A CHART FOR THE Chemical Examination of Urine; ALSO, Tables of the Metric Weights and Measures, and Rules for converting the Apothecaries’ Weights and Measures into Metric terms. BY WM. L. DUDLEY, Professor of Analytical Chemistry and Toxicology, Miami Medical College of Cincinnati, Ohio. FOR THE USE OF THE STUDENTS. 1880. CHEMICAL EXAMINATION OF URINE, Books of Reference: Neubauer & Vogel, Harley, Tyson, Flint, and Hofmann & Ultzmann. In the examination of urine, observe: I. Quantity passed in twenty-four hours. 1 II. Color and Transparency.2 III. Odor. IV. Reaction.3 V. Specific gravity.4 VI. Presence or absence of sediments. EXAMINATION OF THE CLEAR URINE. 5 VII. Albumen. 6—If the urine has a distinctly acid f reaction heat to boiling, and if a precipitate forms, add an excess of nitric acid (HNOs). In case the precipitate remains undissolved, it indicates the presence of Albumen. If the urine is neutral or alkaline, add nitric acid until it has a strong acid reaction, and boil. A white precipitate or opacity, indicates the presence of Albumen. VIII. Sugar. 1. (Trommer’s Test)—Remove the albumen, 21 if present, by fi'tering the above, and to the filtiate add an equal amount of sodium or potassium hydrate (NaOII or KOll.) and a drop or two of a dilute solution of copper sulphate (CuS04), heat nearly g to boiling without shaking, when a yellow cloud will form on the surface, and soon a yellow or red precipitate of the oxide of copper will follow without further heating, if sugat be present. To confirm the presence of sugar, pre- pare another sample in the same manner, and allow it to stand quietly for ti-24 hours, without heating. 2. (Fehling’s Test).—This test is based on the same reaction as the above, but is more delicate. Prepare two solutions, as follows : No. 1. Copper Sulphate, (pure crystals,) hi.98 grams, (801.25 grs.) Water 500 c. c. (17 floz.) No. 2. Rochelle Salt, (pure crystals,) 259.9 grams, (4011, 29 grs.) Solution Sodium Hydrate Sp. gr. 1.12 .1000 c. c. (38.8 floz.) In using, mix in a test-tube one volume of No. 1, and two volumes of No. 2; shake, add an equal volume of the urine to be tested, and boil. If sugar is present, the same changes will take place as those described in Tromme?Js test. IX. Normal Coloring Matters.—1. Urohaimatin or Urochrom.—Dilute the 24 hours’ urine with distilled water until it measures 1800 c. c. (00 floz.); or, if the quantity exceeds 1800 c. c. concentrate to this amount, then add to about 7 c. c., (1.9 dr.) of it in a test-tube, 2 c. c. of pure con- centrated nitric acid, and allow the mixture to stand for some time. If Urohccmatin is in normal quantities, only a slight change of color will be seen ; but if in excess, it will become pink, red, crimson, or purple, according to the amount present. 2. Indican or Uroxanthin.—To 3 or 4 c. c. of pure concentrated hydrochloric acid (H Cl.) in a beaker, add while stirring, 10 to 20 drops of urine. II in normal quantity, the solution will be colored pale yellowish-red. If in larger quantities, the coloration will be violet or blue. If biliary acids are present, add lead acetate [Pb.(C2H302)2], filter, and then test for Indican. NOTES. 1. The normal amount of urine passed in 24 hours is about 1200—1500 c. c., (40—50 floz.) 2. The normal color of urine is pate yellow or amber hued. 3. The reaction of normal urine is acid, but continued vegetable diet will cause it to become alkaline. The urine of herbivorous animals is normally alkaline, while that of carnivorous uuimals is strongly acid. 4. The specific gravity of normal urine varies from 1.005 to 1.030, according to age and sex, constitution of body, and food. 5. If the urine is not clear it should be filtered before beginning the examination. 6. A rough test for albumen may be made in the sick room by boiling some of the urine in a spoon. The result should always be verified by the regular method. 7. In cases where the urine is only feebly acid, a precipitate of earthy phosphates may occur where they exist in excess, which might easily be mistaken for albumen; consequently it will be necessary to add an excess of nitric acid, which will dusolve them while the albumen, if preseni, will remain insoluble. 8. In Trommer’s test, do not boil. 9. Urine containing bile has a brown color. 