and Mitchell, showing that they have found casts for years in healthful individuals, we must be impressed with the idea that little significance can be attached to them. In concluding this section, let me refer to one writer, Edwards (q. v.), who says: "Our conception has been broadened concerning the significance of casts, especially hyaline, now regarded as occurring in urine otherwise normal," and to Symonds,23 who speaks of casts of "functional origin," or as I would prefer to call them,

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... siologic casts. 3. Given a case of chronic Bright's disease attended with albuminuria, the fact of its presence or its constancy or its amount has absolutely no prognostic significance. For some time it ha3 been the personal opinion of the writer, based on the observations of something over one hundred cases, that the amount of destruction in the renal parenchyma is, in chronic nephritis, a measure of the prognosis, but that the amount of albumin in the urine is in no sense indicative of such destruction, and, further, that we to-day have nothing, unless it be the absolute toxicity of the urine or the degree and character of the albuminuric retinitis, that at all serves as a measure of this destruction. Albumin may simply indicate a lesion of the glomerular filtering membrane, nothing else, and to form an idea of its profundity, extent, or gravity, other sources of information are to be searched. Leeorche and Talamon (1. a), in speaking on this point, say: "It is impossible to attach any prognostic value direct or remote to this condition, as the percentage of albumin in the urine is not proportionate to the degree of renal lesion." In a recent address before the Academy of Medicine, Paris, Semola25 expressed himself as follows : "There can be no exact relation of cause or effect between the severity of the renal lesion and the degree of albumin excreted, and one can influence the latter only by the state of the blood, albumins without any reference to the condition of the kidneys." Mesnard26 writes: "The intensity and character of this condition (albuminuria) are without value to indicate the degree of pathological changes in the kidneys or the imminence of the grave occurrences common in Bright's disease." That a fatal issue in Bright's disease may be forestalled in some and the prognosis as to time materially modified in almost all cases, is beyond question, for those are not uncommon where the individual life has been prolonged fifteen, twenty, or even thirty years under the influences of judicious medication and dietary. It would seem, from what has been written, that Bright's disease might be difficult of diagnosis, and I believe it is more often overlooked than any other common disease. Insidious in its approach, indefinite in its manifestations, and far-reaching in its effect, it often baffles the most acute of diagnosticians until one realizes the full force of what was written by Edes, who says: "If in such a case as is reported by Edwards, nephritis is suspected when there are no suggestive cardio-vascular findings, no albumin, no casts, no decrease in total solids, specific gravity or quantity, no edema mentioned, and the possible diagnosis is confirmed by autopsy, we can only congratulate the physicians on their acuteness and feel that when a diseased organ presents absolutely no symptoms of abnormality in its products and no evidence -except so very indefinite one as nausea-of impaired functions, nobody but a clairvoyant can be blamed for overlooking it." The clinical value of the estimation of the proportion of the ethereal to the simple sulphates in the urine is an indication of the extent of intestinal putrefaction from the most common forms of intestinal organisms and the consequent associated formation of intestinal toxins is very great. The importance of the estimation of the ethereal sulphates is based on the fact that they are the result of a combination of the simple sulphates of the urine with certain aromatic principles, the products of bacterial action in the intestinal tract. The principal compounds of this class of aromatic substances are phenol, indol, skatol, cresol, and pyrocatechin. Most of these substances are, so far as we know, the exclusive result of bacterial action, which may occur anywhere in the organism, as in an abscess cavity, but which as a matter of fact nearly always occurs in the intestinal canal. The quantity of ethereal sulphates, otherwise known as conjugate, aromatic, or combined sulphates, or ester compounds therefore becomes in large measure an index of the intensity of bacterial processes. These substances may have, some of them, considerable importance on account of their own toxic properties, but are perhaps more important as indicators of a process which would have associated with them other substances more toxic than these, but not so far as we know responsive to any chemical test after their elimination through the kidneys. It is perfectly well understood that there may be other toxic processes in the intestines which do not produce aromatic substances and would not therefore lead to an increase of ethereal sulphates; the absence or normal amount of the latter has not thus the same clinical importance as an excess. It is the more unfortunate, therefore, that the methods in vogue are so cumbersome and time-consuming as to preclude their use in ordinary routine clinical work. My first attempt at a practical solution of the question in my private clinical laboratory was with the ordinary titration method. This is intolerably slow, owing to the fact that after each addition of barium solution the specimen under examination ought to be boiled in order to insure the combination of the sulphates with the barium, and then allowed to settle before the further addition of Downloaded From: http://jama.jamanetwork.com/ by a University of California -San Diego User on 06/11/2015 the latter solution. This settling process, which is recommended by Purdy1 is very tedious, owing to the finely divided state of the barium salt, aided perhaps by the proteid matter of the urine with which it sometimes appears to form a sort of gelatinous mixture. The method hereinafter described is, as I think can be easily shown, more accurate than some of those described in the textbook, while it consumes much less time. For instance,