Chapter LXXXI: Part 2 (42)

It sometimes happens that during poulticing, _proud flesh_ may form in an ulcer. When this is the case, a little sugar in powder may be sprinkled over the unhealthy excrescence, or some red precipitate ointment be applied to it. Taking care not to use too much of either. When the ulcer has a bad or fetid odour, it should be washed with a lotion composed of one part of solution of chlorinated soda to sixteen parts of water; or it may be sprinkled over with charcoal powder; or with a mixture of starch and salicylic acid. The best application to bad smelling ulcers caused by varicose veins is a lotion consisting of nitric acid considerably diluted with water. Directions are given for the treatment of varicose veins, under VARIX, further on. If the veins be ulcerated, the ulcers should be dressed with acetate of lead ointment previous to the application of the bandage. Very irritable ulcers are often greatly relieved by the gentle application to them of lunar caustic, and indolent ones by dressing with yellow basilicon ointment, or by the judicious use of black wash. The general health should be attended to by the administration of tonics consisting of the mineral acids, gentle aperients, and a digestible and nourishing diet. Small ulcers on the mucous membrane of the mouth or on the gums may be made to disappear instantly upon touching them with a piece of lunar caustic. Where any difficulty is experienced in the healing of an ulcer, or if it be at all of a serious nature, the medical practitioner should be consulted.

=UL′MIN, ULMIC ACID.= By boiling sugar in dilute sulphuric acid for a long time, a brownish-black substance is produced. Boullay and Malaguti state that this is a mixture of two distinct bodies——ulmin (sacchulmin——Liebig) and ulmic acid (sacchulmic acid——Liebig). The first is insoluble in solutions of the alkalies; the latter dissolves in them freely. A number of black uncrystallisable substances, produced by the action of powerful chemical agents upon vegetable matter, have been confounded under these names.

=ULTRAMARINE′.= _Syn._ LAPIS-LAZULI BLUE, ULTRAMARINE B.; CÆRULEUM ULTRAMONTANUM, L. This beautiful pigment is obtained from the blue mineral azure stone, lazulite, or lapis lazuli, the finest specimens of which are brought from China, Persia, and Great Bucharia.

_Prep._ Pure lapis lazuli (reduced to fragments about the size of a pea, and the colourless pieces rejected), 1 lb., is heated to redness, quenched in water, and ground to an impalpable powder; to this is added, of yellow resin, 6 oz.; turpentine, beeswax, and linseed oil, of each 2 oz.; previously melted together; the whole is next made into a mass, which is kneaded in successive portions of warm water, as long as it colours it blue; from these it is deposited on repose, and is then collected, well washed with clean water, dried, and sorted according to its qualities. The first water, which is usually dirty, is thrown away; the second gives a blue of the first quality; and the third, and following ones, yield samples of less value. The process is founded on the property which the colouring matter of azure-stone has of adhering less firmly to the resinous cement than the foreign matter with which it is associated. When azure-stone has its colour altered by a moderate heat, it is reckoned bad or factitious.

_Obs._ Ultramarine is the most costly, but at the same time the most splendid and permanent, of our blue pigments, and works well in oil.

=Ultramarine, Artificial.= _Syn._ AZURE BLUE, MEISSNER ULTRAMARINE, PARIS B., VIENNA B.; CÆRULEUM ULTRAMONTANUM FACTITIUM, L. From the researches of Clement, Desormes, and Robiquet, it has been inferred that the colour of ultramarine depends on the presence of sulphuret of sodium in a peculiar state of combination with the silicates of soda and alumina; but, according to Elsner and Tirnmon, a minute quantity of sulphuret of iron is also an essential ingredient. It is by heating mixtures of this kind that the artificial ultramarine of commerce is prepared. The finer specimens, thus obtained, are quite equal in durability and beauty of colour to those prepared from lazulite, while they are very much less expensive.

_Prep._ 1. Kaolin, 37 parts; sulphate of soda, 15; carbonate of soda, 22; sulphur, 18; charcoal, 8; intimately mixed and heated from 24 to 30 hours, in large crucibles; the product is then heated again in cast-iron boxes, at a moderate temperature, till the required tint is obtained; it is, finally, pulverised, washed, and dried.

2. (Gmelin.) Sulphur, 2 parts; dry carbonate of soda, 1 part; mix well; gradually heat them in a covered crucible to redness, or till the mixture fuses, then sprinkle in, by degrees, another mixture of silicate of soda and ‘aluminate of soda’ (containing 72 parts of silica and 70 parts of alumina), and continue the heat for an hour. The product contains a little free sulphur, which may be separated by water.

3. (Robiquet.) By exposing to a low red heat, in a covered crucible, as long as fumes are given off, a mixture of pure kaolin, 2 parts; anhydrous carbonate of soda and sulphur, of each 3 parts. Some manufacturers who adopt this process use 1-3rd less carbonate of soda.

4. (Tirnmon.) Take of crystallised carbonate of soda, 1075 gr.; apply a gentle heat, and, when fused in its water of crystallisation, shake in of finely pulverised orpiment, 5 gr., and, when partly decomposed, add as much gelatinous hydrate of alumina as contains 7 gr. of anhydrous alumina; finely sifted clay, 100 gr., and flowers of sulphur, 221 gr., are next to be added, and the whole placed in a covered crucible, and at first gently heated, to drive off the water; but as soon as this is effected, raised to redness, the heat being so regulated that the ingredients only ‘sinter’ together, without actually fusing; the mass is then to be cooled, finely pulverised, suspended in river water, and brought upon a filter; the product has now a very beautiful delicate green or bluish colour, but on being heated in a covered dish, and stirred about from time to time, until the temperature reaches that of dull redness, at which it must be kept for 1 or 2 hours, it changes to a rich blue. If the heat of the first calcination has been properly regulated, the whole of the mass taken from the crucible will have uniform colour; but if too little heat has been used, and the ingredients have not been properly mixed, there will be colourless parts, which should be rejected; if too much heat has been used, or the mass allowed to fuse, brown parts will appear, especially if the crucible is of a bad kind, or easily destroyed; these must also be rejected. (‘Compt. Rend.,’ 1842.)

