CHEMISTRY. 411 



acid was determined in the combined water solution and citrate extract, 

 the following- percentages were found, viz, 17.79, 14.94, and 13.91. Sub- 

 tracting the percentages of water-soluble phosphoric acid from these 

 figures, we have for citrate-soluble phosphoric acid, by difference, 3.47, 

 0.81, and 3.71 per cent, figures which are much higher than those 

 obtained by determining the citrate-soluble phosphoric acid separately. 

 The author recommends the method of determining phosphoric acid in 

 the combined solutions as more rapid and accurate than separate deter- 

 minations, especially when, as is usual in superphosphates, the amount 

 of citrate-soluble phosphoric acid is small. 



A new method for determining crude fiber in foods and feeding 

 stuffs, J. Konig- (Ztschr. Untersuch. Nahr. u. Genussmtl.,1898, No. 1, p. 3; 

 abs. in Gentbl. Agr. Client., 27 {1898), No. 10, pp. 706-711).— The author 

 calls attention to the fact that the treatment with 1.25 per cent sulphuric 

 acid and potash solution by the Weende method for crude fiber only 

 dissolves a part of the pentosans, and describes a method which he 

 has worked out for the determination of crude fiber freed so far as pos- 

 sible from pentosans. The method is as follows : Three grams of air-dry 

 substance is mixed in a porcelain dish of 500 cc. capacity with 200 cc. 

 of glycerin containing 20 gm. of concentrated sulphuric acid to the 

 liter. The glycerin used is of 1.23 sp. gr., i. e., contains 87.5 per cent 

 of glycerin. The dish is placed in an autoclave and heated under three 

 atmospheres pressure, i. e., 137° C, for 1 hour. After cooling to 80 to 

 100° the dish is removed, the contents diluted with 200 to 250 cc. of 

 boiling water, and filtered hot on a porcelain filter plate covered with 

 finely divided asbestus, or on a Gooch crucible. The residue is washed 

 with boiling water, alcohol, and a mixture of alcohol and ether until 

 the filtrate is colorless, after which it is dried to constant weight, incin- 

 erated, and weighed, the loss in weight on ignition being taken as ash- 

 free crude fiber. With an autoclave 25 cm. deep and 25 cm. in diameter 

 4 determinations can be made simultaneously. In the absence of an 

 autoclave the digestion may be carried on in a 600 cc. flask with a 

 reflux condenser, heating at boiling for 1 hour. At a temperature of 

 120 to 130° frothing usually occurs, but as soon as the liquid comes to 

 boiliug there is no further danger of this. The method gives a crude 

 fiber containing from to 6.62 per cent of pentosans. It was found 

 more difficult to remove the pentosans from leguminous coarse fodders 

 than from grasses. 



Decomposition of monobarium and monocalcium phosphates 

 by water at 100° C, G. Yiard {Compt. Rend. Acad. Sci. Paris, 127 

 (1898), No. 3, pp. 178-180).— Joly and Sorel 1 have shown that monobasic 

 phosphates of the alkaline earths partially decompose in cold water 

 with the formation of dibasic phosphate, which is precipitated, and 

 free phosphoric acid, which remains in solution with the undecomposed 

 monobasic phosphate. The author's experiments show that the same 



'Compt. Rend. Acad. Sci. Paris, 118 (1894), pp. 738-741. 

 10222— No. 5 2 