10. When a water-bath cannot be had, an ordinary tin cup (pint) may be used as a substitute. Fill it about one-half full of water, rest the evaporating dish containing the urine on the top of the cup, and heat the water to boiling, continuing until the urine has evaporated sufficiently. X. Abnormal Coloring Matters.—1 Blood.—Add sodium hydrate to the urine, and the earthy phosphates will be precipitated. If blood is present the precipitate will be blood-red instead of w'liite. 2. Uroerythrin.—Known by the pink coloration of the sediment known as “lateritious,” or by the formation of a pink-colored precipitate, with a fewr drops of lead acetate. If the urine con- tains limmatin, or the coloring matter of blood, it must first be removed. 8. Vegetable Coloring Matters.—Known by the red alkaline urine turning yellow on the addition of an acid, and acquiring a red color again on the addition of ammonium hydrate (NH4OH). 4. Biliary Coloring Matters. 9—Pour into a beakerfi c. c. of pure concentrated hydrochloric acid, and add to it, drop by drop, just sufficient urine to color it; “underlay” the mixture with pure con- centrated nitric acid. A beautiful play of colors will appear if biliary coloring matters are present. Or, add to the suspected urine, albumen, and coagulate with nitric acid ; after standing the coagulum will have a bluish color. A solution of lead acetate added to urine containing bile, produces a yellowish precipitate. Tincture of iodine produces a beautiful green, varying from rose to yellow color. No secretion, except bile, will give this green coloration. (M. Marechalt’s test). XI. Uric Acid.—A small portion of the sediment, or residue, after evaporation, is placed in a porcelain dish, and a drop or two of nitric acid added to dissolve it; it is then carefully evaporated to dryness on a water-bath. 4 0 When dry, add a drop or twro of ammonium hydrate, and a beautiful purpie-red color will instantly be seen. XII. Urea- JJ—Take of the fresh 24 hours urine 12 two samples; to the first add about one- third of its volume of pure concentrated nitric acid; if crystals form in this immediately, or within a few moments, the amount of urea is above the normal. The second sample should be twice the bulk of the first. Evaporate it to one-half its volume (on a water-bath), allow it to cool, and add nitric acid as before. If the crystals do not form within a few moments, the proportion of urea is below the normal. XIII. Chlorides.! 3—Add silver nitrate (AgN03) and nitric acid. A white precipitate indi- cates the presence of chlorides. 14 XIV. Phosphates. — 1. Earthy Phosphates 15 — Add ammonium hydrate in excess, and boil. A precipitate indicates earthy phosphates. 2. Alkaline Phosphates 16 Filter the above, and to the filtrate add a solution of magnesium sulphate (MgS04). A white crystalline precipitate indicates the presence of alkaline phosphates. XV. Sulphates. ] 7—Add to the urine a solution of barium chloride, and an excess of hydro- chloric acid. A white precipitate indicates the presence of sulphates. EX A MIN ATION OF THE SEDIMENT. Decant as much of clear urine as possible, and shake up the remainder in order that the sedi- ment may be suspended. I. Urates. 2 2—Heat a portion of the above to boiling, and the urates will dissolve. If a residue remains, tilter, and test the filtrate for uric acid according to XII, or cool the filtrate, and crystals of the urates will slowly form. II. Phosphates. — If a residue remains undissolved in the proceeding, heat another portion of the sediment with acetic acid (C21I402), and, if necessary, filter, and to the filtrate add ammonium hydrate and heat. A white precipitate will indicate the presence of phosphates. III. Pus.—Take a fresh sample of the sediment, and add a solution of sodium or potassium hydrate. If pus be present, a gelatinous mass will be produced. Further examination of the sediment for mucus, pus, urea, etc , is best made by the aid of the microscope, 18. 19. 20. 11. When acid is added to the urine and effervescence takes place, it indicates the presence of ammonium carbonate, which is due to the decomposition of urea in the bladder. 