URONOLOGY and its Practical Applications: A GUIDE TO THE EXAMINATION OF URINE AND ITS DIAGNOS- TIC VALUE, WITH EXTRACTS FROM THE WORKS OF THE MOST MODERN INVESTIGATORS. BY GEORGE M. KOBER, M. D., MEMBER OF THE CLINICO-PATHOLOOICAL SOCIETY AND MEDICAL SOCIETY OF THE DISTRICT OF COLUMBIA. REPRINT FROM THE RICHMOND AND LOUISVILLE MEDICAL JOURNAL, SEPT., OCT., NOY. AND DEC., 1874. LOUISVILLE, KY.: RICHMOND AND LOUISVILLE MEDICAL JOURNAL PRINT. 1875, TO CHARLES H. CRANE, M. D., ASSISTANT SUKGEON—GENERAL UNITED STATES ARMY, IS TOKEN OF ADMIRATION, GRATITUDE AND REGARD, this little volume is RESPECTFULLY inscribed by THE AUTHOR. PREFACE. In offering this little volume to the Medical Profession, the author begs leave to state, that it was written two years ago, at a time when there existed, in reality, a necessity for a concise guide to the examination of urine. A year ago it made its appearance seriatim in the “ Richmond and Louisville Medical Journal,” and through the generosity of its editor, Dr. E. S. Gaillard, I am enabled to present the subject to my medical friends in a more compact form. COTTTE1TTS. PAGE. Normal Urine ...... 3-19 Composition . . . • . . 3 Physical Character of Urine . . . . . 9 Reaction ...... 10 Accidental Ingredients . . . . - 13 Changes in Urine during Decomposition. ... Abnormal Urine . . - 19 Color ....... 22 Odor . . . . . . - 28 Specific Gravity ..... 29 Reaction . . . . . . - 32 Urea Increase and Deficiency .... 38 Creatine and Creatinine . . . . -47 Uric Acid and Urates . , 47 Phosphates . . . . 54 Chlorides . . . . 53 Sulphates ....... q% Oxalate of Lime ..... 33 Bile • . - . . . 67 Sugar ...... 70 Inosite . . . -75 Extractive Matters ..... 75 Albumen . , . . . , 76 Blood. . . . . . 30 Fibrin . . . . . .79 Fat . . • - . 83 Hippuric Acid . , .35 Leucine ..... 85 Tyrocine . Cystine ...... 86 Xanthine . . . ,86 Hyppxanthine .... 37 Allantoine . . .87 Mucus and Epithelium .... 37 Bus . . . .. ... 89 Cancer and Tubercle Masses . . . 90 Cylinders and Renal Casts . . . . - 91 Kidney Structure . . . . . 93 Spermatozoa . . . . . 93 Entozoa . ... . . . 93 Systematic Analysis of Urine . ' . .93 Prostatic Calculi . . . . 99 Urinary Calculi . . . . .99 Explanation to Illustrations .... 101 Uro-micros copy, after Dr O. Funke PLATE 1. Fig. 1 Fig 2. Fig 3. Fig. 4. Fig 5. Fi §. 6. /r// yy/ry/y/ rf//s/ . /- syy-y / y //F c //sr/srs// IM. PHOTO LITHOGRAPHIC Co. NX OSBORNE 'S PPOCCSS) Uro-microscopy, after Dr 0. Funke, PLATE 2, FiL.l. Fig. 2. Fig. 3. Fig, 4. Fig. 5. Fig. 6, AJ zW/zz/za/s/ ant/ /tzztliz'z//zf - //rt/t'ztz/\J/att itztz/. 4M. PHOTO-LITHOGRAPHIC CaM Y.( OSBORNE’S PROCiSSJ PLATE 3. Uro-microscopy after 0.-Funke, Vogel lambi Fig.l. Fig. 2. Fig. 3. Fig. 4. Fig. 5. Fig. 6. AJvv/y yyyy yyy/ a-yyy/ /svy/y / vV/y - /Zw/ssrs/ ' Sysy tyyv//. dM. PHOTOLITHOGRAPHIC CaM YfOSBORHtS ffiOC URONOLOGY AND ITS PRACTICAL APPLICATIONS: A GUIDE TO THE EXAMINATION OF URINE AND ITS DIAG- NOSTIC VALUE, WITH EXTRACTS FROM THE WORKS OF THE MOST MODERN INVESTIGATORS. With the progress of medical science, the study of urine has been well presented, and I am glad to say, with the most satis- factory results. It seems strange that medical men have not heretofore attached more importance to urine in diagnosis; but when we remember that there were and are a class of physi- cians who pretend to diagnosticate and treat their cases by an ocular inspection only of the fluid, we need not wonder that the earnest and educated physician, as well as the enlightened public, became disgusted with the subject of “ urinary diagno- * So much time and labor have been expended upon this very valuable series of papers, that the editor of this Journal has bad prepared, as an accompani- ment, accurate plates of all normal and abnormal urinary deposits. These beautiful and complete plates are copied from Neuhauer’s and Vogel’s masterly work on Urinary Analysis, and Otto Funke’s valuable Physiological Atlas. The whole will form the most valuable guide to be found in the study of urines and the varied urinary deposits manifested by the microscope.