RECENT WORK IX ACRICUEITRAL SCIl-XCM 



CHEMISTRY. 



The insoluble carbohydrates of wheat, H. C. Sherman {'Jour. 

 Amer. Cliein. aSVx'., 1!) {1S9?'), Xo. J, pp. :,>!fl-:i/(l). — The author lias devised 

 a method for the estimatiou of ditfereiit carbohydrates iu foods aud feed- 

 ing stiitts whicli includes the determiuation of soluble carbohydrates, 

 starch, pentosans, cellulose, and liguin and allied substances. The 

 reported tests of the method were made principally with wheat bran. 

 The different carbohydrates were isolated aud identified. The ana- 

 lytical method is briefly described as follows: Five grams of substance 

 (previously extracted with ether to remove the fat) is stirred with 

 about 100 cc. of water for a few minutes, filtered, aud washed. To the 

 filtrate one-tenth its volume of 25 per cent hydrochloric acid is added 

 and all heated in a flask with a reflux condenser for 2.] hours on a 

 water bath or boiled for 30 minutes on a sand bath. The solution is 

 clarified if necessary aud the dextrose determiued in an aliquot portion 

 with Fehling's solution. The soluble carbohydrates are calculated as 

 dextrin. The residue from the above filtrate is washed into a beaker 

 with 100 cc. water, or more if the percentage of starch is high, heated 

 to boiling, partially cooled, and inverted with malt extract until the 

 starch disappears. It is then filtered and washed. The filtrate is 

 treated as before Avith hydrochloric acid aud the dextrose determined 

 with Fehling's solution and calculated to starch. The residue from 

 the above filtrate is boiled for 30 minutes with 1| per cent sulphuric 

 acid, filtcned and washed with water and alcohol. To the filtrate 

 sutticieut sulphuric acid is added to make 2 per cent and all gently 

 boiled with a reflux condenser for hours. The reducing- power is 

 determined and the result first calculated to i)entoses and then to free 

 pentosans. The residue from the filtrate is dried and weighed, correc- 

 tion being introduced for i)rotein and ash (which must be determined in 

 a duplicate sample). The dry material is chlorinated according to Cross 

 and lievan's' method and extracted with alcohol. The residue is dried 

 and weighed. The loss of weight (corrected for ash aud protein) 

 equals the lignin and allied substances. The residue (less protein 

 and ash if present) equals cellulose. The author renuirks that lignin 

 chlorid has not been obtained before from other sources than com- 

 mercial fibers. He calls attention to the fact that cellulose and lignin 



1 Cellulose, p. 135. 



951 



