An Experimental Study of the Reflection of X-Rays from Calcite

Per cent., of monochromatic X-rays reflected from calcite, for wave length ranging from.3 Å.8 Å was studied by means of a double X-ray spectrometer. A narrow beam of general radiation fell at an angle upon a crystal designated as $A$ and the reflected beam was allowed to fall upon a second crystal designated $B$. The intensity of the beam from $B$ was then compared, by means of the ionization produced in an ionization chamber with the direct beam from $A$. Per cent., reflection was found surpisingly large when the surfaces of the two crystals were strictly parallel. The per cent., reflection will depend upon the character of the beam reflected and therefore upon crystal A.