=Ultramarine Ashes.= _Syn._ SAUNDER’S BLUE. Obtained from the resinous mass from making ultramarine, by melting it with fresh oil, and kneading it in water containing a little potash or soda; or, by burning away the wax and oil of the mass and well grinding and washing the residue with water. Very permanent, but much less brilliant than ultramarine.

=Ultramarine, Cobal′tic.= _Syn._ CHINESE BLUE, COBALT B., LOUISA B., HÖFFNER’S B., THÉNARD’S B. A very rich blue pigment, with many synonymes, prepared by slowly drying and heating to dull redness a mixture of freshly precipitated alumina (freed from water as much as possible), 8 to 10 parts; arseniate or phosphate of cobalt, 1 part. By daylight it is of a pure blue, but by artificial light the colour turns on the violet. For other formulæ see BLUE PIGMENTS.

=U′PAS.= The Javan name for several deadly poisons. ‘Bohun upas’ is a gum-resin obtained from the bark of the _Antiaris toxicaria_. (See ANTIARINE.) The ‘upas tieuté’ is obtained from the _Strychnos Tieuté_, and owes its fatal power to strychnine. They are both used to poison arrows and other deadly weapons.

=URA′′NIUM.= U. A rare metal, discovered by Klaproth in 1789. It occurs in the pitchblende of Saxony, and the uranite of Cornwall. The chief oxides of uranium are the protoxide and the sesquioxide, or uranic oxide.

=Uranic Oxide= (U_{2}O_{3}) may be obtained in the anhydrous state by heating the hydrated sesquioxide to a temperature of 572° Fahr. The sesquioxide is capable of acting both as an acid and a base. The uranic salts are yellow.

=Uranous Oxide.= (UO.) This may be procured by igniting uranium oxalate in a closed vessel, or in a stream of hydrogen gas. Acids are without action upon this oxide. When, however, it is obtained as an hydrate (which it may be by treatment of its chloride with ammonia) this latter is easily acted upon by acids, and gives rise to salts having a green colour, which rapidly absorb oxygen. Peligot proposed to call this oxide _Uranyl_ (UO.), from the tendency it showed to follow the deportment of a metal when it combined with elementary bodies.

=Chlorides of Uranium.= Uranium forms two chlorides, U_{2}Cl_{3} and UCl_{2}.

_Uses._ Its ores and oxides are occasionally used to colour glass and enamels.

=U′RATES.= Salts of uric acid.

=U′REA.= COH_{4}N_{2}. _Syn._ CYANATE OF AMMONIUM (Anomalous). A crystalline, colourless, transparent substance, discovered by Fourcroy and Vauquelin in urine, and by Wöhler as the first organic compound artificially produced.

Urea generally occurs in slender, striated, colourless prisms, as shown on next page. It is slightly deliquescent. It has a neutral reaction and a bitterish taste. It is extremely soluble in water and in hot alcohol, but very slightly so in ether. At about 248° Fahr. it melts. At a little higher temperature it becomes decomposed into ammonia, carbonate, cyanate of ammonium, and cyanuric acid; this latter being left in the retort.

The ammoniacal odour acquired by urine after a few days is due to the conversion of the urea into carbonate of ammonia, as shown by the following equation:

Urea. Water. Carb. Ammonia.
CH_{4}ON_{2} + 2H_{2}O = (NH_{4})_{2}CO_{3}.

This change is effected by the mucus of the bladder present in the urine. A solution of pure urea may be kept at ordinary temperature, or even boiled, without undergoing alteration.

Urea occurs as an essential component of the urine of man and animals, being more particularly abundant in the urinary excretion of the flesh-eating mammalia; nor is it altogether absent from the urine of birds and amphibia. According to Bischoff and Voit, urea is the result of tissue metamorphosis. The greater number of inquirers, however, hold an opposite opinion, and believe that it is derived from the albuminous constituents of the food, when these preponderate over the quantity required for the nutrition of the body. Dr Lionel Beale says his “own researches render it probable that all pabulum entering the system must, before its elements can he applied to the nutrition of the tissues, or removed by the organs of respiration or secretion, be first of all taken up by cells (chyle-corpuscles, white blood-corpuscles), and become living or _germinal matter_, which, after passing through certain definite stages of existence, becomes serum of the blood, and the _formed_ matter of the red blood-corpuscles.

“The products resulting from the disintegration of this formed matter may be taken up by the germinal matter of the tissues, and at length become tissue, or by that of secreting cells, in which case it is removed in the form of the constituents of various excretions from the body altogether.” About an ounce and a quarter of urea is daily excreted by a healthy man, although of course there will be a variation in this amount principally depending upon the quantity of animal food and active exercise taken during the twenty-four hours. As might be anticipated a smaller quantity of urea is excreted by women than by men, since they are unable to indulge to the same extent in muscular exercise. A diminished quantity also results from breathing impure air, and from a diseased and unhealthy condition of the lungs or of the circulation, and also, as might be expected, from an insufficiency of food.

