【正文】 hydrogenated cottonseed oil remain in the group that is difficult to saponify. We believe the reason for its improved success is the intimate mixing caused by the mechanical stirring which liberates the oil particles occluded by the soap formed in the initial reaction. The emulsion is very stable in the 105 176。 C. The oxidation is done by means of potassium dichromate, the excess of which is titrated with sodium thiosulphate solution using starch as the indicator. Results by this method pared with those of Method I as well as those determined from the ester values are given in Table II. It will be seen that in the first four cases the results of Method I and the Carius Method agree very well, but both vary from the percentage glycerol determined from the ester value. The variation is greater for the acidulated oils than for the unrefined oils, a fact which is in agreement with laboratory experience. Method I is not applicable to such oils as refined tallow, but it will be noted in these cases that the results of the Carius Method agree very well with those calculated from the ester values. This work was extended to the refined and pure oils, the results of which are given in Table III. After this set of experiments was pleted it was found that coconut oil requires a lower temperature than the other oils, and probably if the effect of temperature were studied, a condition for plete saponification could be ascertained. The averages of several determinations for Cottonseed oil, hydrogenated cottonseed oil, and tallow vary +, +, and + percent, respectively, from the calculated values obtained from the saponification and acid numbers, while the greatest deviation of a single determination differed from t39。 C. However, to ascertain the exact influence of temperature, a series of experiments in which the temperature was increased by 10 176。C., was performed. The observations made are recorded in Table V. The earlier experience was definitely substantiated and 140150 176。 C., and the percentage of glycerol determined and found to be % as pared with %, calculated from the saponification and acid values. In other words, a grainy emulsion will not lead to plete saponification. The next factor to be studied was that of quantity of stearic acid most efficient in producing a good emulsion. The amount was varied from 0 to % of the weight of the Oil A in increments of %. The appearance of the resulting emulsions is listed in Table VI. Four per cent of stearic acid was found to produce as fine an emulsion as larger amounts, and that quantity was then standardized as the most efficient. After these conditions were established, the time factor was series of determinations was made, in which each one was started five minutes after the previous one, the first one being kept in the 105 176。 C. oven was ascertained by two series of determinations of percentage glycerol available from Oil A, similar to those made for stearic acid. The results are found in Table VIII. Again 20 minutes was selected as a reasonable length of time for plete saponification. The catalysts, stearic acid and bentonite, were then applied to the saponification of the highly purified oils。 C. for the initial temperature of the oils when the caustic is added was too bigb for Coconut Oil and Tallow and that good emulsions are not formed. A temperature of 110120 176。C.,so that instead of heating the flask containing the oil in an oil bath at 160 176。C. oven where the saponification is pleted. If a 105 176。 grams,is accurately weighed in a 100 flask on an analytical balance. Roughly grams of stearic acid or to grams of bentonite are added ( grams for tallow and coconut oil, grams for hydrogenated cottonseed oil and grams for cottonseed oil). The stearic acid is conveniently added by dropping from a roughly calibrated dropper. The fat containing the stearic acid is heated to 140150 176。 C. for tallow and coconut oil by immersing in an oil bath at 160165 176。 C. in a water bath or 105 176。 C. oven. After 20 minutes it is removed, the soap is dissolved and the solution is cleared, oxidized and the excess oxidant titrated. SUMMARY Several methods of saponification of fats for the determination of available glycerol are considered. 1. The Direct Saponification Method? 2. A Method proposed by the . Committee on Glycerine Determination. 3. The Carius Method. 4. A Method for Rapid Saponification of fats and oils is proposed for laboratory use in determining glycerine yields in which stearin acid or bemonite is added as a catalyst. Upon the addition of potassium hydroxide and vigorous shaking, a fine emulsior~ is formed provided the proper conditions are regarded. The saponification takes place in a 105 o C. oven and is pleted in 20 minutes. The proposed method has the followingadvantages : saponification is pleted in 20 minutes. 2. No special apparatus is required. 3. Saponification takes place at the paratively low temperature of 100 to 105 176