On dumb-bell crystals of uric acid discovered in the urine / by Marris Wilson.

  • Wilson, Marris.
Date:
1850
Catalogue details

Licence: Public Domain Mark

Credit: On dumb-bell crystals of uric acid discovered in the urine / by Marris Wilson. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

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    occur very frequently in the same deposit, and from their combined presence different forms of dumb-bell crystals are found together; it is therefore of the first importance to sepa- rate each salt carefully, before proceeding to subject it to experiment. While analyzing some urine of high specific gravity, and in which there was a copious precipitate of uric acid, I added a solution of caustic potash in sufiicient quantity to dissolve the deposit. The urine thus treated was twice filtered; a light flocculent cloud of uric acid, in combination with potash, made its appearance in a short time, and gradually subsided to the bottom of the vessel. The supernatant fluid being decanted off, hydrochloric acid, in great excess, was poured suddenly upon the sediment, which, after a rest of about a quarter of an hour, was found converted into a thin layer of opake dark-brown uric acid dumb-bells. These differed in the most marked degree from the dumb-bell of oxalic origin by their great insolubility in water. But the experiment is open to the doubt that an oxalate might have gained entrance. I separated some highly crystallized uric acid from the urine in which it was deposited, and washed it thoroughly with large quantities of warm water; it was then dissolved in pure caustic potash, and filtered through paper. On adding strong hydrochloric acid in excess to this solution, dumb-bell crystals were deposited, some being of very perfect form, others not so. Some pure lithic acid was dissolved in concentrated sulphuric acid; to this solution two-thirds of water were added, and there occurred an instantaneous precipitation of imperfect dumb-bells. To show the difficulties of this kind of demon- stration, and the changes likely to result from varied circum- stances, a small quantity of this concentrated sulphuric solu- tion being dropped into a large bulk of water, the resulting deposit consisted of thin broad plates, the two edges of which, in the longitudinal direction of the spiculse, were considerably thickened, forming ridges; but these plates, when rolled over