_Prep._ (Thénard.) Fresh urine, gently evaporated to the consistence of a syrup, is treated with its own volume of nitric acid of sp. gr. 1·19; the mixture is shaken and immersed in an ice bath, to solidify the crystals of nitrate of urea (p. 1689); these are washed with ice-cold water, drained, and pressed between sheets of blotting paper; they are next dissolved in water, and the solution is decomposed and precipitated with carbonate of potassium (or carbonate of barium); the whole is then gently evaporated nearly to dryness, and the residuum is exhausted with pure alcohol, which dissolves the urea, which crystallises out as the solution cools.

=Urea, Factitious.= Mix 28 parts of well-dried ferrocyanide of potassium with 14 of black oxide of manganese (both in fine powder), and heat them to dull redness on an iron plate. Lixiviate with cold water, add 22-1/2 parts of dry sulphate of ammonia, concentrate by evaporation with a heat not exceeding 212° F., decant the concentrated liquid, treat it with rectified spirit, and crystallise. This is intended as a cleanly substitute for the preceding.

=Urea, Ni′trate of.= _Syn._ UREÆ NITRAS, L. _Prep._ From urine, as described above; or it may be prepared by saturating artificial urea with nitric acid. Diuretic.——_Dose_, 2 to 5 gr. twice or thrice daily; in dropsy.

=U′RIC ACID.= C_{5}H_{4}N_{4}O_{3}. _Syn._ LITHIC ACID; ACIDUM LITHICUM, A. URICUM, L. A substance discovered by Scheele, and peculiar to the urine of certain animals, and the excrement of serpents and several birds. The fæces of the boa constrictor consist of little else than urate of ammonium. It constitutes one of the commonest varieties of urinary calculi, and of the red gravel or sand which is voided in certain morbid states of the urine. Guano derives its principal value as a manure from the presence of urate of ammonium. The gouty concretions of the joints, popularly known as chalk-stones, consist chiefly of urate of sodium.

_Prep._ Dissolve the chalk-like excrement of serpents, reduced to fine powder, in a solution of caustic potassa, by boiling; then add hydrochloric acid in excess, again boil for 15 minutes, and well wash the precipitate with water.

_Prop., &c._ Brilliant, very minute, white and silky scales, which are tasteless, inodorous, slightly soluble in boiling water, and dissolve in strong sulphuric acid, but are again precipitated by water. It forms salts with the bases called urates, all of which are very sparingly soluble. The characteristic reaction of uric acid is, that when moistened with nitric acid and heated, it dissolves, and by evaporation yields a red compound, which, upon the addition of a drop or two of solution of ammonia, assumes a magnificent crimson colour, being converted into murexide.

Uric acid is a constituent of healthy human urine, in which it exists combined with bases in the form of urates, which, being in small quantity, are soluble in the urine. 1000 grains of the urine contain from 1/2 grain to 1 grain of the acid. Drs Beale and Thudichum respectively estimate the amount of uric acid excreted in twenty-four hours by a healthy adult man at from 5 to 8 grains. To determine the amount of uric acid in urine proceed as follows:——To a certain weight of the urine, hydrochloric or nitric acid is added, and the urine set aside for some hours, at the end of which time, the insoluble crystals of uric acid which are formed, are washed, dried, and weighed.

With the exception of the urates, uric acid is one of the deposits most frequently met with in abnormal urine, wherein it occurs as a small reddish powder adhering to the bottom or sides of the containing vessel. As a urinary deposit, uric acid assumes a great variety of forms, that of most frequent occurrence being the rhombic, modified in many of the crystals by the rounding of two of the angles, as shown in the engraving on next page.

=URINARY DISEASES.= This class of disorders, which in general terms may be said to embrace affections of the kidneys, bladder, ureters, &c., comprises diseases of these parts varying greatly in character and pathological importance.

The most serious forms of kidney disease are CONGESTION of the kidney, a very frequent accompaniment of heart or lung disease; PYELITIS, or inflammation of the pelvis of the kidney; SUPPURATIVE NEPHRITIS, or inflammation of the substance of the kidney, which ends in suppuration; ACUTE NEPHRITIS, or ACUTE BRIGHT’S DISEASE, acute inflammation of the kidney, frequently arising from scarlatina or cold; CHRONIC NEPHRITIS, or CHRONIC BRIGHT’S DISEASE, a formidable and incurable variety of kidney affection, giving rise to dropsy, and, owing to the disintegration of the organ, to poisoning of the blood by urea. In advanced cases of this disease the urine contains a large quantity of albumen and casts of the urinary tubes.

CALCULUS OF THE KIDNEY. The most dangerous diseases of the bladder are those caused by the deposition in it of earthy and other concretions, known as URINARY CALCULI, which are described in the present work under CALCULUS. The presence of these calculi is indicated by acute pain in the bladder and urinary passages, extending to the adjacent parts, the pain being excruciating immediately after passing the urine. Sometimes during the act of excretion the stream of water is suddenly stopped.

Inflammation is another dangerous disease of the bladder, calling for the prompt summoning of the medical practitioner wherever possible.

The following particulars as to its symptoms and treatment are offered for adoption to emigrants and others so placed as to be beyond the means of medical succour.

Inflammation of the bladder commences with pain in the region of that organ, the pain becoming continuous and increasing in violence, and being accompanied with a sense of burning heat and of tenderness on pressure. The urine is frequently voided. The inflammation is sometimes so acute as to give rise to suppuration and the consequent discharge of pus with the urine. Sometimes the disease assumes a chronic character.

