1. The extent to which various levels of fats and proteins in rations could influence the effects of elementary sulphur on rats as judged from growth, food utilization and pathological lesions, was studied.
2. The growth-promoting value (gain per unit protein consumed) of the low protein ration was significantly greater than that of the high protein diet.
3. On the same ration the males utilized their food significantly better than the females.
4. Within both low and high fat rations the audition of elementary sulphur significantly lowered the animals' efficiency of food utilization.
5. Irrespective of the fat and protein contents of the diets the livers and kidneys of the sulphur fed rats, as compared with those of the control groups, d id not exhibit any constant pathological changes.