—E. S. G. sis.” It would be simply absurd to attempt to diagnosticate every case by the character of the urine, or to resort to an examination in every simple and well-pronounced disease; yet the value of urine in diagnosis is certainly great, and will aid and supply us with light in obscure cases of the many diseases of mankind. It is difficult to say how much information can be obtained from an examination of urine. We can form some idea, how- ever, when we remember that the kidney and its functions are important to the human economy* and that disease of this or any other organ or part of the body would materially influence the quantity or quality of the excreted fluid, and thus indicate not only the condition of the secreting organ, but also the state of the blood, as well as other changes which may be going on in the body. We not only obtain valuable information from an examination of urine in disease, but can judge the condition of the system in general. Thus the surgeon often receives encour- agement to operate, if the urine is in a normal condition, or a warning, by some abnormal ingredient in the fluid, not to per- form the operation. During my studies of general and special pathology, I was impressed with the importance of a knowledge of normal and abnormal urine, and became convinced that the study of the changes of this excretion during disease would prove an invalu- able aid in diagnosis, prognosis, and treatment. But I also felt that the student and practitioner were in want of a concise guide to the examination of urine and the study of its pathological indications. I therefore determined to gather as much information on the subject as time would permit. It has been my aim in these papers to arrange and adapt from various sources the points of most importance to the phy- sician, not the professed chemist, and I can but hope that this will meet with the approval of the Profession. Much of the information contained in this “Guide” is ob- tained from Dalton’s “Physiology,” Neubauer’s and Vogel’s “Analysis of Uurine,” Thudichum’s “Manual of Chemical Physiology,” Bird and Beale on “ Urinary Deposits,” Flint’s 3 and Aitken’s “ Practice of Medicine,” and last, but not least, DaCosta’s “ Medical Diagnosis.” I have carefully weighed the statements of these eminent writers, and have taken the liberty to differ from them whenever I had good reason to do so. Normal Urine.—Before we can appreciate the changes which take place in urine during disease and their pathological rela- tions, it is necessary to be acquainted with physiological urine and its chemical composition. We know that the functions of the kidney are to eliminate from the system water and nitro- gen, and to take from the blood many of its salts and certain effete materials, whose presence would otherwise prove injuri- ous to the economy. This beautiful and interesting process is constantly going on in the kidneys, the excreted fluid is brought from there to the bladder, from which it is finally discharged. Urine is chemically composed, according to the analyses of Berzelius, Lehman, Becquerel, and others, of the following con- stituents : Water, ------ 938.00 Urea, 30.00 Creatine, ------- 1.25 Creatinine, - - -• - - - - 1.50 Urate of soda, 1 Urate of potassa, > - - - - 1.80 Urate of ammonia, j Coloring matter and mucus, - - - - - .30 Biphosphate of soda, 1 Phosphate of soda, Phosphate of petassa, } ----- 12.45 Phosphate of magnesia, Phosphate of lime, j Chlorides of sodium and potassium, - 7,80 Sulphate of soda and potassa, ----- 6.90 1000.00 Some physiologists regard traces of lactic acid and. oxalate of lime as normal constituents. I need hardly say that the pro- portionate quantity of the above ingredients is not absolute, but only approximate, and that they vary from time to time, ■within certain physiological limits, like the ingredients of all other animal fluids. Water.—We find that the quantity of water is sufficiently 4 large to hold all the solid constituents in solution, being in ex- cess of nature’s want, it is eliminated, like any other useless material in the human economy. The quantity of water in urine varies considerably in health; of its variations, I shall speak more fully hereafter. Urea. c ] a nen^ral; crystallizable, ni- trogenous substance, readily soluble and easily decomposed by external influences. The blood is the true source from which it is supplied to the urine; according to Picard it exists in the blood in the proportion of 0.016 per thousand. Owing to the constant elimination by the kidneys, an accumulation in the cir- culating fluid is impossible, but this condition takes place when the kidneys are extirpated, the renal arteries ligated, or the functions of the organ, by inflammation (or otherwise) inter- fered with. Under such circumstances it has been found in the proportion of 1.4 per thousand. Urea is doubtless the product of