phate, and is precipitated, phosphoric acid passing into solution. But in normal urine no such precipitation, or only a slight one, occurs, because of the presence of the other salts just alluded to. If, however, the normal relation between these salts be upset, then we get precipitation of the normal calcium phosphate. Origin of, and variations in, the urinary phosphates.-The phosphoric acid in the urine is partly derived from the food, and is partly a decomposition product of lecithin and nuclein. The amount of the acid in the twenty-four hours' urine varies from 2·5 to 3.5 grammes, of which the earthy phosphates constitute about half (1 to 15 gramine). The excretion of phosphoric acid varies in amount with the food taken: after the midday meal, especially if it consists of meat, it rises, reaching its maximum in the evening; it falls during the night, reaching its minimum at midday. The average of Ott's analyses shows that the ratio of P2O, combined as normal phosphate to that combined as acid phosphate was as follows:- Evening urine (2 to 10 P.M.), 91: 100; night urine (10 P.M. to 8 A.M.), 58: 100; morning urine (8 A.M. to 2 P.M.), 69: 100. An interesting point in connection with this subject is whether activity of the nervous system produces an increased output of phosphoric acid from increased metabolism of lecithin. Mendel' found it diminished in chronic brain diseases. Vanni and Pous, with certain reservations, came to the same conclusion. Mairet concludes that brain work increases the excretion of alkaline phosphates. The question, however, appears to me to be an especially difficult one to investigate; the quantity that arises from decomposition of brain substance must under any circumstances be small, and such small differences are particularly hard to recognise when one remembers, as Mairet himself points out, that effective brain. work is difficult on an insufficient diet) The increase noted may just as probably be due to the food taken to sustain mental activity as to the mental activity itself. Several observers have found that muscular work increases the output of phosphoric acid (Mosler, 'Lehmann "), while others have found that it does not (Pettenkofer and Voit, Byassan,' North *). In various pathological conditions the output of phosphoric acid varies: it is diminished in gout," in most acute diseases, probably because only a small amount of food is taken (Vogel), in kidney disease,1o in the intervals of intermittent fever," after large doses of chalk, ether, and alcohol, and during pregnancy (owing to the formation of foetal bones). It is increased after copious draughts of water, after sleep produced by potassium bromide or chloral hydrate (Mendel 12), in inflammation of the brain, in chorea, acute atrophy of the liver, phthisis, and leucocythæmia. An increase of phosphates in the urine is termed phosphaturia. A deposit of earthy phosphates may be due to disturbance of the unstable equilibrium of the 1 Arch. f. Psychiatrie, vol. iii. 1872, p. 636. 3 Compt. rend. xcix. 282. 2 Chem. Centralbl. 1887, p. 1526. 4 Beiträge zur Kenntniss der Urinabsonderung, Giessen, 1853. 5 Arch. f. Anat. u. Physiol. 1871, p. 14. 7 Essai, Paris, 1868. 6 Zeit. Biol. ii. 459. 8 Proc. Roy. Soc. xxxix. 443 (see also p. 437 of this book). 9 Stokvis, Centr. med. Wiss. 1875, No. 47. 10 Brattler, Ein Beitrag zur Urologie, München, 1858. 11 Haxthausen, Diss. Halle, 1860. 12 Loc. cit. urinary phosphates, and not to actually increased excretion; a careful analysis of the twenty-four hours' urine should always be made. In true phosphaturia, of which the chief symptoms are nervous irritability and digestive troubles, the amount of P2O, in the twenty-four hours may rise to 7 to 9 grammes.' Calculi consisting wholly of calcium phosphate are exceedingly rare ; uric acid' calculi, however, are often covered with a coating of phosphates; the presence of the stone in the bladder sets up inflammation, the urine is thus rendered aikaline, and calcium phosphate is precipitated. OTHER INORGANIC SUBSTANCES Iron occurs in small quantities; the compound in which it is present is unknown (Hamburger "). Traces of silicic and nitric acids,3 derived from drinking water, have been found. Traces of fluorine are sometimes present. Free ammonia occurs in mere traces also, but is increased when putrefaction sets in. Hydrogen peroxide was found in traces in fresh urine by Schönbein." Sulphuretted hydrogen develops in putrid urine, probably not from the sulphates, but from other combinations of sulphur, such as sulpho- (thio-) cyanic acid, and cystin (see Cystinuria, Chap. XLIV); hyposulphites may occur in typhoid fever urine." The gases. The following table represents the chief analyses that have been made. The numbers are volumes per cent. :— 350. 1 Tessier, Du diabète phosphatique, Lyons, 1877. 2 Zeit. physiol. Chem. ii. 191; iv. 248. 5 Röhmann, Zeit. physiol. Chem. v. 94. 4 Sitzungsber. d. Bayer. Akad. d. Wiss. vol. i. (2), 1864, p. 115. 5 Munk, Arch. f. path. Anat. lxix. 354; Gschleidlen, Pflüger's Archiv, xiv. 401; xv. 6 Müller, Chem. Centralbl. 1887, p. 807; Berlin. klin. Woch. xxiv. 405. 7 Zeit. d. Gesellsch. d. Aerzte in Wien, 1859, p. 465. Pflüger's Archiv, ii. 165. 10 Pflüger's Archiv, vi. 93. 9 Arch. f. Anat. u. Physiol. 1878, p. 1. CHAPTER XLIV ABNORMAL AND PATHOLOGICAL URINE MORBID conditions of the urine are exceedingly numerous. The urine may contain excess or diminution of one or other of its normal constituents. These conditions have been already described in the preceding chapters; we may thus have urea, urates, phosphates and other salts in greater or less abundance than usual. The alterations in the pigments of the urine have already been described. We have, however, now to consider alterations in the urine, in which substances normally absent from, occur to a greater or less extent in, that secretion. We shall also have to take up in a rather more connected way than we have done hitherto the deposits that occur in the urine. The substances which occur in the urine under abnormal conditions are those introduced into the body with food or in the form of drugs; and those which are due to the presence of disease of the urinary tract or other parts; among these blood, pus, bile, albumin, and sugar are the most important. It will be convenient to describe the heterogeneous group of cases we have to consider in the following order : 1. Substances that appear in the urine as the result of the administration of drugs. 