He has found the sweetbread meal an aid in diagnosis, and the following is his method of procedure: “The patient is placed on a purin-free diet, and the daily output of uric acid in the urine determined. After having been on this diet for at least four days the blood is analysed for uric acid, and 150 to 300 grams of sweetbread (weighed raw) are fed. The purin-free diet is then resumed. The blood of gouty subjects forty-eight to seventy-two hours after the sweetbread meal has shown in every case examined an abnormally high amount of uric acid, while in control subjects this was not found. It is not improbable that this rise in the uric acid content of the blood may occur in certain cases of nephritis and other pathological conditions.” A _bacteriological_ examination of the _urine_ should be undertaken. Trautner held _mucous colitis_ as one of the initial manifestations of gout, and believes that the _bacillus coli communis_ is the primary agent in gouty affections. He suggests that it produces a reducing substance which during its passage through the body is transmuted into xanthin and uric acid. Be this as it may, there is increasing evidence that an etiological potency may attach to coliform bacilli, streptococci, and other organisms. Dr. Munro in his researches at the Royal Mineral Water Hospital, Bath, noted that the blood serum in one of my cases of acute gout agglutinated _B. coli_. He has also found streptococci in the urine in acute gout, and these subjects certainly enjoy no immunity from other forms of bacteriuria. It is beyond the scope of this volume to outline the methods of differentiating and determining the exact organisms which may be responsible for gouty arthritis. But if we aim at rational as opposed to purely haphazard serum or vaccine therapy, we must effect a differential specific diagnosis in a bacteriological sense. How searching our investigations must be in these cases we learn from Adami’s brilliant address on _sub-infection_ when he laid down the axiom that in all cases “there ought to be routine blood cultures, routine examination and reports on the stools and their predominant bacterial types, blood counts, hæmoglobin examination, in fact the full clinical study of each case, so that nothing is neglected.” No apology is needed for our insistence on the imperative necessity of routine systematic investigation from all sides of these cases of gouty arthritis. For its origin still remains hidden, and who can doubt that, to remove this long-standing reproach, we must approach our study of these cases in a more catholic attitude of mind, one bent on _etiological_, not merely nosological, diagnosis? CLINICAL DIAGNOSIS _Introductory Remarks_