A manual of medical diagnosis / by A.W. Barclay.

  • Barclay, A. W., 1817-1884.
Date:
1857
Catalogue details

Licence: Public Domain Mark

Credit: A manual of medical diagnosis / by A.W. Barclay. Source: Wellcome Collection.

Provider: This material has been provided by Royal College of Physicians, London. The original may be consulted at Royal College of Physicians, London.

    563/642 (page 539)
    tlliey are less soluble in cold than warm urine, and tlliey are precipitated; if free alkali be present, their ccondition is changed, and they are held in solution by !ia much smaller quantity of water. The deposition of iphosphatic or eartliy salts is not so dependant on the ]proportion of water, for they are very easily dissolved tby free acid, and are very insoluble when free alkali iis present. This explains to us why in acute rheumatism, when ;iacid abounds, and there are copious sour-smelling 1 perspirations, the urine is always loaded with lithates; mhereas in typhus, when the powers of life are low. Hand free alkali is liable to be secreted by the kidney, tthe urine may be very scanty and very deep-coloured, nand yet there is no deposit till some acid be added, \when the whole becomes turbid. Such urine often- Itimes appeal’s slightly acid to test-paper, and it would aappear that the lithate is secreted in a soluble form iwith exce.ss of alkali, and that the affinity of the acid is ttoo weak subsequently to convert it into the insoluble tform. The fact is certain, the explanation jierhaps iunsatisfactory; but it is the only one which our (cliemical knowledge of tliese salts at present gives. When acid is formed in excess in the stomach in dyspepsia, and afterwards passes off by the kidney, it I tends to check the flow of urine, causing a deficiency < of water, and at the same time it determines the forma- I tion of the less soluble lithates, which the small quan- itityof water pre.seut cannot hold in solution when (cold. To speak therefore of an excess of lithates is a I fallacy, because their deposition may depend merely (on the proportion of water, or may be wholly pre- ’ vented by deficiency of acid. When lithic acid is I really in excess, it is more likely to occur in a crystal- 1 line form, uncoinlhned with any base; and to this the I name of the “ lithic acid diathesis” more properly 1 belongs than to that in which the deposit is amorphous. To speak of an excess of earthy phosphates is a imore comjilete fallacy than that just alluded to. They