Abstract
The blood urea level seemed to have a significance on nutritive physiology as previously reported, where the blood urea content was remarkably increased provided that the low-protein diet was fed for a certain period. Blood urea was measured in this experiment, in which blood urea contents in the case of essential hypertension, kid ney diseases, hepatom, Kimmelstill-Wilson's syndrome often reached a considerably higher level than normal. No seasonal variations in blood urea content were observe.