9 



RECENT DEVELOPMENTS OF X RAYS. 



BY 



WILLIAM WEBSTER, F.C.S. 



Abstract of a Paper read at the Meeting of the 

 Society, on 25th March, 1903. 



T is a curious fact that so many eminent workers in the 

 Section of Scientific Research connected with Electri- 

 cal Discharge in High Vacuo, should have missed the 

 discovery of the Higher Vibrations emanating from Glass 

 Tubes employed in experiments of little value except for 

 pleasing lecture demonstrations. 



As far back as 1665 it was noticed that when the mercury 

 column in a glass tube forming the Torricellian Barometer was 

 made to rise and fall rapidly, in the empty tube above the 

 mercury a greenish phosphorescence appeared in the vacuum ; 

 although Frictional Electricity was then known, it was evidently 

 not suspected that the attended discharge of Electricity was 

 produced by the friction of the mercury. 



The published records of the work of De la Rue, Gassiot, 

 Geissler, &c, all show the same " miss-fires," for if these 

 workers had suspected the great secret they might have 

 succeeded. 



Sir William Crookes, the inventor of the tube which 

 bears his name, failed to recognise the action of the then 

 known mysterious vibrations, although they were signed on a 

 photographic plate as developed shadows of fingers. Although 

 Professor Rontgen undoubtedly demonstrated the chemical 

 action of these Rays, Professor Jackson, of King's College, was 

 lecturing before this discovery, on the penetrative power of the 

 vibrations, illustrating their action on a chemical screen. 



