Medical and surgical monographs / by Andral [and others] with occasional comments by the editor of the library and others.

Date:
1838
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Licence: Public Domain Mark

Credit: Medical and surgical monographs / by Andral [and others] with occasional comments by the editor of the library and others. Source: Wellcome Collection.

Provider: This material has been provided by the University of Massachusetts Medical School, Lamar Soutter Library, through the Medical Heritage Library. The original may be consulted at the Lamar Soutter Library at the University of Massachusetts Medical School.

    40/608 (page 24)
    The experiments of MM. Prevost and Dumas (Annales de Chimie, vol. xxiii.) which have since been repeated by Gmehn and Tiedemann (PoggendorlT's Annalen), prove satisfactorily that urea exists in the blood after the kidneys have been extirpated, and consequently that it is not formed, but merely abstracted, by those organs. So long, however, as the kidneys act, we cannot expect to find it, since it is removed from the circulation as fast as it is formed, and never exists in any considerable quantity. In these cases of diseased kidney a result analogous to that which follows extirpation occurs; for while that organ is permit- ting albumen to pass through it unchanged, the urea which it should separate is very generally, if not always, found in the blood. This I have proved in repeated instances, and it is now so gene- rally admitted, from the experiments of Front, Christison, and others, that it is scarcely worth while to cite cases. Dr. Bright, vol. ii. p. 447, alludes to several specimens of serum from patients under this disease, which he had sent me for examination, in some of which I did, and in others I could not, detect urea. In one very remarkable instance of a young woman, the albuminous state of whose urine constantly existed for above three years, the urine contained less than one third of the normal proportion of urea, while about one per cent, of albumen supplied the deficiency. The serum of the blood was, as I liave already remarked to be usual in this disease, of very low specific gravity, being only 1.021. The quantity of albumen in 1000 grains amounted, after careful drying, to only fifty grains instead of seventy-eight (Lecanu's healthy standard), and it contained fully as much urea as the urine itself— the 1000 grains yielding nearly fifteen grains of that principle. It may not be out of place here to observe, that in this disease not only does the blood itself contain urea, but all those effusions also which are formed from it, and which take place in the differ- ent serous cavities. I have repeatedly detected urea in these cases in the serous effusion into the ventricles of the brain ; and Dr. Barlow foimd it in one case, 1st, in abundance in the ventricles of the brain ; 2dly, scantily in the efflision into the pleura and peri- cardium; and 3dly, in abundance in the peritoneum. In a second case of a similar nature urea was obtained in abundance from the fluid of the pericardium. In a third, the eftusion collected after death from the pleura of a man who had suflered from general dropsy and mottled kidney yielded a very satisfactory specimen of urea. 1 have dwelt at some length on this subject, as it is only of late years that the attention of the medical world has been drawn to it through the writings of Dr. Bright, and still more recently that the morbid changes presented in the blood have been investigated. Diabetes.—In this complaint the blood unquestionably under- goes some material change, although its nature has not hitherto been very successfully investigated. Tiiis may be inferred from the great length of time during which it is capable of resisting putrefaction—a circumstance first noticed by Hollo, and which,