4Sr) EXPERIMENT STATION RECORD. 



In the estimation of cmkIc lilx-r, tlic ofliciiil iiictlidil, the Konig nu'thdil, and tlie 

 Konig method modilk'<l liy tlu' additional tiuatnu-nl of the liV)er with wxhuni liydrate 

 as in tht> otticial method, were e()nii)ared. Tlie average resnlts l)y the official method 

 were I4.9(> percent for distillers' grains and 11.74 per cent for l)ran, by the Konig 

 method 1W.73 per cent for distillers' grains and 12.49 for bran, and l)y the modified 

 Konig method 12.12 per cent for distillers' grains and 10.48 f(jr bran. Inasmucli as 

 the official method does not remove the })entosans and the Konig method fails to 

 remove all)uminoids, the two methods were not considered comparable. The modi- 

 fied Konig method gives a much purer fiber. 



The nitrogen content of the crude fiber obtained from distillers' grains by the 

 official method was 0.27, by the Konig method 1.94, and by the modified KiJnig 

 method 0.26 per cent. In the crude fiber obtained from wheat bran by the K(')nig 

 method the nitrogen content was 0.195, none being obtained from the crude fiber by 

 the other two methods. The referee did not believe that the higher results by the 

 official method were due entirely to the presence of j)entosans, })ut that the glycerol- 

 sulphuric acid mixture exerted a hydrolytic action upon the fiber in the Konig 

 methods. From practically pure cellulose prepared by treating absorbent cotton 

 successively with dilute sulphuric acid and dilute sodium hydrate only about 87.6 

 per cent of crude fiber was recovered by the Konig method. 



The referee recommended research work to determine the true nature of the ether 

 extract obtained after digesting the residue from the ofiicial method of fat extraction 

 with pepsin and to prove or disprove that the glycerol-acid mixture of the modified 

 Konig method has a hydrolytic action upon crude fiber. 



Notes upon the analysis of feeding materials, C. A. Browne, Jr. — The atten- 

 tion of tlie association was directed one year ago by Dr. Browne as referee on cattle 

 feeds to work by Beger, in which additic^nal quantities of fat were obtained from 

 certain materials rich in protein ])y suV>jecting the residues from ordinary ether 

 extraction to digestion with pepsin and again extracting. During the year pepsin 

 digestion before extraction was compared with the oflScial method of the associa- 

 tion on samples of rice bran and rice polish, the results showing no appreciative 

 differences. 



In the examination of the feces from steers fed these materials, on the contrary, 

 very decided differences were obtained, the excess of fat extracted by the pepsin 

 method amounting in one instance to over 4 per cent. In this particular case the 

 coetficient of digestion of the feeding stuff calculated from the results obtained by 

 the official method was 78.2 per cent and from the results obtained by the pepsin 

 method 66 per cent, indicating the possibility of introducing a serious error in tables 

 of digestive coefficients by the incomplete extraction of the fat. A similar source of 

 error was observed in mixed feeds containing molasses, the occlusion in this ease 

 being attributed to the dried residue of sugars instead of to the protein constituents. 



In determining the total acidity of feeding stuffs the author found extraction with 

 90 per cent alcohol and titration with deci-normal alkali very satisfactory. The 

 results by this method in the case of rice meal were slightly higher than those cal- 

 culated from the acid numl)er of the fat, iuflicating the presence of other acids than 

 free fatty acids. 



FOOD ADULTERATION. 



Upon the suggestion of the referee, W. D, Bigelow, the reports and 

 papers on this subject were this 3^ear considered by the association as 

 a whole, instead of in committee as heretofore. No reports were 

 presented b}^ the associate referees on saccharin products, wine, beer, 

 vinegar, baking powder and baking chemicals, meat and fish, cereal 



