A study of the distribution, nature and metabolism of glyceryl ethers in natural fats is in progress, and as a preliminary to the publication of results, a method which has been used for the quantitative estimation of α‐glyceryl others in the unsaponifiable fractions of natural fats is described. In this method the unsaponifiable matter of the fat is treated in solution in ethyl alcohol or ethyl acetate with an excess of periodic acid solution, and the formaldehyde generated is estimated gravimetrically. The results obtained have been checked by volumetric estimation of the periodic acid consumed in the reaction. In very many cases, as with batyl alcohol itself, agreement has been observed between the results of the two methods. Diserepancies with a number of fats indicate, however, the existence in their unsaponifiable matters of substances other than α‐glyceryl others which are attacked by periodie acid. These cases are under fuller investigation.