THE ORIGIN OF THE PROTEINS OF NEPHRITIC URINE

From time to time attempts have been made to determine the source of the protein present in albuminous urine. Chemical methods are, in most forms of albuminuria, entirely incapable of distinguishing between blood proteins, kidney proteins and urinary proteins. The most definite exception to this statement is furnished by the peculiar protein of "myelopathic albumosuria," which is distinctly different from any protein found in normal blood or tissues. With the advent of the precipitin reaction came the possibility of distinguishing sharply between proteins from different species of animals, which made it feasible to investigate the urinary proteins in relation to their original source, i. e., to determine whether they come unchanged from the food proteins, or have the character of human proteins. Several studies of this kind have been reported, but not with constant results. So discordant and widely scattered is the literature on this topic that it