Lectures on the diseases of the kidney, generally known as "Brights' disease", and dropsy / by S. J. Goodfellow.

  • Goodfellow, S. J. (Stephen Jennings)
Date:
1861
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Licence: Public Domain Mark

Credit: Lectures on the diseases of the kidney, generally known as "Brights' disease", and dropsy / by S. J. Goodfellow. Source: Wellcome Collection.

Provider: This material has been provided by University of Bristol Library. The original may be consulted at University of Bristol Library.

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    the tube, when, as it falls to the bottom, it will coagulate the albumen, and thus three layers may be produced, the lower- most one being white, or opalescent, from albumen coagulated by nitric acid, the middle layer transparent, and the upper- most opalescent, or exhibiting a precipitate more or less evident of albumen coagulated by heat. As a white precipi- tate is produced by boiling, when the urine, free from albumen, contains an excess of earthy phosphates, it is in all cases necessary to add a few drops of nitric acid, which, in case the precipitate consists of phosphates, at once redissolves it, but if albuminous, leaves it still insoluble. If the albumen be pre- sent in very small quantity, the addition of a very slight excess of nitric acid may redissolve it, and thus lead to the supposition that the precipitate is phosphatic. A few drops more of the acid, however, will immediately cause it to re- appear, if albuminous. The test-tube should in all cases be carefully freed from any nitric acid that may have been used for a former experiment, for if a trace of nitric acid remain, no precipitate will be formed by boiling. Dr. Beale is disposed to think (and in this he has been confirmed by the results of some experiments on the subject) that this is owing to the decomposition of the phosphates by the nitric acid, and the consequent extrica- tion of free phosphoric acid, in which albumen is freely soluble. The presence of acetic acid will also prevent the coagulation of the albumen by heat; but after it has been co- agulated, a considerable quantity added will not redissolve the precipitate. In all cases the precipitated albumen should be allowed to subside, in order that a rough approximation of the propor- tion of this principle in the urine may be arriv'ed at. To accurately determine the quantity, it will be necessary to wash the precipitate, after being certain that the whole has been coagulated, in distilled water, carefully dry it on a filter,