224 EXPERIMENT STATION RECORD. 



point 24° C, acid miiii))cr 1GG.2, saponification number 193.5, ether number 27.3, 

 iodin nundier91.()5, Reichert-Meissl number 1.1, mean molecular weight of in.soluble 

 fatty acids 289.3, melting jioint of in.soluble fatty acids 30°. The development of 

 acidity in rice oil was found to be due mainly to a fat-splitting enzym. In experi- 

 ments with steers the average coefficient of digestibility of rice oil in bran was 54.8 

 per cent, and in rice ixdish 73.6 per cent. 



The determination of commercial glucose in molasses, sirups, and honey, 

 A. E. Leacji [Join: Amrr. Vlwm. ,%(■., :i', {lOO-i), Xo. !',2>P- .''<SV-,9<S7). — This is mainly 

 in reply to an article by E. Gudeman (E. S. R., 14, pp. 224, 1045). The author justi- 

 fies for jjractical purposes in the inspection of molasses, sirups, and lioneys, as found 



, , . n .. (a— S) 100 . , . , ^, 

 on the market, the use of the formula G= tt^h — , in which G represents the per- 

 centage of commercial glucose in the sample, a the direct jxilarization, and S the 

 percentage of cane sugar as calculated from direct and invert jjolarization according 

 to Clerget's formula. 



Disappearance of reducing sugar in sugar cane, H. W. Wiley {Jour. Amer. 

 Chem. Sor., Jo {lHO.i), Xo. S, ]>]). S!'>6-S.'>7). — The author reports the absence of reduc- 

 ing sugar in 4 samples of sugar cane grown in Florida and analyzed by A. Given. 

 Inasmuch as the jjroportion of reducing sugar to sucrose in the cane is greatest in the 

 early stages of growth and decreases as maturity approaches, this unusual occurrence 

 is attributed to the perfect maturity of the plant and the absence of the deterioration 

 due to overripeness or other causes. The author considers it probable that the 

 meteorological conditions which pro(h;ced so comjdete a growth do not often obtain. 



Coloring matter in yellowish-gray sugar, Y. Nikaido {Jour. Amer. Chem. Soc, 

 25 {1903), No. 8, pp. 857-860). — A slight yellowish gray tint to crystallized l)eet 

 sugar observed in a few instances was believed to be due to iron oxid, the evidence 

 pointing toward the lime rock as its source. 



The volumetric determination of nitric nitrogen, Debourdeaux {Compt. 

 Rend. Acad. Sd. Paris, 136 {1903), No. 26, pp. 1668, 1669).— The method is based 

 upon the oxidation, at a boiling temperature, of oxalic ac.Vl by the nitric acid, the 

 amount of oxidation being measured by titration in the presence of not more than 

 20 per cent of sulphuric acid with potassium permanganate. The method may be 

 applied in presence of reducing substances by precipitating the oxalic acid with lime 

 and determining it either gravimetrically or volumetrically. 



A colorimetric method for the determination of small quantities of 

 potassium, L. A. Hill {Jour. Amer. Chem. Hoc, 25 {1903), No. 9, pp. 990-992).— 

 The method here described is intended primarily for use in the analysis of soil 

 extracts and drainage waters containing such small amounts of potassium that it is 

 impracticable to use the gravimetric method. "The method depends ujion the pre- 

 cipitation of the potassium in the usual way with chlorplatinic acid, and the subse- 

 quent reduction of the potassium chlorplatinate with stannous chlorid in the 

 presence of free hydrochloric acid. . . . 



"The analytical process, up to the point of adding the stannous chlorid, is essen- 

 tially the same as that used in ordinary analysis. 



"To 50 cc. of the solution to be tested add 1 cc. of dilute sulphuric acid, evaporate 

 to dryness, and ignite to whiteness. Dissolve the residue in hot water, acidified 

 with a few droi)S of hydrochloric acid, and add an excess of chlorplatinic acid. The 

 solution is then evaporated to a thick paste in a small dish and 80 per cent alcohol 

 added. "Wash the precipitate thoroughly with 80 per cent alcohol, then dissolve in 

 boiling water, cool, and make up to a definite volume (100 or 200 cc. ). 



"Transfer 50 cc. of this solution to a color-comparison cylinder and add 3 cc. of 

 the stannous chlorid solution. A yellow color is produced, the intensity of which 

 is proportional to the amount of potassium chlorplatinate present. This color is 

 exactly matched by introducing into other cylinders quantities of the standard 



