paper were begun with the object 

 of assisting in the determination of the relative values of the atomic 

 weights of cobalt and nickel, but were continued with the further 

 purpose of testing the validity of the law of Dulong and Petit. 



The metals cobalt and nickel closely resemble each other in density, 

 melting point, and other physical properties, as well as in atomic 

 weight. The pure metals were prepared for the purposes of these 

 experiments with the most scrupulous care, the cobalt by taking 



