26 SECTIONAL ADDRESSES 



these disturbed days science should have a message of goodwill to the 

 world ; and to such a message, fortified at each of our sessions by practical 

 demonstration, we have put our hand at this sectional gathering, now 

 meeting for the third time in the great industrial city of Nottingham. 



A generation ago it was fashionable to draw a working distinction 

 between the applied and pure physicist, it being considered that when 

 given a piece of research to carry out, the former consciously or un- 

 consciously applied Benjamin Franklin's stock question ' What is the use 

 of it ? ' Nowadays it is appreciated that any such distinction can only 

 be largely artificial, for there have been many outstanding illustrations 

 during the last half century of how speedily and inevitably results of no 

 preconceived practical value may glide into widespread industrial utilities. 

 For example, when only forty years ago Sir. J. J. Thomson discovered 

 the electron, no one could ever have imagined that, as Dr. K. T. Compton 

 recently informed us, an industrial business amounting to some hundreds 

 of millions of pounds a year would now owe its existence to electronic 

 devices. Already, both neutrons and radio-sodium are being experi- 

 mented with in radiation therapy ; and furthermore, some of the artificial 

 radioactive elements have found an important field of use in biological 

 processes, both in animals and plants, providing, as they do, by their 

 characteristic radioactive decay, a method of identifying migrating atoms 

 a million times more sensitive than any that analytical chemistry can off"er. 

 Again, to judge by the 1936 report of the Comptroller-General of the 

 Patent Office, technical applications are also being sought for the trans- 

 mutation of elements by bombardment with short-wave radiation or 

 high-speed particles. 



Thus even the most practically minded among us need find no difii- 

 culty in appreciating the profound fascination and basic significance of 

 some of the present-day developments of modern physics, and recog- 

 nising the driving genius behind them. But applied physics has its 

 victories no less than pure physics ; and speaking as one who has spent 

 some thirty happy years in both the pure and applied schools of physical 

 research, I can testify that dealing with materials which are neither 

 intangible nor ephemeral, does not necessarily cramp outlook or stifle 

 enthusiasm ; and applied workers are no less able to share the stimulus 

 of conquering a stubborn investigation, and with it all, enjoy the satis- 

 faction of seeing many of their labours turned to early account in the 

 interests of the community. Perhaps some day they will also take to 

 heart some of the social implications of their work. 



There must be many of us, both workers and onlookers, who at times 

 feel a little overwhelmed by the way the ramifications of physical research 

 year by year continue to extend. Not uncommonly, the methods of 

 attack are so involved and the technique so formidable, that despite the 

 great all-round improvements in equipment, the calls on the pertinacity 

 and patience of the worker are no less than in the past. Incidentally, 

 while present-day equipment is often much more elaborate and efficient, 

 it is also apt to be much more costly than that of a generation ago, as 

 those who direct physical laboratories are well aware. This applies alike 

 to the pure and the applied physics laboratory ; and although their 



