The ammoniacal decomposition of urine / by Wm. Robert Smith.

  • Smith, William Robert, 1850-1932.
Date:
[1887]
Catalogue details

Licence: Public Domain Mark

Credit: The ammoniacal decomposition of urine / by Wm. Robert Smith. 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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    THE AMMONIAOA The Ammoniaca ITION OP UEINE. 871 position of Urine. By Will. Robert Smitli, II.D., ]>.Sc., F.R.S.Ed., Examiner ia Chemistry and Forensic Medicine, University of Aberdeen. With Plate XXX, figs. 1 and 2. When freshly voided, healthy urine, as is well known, is a clear, transparent, amber-coloured fluid, with a distinct acid reaction, and a peculiar aromatic odour. If left to itself in an open vessel slight clouds of mucus soon appear which gradually sink to the bottom. After a time the acid reaction is noticed to be slightly increased, and crystals of uric acid and oxalate of lime are deposited. After a longer or shorter interval, de- pendent on the temperature of the surrounding media, this marked acidity begins to diminish and finally disappears, the urine becomes lighter in colour, a whitish scum forms on the surface, and the well-known ammoniacal odour indicates that it has become alkaline; the uric acid crystals disappear, and whitish granules of urate of ammonia and prismatic crystals of urate of soda take their place, beautiful crystals of phosphate of magnesia and ammonia being subsequently thrown down. The increase of acidity is called by Scherer the acid fermen- tation, and is considered by him to be owing to the presence of the vesical mucus. The alkaline change is spoken of as the alkaline or ammoniacal fermentation, and is owing to the de- composition of the urea into carbonate of ammonia. These so-called fermentative changes are well known, and have long been recognised. So far back as 1682 Van Helmont spoke of the odour of urine as the ef£ect of a putrefactive