TRANSACTIONS OF THE SECTIONS. 43 



On a new Form of SprmgeVs Air-pump. 

 By C. H. Stearn and J. W. Swan. 



Solutions of Laplace s Tidal Equation for certain, special Types of Oscillation. 



By Sir W. Thomson, F.R.S. 



Diurnal and Semidiurnal Harmonic Constituents of the Variation of Baro- 

 metric Pressure. By Sir W. Thomson, F.R.S. 



Oh a Marine Azimuth Mirror and its Adjustments. 

 By Sir W. Thomson, F.R.S. " 



On the Possibility of Life on a Meteoric Stone falliny on the Earth. 

 By Sir W. Thomson, F.R.S. 



On a neiv Form of Apparatus to illustrate the Interference of Plane Waves. 



By C. J. Woodward. 



CHEMISTEY. 



Address by Professor Abel, F.R.S., President of the Section. 



The subject which my predecessor, in the honourable position of President of this 

 Section, made the chief topic of his interesting- and instructive Address, affords 

 excellent illustrations of the operation of purely scientific research in creating- and 

 developing important branches of industry. Mr. Perkin, whose name has from 

 the very commencement of the history of coal-tar colours been identified wit li their 

 discovery and their scientific and technical history, referred to several series of 

 researches, each one of which formed a link in a chain of discoveries in organic 

 chemistry of the highest value as establishing, illustrating, or extending important 

 chemical theories, but at the time, and for long afterwards, of value purely from a 

 scientific point of view. These researches, undertaken and pursued by ardent and 

 philosophical investigators under more or less formidable difficulties, and solely in 

 the interests of science, resulted in the discovery of certain organic bodies which 

 were produced originally only on a very small scale and at great cost, but which, 

 after the lapse of years, have been readily manufactured from abundant sources, 

 and have constituted important elements in the development of the industry of 

 artificial colouring-matters. In fact this industry, which owes its origin to the 

 discovery of mauve by Mr. Perkin about twenty years ago, and which is second 

 to no branch of chemical industry in regard to the rapidity of its development and 

 its influence upon other important branches of manufacture, affords more copious 

 illustrations thau any other of the immediate influence of pure science upon indus- 

 trial progress. It therefore affords a topic which the chemist may well be excused 

 for continually recurring to, with an interest bordering on enthusiasm, when 

 illustrating the material advantages which accrue to communities from the pro- 

 motion of scientific training and the encouragement of chemical research. 



4* 