In the acute form of the disease recourse should be had to leeches, hot fomentations, and warm baths; a dose of calomel, to be followed by a brisk dose of castor oil, should likewise be administered. Alcoholic drinks of any kind must be carefully avoided, the patient being allowed to drink only cool demulcent beverages. With these should be combined effervescing draughts, frequently repeated, and small doses of Dover’s powder. Great relief will also be derived from the use of enemas of gruel containing laudanum. Where inflammation of the bladder arises from gout or rheumatism, it must be treated as for these diseases. A suppository, consisting of two grains of opium, combined with twenty grains of soap, is frequently of great benefit.

Should the disease become chronic, the best method of treatment will be the repeated use of mild aperients, the combined employment of uva ursi in infusion or powder, with either tincture of perchloride of iron, or the mineral acids. Spirituous liquors of any kind must be avoided. Demulcent drinks form the best beverage, and a farinaceous or milk diet the most desirable food.

NEURALGIA OF THE BLADDER. The pain which attends this disease is unaccompanied either by inflammation or irritation, and is recurrent in character. It may generally be arrested by tincture of perchloride of iron, or of iron and quinine, administered three times a day.

IRRITATION OF THE BLADDER. The patient affected with this disorder gratifies the frequent desire he has to pass his urine, the operation being accompanied with pain and forcing, the most severe pain being experienced after the excretion has taken place. The tincture of perchloride of iron will also be found the best remedy for this disorder. It should be given in conjunction with the infusions of uva ursi, Pareira brava, or buchu.

Mucilaginous drinks should also be had recourse to.

CATARRH OF THE BLADDER. The symptoms of this disease are irritation, and the presence of much mucus in the urine. The same treatment may be adopted as recommended for irritation of the bladder. If there be an absence of pain, spirits of nitre and copaiba balsam in moderate doses frequently afford relief.

STRANGURY. Constant micturition, only a few drops of urine passing at the time, occasioning burning and cutting pains around the parts. Strangury is generally due to some irritating cause, which should, if possible, be discovered and removed. Cantharides taken either internally, or applied externally, as in the form of a blister, will sometimes give rise to it. The patient should drink copiously of mucilaginous beverages, such as linseed tea, slippery elm bark, barley water, with gum Arabic dissolved in it. An injection consisting of thirty or forty drops of laudanum in a spoonful of gruel will be found to afford immediate relief. If the above means fail, a pill containing a grain of camphor in five grains of extract of henbane should be given, and a warm bath taken. See GRAVEL.

=U′RINE.= The density of the urine varies from 1·005 to 1·030;[247] the average, in health, being 1·020, when it contains about 380 gr. of solid matter in the pint. According to Berzelius, the proportion is about 6-3/4%, the rest being pure water. It exhibits a decidedly acid reaction, and is never alkaline, except during disease, or the use of large quantities of alkaline salts of the vegetable acids. The average quantity secreted during 24 hours may be taken at 2 pints to 3 pints; as might be supposed, a larger quantity is passed during the summer than in the winter months.

[Footnote 247: From 1·015 to 1·025, Beale.]

Miller gives the following as the composition of healthy urine:——

In 100
Specific gravity 1·020 parts of
solid
Water 956·80 matter.

{ { Urea 14·23 33·00
{ { Uric acid 0·37 0·86
{ Organic matters, 29·79 { Alcoholic extract 12·53 29·03
{ { Watery extract 2·50 5·80
{ { Vesical mucus 0·16 0·37
{
{ { Sodic chloride 7·22 16·73
A { { Phosphoric anhydride 2·12 4·91
{ { Sulphuric anhydride 1·70 3·94
{ Fixed salts, 13·35 { Lime 0·21 0·49
{ { Magnesia 0·21 0·28
{ { Potash 1·93 4·47
{ { Soda 0·09 0·12
{
Loss 0·03
—————— ——————
1000·00 100·00
A = Solid matters, 43·2.

The presence of bile in urine, or other like fluids, may be detected as follows:——Put a small quantity of the suspected liquid into a test-tube, and add to it, drop by drop, strong sulphuric acid, until it becomes warm, taking care not to raise the temperature above 122° Fahr.; then add from 2 to 5 drops of syrup (made with 5 parts of sugar to 4 of water), and shake the mixture. If the liquid contain bile, a violet coloration is observed. Acetic acid may be substituted for sugar.

Another test for bile consists in pouring a little of the suspected urine into a test tube, and adding to it a few drops of tincture of iodine, when if bile be present the fluid becomes distinctly green. Rosenbach says that urine containing bile, when passed through white filtering paper, imparts a yellow or brown colour to the paper. On allowing one drop of strong nitric acid to run down the side of the moist filter it leaves a yellow streak, soon changing to orange, with a violet border, on the outside of which blue and emerald-green zones may be observed. These colours remain visible for some time.

Dark-coloured urine, owing to substances other than bile, does not produce this play of colours.

The reagents most generally employed for detecting the presence of sugar in urine are Trommer’s (_see_ SUGAR) and Fehling’s solutions. For the effective application of Fehling’s test, Dr Roberts[248] advises the following method of procedure:——Pour some of the Fehling’s solution into a narrow test tube to the depth of 3/4 of an inch; heat until it begins to boil; then add 2 or 3 drops of the suspected urine. If the sugar be abundant, a thick yellow opacity or deposit of yellow suboxide are produced (and this changes to a brick-red at once if the blue colour of the test remains dominant). If no such reaction ensue, go on adding the urine until a bulk nearly equal to the test employed has been poured in; heat again to ebullition, and no change occurring, set aside without further boiling. If no milkiness is produced as the mixture cools, the urine may confidently be pronounced free from sugar, or, at any rate, it contains less than 1/40th percent.

[Footnote 248: ‘Urinary and Renal Diseases,’ by Dr W. Roberts.]

