The results reported in a foregoing paper1 show that because of the diversity of anatomic renal defects orthostatic albuminuria cannot be regarded as a distinct disease entity. Even the purely clinical definition of orthostatic albuminuria shows a lack of precision. It is incorrect to state that orthostatic albuminuria is a condition characterized by the presence of albumin in the urine while the subject is erect and by the absence of albumin in the urine while he is supine, because albumin (protein) is always present under all conditions. What is really meant is that more albumin is present under certain circumstances than under others. Since this is the case, quantitative methods are essential.
The same five subjects with orthostatic albuminuria who were studied roentgenographically after the injection of diodrast, reported on in the foregoing paper,1 were further investigated by means of the Addis urea ratio, the Rehberg (creatinine) glomerular