ADAMS. — TIIANSMISSION OF RuNTGEN RAYS. 



679 



or 0.470, and the whole energy of the rays was then ^ ' — , or 



0,00268 gm. cal. per sec. A correction for the absorption in the 

 aluminium window of the instrument, obtained by assuming expo- 



TABLE II. 



ApPROXIMATIO MKASUnEMENT OF ExEKGY. 



nential absorption in aluminium, increased this result to 0.00325 gm. 

 cal. per sec. 



As a quantitative determination of the energy of R-ontgen rays, 

 not too much importance should be attached to this measurement, be- 

 cause the method is subject to obvious inaccuracies, and also because 



