186 QUANTITAT1 VK AGltK'ULTl'RAL AXA/A'MH acids carried over by the steam, receiving the filtrate in a flask graduated to contain 100 cc. Titrate 100 cc of the filtrate with standard potassium hydroxide. Make the proper correction for the fact that only 100 cc of the distillate was used, also correct the number of cubic; centimeters of standard potassium hydroxide used, in case this solution was not exactly tenth-normal or in case the sample weight was not exactly 5 gm. The* result IB the Jleichert-Meissl number. Polenske Value.—-One of the very important constituents of some butter substitutes is cocoanut oil, a pure white vegetable fat having a pleasant taste* and a con- sistemjy which is about the same as that of butter. Its Iteieheirt-MeiHsl number is lower than that of butter, as is shown in Table IX, pages 184. The ve>latile acids obtained from cocoanut oil in the Reiehertr-Meissl distillation contain much larger quantities of adds insoluble at 15° than do the volatile* adds from butter. Butyric aciel comprises from 00 te> 70 per cent of the* volatile acids fmm butter and this aciel in soluble in water in all proportions. The volatile^ acids from cocoanut oil contain larger quantities of e*aproic, cuprylie, capric anel lauric acids, these* being almost insoluble at 15°. The Polenske value (called by its author the "new butter value1') is the number of culric centimeters of tenth-normal bane required to titrate Ike insoluble acids obtained in the Reichert-Meixxl distillation. The Polenske value for pure butler varicw from 1.5 to 3.0, while that for cocoanut oil varies from IB to 18. It is necessary to avoid the use of alcohol in the Haponification of the fat and therefore the determination of Keiehert-Meissl number must be modified if the two determinations are.to be combined Polenske's modification IB essentially an follows: Betennination.—Saponify 5 grn of the fat by healing in n 250-fc* round flask, using a reflux condenser. For the* HapomhVation use 20 #m of glycs erol arid 2 cc of a /K)-per cent solution of sodium hydroxide in water. When «ape>nifie.ation in complete dissolve the soap in 135 ee of recently i)oile