If the quantity of sugar is very small, viz. from a 1/2 to 1/40th per cent., the precipitation of the yellow or cuprous oxide does not take place immediately, but occurs after some time as the liquid cools, and the manner of the change is peculiar. First, the mixture loses its transparency, and passes from a clear bluish green to a light greenish opacity, just as if some drops of milk had fallen into the tube. This green milky appearance is quite characteristic of sugar.

Before using the Fehling’s solution it should be always examined previously to the addition of the urine, by being first boiled alone, when if it remains clear it may be pronounced in fit condition. On the contrary, should the preliminary boiling give a deposit, the solution must be discarded, and some freshly made employed instead.

Böttger has proposed the following quantitative test for the presence of sugar in urine:

He first adds some potash to the sample of urine, and then a small quantity of subnitrate of bismuth, and boils the mixture. If sugar is present, the suboxide is reduced, and metallic bismuth being liberated is precipitated as a black powder.

Another method of applying the bismuth test is as follows:——One part of crystallised carbonate of soda is dissolved in three parts of water, and added to an equal quantity of the urine. A small quantity of basic nitrate of bismuth is then added to the mixture, which is then heated to the boiling point. A black precipitate is formed if the urine contains sugar.

Horsley’s test consists in boiling with the suspected urine a mixture of equal parts of neutral chromate of potash and solution of potash, when, if sugar be present, a green colour will be produced, owing to the formation of the sesquioxide of chromium.

M. Luton’s, which is a modification of Horsley’s test, a solution of bichromate of potash is decomposed by excess of sulphuric acid, and upon the urine being boiled with the mixture, a splendid green colour is imparted to it. Urea, albumin, and the urates do not interfere with this reaction.

Vidau has observed that a mixture of equal parts of hydrochloric acid and oil of brune (oil of sesame), either in the cold, or when slightly heated, assumes a distinct rose colour in the presence of cane or grape sugar, provided 0·001 gramme of sugar is present for every c.c. of mixture.

One of the best methods for the accurate and quick estimation of the amount of sugar in urine is, perhaps, the volumetric, devised by Fehling, who employed a standard copper solution, known as ‘Fehling’s solution,’ of the following composition:

Sulphate of copper 90-1/2 grains.
Neutral tartrate of potash 364 ”
Solution of caustic soda, sp. gr. 1·12 4 fl. oz.
Add water to make up exactly 6 ”

Of this solution 200 grains are exactly decomposed by one grain of sugar.

The following is the mode of performing the analysis given by Dr Roberts[249]:——Measure off 200 grains of the above standard solution in a 200-grain tube, pour this into a flask, and add about twice its volume of water; then place over a spirit lamp to boil. While the copper solution is being heated the urine to be analysed should be diluted with water to a known degree. In the case of ordinary diabetic urines the best dilution is one in ten. This is obtained by carefully filling a 6-ounce measure with water to the depth of 4-1/2 ounces, and then adding urine so as to make up exactly 5 ounces. The mixture will then contain exactly one tenth of urine (when the quantity of sugar in the urine is very small, a dilution of one in five, or even the undiluted urine may be employed). The next step is to fill a burette (which must be graduated to grains) with the diluted urine to 0. Then proceed to add it in successive small portions to the boiling copper solution until the blue colour has entirely disappeared. After each fresh addition from the burette, the mixture should be raised to the boiling point, and then allowed to stand a few seconds, so that the precipitated copper may subside, and the observer may see, by holding the flask between the eye and the light, whether the mixture still retains any blue colour.

[Footnote 249: ‘Urinary and Renal Diseases,’ by Dr W. Roberts.]

As soon as the blue colour has disappeared the analysis is complete, and the quantity of diluted urine may be read off. The percentage of sugar in the urine can now be readily calculated. Suppose 125 grains had been added from the burette, this represents one tenth, or 12·5 grains of undiluted urine, and contains exactly one grain of sugar; by dividing 12·5 into 100 the per-centage of sugar is obtained, or 100/12·5 = 8; the urine contains 8 per cent. of sugar.

Another process for the quantitative determination of sugar in urine, called by its author, Dr Roberts, “the differential density method,” is based upon the loss of density, experienced by diabetic urine, after all the sugar has been removed by fermentation. Dr Roberts says repeated examples derived from diabetic urine so treated, together with corresponding experiments made with solutions of sugar of known strength in normal urine, and in pure water, as well as theoretical calculation have warranted the conclusion, _that the number of degrees of density so lost indicates as many grains of sugar per fluid ounce_.

The method, which is extremely simple, is thus performed:——Into a 12-ounce bottle measure 4 fluid ounces of the diabetic urine, and drop into it a piece of fresh German yeast, about as large as a cobnut or walnut; insert a cork in the bottle, and let the cork have a nick cut in the side, to allow of the escape of the carbonic acid. Then fill an ordinary 4-ounce bottle with the same sample of urine, omitting to add any yeast, and cork it in the ordinary manner. Place both bottles in a warm situation, where the temperature is about 80° or 90° Fahr., for twenty or twenty-four hours; at the end of which time, the fermentation being over, the scum will either have cleared off or subsided. The fermented urine is then poured into a proper urine-glass, and its specific gravity ascertained.

The specific gravity of the unfermented companion portion is also taken, and by comparing the two results the loss of density is thus arrived at. Before the respective densities are taken it is best to remove the two samples to a cool place, where they should remain for two or three hours, in order that they may acquire the temperature of the surrounding air.

The two following examples may serve as illustrations of the method.