the change of nitrogenized substances, and will hence vary considerably with the food partaken of, as well as with the ac- tivity of transformation of structures in the system. The pro- portion found in urine is 30 parts per 1000. The quantity ex- creted by an adult in twenty-four hours is stated by different authors as 408, 487, 500, 542, and 670 grains. Mental and bodily exercise, age, weight, and sex, and many other influ- ences, will produce variation. The following table of Lehman illustrates variation produced by the differet kinds of food; Kind of Food. Daily quantity of Urea. Animal, ------ 793 grains. Mixed, ------ 437 “ Vegetable, ------ 337 “ Non-nitrogenous, ----- 231 “ The diurnal variation is also to be remembered by the physi- cian; a smaller quantity is produced during the sleeping hours than during the day; this is probably due to the greater ac- tivity, during waking hours, of the muscular, mental, and diges- tive functions. This difference is observed in patients confined to bed. More urea is produced in the latter half than in the 5 -earlier half of the day ; and the greatest quantity is discharged during the four hours from 6| to 10| A. M. To obtain urea from the urine, evaporate the latter while fresh in a water-bath until it has a syrupy consistency. It is then mixed with an equal volume of nitric acid, which forms nitrate of urea. This salt being less soluble than pure urea, rapidly crystallises, after which it is separated by filtration from the other ingredients. It is then dissolved in water and decom- posed by carbonate of lead, forming nitrate of lead, which re- mains in solution, and carbonic acid which escapes. The solu- tion is then evaporated, the urea dissolved out by alcohol, and finally crystallized in a pure state. Urea has no tendency to spontaneous decomposition, and may be kept, when perfectly pure, in a dry state or dissolved in water, for an indefinite length of time. If the watery solution be boiled, however, the urea is converted, during the process of ebullition, into carbonate of ammonia. One equivalent of urea unites with two equiva- lents of water, and becomes transformed into two equivalents of carbonate of ammonia. Organic impurities, acting as catalytic bodies, will induce the same change, if water be present. Animal substances in a state of commencing decomposition are particularly liable to act in this way. In order for this conversion of the urea to take place, it is necessary that the temperature of the mixture be not far from -70° to 100° F. r ~ G4 H9 N3 O2 +H2 0 [new formula]. m.; Creatine. C 8 H9 Na 0* +2 H 0 [old formula]. rhls 18 described as a neutral cry stall! zable substance, soluble in water, slightly so in alcohol, and not at all in ether. It is derived from the disintegration of muscular tissue; it is found in the blood, its proportion, however, is not determined; in the muscles it is found in the proportion of about 0.67 parts per thousand; in the urine in proportion of about 1.25 parts per thousand. It is converted into creatinine by being heated with strong acids, when it loses two equivalents of water. Boiling it with ■an alkali will either convert it into carbonic acid and ammonia, 6 or will decompose it, with the production of urea and an artifi- cial nitrogenous, crystallizable substance, called sarcosine. Creatinine.—C 4 H7 N3 O [C8 H7 Ns 02J. Is also a crystalli- zable substance, the only difference between it and creatine- consists in its having two equivalents less of water. It is found,, like creatine, in the blood, muscles, and urine, and is probably produced by transformation of parts of creatine, since we find it in less quantity than creatine in urine. It is more soluble in water and alcohol, and slightly so in ether. It has a distinct alkaline reaction. Urate of Soda.—This is a neutral salt, formed by the union of soda and a nitrogenous animal acid, known as uric acid C 5 H4 N4 O3 [C10 H4 N4 0&]. Many authors consider uric acid as though it were itself a proximate principle and a constituent of the urine; but it can not properly be regarded as such, since it never exists in a free state in normal urine, and its presence can only be determined by the addition of strong acids, which will decompose the soluble urates and liberate uric acid. When- ever uric acid is present, therefore, it has been produced by the decomposition of the urate of soda. Urate of soda is found in the urine and blood, and is, like urea, the product of the metamorphosis