470 Molecules, Ultimate?, Atoms, and Waves. [October, 



in the absence of all external stimulus from the ethereal 

 waves. This phenomenon presents two varieties. In the 

 one, when the eyes are opened after sleep in a perfectly dark 

 chamber, there is perceived a general brightness, and occa- 

 sionally spectral images of various kinds are formed in this 

 apparently phosphorescent haze. In the other variety, the 

 eye is itself phosphorescent, and near objects are seen by the 

 light thus strangely generated within the organ. The author 

 has had numerous opportunities of observing the former 

 phenomenon, and several of noticing the latter, which in 

 like manner manifests itself when the eyes are first opened 

 after sleep. White or light-coloured objects are then 

 clearly perceived as if illuminated by Canton's phosphorus, 

 only brighter. The illumination resembles that thrown 

 upon an object by a lens or bull's-eye, exhibiting a bright 

 central disc, from which it gradually fades away. On closing 

 the eyes for a short time and re-opening them, the bright- 

 ness is found to have vanished, and to be replaced by abso- 

 lute darkness, both in the first and second varieties of the 

 phenomenon. 



It appears not improbable that the eyes of some nocturnal 

 animals may have this same phosphorescent property in a 

 higher degree, and that they may be thus enabled to find 

 and follow their prey by means of light proceeding from their 

 own eyes. No stronger proof than this could be adduced to 

 confirm the conclusion already established by so many other 

 phenomena, that light consists of the vibrations of an 

 ethereal medium. For we have here similar vibrations 

 excited in the eye itself from an internal cause, and these, 

 reacting on the external ether, excite synchronous vibra- 

 tions which are propagated in waves, first from the eye to 

 the outward object, and thence back from the object to the 

 eye. The phosphorescence of the eye in man is believed to 

 be very rare ; but the author has been assured that other 

 individuals besides himself have observed the same pheno- 

 menon. 



