Meeting of the British Association, 219 



and before, to the past and to the future, and it promotes in him 

 a moral training by the influence it exercises over his thoughts and 

 habits. (Cheers). Many, no doubt, will feel anxious to see 

 principles immediately appHed to practice ; in common language, 

 to see principles made useful. They, I have no doubt, will be 

 highly gratified in the Mechanical Section. Here they may, per- 

 haps, occasionally see the same thing ; but more frequently they 

 will find that the results are but stepping stones, which prepare 

 the way for further progress — (Applause). 



B— CHEMICAL SCIENCE. 

 President. — Dr Lyon Playfair, C. B. ; F. R. S. 



ADDRESS OP DR. LYON PLAYFAIR, F. R. S. 



This section was quite crowded. Precisely at half-past 11 

 o'clock. Dr. Lyon Playfair took the chair, and intimated that the 

 section would not open until the arrival of H. R. H. the Prince 

 Consort. At 12 o'clock Prince Albert arrived, and was received 

 by the company standing. Immediately on the Prince being 

 seated, the President began to read his opening address. Its chief 

 topic was the combining proportions of the elements of bodies, 

 and was as follows : — 



My predecessor in this chair, Sir John Herschel, drew our at- 

 tention to the great importance of studying with increased accu- 

 racy, the combining proportions of bodies in the hope of deter- 

 mining the exact numerical relations which prevail between the 

 elements. He justly regarded it as a subject worthy of the most 

 accurate experiment, to ascertain whether the combining propor- 

 tion of the elements or multiples of the combining of Hydrogen, 

 be as suggested by Prout, cautioning chemists at the sametime 

 not to accept mere approximative accordances as evidence of this 

 relation. 



I have now to congratulate the Section on the publication of 

 the laborious investigations of Dumas on this important enquiry. 

 It required a chemist of great manipulative skill as well as of fer- 

 tile experiment, to obtain combining numbers for the elements 

 upon which a greater reliance could be placed, than upon those 

 determined with such admirable precision by Berzelius that great 

 master of analysis. The atomic weights found by that chemist did 

 not, for many of the simple bodies, confirm the suggestion of Prout 



