SIR WILLIAM CROOKES ON PSYCHICAL RESEARCH. 201 



are as yet ignorant what are the functions of vibrations of the rates 

 just mentioned. But that they have some function it is fair to 

 suppose. 



Now we approach the region of light, the steps extending from 

 the forty-fifth to between the fiftieth and the fifty-first, and the 

 vibrations extending from 35,184372,088832 per second (heat rays) to 

 1875,0000O(),00()0()0 per second, the highest recorded rays of the spec- 

 trum. The actual sensation of light, and therefore the vibrations which 

 transmit visible signs, being comprised between the narrow limits of 

 about 450, 000000, 000000 (red light) and 750,000000,000000 (violet 

 light) — less than one step. 



Leaving the region of visible light we arrive at what is, for our 

 existing senses and our means of research, another unknown region, 

 the functions of which we are beginning to suspect. It is not unlikely 

 that the X-rays of Professor Rontgen will be found to lie between 

 the fifty -eighth and the sixty -first step, having vibrations extending 

 from 288220,576151,711744 to 2,305763,009213,693952 per second, or 

 even higher. 



In this series it will be seen there are two great gaps, or unknown 

 regions, concerning which we must own our entire ignorance as to the 

 part they play in the economy of creation. Further, whether any 

 vibrations exist having a greater number per second than those classes 

 mentioned we do not presume to decide. 



But is it premature to ask in what way are vibrations connected 

 with thought or its transmission ( We might speculate that the 

 increasing rapidity or frequency of the vibrations would accompany a 

 rise in the importance of the functions of such vibrations. That 

 high frequency deprives the ra3's of many attributes that might seem 

 incompatible with " brain waves " is undoubted. Thus, ra3"s about the 

 sixty-second step are so minute as to cease to be refracted, reflected, 

 or polarized; they pass through many so-called opaque bodies, and 

 research begins to show that the most rapid are just those which pass 

 most easily through dense substances. It does not require much stretch 

 of the scientific imagination to conceive that at the sixtv -second or sixty- 

 third step the trammels from which ra3's at the sixty-first step were 

 struggling to free themselves have ceased to influence rays having so 

 enormous a rate of vibration as 9,223052,036854,775808 per second, and 

 that these rays pierce the densest medium with scarcely any diminution 

 of intensity, and pass almost unrefracted and unreflected along their 

 path with the velocity of light. 



Ordinarily we communicate intelligence to each other b}- speech. I 

 first call up in m}' own brain a picture of a scene I wish to describe, 

 and then, by means of an orderl}" transmission of wave vibrations set 

 in motion b}' my vocal chords through the material atmosphere, a cor- 

 responding picture is implanted in the brain of anyone whose ear is 



