An introduction to human physiology / by Augustus D. Waller.

  • Waller, Augustus.
Date:
1896
Catalogue details

Licence: Public Domain Mark

Credit: An introduction to human physiology / by Augustus D. Waller. Source: Wellcome Collection.

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

    243/678 (page 225)
    fluid, of acid reaction, with a specific gravity of 1,015 to 1,025, being a solution in water of urea and salts, viz. about 2 per cent, of urea and 1^ per cent, of salts. Stated more in detail, the composition of urine as regards its most important constituents, and the average daily discharge of such constituents, are as follows:— per 1,000 . 960 . 20 Water . Urea Uric acid Hippuric acid Creatinin Phosphates . Chlorides . . . [ 15 Sitlphates &c., e.g. mucus and extractives 3 PO. ]hci per diem 1,440 com. 30 grammes 0-75 0- 75 1- 5 3 7-5 3 ' „ The acidity of urine is not due to the presence of any free acid; methyl orange, which is reddened by free acid, is not affected by urine; sodium hyposulphite, which with free acid gives a precipitate of sulphur, gives none with urine. The acidity is attributable to the presence of acid sodium phosphate, NaH,P04, of ^^'^^ carbonic acid gas. Normally the acidity of fresh urine increases a little at first; it subsequently diminishes and is replaced by alkalinity, this last change being due to a fermentation, in the course of which urea is converted into ammonium carbonate. The normal acidity of urine is equivalent to that of a 1 per 1,000 solution of H2SO4. The acidity is some- what more pronounced in the urme passed in the morning, less so in that passed after a meal, and it varies greatly with the nature of the diet; the urine of herbivorous animals and of vegetarians is alkaline and turbid, that of carnivorous animals and of ordinary men is acid and clear, that of herbivorous animals during starvation and during hibernation—when they are practically carnivorous of their own flesh—is also acid and clear. Abnormally the urine may become excessively acid or alkaline. In the first case, a ' cayenne-pepper ' deposit of uric acid (visible to the naked eye), and ' envelope crystals ' of oxalate of lime, are discoverable by the microscope in the urine that has been allowed to stand. The second state may be due to disease of the kidney or bladder, causing the urine to decompose before it is discharged, or it may be caused by nothing more serious, than an excessive consumption of fruit or vegetables; ' knife- rester ' crystals of ' triple phosphate ' (MgNH^PO J and ' hedge- Q