I. II.
Density before fermentation 1053 1038
Density after fermentation 1004 1013
Degrees of density lost 49 25
———— ————
Grains of sugar per fluid ounce 49 25

If it be desired to bring out the result as so much per cent., this is accomplished by multiplying the number indicating the “density lost” by the coefficient 0·23. Thus, in the first of the above examples, 49 × 0·23 = 11·27; and in the second 25 × 0·23 = 5·69, which are amounts of sugar respectively per 100 parts.[250]

[Footnote 250: Roberts.]

In taking the densities Dr Roberts advises the operator to employ a urinometer having a long scale, since the degrees are much further apart than in the scales of the short-stemmed instruments, and are therefore more distinct and can be more easily read off.

The following are examples of diabetic urine:

No. 1 (Simon).

Specific gravity 1018·
Water 957·00
Solid constituents 43·00
Urea Traces.
Uric acid Traces.
Sugar 39·80
Extractive matter and }
soluble salts } 2·10
Earthy phosphates 0·52
Albumen Traces.

No. 2 (Dr Percy).

Specific gravity 1042·
Water 894·50
Solid constituents 105·50
Urea 12·16
Uric acid 0·16
Sugar 40·12
Extractive matter, and}
soluble salts } 53·06

No. 3 (Bouchardat).

Water 837·58
Solid constituents 162·42
Urea 8·27
Uric acid Not isolated.
Sugar 134·32
Extractive matters, and }
soluble salts } 20·34
Earthy phosphates 0·38

“Diabetic urine usually possesses a peculiar smell, which has been compared with that of violets, apples, new hay, whey, horses’ urine, musk, and sour milk. Such comparisons serve only to show how difficult it is to give by description a correct idea of a particular odour. The colour of diabetic urine is generally pale. Sometimes, but not usually until after two or three days, the surface becomes coloured with a whitish film, owing to the development of the _sugar fungus_, and the _penicillium glaucum_, and gradually the urine becomes opalescent in consequence of these fungi multiplying in great numbers in every part of the fluid. See URINARY DEPOSITS (FUNGI).

“Diabetic urine has a sweet taste, and often numbers of flies are attracted to it, which fact sometimes leads the patient to suspect that the urine is not healthy.”[251]

[Footnote 251: ‘Kidney Diseases, Urinary Deposits,’ &c., Dr Lionel Beale.]

White merino, that has been wet with a solution of bichloride of tin, is also said to form a ready test for sugar in urine.

Albumen in urine may be detected by the nitric acid, or by the heat test. The nitric acid test is performed as follows.——Fill a test tube to about an inch with the urine, then incline the tube and pour in strong nitric acid down the side of the tube, so that the acid sinks to the bottom and displaces the urine, which by reason of its smaller specific gravity rests above it. Let the acid be added till it forms a stratum about a quarter of an inch thick at the bottom.

If the urine contain albumen three layers will be perceptible——one, perfectly colourless, of nitric acid at the bottom; immediately above this an opalescent zone of the coagulated albumen; and, on the top, the unaltered urine.

In his work, ‘Kidney Diseases and Urinary Deposits,’ Dr Lionel Beale directs attention to the very important fact that “two or three drops of nitric acid to about a drachm of albuminous urine in a test tube will produce a precipitate of albumen which will be _dissolved on agitation_, while, on the other hand, about half as much strong nitric acid as there is of urine will redissolve the precipitate of albumen, unless the quantity present be excessive. Albumen precipitated by nitric acid is _soluble in weak nitric acid_, and in a considerable excess of urine, and it is also _soluble in strong nitric acid_. _It is therefore necessary in employing the nitric acid test to add from ten to fifteen drops of the strong acid to about a drachm of the urine suspected to contain albumen._”

Dr Roberts gives the following directions for applying the heat test:——If the urine have its usual acid reaction it becomes turbid on boiling when it contains albumen, and this turbidity persists after the addition of an acid. There are two points to be remembered on using heat alone as a test for albumen. First, that albumen is not coagulated by heat when the urine is alkaline; in such cases, therefore, it is necessary before boiling to restore the acidity by a few drops of acetic acid (carefully avoiding excess). Secondly, when the urine is neutral or very feebly acid, it may become turbid on heating, from precipitation of the earthy phosphates, but turbidity from this cause is easily distinguished from albumen by a drop of nitric or acetic acid, which instantly causes the phosphates to disappear. It may sometimes happen that the patient whose urine is to be submitted to examination for albumen may be taking large doses of nitric or hydrochloric acid. Under these circumstances Dr Bence Jones recommends the addition of ammonia to the urine, nearly to the point of neutralisation.

Mr Louis Siebold proposes a modification of Dr Roberts’s method of applying the heat test in acid states of the urine, which is as follows:——Add solution of ammonia to the urine until just perceptibly alkaline, filter, and add diluted acetic acid very cautiously until the urine acquires a faint acid reaction, avoiding the use of a single drop more than is necessary. Now place equal quantities of this mixture into two test tubes of equal size, heat one of them to ebullition, and compare it with the cold sample contained in the other test tube. The least turbidity is thus distinctly observed, and gives absolute proof of the presence of albumen, the error of confounding phosphates with albumen being out of the question, as they are precipitated by the ammonia and removed by filtration.

M. Galipe[252] says the following is a delicate as well as trustworthy test for albuminous urine. A few drops of the urine are carefully added to a solution of picric acid contained in a small conical test glass. If albumen be present a well-marked turbidity will be produced at the point of contact between the two liquids. On applying heat the albumen agglutinates, and rises to the surface. Phosphates and urates are said not to interfere with this test.

[Footnote 252: ‘Pharm. Zeitung for Russland,’ xiv, 48 (‘Pharm. Journ.’).]

