911 



Results of crude fiber determinations. 



r.lvccrin- 



:ilk:ili 

 inetliod. 



Weende 

 method . 



Lupine seed 



Hay 



Sheep dung. . 

 Barley straw 



Oats 



Beets 



Beech 



Per cent. 

 16.49 

 21.11 

 24. fi!) 



40. 0(1 

 11.22 

 4.83 

 56.50 



Per cent. 

 16.63 

 26.28 

 28.69 

 39.51 

 10.92 

 4.96 

 60.39 



In general the agreement between parallel determinations was closer 

 by the glycerin-alkali than by the Weende method. The former method 

 is believed to more completely exclude tlie non-cellulose, nitrogen-free 

 substances from the final product than the Weende method. Swedish 

 filter paper, containing 0.62 per cent water, 0.38 per cent ash, and (by dif- 

 ference) 93 per cent cellulose, was tested by the glycerin-alkali method, 

 which indicated 84,37 j^er cent of cellulose, a loss of 8.03 per cent of 

 cellulose, which is supposed to have been dissolved by the reagents, 

 but which is within the minimum limit of loss (8.9 per cent) observed 

 by Kern with the Weende method. 



The description of the working method, as finally modified by the 

 author, is given as follows : 



Two grams of finely ground substance are digested at 180° C. with 

 60 c. c. glycerin-alkali solution (33 grams KOH in 1 liter glycerin), in a 

 250 c. c. flask, heating on wire gauze. A lively reaction, accompanied by 

 frothing, takes place at 130° to 140°. At frequent intervals the flask is 

 given a gyratory motion to wash down the substance. At 100'^ the prin- 

 cipal reaction is over, but the temperature is gradually raised to 180°. 

 After cooling to 140° the contents of the flask are poured into a dish con- 

 taining 200 c. c. of boiling Avater, thoroughly stirred, allowed to settle, 

 and the supernatant liquid siphoned oft" with a siplion similar to that 

 commonly used in the W^eende method. The residue is washed twice 

 more in this way with 200 c. c. of water, allowing the water to come to 

 a boil each time, and the last time adding 5 c. c. of 25 per cent hydro- 

 chloric acid. The residue is then, as by the Weende method, washed 

 with alcohol and with ether, dried and weighed, and the ash is deter- 

 mined. In many cases the determination of the nitrogen in the product 

 may be omitted as this is so small by this method as to be without 

 appreciable effect on the final result. 



The modified method is believed to compare favorably with the 

 Weende method in every respect, and in j^oint of rapidity to have the 

 advantage. Three hours are said to be sufficient for making three 

 determinations from weighing out to final washing. 



Pentagjucoses, their occurrence in plants and their analytical 

 determination, B. Tollens, A. G-iinther, and G. de Chalmot, reported 

 by B. Tollens [Jour. /. Landw., 40, pp. 11-17). — For some time the 

 author has been engaged in studying the coustituents of the so-called 



