A modification of Feldman's porous e lectrode method is described for t he spectrochemical analysis of bronze (3 Sn, 3 Zn , 2 Pb, 2 N i, 90 eu). A I-gram sample of bron ze drillings is dissolved by the addition of 4 millili ters of hydrochloric a cid and 16 milliliters of nitric acid and after dilution to 40 milliliters wit h wate r, t he solution is transferred to t he hollow e lectrode for ~par k ~xcitation . The a nalysis is made with reference to standard solut io ns p repared in a similar

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... anner. Studies of t he effect of electrode shape on t he reproducibili ty of excitation le d to t he adoption of a porous electrode having a t ip in t he shape of a t runcated cone. With t h is electrode t he precision was greater by a fa ctor of 1.2 t o 2.1 over that obtained wi t h a flat-tipped e lectrode. T he precision of t he method, determined as the coefficient of variation of a group of duplicate runs on 50 samples, ranged from 1.6 percent for nickel to 4.3 percent for lead. On t he a verage, t he res ults of routine s pectrochemical determ inations agree wi th the res ul ts of chemical determinations 011 t he same samples to within ±5 percent.