858 EXPERIMENT STATION RECORD. 



wool cotton" lost 1G.87 per cent by the new method and 16.64 per cent 

 by the Weende method. 



The conclusion is reached that the new reagent does not attack the 

 cellulose of these materials, but it is quite as capable of dissolving 

 their impurities as the Weende method, which is the more energetic in 

 its action.^ 



Gluten ])repared from wheat Hour, the commercial preparation of 

 gluten (aleuronat), and nuclein (in wheat bran) were all dissolved by 

 treatment with peroxid of hydrogen and ammonia. It is assumed that 

 the other constituents — coloring matters, organic acids, tannins, alka- 

 loids, and f\it — are removed by this treatment. 



The method as finally elaborated is described as follows: Three to 

 five grams of flour or bran is passed through a 0.2 mm. sieve, inti- 

 mately nuxed with 100 cc. of water in a beaker, and boih^d a half hour 

 to gelatinize the starch. To this is added 50 cc. of a 20 per cent solu- 

 tion of peroxid of hydrogen, and the whole boiled for 20 minutes, 15 

 cc. of 5 per cent ammonia being added in 1 cc. portions during the 

 boiling. It is then boiled 20 minutes longer, and filtered while still hot 

 through a weighed filter, washed with hot water, dried, and v/eighed. 

 The ash is deducted from the residue, and in case of materials very 

 rich in protein this also is dedu(;ted. The solutions are said to filter 

 readil}', which is quite an advantage. 



Comparisons on rye bran showed 37.10 percent of crude fiber by 

 the new method, and only 0.78 per cent by the Weende method ; and 

 on "black flour" (similar to bran), 12.63, 12.85, 12.55, and 12.93 per 

 cent by the new method, and 3.69 and 3.645 j)er cent by the Weende 

 method. As a rule, the parallels by the new method agree fairly well. 

 Thus, a sam])le of rye bran gave 14.11 and 14.28, 12.96 and 13.37, 

 14.19 and 14.34 per cent; wheat bran, 19.83 and 19.80; wheat kernel, 

 5.36 and 5.72 per cent. "The results obtained are sufficiently con- 

 stant." Slight changes in the strength of the peroxid of hydrogen 

 solution are said to be of no importance. 



A modification of Stutzer's method for the determination of 

 albmninoid nitrogen in substances rich in starch, H. Teyller 

 {Chi'iii. Zt<j., JJI {1S97), Xo. 6', j>. 51). — The determination of albuminoid 

 nitrogen in substances containing inuch starch by Stutzer's method is 

 both tedious and liable to inaccuracy, owing to the difficulty of thor- 

 oughly washing the precipitate made by the copper hydrate. The 

 author proposes to dissolve the greater part of the starch by means of 

 diastase to facilitate the filtration. 



He reports experiments with a variety of substances, using the fol- 

 lowing method of comparison: For 1 gin. samples of each substance 

 were weighed out in beakers, 100 cc. water added, and the mass stirred 

 until it became of uniform consistency. The beakers were heated for 



1 Suringar and Tollens have recently shown (E. S. R., 8, p. 741) that the reagents of 

 the Weende method change and dissolve the true cellulose. — Ed. 