In order to determine the quantity of albumen in urine proceed as follows:——Add a little acetic acid to the urine, and then heat it in a water bath until it boils. Or the albuminous urine may be dropped into boiling water acidulated with acetic acid. In either case collect the precipitate on a weighed filter, wash it well, dry it, and weigh it. The albumen must afterwards be incinerated, and the resulting residue, which consists of earthy salts, must be deducted from the dried precipitate.

Stolnikow[253] adopts the following method for the quantitative estimation of albumen in urine:——The urine is diluted with water until a sample poured upon some nitric acid contained in a test tube produces still a faint white ring at the point of contact after the lapse of forty seconds. The number of volumes of water added to the volume of urine (which may be taken as one) is divided by 250, and the quotient will be the percentage of albumen in the urine. This relation has been established and confirmed by gravimetric determinations.

[Footnote 253: ‘Chem. Central.’ (‘Pharm. Journ.’).]

It is sometimes desirable to remove the albumen from the urine before proceeding to search for other substances. There are several methods of accomplishing this. If the urine be boiled the albumen will become coagulated, but in many cases it may happen, owing to the urine being slightly alkaline or neutral, that a small quantity may remain in solution. Hence it will be advisable to add a little acetic acid to the urine before applying heat to it, to remove the precipitated matters by filtration, and to exactly neutralise the acid in the filtrate. If a few crystals of sulphate of soda be heated with albuminous urine, the albumen and allied matters may be entirely removed without injury to other organic matters dissolved, and without interfering with the employment of other reagents. When it is desirable to free the urine from albumen previous to testing for sugar, this latter method will be found the best and most convenient.

The following analyses represent the amount of albumen present in the urine of two patients suffering from Bright’s disease:

No. 1 (Simon).

Specific gravity 1014·
Water 966·10
Solid constituents 33·90
Urea 4·77
Uric acid 0·40
Fixed salts 8·04
Extractive matters 2·40
Albumen 18·00

No. 2 (Dr Percy).

Specific gravity 1020·
Water 946·82
Solid constituents 53·18
Urea 7·68
Uric acid, and indeterminate }
animal matter } 17·52
Fixed soluble salts 5·20
Earthy phosphates 0·14
Albumen 22·64

Dr Parkes records the case of a patient suffering from albuminuria, who excreted 545 grains of albumen in twenty-four hours. See URATES.

Urine frequently contains an abnormally large quantity of urea. Such urine is of high specific gravity——1·030 or more. When present in large excess the urea becomes deposited in ‘sparkling crystalline lamellæ’ of the nitrate, if it be mixed with an equal quantity of strong nitric acid in the cold.

The crystals vary slightly in character, according to the amount of nitric acid employed and the degree of concentration of the urine. Urine which thus yields, without previous concentration, the nitrate, is said to contain an excess of urea. See page 1689.

The quantity of urea present in urine is best determined by a process invented by Liebig. When a solution of pernitrate of mercury is added to one of pure urea the urea and mercuric salt unite and form an insoluble compound, of undetermined constitution. If, however, the chlorides of the alkalies and alkaline earths are present, this combination does not take place, owing to the decomposition of the mercuric nitrate, and the formation of bichloride of mercury, and a nitrate of the alkali or alkaline earth, both of which are soluble. When, however, the decomposition of the chloride has been completed, the urea may be entirely precipitated, provided a sufficient quantity of mercuric nitrate be added to the solution. In estimating the amount of urea in urine, therefore, it is only necessary to add to the urine a solution of the mercuric salt of known strength, since from the quantity of this latter which has been employed in throwing down the urea, this can easily be calculated.

In performing this analysis, three special solutions are requisite:

1. A solution consisting of one part by measure of a cold saturated solution of barium nitrate with two parts (also by measure) of saturated baryta water. This serves for the removal of the phosphates and sulphates, the presence of which in the urine would interfere with the analysis.

2. The standard solution of mercuric nitrate, which is made as follows:——772 grains of red oxide of mercury placed in a beaker are dissolved in a sufficient quantity of nitric acid (sp. gr. 1·20) by a gentle heat, and evaporated over a water bath until all _excess of free acid_ is driven off. This may be known by the liquid becoming dense and syrupy in appearance. It is then poured into a properly graduated vessel and diluted to 10,000 grain-measures. Of this solution, 10 grain-measures = 0·1 grain of urea.

3. A solution of carbonate of soda in distilled water, 20 grains to the ounce. This solution is employed to indicate when the titration is complete, and to show the operator that all the urea has been precipitated by the mercuric salt.

The operation is thus performed:

(_a._) 400 grain-measures of the clear urine are mixed with 200 grain-measures of the baryta solution, No. 1. The mixture is poured into a filter, and of the clear filtrate which passes through 150 grain-measures are carefully measured off, and poured into a small beaker. This quantity of course contains two thirds, or 100 grain-measures of wine.

(_b._) A graduated burette (each division of which equals a grain-measure of water) is next filled with the solution (No. 2) of mercuric nitrate, which is then dropped into the beaker containing the filtered urine, until the mixture becomes turbid. The quantity of solution that has been required to just reach the point of turbidity is then noted down; it shows that all the chloride of sodium has been decomposed, and that the urea is now beginning to precipitate.

(_c._) The solution (No. 2) is now added more liberally, and thoroughly mixed with the contents of the beaker by means of a glass rod; a copious white precipitate is being formed. The operation is completed, when, of course, no more precipitate is thrown down.

(_d._) This point is ascertained by means of the solution of carbonate of soda (No. 3), to a few isolated drops of which dotted about a white plate, or slab, or placed on a watch glass, give, when mixed by means of the stirring rod with a drop of the turbid mixture from the beaker, a yellow tinge, owing to the formation of hydrated oxide of mercury.

