The discontinuity in the "continous spectra" of x rays. - By studing photometries, repeated several times, the following facts are proved:
1.º - That the "continuous spectre" contains a considerable number of lines.
The structure disappears at the points corresponding to the characteristic radiation and begings again after these points. From this fact is possible to suppose that the continuous spectre really exists and that the lines found respond to a cause as yet unknown.
2.º - The absence of structure in the field of the characteristic radiation shows that the lines given in the tables are originated by the radiations emergin from the anticathode.
3.° - We attribute the existence of the structure to phenomenons that take place in the fine slit of the spectrograph.