78 LIFE AND WORK OF SIR JAGADIS C. BOSE 



as Maxwell had foreseen and Hertz had shown, analogous 

 to those of light ; and then with their correspondence, 

 increasingly determined by Bose's work, as regards their 

 reflection, refraction, polarisation and other phenomena 

 in short, an advance of electro-optics. 



But now, leaving the direct study of the varied yet 

 profoundly similar rays of this long spectrum of radiation, 

 which we call ultra-violet, luminous, thermal and electric, 

 we come to a third class of problems touching the effects of 

 diverse radiation on different kinds of matter. As to the 

 effect of electric radiation, Bose was able to show that it 

 induces a state of temporary or permanent molecular strain 

 in matter attended by physical or chemical change in the 

 substance. Since electric waves have turned out to be so 

 similar in their nature and behaviour to those of light, may 

 they not also have molecular reactions more or less similar 

 to the photographic effect ? In the concluding part of 

 his Electric Touch paper, Bose says : 



The effect of electric radiation (like visible radiation of light) 

 is to produce rearrangement of the atoms or molecules of a sub- 

 stance ; so does light produce new atomic or molecular groupings 

 in a photographic plate. The contact-points of the coherer 

 may therefore be regarded as corresponding to the particles 

 of a photographic plate. Investigation on this aspect of the 

 subject has given me some extraordinary results. They seem 

 to connect together many phenomena which at first sight do not 

 seem to have anything in common. I am at present trying to 

 arrange an apparatus which will, by means of the pulsating 

 galvanometer spot of light, automatically record the various 

 molecular transformations caused by external forces. 



While the speculative hypotheses with which so many 

 fruitful investigations begin have to be experimentally tested 

 and verified before they can be published as contributions 

 to positive science, it is their inception and development 

 which are the main interest in any biographic treatment. 

 Moreover, is not this view of any investigator, as struggling 

 to criticise his dream, interesting and suggestive to other 



