In the spring of 1925, in the course of an extensive investigation of the excretion of lead in the human subject, certain results were obtained which are sufficiently at variance with previous opinion and observation, and which are of such intrinsic importance as to merit their presentation apart from the problems being investigated. The results, detailed in the following paragraphs, show that the secretion of lead in the urine and feces of apparently healthy, normal men is a matter of almost uniform occurrence. METHODS OF ANALYSIS It developed that the method proposed by Fairhall, 1 in the hands of the laboratory staff, gave results not so consistent or accurate as were desired. After extensive study, this method was slightly modified into the following procedure: Analysis of Urine. —The samples of urine were received in gallon jugs of the type used for fruit juices. The volume was measured, and the samples