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ROYAL SOCIETY OF CANADA 



47. From foregoing results average of all periodicities for E sen- 

 sation equal -526, and for I B sensation equal -489. It will be noted in 

 the above table that the oscillations for both sensations are quicker when 

 I B light is in the right eye and E light in the left eye, than when 

 the glasses are reversed for the two eyes, but whether there is a real 

 difference in periodicity for the two eyes, or whether this difference is 

 purely accidental is a matter not yet decided, although the writer 

 hopes in the near future to settle the question. 



48. Some experiments made about this time to determine the 

 influence on the periodicity of the heart-beat and body temperature, 

 met with negative results. 



49. The results of some experiments to ascertain the relative 

 periodicities for colours and their complementary after-images are given 

 in the following table — the coloured plate (used with the Lambert 

 apparatus par. 22 ) was " fixed '" for a short time and then two readings 

 were taken, after these the eyes were closed, light excluded with the 

 hand, and two readin2:s more were taken. 



50. It will 1)6 noted from the foregoing talkie that the oscillations 

 for the Gr B and I B after-images become at first a little quicker than 

 the second readings for the E and Y glasses, respectively, but for the 

 E and Y after-images the oscillations are a little slower than those 

 given by the second readings for the C B and I B glasses, respectively. 



51. The rather slow and relatively irregular periodicities read in 

 the case of the " fixed " coloured plates was probably caused by the 