(_e._) The quantity of solution of mercuric nitrate that it has taken to produce the above reaction is then noted down, and from this the portion used before the occurrence of the turbidity is deducted, the remainder, of course, being the amount required to precipitate the urea. By bearing in mind the statement already made that 10 grain-measures of the mercurial solution indicate 0·1 grain of urea, the quantity excreted in 24 hours may be arrived at by a very easy and obvious calculation.

_Dr Davy’s method of estimating Urea._ This consists in the decomposition of a known quantity of urine by sodium hypochlorite, the amount of urea being calculated from the resulting nitrogen. A glass tube, 12 or 14 inches in height, and graduated to tenths and hundredths of a cubic inch, is filled to more than a third of its length with mercury; a measured quantity of urine, varying from a quarter of a drachm to a drachm, is next poured into the tube, which is then filled up with a solution of sodium hypochlorite (the liquor sodæ chlorinatæ of the Dublin Pharmacopœia). This latter must be poured in quickly, and the open end of the tube immediately closed with the thumb. The tube is then shaken to ensure admixture between the urine and hypochlorite, and stood with the open end downwards in a cup filled with a saturated solution of common salt; the mercury escapes into the tube, its place being filled by the solution of salt, which being heavier than the mixture of urine and hypochlorite, retains them in the upper part of the tube. The urine becomes soon decomposed, the carbonic acid, which is one of the products of its decomposition, being absorbed by the excess of chloride of sodium present, whilst the liberated nitrogen bubbles up to the top of the tube. When no more evolution of gas takes place, the volume of nitrogen is read off, and from its amount the quantity of urea present in the amount of urine experimented upon is calculated: one-fifth of a grain of urine = 0·3098 parts of a cubic inch of nitrogen at 60° Fahr. and 30” barometric pressure.

_Haughton’s method of estimating Urea from the specific gravity of the Urine._ After having measured the urine voided during 24 hours, and determined the specific gravity of the whole collected amount, and then consulting the accompanying table, compiled by Professor Haughton, the number of grains of urea excreted per diem is immediately ascertained. This quantity will be shown by the figures which stand at the points where the lines running respectively from the number of fluid ounces and the ‘specific gravity’ intersect each other. Thus, suppose the daily amount of urine to have been 30 ounces, and the specific gravity 1006, the number of grains of urea contained in it will be 85. This method is inserted for urines containing sugar and albumen.

_Determination of the Water._ The amount of water in any sample of urine may be determined by weighing 1000 grains of the recently excreted urine into a counterpoised platinum or porcelain dish, and ascertaining the loss it has undergone after evaporation to dryness. The operation should be performed as speedily as possible. The best plan is to concentrate the urine in a water bath, the evaporation should be continued _in vacuo_ over strong sulphuric acid, until the weight of the residue remains constant. By way of control, another sample of the same urine, consisting of 500 grains, may be operated upon at the same time, and under the same conditions.

URINARY DEPOSITS, &c. These differ from the albumen, sugar, bile, &c., previously described, in being insoluble in abnormal urine. Sometimes they are diffused throughout the whole body of the urine, when they give it an opaque appearance. Sometimes they may be met with floating on its surface; at others they are only partially diffused through the fluid, frequently in the form of a transparent or opaque cloud, when they occupy a considerable space; whilst very often they occur in a crystalline or granular form, deposited sometimes at the bottom and sometimes at the sides of the vessel holding the urine.

Of the numberless insoluble substances met with in urine, both in health and disease, our limits will only permit us to notice those which are most important, and of frequent occurrence.

For the detection of the generality of these the microscope is indispensable. An instrument magnifying 200 to 220 diameters (1/4 of inch objective) will generally be found sufficiently powerful, and in some instances an inch objective, magnifying 40 diameters (as in the larger forms of crystalline deposit) will answer all the purposes.

Some of the varieties of these deposits admit of a double examination, viz. a microscopical and chemical one. When this is the case, the particulars applying to each kind of investigation will be given.

_Mucus._ Mucus is always present in small quantity in healthy urine, in which it shows itself within a few hours after the urine has been excreted in the shape of a transparent cloud towards the bottom of the vessel containing the urine.

_Pus._ The presence of pus in urine is indicated by an opaque, more or less bulky, cream-like deposit at the bottom of the vessel holding the urine, to which some separated pus globules, finding their way to the supernatant liquid, give an appearance of slight turbidity. By shaking the vessel the whole of the liquid becomes turbid, owing to the equal dissemination through it of the pus globules. The pus again deposits on standing. A small quantity of albumen is always met with in the clear part of urine which contains pus; the albumen being derived from the _liquor puris_, the liquid by which the pus-corpuscles are surrounded.

Whenever it can be obtained in sufficient quantity, pus should always be examined chemically, as follows:——The supernatant urine being decanted, the suspected sediment is shaken up with liquor potassæ, when if it become converted into a gelatinous, viscid substance, incapable of being dropped from the tube, and when poured from it running as a slimy and almost continuous mass, it may be pronounced pus. This same gelatinous viscid mass is met with in alkaline urines containing pus, adhering to the sides of the vessel in which the urine is placed, where it has been formed by the action of the carbonate of ammonia (caused by the decomposition of the urea) upon the pus. The reaction upon the pus is the same as that which takes place when liquor potassæ is employed. The stringy viscid substance due to the last cause is frequently, but erroneously, termed _mucus_.

Professor HAUGHTON’S _Table for the Estimation of the
Daily Excretion of Urea from the Specific Gravity_.