202 SIR WILLIAM CKOOKES ON PSYCHICAL RESEARCH. 



capable of receiving such vibrations. If the scene I wish to impress 

 on the brain of the recipient is of a complicated character, or if the 

 picture of it in m}^ own brain is not definite, the transmission will be 

 more or less imperfect; but if 1 wish to get my audience to picture to 

 themselves some very simple object, such as a triangle or a circle, the 

 transmission of ideas will be well-nigh perfect, and equally clear to 

 the brains of both transmitter and recipient. Here we use the viljra- 

 tions of the material molecules of the atmosphere to transmit intelli- 

 gence from one brain to another. 



In the newly discovered Rontgen rays we are introduced to an order 

 of vil)rations of extremest minuteness as compared with the most 

 minute waves with which we have hitherto been acquainted, and of 

 dimensions comparable with the distances between the centers of the 

 atoms of which the material universe is built up; and there is no reason 

 to suppose that we have here reached the limit of frequency. Waves 

 of this character cease to have manj^ of the properties associated with 

 light waves. They are produced in the same ethereal medium, and are 

 proba1)ly propagated with the same velocit}^ as light, but here the 

 similarit}'^ ends. They can not be regularly reflected from polished 

 surfaces; they have not been polarized; they are not refracted on pass- 

 ing from one medium to another of difi^erent density, and they pene- 

 trate considerable thicknesses of substances opaque to light with the 

 same ease with which light passes through glass. It is also demon- 

 strated that these rays, as generated in the vacuum tube, are not 

 homogeneous, but consist of bundles of different wave-lengths, analo- 

 gous to what would be differences of color could we see them as light. 

 Some pass easily through flesh, but are partially arrested by bone, 

 while others pass with almost equal facility through bone and flesh. 



It seems to me that in these rays we may have a possible mode of trans- 

 mitting intelligence which, with a few reasonable postulates, may 

 supply a key to much that is obscure in psychical research. Let it be 

 assumed that these rays, or raj^s even of higher frequency, can pass 

 into the brain and act on some nervous center there. Let it be con- 

 ceived that the brain contains a center which uses these rays as the 

 vocal chords use sound vibrations (both being under the command of 

 intelligence), and sends them out, with the velocity of light, to impinge 

 on the receiving ganglion of another brain. In this way some, at least, 

 of the phenomena of telepathy, and the transmission of intelligence 

 from one sensitive to another through long distances, seem to come 

 into the domain of law and can be grasped. A sensitive may be one 

 who possesses the telepathic transmitting or receiving ganglion in an 

 advanced state of development, or who, by constant practice, is ren- 

 dered more .sensitive to these high-frequency waves. Experience 

 seems to .show that the receiving and the transmitting ganglions are 

 not equally developed; one may be active, while the other, like the 



