Part 1. The chronic toxicity of naturally occurring food selenium, by M.I. Smith and R.D. Lillie, p. 1-14--part 2. Gastric acidity in chronic selenium poisoning, by M.I. Smith and E.F. Stohlman, p. 15-20--part 3. Liver function and bile pigments in experimental chronic selenium poisoning, by M.I. Smith, B.B. Westfall, and E.F. Stohlman, p. 21-44--part 4. Selenium in the hair as an index of the extent of its deposition in the tissues in chronic poisoning. by B.B. Westfall and M.I. Smith, p. 45-49.