308 Pro/. Bose on the Polarisation of the Electric Ray. [Jan. 29, 



of vibration — from about 400 to 800 billions in one second. As the 

 frequency of vibration rises still higher, our organs of perception fail 

 us completely ; a great gap in our consciousness obliterates the rest. 

 The brief flash of light is succeeded ^by unbroken darkness. 



These great regions of invisible lights are now being slowly and 

 patiently explored. In time the great gaps which now exist will be 

 filled up, and light-gleams, visible and invisible, will be found merg- 

 ing one into the other in unbroken sequence. 



Before I conclude I may be permitted to express my sincere 

 thanks to the managers of the Eoyal Institution for according me the 

 privilege of addressing you this evening. I cannot sufficiently ex- 

 press my gratefulness for all the kindness I have received in this 

 country. When the managers of this Institution, which has done so 

 much to advance the cause of Science and Arts, invited me here, I 

 felt that the scope of this great Institution was not merely confined to 

 these shores, but embraced other countries, even the most distant. 

 The land from which I come did at one time strive to extend human 

 knowledge, but that was many centuries ago ; a dark age has since 

 supervened. It is now the privilege of the West to lead in this work. 

 I would fain hope, and I am sure I am echoing your sentiments, that 

 a time may come when the East, too, will take her part in this 

 glorious undertaking ; and that at no distant time it shall neither be 

 the West nor the East, but both the East and the West, that will 

 work together, each taking her share in extending the boundaries of 

 knowledge, and bringing out the manifold blessings that follow in its 

 train. 



[J. C. B.] 