12. If the quantity of urine passed in 24 hours is less th in 1200 c. c. (40 floz.), it should be diluted with distilled water to that amount; and on the contraiy. if it exceeds 1200 c. c., it should be evaporated to that quantity on a water-bath. 13. The presence of a moderate amount of albumen does not interfere with the tests for chlorides, but if it is abundant, it must be removed. 14. If the amount of urine passed in 24 hours is normal, the precipitate of the chlorides, according to XII, should be about of the consistency of milk. 15. Normal urine, which has been recently passed, should contain no sediments of earthy phosphates. 16. A milk-like cloudy appearance indicates about a normal amount of alkaline phosphates. 17. A milk-like cloudy appearance indicates about a normal amount of sulphates. 18. Urine containing mucus is generally cloudy, ropy and alkaline. 10. Urine containing pus always contains albumen, and the pus settles to the bottom readily. 20. Urine containing fat, is milky, opaque and albuminous. The fat comes to the surface on standing. 21. Albumen is very rarely present with sugar. 22. A sediment rarely contains both urates and phosphates. METRIC SYSTEM OF WEIGHTS AND MEASURES. MEASURES OF LENGTH. 10 Millimeters. = 1 Centimeter. 10 Centimeters, = 1 Decimeter. 10 Decimeters, = 1 Meter. 10 Meters, = 1 Decameter. 10 Decameters, == 1 Hectometer. 10 Hectometers, = 1 Kilometer. 10 Kilometers, = 1 Myriometer. 1 Kilometer,=4 Furlongs, 213 yds , 1 foot and 10.43 inches. 1 Meter,=39.37043 inches. 1 inch,= 25 milli- 0.025 meter. MEASURES OF CAPACITY. 1 Milliliter, (1 Cubic Centimeter). 10 Milliliters, = 1 Centiliter. 10 Centiliters, = 1 Deciliter. 10 Deciliters, = 1 Liter, or cubic decimeter. 10 Liters, = 1 Decaliter, or centister. 10 Decaliters, = 1 Hectolitre, or decister. 10 Hectoliters, = 1 Kiloliter, or stere or cubic meter. 10 Kiloliters, = 1 Myrioliter, or decaster. 2 1 Liter, = 01.027052 cubic inches,=2.1 pints, (nearly). 1 Fluidounce,=29.573 c. c. MEASURES OF WEIGHT. 10 Milligrams, = 1 Centigram. 10 Centigrams, = 1 Decigram. 10 Decigrams, = 1 Gram. 10 Grams, — 1 Decagram. 10 Decagrams, = 1 Hectogram. 10 Hectograms, = 1 Kilogram. 10 Kilograms, = 1 Myriogram. 1 Gram,= 15.432340 grains. 1 Kilogram= lbs. (about). Value of Apothecaries’ or Troy Weights in Metric Weights These equivalents are only approximate, but are sufficiently accurate for practical- purposes. Grain. Grams. Grains. Grams. Apoth.Wt. Grams. 1-64 0.00101 i 0.0648 3* 3.887 1-60 0.001O7 ij 0.1295 3'j 7.775 1-50 0.00120 iij 0.1943 11.663 1-48 0.0O134 iv 0.2591 3iv 15.550 1-40 0.00161 V 0.3239 3V 19.438 1-36 0.00179 vi 0.3887 23.325 1-32 0.00202 vij 0.4535 ■5 viJ 27.218 1-30 0.00215 V11J 0.5183 51 31.103 1-25 0.00259 ix 0.5831 62.207 1-24 0.00269 X 0.6479 duj 93.311 1-20 0.00323 xij 0.7775 31V 124.415 1-16 0.00404 XV 0.9718 155.519 1-15 0.00431 xvi 1.036 jfvi 186.623 1-12 0.00539 xviij 1.166 % vij 217.726 1-10 0.00647 XX 1.295 .1 viij 248.830 1-8 0.00809 xxiv 1.655 li* 279.934 1-6 0.01079 XXV 1.619 3X 311.038 1-5 0.01295 XXX 1.943 SX1 342.141 1-4 0.01619 xl 2.591 Ibi 373.245 1-3 0.02159 1 3.239 lt»ij 746.491 1-2 0.03239 lx 3.887 Ibiij 1119.736 To express quantities by weight of the Apothecaries’ system in Metric terms, (1) Reduce each quantity to grains; then divide the number by 10, and from the quotient sub- tract one-third. Or, (2) reduce each quantity to drachms, anti multiply the number by 4. Or, (3) reduce each quantity to ounces, and multiply the number by 32. The product in each case will be the number of grams representing (nearly) the same quantity. To express quantities by measure of the Apothecaries’ system in Metric terms. (1) Reduce each quantity to minims; then divide the number by 10, and from the quotient subtract one-third. Or, (2) reduce each quantity to fluidrachms. and multiply the number by 4. Or, (81 reduce each quantity to fluidounces, and multiply the number by 32. The product in each case will be the number of cubic centimeters representing (nearly) the same quantity. PRESCRIPTION WRITING.—In writing prescriptions in the metric system, the abbreviation, “gm.” may be used for gram, and “c. c.” for cubic centimeter. It may also be well to underscore the abbreviations, thus “gm.” and “c. c.” in order to prevent mistakes in the case of careless writing.