ORIGIN OF X-RAYS.

New Zealand Herald, Volume LX, Issue 18293, 9 January 1923, Page 9

ORIGIN OF X-RAYS.

MANCHESTER DISCOVERY. t " ■ At la meeting of the Manchester Literary' and Philosophical Society Mr. v William Thomson, of Manchester,' presented the v societywith \ some' phosphorescent metallic sulphides; contained in four.-.tubes,; Which, : ,_. he ; claimed, led ultimately to ;,the -.4?s*:;., covery of X-rays by Professor Rontgen. ,• The - tubes, > Mr. Thomson sxplained, were \ fixed on a wooden stand arranged so; that : a high-tension!electric: current .could be , passed through the four; at 'the's same ; time, .which had the effect of making the: Lsulphidss 'glow r brilliantly ;in different 1 colours. , i " This frame and the tubes,; Mr. Thomson said, he had found in a cupboard in, his ;■■ laboratory- some months ago, where] they had lain for the last 45 years; During 1875 , ; he"had ' been 1- interested in the wonderful beauty of the .colours and /brilliancy. of certain metallic /sulphides ;Srsfc brought to notice r . by. BecquereJ, of Paris.;' He made "experiments with them,- and. in ■January, 1877, read a paper.'; befogs that., society '-. exhibiting the . very, tubes, which he now presented tothem; V At:the.time he was impressed with the idea that>spme important; discovery could ; bo ;, made through l the study of the light emanating; from: the sulphides, but he was unable to. devote the necessary time::to the subject. ; L The same "■■ year,' however,-; he wrote to Mr.- William Crookes) '{ai : Sir Wil-. ltaih;'Crookes)i who waa then working high i vacua, ■ suggesting that-.\Sfe; would be interesting to study the-sdlphides ] in the high vacua he, was then r able to produce. A s few day^;later, Mr. -Thomsoh ,said f Sir:. Williams Crookes' .came, to ; Manchester.;, when, he showed him the vacuum tubes he had-, produced,; which?; glowed brilliantly under the electric current,'and gaye.liim. some':'■■': of -.: those/sulphides -with/ which Sir William afterwards made &$ classical re-" 'searches bhrafdiant matter. > Subsequently; ; tubes containing sulphides in::high . vacua:' were reproduced by philosophical;.' instru-'. meht- makers arid sold as : "Crookes* Tubes." Arid it was while exhibiting one': of- : .tubes that Professor , Eontgea; 'accidentally;discovered /thai the rays-from.;" it, /which : were now known 'as -Xrrayfl. ' penetrated : : what : : we -regarded'.' as. opaque: .bodies;,:'..'■■ ' > v „• .t-\ , ;; Some years ago,. Mr; ; Thomson, :said, r he received a letter from Sir William :Crookes, : -" : in, - which . he. ' expressed the.' opinion; that when., 'history of "the Rontgen Rays came to be published, the part which .Mr.Thomson had, taken in it would be duly acknowledged. \ -/ . ■-■."'■-.. ; '-' C6ricludmg,v.Mr?, Thomson said- that jhfir considered he was i justified ; in; claimingfor :'/'. Manchester and the }■ Mancheste?-} Literary and-,. Philosophical - Society that thefirst -step toward the discovery of the X-ray was taken .in this city by -'ItSxii"- inducing' Sir". Williami:Crookes to-turn his attention to; those sulphides which,led to his researches on. radiant matter, ■, the: ; second'step; while the;third-was the dis/covery by 'Rontgeh that the rays passed through "bodies-which were ; opaque//to /ordinary; light. '■■'■;- - ;./" 'y/:y^.