THE PRESIDENT'S ADDRESS. 113 



cry of " Excelsior " high up in the air ; objectives which formerly 

 were sources of satisfaction are now no longer sufficiently powerful; 

 higher and still higher powers are demanded till the limits of 

 illumination forbid his further advance, but still the longing desire 

 to see more and farther into the invisible is unsatisfied, and in our 

 present stage of progress ever will be. 



To gain some insight into the magnitude and universality of 

 this interest, we have only to look back over past ages to the early 

 dawn of the science of optics, when the refrangibility of the light 

 rays first arrested the observation of mankind, and then, tracing up 

 the successive steps by which men sought to understand the various 

 phenomena presented to their notice, we shall find that the desire 

 for further information in this direction led to further investigations. 

 Men were not satisfied by the bare glimpses revealed, as it were* 

 through chinks and crevices, they longed to burst open the vast 

 and wondrous storehouse which, by deductive reasoning, they felt 

 lay beyond, and so they laid fact to fact, till law after law was 

 eliminated from the hitherto unknown. 



It is my wish this evening to endeavour to trace, shortly and 

 briefly, because of the shortness of the time that can be allotted to 

 me, some of the successive steps by which we have attained to our 

 present position in the use of the microscope. 



In our endeavours to trace the history of Optics back to remote 

 times, we are met by much obscurity and no small difficulty in 

 extricating ourselves out of a great deal that is uncertain, and our 

 perplexity is not diminished by the considerable difference of 

 opinion prevalent amongst the ablest critics relative to the first 

 observers of that wonderful mode of motion upon which all our 

 microscopical studies are based, and which we call Light. We 

 shall readily concede that the earliest inhabitants of the earth were 

 cognisant of the contrasts of light and shade, but beyond that 

 point their observations did not probably extend. Then we read 

 iu history of the Chaldeans, Egyptians, and Chinese who, in early 

 days, were acute astronomers, but we are not warranted in believ- 

 ing that they knew anything of the science of Optics, and certainly 

 did not possess astronomical glasses; and although their observa- 

 tions were very accurate with such means as they did possess, it 

 remained for successive generations to work out the laws of Light, 

 which work has culminated in the finished and elaborate apparatus of 

 to-day. In dealing with this subject we cannot overlook the im- 



