206 EXPERIMENT STATION RECORD. 



As to the presence of plant fats in supposedly animal fats the question is pro- 

 pounded whether phytosterol is present in a free state lilie cholesterol. Other 

 investigations have shown that the phytosterols exist chiefly in ester combina- 

 tions in plant fats and oils ; conseciuently when these fats are present in animal 

 fats saponification is necessary for their determination. The digitonin method 

 gives higher results than Burner's method. 



The results of the investigation on the quantitative determination of phy- 

 tosterol will be reported on later. 



Method for determining extremely small quantities of boron in organic 

 substances, G. Bertrand and H. Agulhon {Ann. Falsif., 7 (1914), ^^o. 6.'f, pp. 

 67-69, fig. 1). — In this method the length of color obtained by capillary attrac- 

 tion, etc., on strips of turmeric paper placed in a receptacle containing the solu- 

 tion to be tested and hydrochloric acid is noted. 



Rapid estimation of phosphoric acid in baked goods, etc., L. Sobbx 

 (Schweis;. Wchnsclu: Chem. n. Pharm., 51 {1913), No. J,o. pp. 677-679; ahs. in 

 CJiem. Ztg., 3S {1914), ^o. 26, Repert., p. i76).— Twenty-five gm. of well-dried 

 and finely pulverized goods is rubbed up three successive times with 100 cc. of 

 96 per cent alcohol and filtered from the residue. The residue is then washed 

 with alcohol until a total bulk of 300 cc, inclusive of the original extracts, is 

 obtained. An aliquot of the upper clear fluid is evaporated carefully with from 

 2 to 3 gm. of magnesium chlorid and 3 gm. of sodium nitrate, and then ashed 

 and the ash taken up with dilute hydrochloric acid. The phosphoric acid is 

 determined in the filtrate as magnesium ammonium phosphate, etc. 



A study of the methods for the determining of sulphur dioxid in dried 

 fruits, M. E. Jaffa {California Sta. Rpt. 1914, PP- 131-13S). — On reviewing the 

 literature on the determination of sulphur dioxid in dried fruits the data found 

 were too inadequate to enable the analyst to obtain correct and duplicate results. 

 A study was made with apricots, peaches, pears, nectarines, prunes, and raisins, 

 for the purpose of obtaining an adequate procedure for this work, and consid- 

 ered the following points: Precautions against extraneous sulphur, amount of 

 sample to be used, amount of distillate, number of distillations necessary, number 

 of absorption jars, nature of the oxidizer, quality of the carbon dioxid, and 

 amounts of other reagents. 



" Sulphur dioxid determinations in fruits are now being made according to 

 the following method: Side neck 500 cc. distillation flask with a cork stopper, 

 fruit finely macerated and thoroughly mixed, 8 gm. sample placed in flask. 20 

 cc. 20 per cent phosphoric acid added, 175 cc. distilled water added to contents 

 of flask; 500 cc. Dreschel absorption jar connected to condenser with as short 

 rubber connection as possible, inlets bent vertically for direct connection with 

 vertical spiral condenser, 100 cc. solution of 20 gm. per liter potassium bromid. 

 saturated with bromin, and 10 cc. 10 per cent sodium carbonate solution used in 

 jar for absorbing medium ; sodium bicarbonate used in second 500 cc. Dreschel 

 absorption jar to catch volatile bromin; current of pure carbon dioxid gas 

 passed through the whole apparatus. Distill with medium flame until about 

 180 cc. have passed over or until the fruit in the distilling flask is m pasty 

 condition. Transfer distillate to 600 cc. Jena beaker, add 5 cc. concentrated 

 hydrochloric acid, and evaporate to about 5 or 10 cc. on electric hot plate in 

 clean hood. Take up with hot water, transfer to 150 cc. beaker, heat to boiling. 

 Precipitate with few drops of barium chlorid. Leave in warm place overnight, 

 filter, wash with hot water, burn, and weigh. The method as given thus in 

 detail gives very satisfactory results. Almost perfect blanks are obtainable at 

 will and duplicate and concordant results are the rule." 



