520 KKl'OKT l)F UFFlCi: OF KXI'KKIMKNT STATH)NS. 



by L. S. Ware." This is not an cxporiment-station publication, ]»ut 

 contains in addition to othrr data suniinaries of iiiNostij^ations cariMcd 

 on at a niunlxT of the stiitions on sujjcar heots, their composition, 

 fiMHliiiL;- vahio, etc. 



ANALYTICAL, METHODS. 



In connoction witii the work rofcM'rcd to above nuich attention has 

 nocossarily ))een j^iven to analytical methods. Any discussion of this 

 subject must refer to the work of the Association of Official A«^ricul- 

 tural Chemists,'' which has devoted much time to the consideration of 

 methods of analyses. 



In the report of the convention held in 1900 it was recommended Dy 

 W. H. Krug, referee, on the l)asis of analyses of samples of wheat, 

 bran, and peas, that the then method of the association for moist- 

 ure be further studied, with the view of fixing the time required and 

 the exact temperature at which the determination must be made. He 

 also recommended further study of the effect of various methods of 

 distillation on the result obtained by the phloroglucin method, and the 

 determination of the effect of the length of time which the precipitated 

 distillate stands upon the amount of phloroglucin ol)tained. 



Recommendations were also made regarding the determination of 

 pentosans and crude fiber by G. S. P'raps. Attention was called to 

 probable sources of error in the official method of distillation in deter- 

 mining pentosans, in the quality of phloroglucin used, and in the 

 composition of the products obtained by distillation of pentosans with 

 hydrochloric acid. A method devised by Konig was proposed for 

 preparing crude fiber practically free from pentosans. A method of 

 purifying phloroglucin was adopted; also several changes in manipu- 

 lation in the provisional method for the determination of pentosans 

 by means of phloroglucin. 



At the convention of 1901 the report of W. H. Krug, the referee 

 on foods and feeding stuffs, related to the determination of moisture, 

 starch, pentosans, and galactan. The recommendation of the referee 

 dealt mainly with minor changes leading to more exact methods. It 

 was recommended that the method used for drying sugars be adopted 

 as optional for the drj^ing of feeding stuffs. AVith the phloroglucin 

 method it was recoumiended that, instead of using 3 grams of material, 

 a quantity of the material be chosen so that the weight of the phloro- 

 glucin obtained shall not exceed 0.3 gram. A number of other minor 

 modifications of this method were suggested. 



A paper on the determination of pentosan-free crude fiber was pre- 



« Cattle Feeding with Sugar Beets, Sugar, Molasses, and Sugar-beet Residuum, by 

 L. S. Ware, Philadelphia, 1902. 



''U. S. Dept. Agr., Bureau of Chemistry Buls. 46 rev., 62, 67, and 7'.i. 



