Contemporary Advances in Physics, XVIII, The Diffraction of Waves by Crystals

This is an elementary introduction to the phenomena of diffraction of waves by crystals, one of the most striking a n d i m p o r t a n t discoveries of the last t w e n t y years of physics. These phenomena have proved t h a t X-rays a n d electrons are p a r t l y of the nature of waves, a n d have supplied the best available methods of measuring their wave-lengths; while on the other h a n d , the s t u d y of the diffraction-pattern of a crystalline substance makes it possible to determine the arrangement a n d the interrelations of the a t o m s w i t h a precision a n d fullness heretofore u n i m a g i n e d , which has already yielded knowledge of great value in all the fields of science a n d promises i m m e a s u r a b l y more.