36 ROYAL SOCIETY OF CANADA 



have been noted by a few writers in describing phenomena, otherwise 

 quite dissimilar to the phenomenon observed by the writer. 



145. In concluding this paper, I wish to thank most heartily those 

 who have assisted me — more especially — my wife, and Prof. E. W. 

 Quick, for helping me many times with the stop-watch experiments, 

 Dr. Mcintosh, for his careful examination of ni}' eyes^ and Prof. E. L. 

 Niçois, for kindly reading and criticizing the manuscript. 



Eothesay, N.B., Canada. 



' My eyes were found to be, in every way, normal, and in respect of colour- 

 fields and acuteness of vision, somevrhat above the average. 