2. Deposits of various kinds that may occur in the urine. 3. Urinary stones, or calculi. 4. Blood and blood-pigment in the urine. 5. Bile in the urine. 6. Proteids in the urine. 7. The urine in diabetes. 8. Glycuronic acid in the urine. 9. Fats in the urine (chyluria) 10. Alkaptonuria. 11. Alkaloids in the urine. DRUGS IN THE URINE Inorganic salts.-Iodide, bromide and chloride of potassium or sodium, appear in great measure unchanged in the urine. Salts of casium, rubidium, lithium, and thallium behave similarly, as also do nitric, boric, and chloric acids. Compounds of arsenic and antimony and lead pass only in slight amount into the urine. The excretion of lead is increased by the use of potassium iodide. Mercury and silver, and other heavy metals, pass into the urine in mere traces, or after prolonged administration. The alkalis and their carbonates pass into the urine, diminishing its acidity or making it alkaline. Acids combine in the body with bases, and pass into the urine as salts. Iodine appears as an iodate, sulphur as a sulphate. Organic substances.-Alcohol when taken in excess appears in the urine only in traces. Chloral appears as urochloralic acid (Jaffe 1); chloroform, partly as urochloralic acid, and partly is decomposed increasing the amount of chlorides. Vegetable acids are, as a rule, changed into carbonates. Gallic and pyrogallic acids are partly excreted as such, partly as pyrogallol, pyrocatechin, and other substances, which turn brown on exposure to the atmospheric oxygen in alkaline urine. Tannin appears chiefly as gallic acid; benzoic acid and allied benzoyl compounds combine with glycocine to form hippuric acid. The fate of other aromatic substances has been already described (Chapter XL.). Quinine, strychnine, and morphine are excreted for the most part unchanged, though sometimes morphine may be totally destroyed in the organism. URINARY DEPOSITS The different deposits that may occur in urine are chemical substances and formed elements. The chemical substances are uric acid, urates, calcium oxalate, cystin, leucine, tyrosine, xanthine, phosphates, and indigo crystals. The formed or anatomical elements consist of blood-corpuscles, pus, mucus, epithelium cells, spermatozoa, casts, fungi, and entozoa. The methods of examining urinary deposits are partly chemical, partly microscopical. We can recognise the chemical substances by their characteristic reactions; the microscope even here comes to our aid, for it enables us to see whether the deposit is crystalline or amorphous, and, if the former, the shape of the crystals is often diagnostic. In the recognition of the anatomical elements, the microscope is the principal method of examination, chemical tests being of secondary importance. In the examination of urinary deposits, it is important to note whether the urine contains the deposit immediately after being passed, 1 See Glycuronic Acid in Urine (p. 793). or whether the sediment forms subsequently; for instance, in the case of concentrated urine, the cooling that occurs after it leaves the bladder is often sufficient to cause a deposit of urates. When urine is allowed to stand for any length of time after being passed, one of two species of fermentation may occur. (1) The alkaline fermentation. Urea is changed into ammonium carbonate by the action of the micrococcus urea; the ammonium carbonate is easily decomposed into ammonia and carbonic acid: this causes the urine to become alkaline, by which means the earthy phosphates are precipitated, and triple phosphate (coffin-lid crystals, fig. 99) is formed. Acid ammonium urates (fig. 95) may also be precipitated in alkaline urine. This fermentation may occur within the bladder in cases of catarrh of that organ, but under these circumstances the deposit of phosphates is mixed with excess of mucus, epithelium, or, in extreme cases, pus. (2) The acid fermentation. The deposition of urates is often accelerated by what is termed the acid fermentation, in which the acidity of the urine increases this seems to be brought about by another fungus. The deposit consists chiefly of amorphous acid sodium urate; crystals of uric acid and of calcium oxalate may also occur. A crystalline calcium phosphate (CaHPO, +2H2O) (Stein) may sometimes occur in acid urine (see p. 762). This fact is of some importance, as it accounts for the presence of calcium phosphate in or around uric acid calculi, even though the urine may have been acid throughout all the time that the stone was forming. The increase of fatty acids in certain cases of disease has been already alluded to, and is called lipaciduria (see p. 756). Hippuric acid is in decomposing alkaline urine often split into benzoic acid and glycocine; perhaps this is also brought about by a bacterial growth. Chemical Deposits in Urine The following paragraphs give the principal facts in relation to the chemical substances that may occur in urinary sediments. Uric acid.-A sandy, reddish deposit resembling cayenne pepper. It may be recognised by its crystalline form (fig. 93, p. 728), and the murexide reaction. The presence of these crystals generally indicates an increased formation of uric acid (see p. 733). Voit and 1 Pfeiffer (Seventh Congress of German Physicians, Wiesbaden, 1888) brought forward a test for discovering excess of uric acid in the urine even when no deposit occurs. The twenty-four hours' urine is divided into two parts; one of these is filtered through a filter on which pure uric acid is placed; the other is not so treated. Equal volumes of each portion, say 100 c.c., are then acidulated with hydrochloric acid, and set aside. The precipitates of uric acid which form in both are collected on weighed filters, washed, and weighed. If the urine is normal, the yield in the two cases is about equal. On the other |