RECENT WORK IN AGRICULTURAL SCIENCE. 



AGKICULTURAL CHEMISTRY— AGROTECHNY. 



The so-called nitrogen-free extract substances in foods and feeding stuffs, 

 J. KciNiG and W. SuTTHOFF (Landw. Vers. Stat., 10 {1D09), No. 5-6, pi). S.'iS- 

 403). — This article deals chiefly with a study of those bodies which are gener- 

 ally included under the term " nonnitrogenous extractive matter " minus the 

 true carbohydrates. 



In connection with this work studies were made of the various starch deter- 

 mination methods with a view to obtaining one which dissolves the least possi- 

 ble amount of substances other than starch during the process. It was found 

 that the Mayrhofer direct method yielded the best results although it can not 

 be employed in all cases because in some instances it yields a cloudy and un- 

 filterable solution. Next to this are preferred the inversion steam pressure and 

 the acid inversion methods, but in both of these deductions must be made for 

 the pentoses produced during the process. The Lintner method (polarimetric) 

 yields good results even with substances having a low starch content. The 

 chief ditficulty lies, with all these methods, in the different conceptions which 

 workers have in calculating the starch content. 



Among the thus far undetermined constituents of the "nonnitrogenous ex- 

 tractive matter " the author states that there are bodies with a high carbon 

 content and which probably belong to the " lignin group." By extracting sub- 

 stances free from starch and soluble carbohydrates with dilute sulphuric acid, 

 bodies were obtained whic"h had a higher carbon content than either cellulose 

 (44.4 per cent of carbon) or pentosan (45.5 per cent of carbon). A portion 

 of this extract is soluble in water only under steam pressure or in Konig's 

 glycerin-sulphuric acid mixture, but the portion soluble in water has a lower 

 carbon content than that soluble in glycerin-sulphuric acid. This is slightly 

 higher than that of the lignin in the " crude fiber." 



Digestion experiments with sheep showed that the digestibility of the crude 

 fiber carbon group is nearly always more than that of the group extracted by 

 sulphuric acid and glycerin and considered physiologically is on a par with cel- 

 lulose. The carbon content of the digested " total nitrogen-free extract " is 

 usually higher than that of the digested nitrogen-free crude fiber, and evidently 

 more cellulose than lignin is digested. The authors show that the analysis of 

 fodders as conducted at present gives us no clue as to the lignin content par- 

 ticularly where this term is to mean bodies which contain more than 45.5 per 

 cent of carbon. These bodies are probably present in a more condensed condi- 

 tion like the hemihexosans, cellulose hexosans, etc. 



The authors conclude that the use of the term " carbohydrates " for food- 

 stuffs and fodder rich in " crude fiber " is not warranted while the name " non- 

 nitrogenous extractive matter " is confusing and imparts the belief that these 

 bodies are easily soluble in water. 



The nature of the kutin contained in crude fiber, W. Sutthoff (Ztschr. 

 Untersuch. Nahr. u. Genussmtl., 11 (1909), No. 11, pp. 662, 663). — With "kutin" 

 obtained according to Konig's method, the author on saponifying with a 20 per 



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