THE DISAPPEARANCE OF PENTOSANS FROM THE DIGESTIVE TRACT OF THE COW
Journal of the American Chemical Society
1252 ORGANIC AND BIOLOGICAL. xoTE.-since the writing of this paper the work of Sebelien, Brynildsen and Haavardsholm (Chem.-Ztg., 33, 795 (1909)) has come to our notice. These investigators report the very satisfactory results obtained by the aeration procedure applied to total nitrogen determination, but they do not give data upon the nitrogen in organic materials. Conclusions. I , The Kober aeration process for the total nitrogen determination in organic materials can be successfully used,
... ccessfully used, except in cases where the elements magnesium and phosphorus are present together in relatively large amounts. 2 . Materials which contain relatively large amounts of both niagnesium and phosphorus can be correctly analyzed for the total nitrogeii by the Kober niethod 7% hen i t is so modified as to keep the aerating solutions in the Kjeldahl flasks warm for the entire period of aeration. 3. The Kober aeration procedure has many advantages over the official distillation procedure and the results are as accurate except as mentioned above. URRANA, ILLISOIS. Within recent years a great deal of energy has been devoted to the study of the physiology of the pentosans and their derivatives, the pentose sugarsf The pentosans make up a large part of the "nitrogen-free extract" of the hays and coarse fodders used in animal feeding, and the degree in which they contribute to the maintenance of the animal i-a matter of the utmost importance. The present paper is a report of a preliminary series of experiments which is being supplemented by further work on special phases of this subject. I t has been repeatedly confirmed that the pentosans of the food disappear from the digestive tract in rabbits and sheep to the extent of 40-80 per c e n t 2 I t seems also demonstrated that the pentose sugars, when absorbed by the animal, are utilized for energy production, and may lead to glycogen f~r m a t i o n .~ C. Neuberg, Ergebnisse der Physiologie, Bd. 3, I , p. 373 (1904), gives an excellent resume of the work in this field and makes reference to individual papers unnecessary.