Accurate photographic X-ray intensities have been obtained for nearly all reflexions within the Mo Ka limiting sphere for two single crystals of aluminum. These intensities have been used to give the X-ray Debye temperature, Oz~, in the first part of an experimental determination of the electron-density distribution in solid aluminum. The results of this work show that OD--393 + 1 °K at 293 °K, varying with temperature to Oo=362+9°K at 559°K. The Debye parameter is found to be 0.849+0.005 A2 at 293 °K.