Castrated lambs given diets containing 200 mg lead per kg and 0·7, 2·3 or 3·8 g sulphate sulphur per kg survived for a mean time of 6, 15 and 30 weeks respectively. A few weeks before death they stopped eating and lost weight rapidly but showed no other signs of toxicity except for histological changes in the kidney. After the first few weeks tissue and blood lead contents were fairly constant and in 2 sheep alive after 40 weeks blood lead concentrations decreased. In another experiment intact male lambs were given diets containing 400 mg lead per kg and 0·7 or 3·8 g sulphate sulphur per kg. The lambs given the lowsulphur diet died within a few weeks and had anorexia, anaemia, osteoporosis and kidney lesions.