1. The inorganic phosphate, soluble calcium and soluble magnesium levels in the various divisions of the stomach of the sheep on different diets have been studied.
2. The concentration of inorganic phosphate and soluble magnesium in ruminal and abomasal liquors was of the same order in these two divisions of the stomachs of three fistulated animals independent of the type of feed or time after feeding at which the samples were taken.
3. The concentration of inorganic phosphate, soluble calcium and magnesium in omasal liquor of slaughtered sheep was higher in all cases than the corresponding value for rumen liquor, lending support to the idea that one of the functions of the omasum is to absorb water.
4. Although the concentration of soluble calcium in omasal liquor was higher than that found in the corresponding ruminal liquor, much higher levels were found in abomasal liquor than in omasal or ruminal liquors.