of tissue, from which it is absorbed by the circulating fluid and carried to the kidney, there to be eliminated in company with other ingredients of the urine. The average daily quantity eliminated by the healthy human adult is, according to Lehman, twenty-five grains. This substance exists in the urine of the carnivorous and omnivorous animals, but not in that of the herbivora. In the latter, it is replaced by another substance, differing somewhat from it in composition and properties—viz., hippurate of soda. The urine of herbivora, however, while still very young, and living upon the milk of the mother, has been found to contain urates. But when the young animal is weaned, and becomes herbivo- rous, the urate of soda disappears, and is replaced by the hip- purate. [Dalton.] Urates of Uotassa, and Ammonia.—These closely resemble 7 urate of soda in their physiological relations; they are found in small quantities in urine. The deposit formed by their pre- cipitation is of a pink color, sometimes brown, or even white. They are decomposed by strong acids with the formation of crystals of uric acid. Both are soluble in hot water, but their deposit takes place as soon as the temperature is low- ered. The substances now described resemble each other, as they all contain nitrogen, are crystallizable, and soluble in water. They are the result of the wear and tear of the body, produced by the decomposition or catalytic transformation of the organic or albuminoid constituents of the body, and being taken up by the blood as effete material, are carried to the kidney, there to be removed. These excrementitious matters are themselves decomposed, after being expelled from the body, under the in- fluence of air and moisture, so that the resolution and destruc- tion of the organic substances are at last complete. The coloring matter of urine consists of a substance called urophcein [urohcematin]; and, according to Heller, uroxanthin [indican, after Schunk], This latter pigment is found only in small quantity. In normal urine, it is decomposable by strong acids and heat into a red pigment urrhodine, and a blue pig- ment uroglaucine. The former identical with indigo-red, and and the latter with indigo-blue. The pigment urohsematin con- tains iron, and closely resembles the pigment of the blood. Dalton describes the coloring matter, urosacine, as yellowish- red, readily adhering to insoluble matters, and that these, when precipitated, are more or less deeply colored, according to the quantity precipitated with them. Thudichum asserts that a substance called by him “ urochrome,” is the only normal color- ing pigment in the urine, and that all other named pigments are only products of decomposed urochrome. Be this as it may, other writers are nevertheless correct as to the significance they attribute to these coloring pigments in dis- ease. It is supposed that they are the product of disintegrated red blood corpuscles; certainly, a very plausible theory. In 8 health, the color of urine is influenced by various sorts of food and drink. The mucus in normal urine is derived from the lining mem- brane of the urinary passages, and is interspersed with epithe- lial cells from the kidneys, ureters, and urethra. It can only be detected after the urine has been allowed to settle in a glass tube, •where it may be perceived as a flocculent, cloudy mixture at the bottom. When I come to speak of the changes in the urine during decomposition, it will be seen that the mucus plays an import- ant part in the process of fermentation, etc. Not unfrequently spermatozoa are seen in it under the microscope. Biphosphate of Soda is held in direct solution in the urine; it is this salt which gives the urine its acidity, as there is no free acid present in its recent condition. [See page 6.] It is most likely derived from the neutral phosphate of soda in the blood, which is decomposed by the uric acid at the time of its formation, thus producing a urate of soda and converting a part of the neutral phosphate of soda into the acid biphosphate. The Phosphates of Lime and Magnesia, the earthy phosphates, exist in urine by indirect solution. They are nearly insoluble in water, but are kept in solution in the urine by the acid phos- phate of soda. They are derived partly from the food, but mostly from the disintegration or oxidation of disintegrated albuminous substances, specially of the nerve structures. When the urine is alkaline, they are deposited as a whitish precipi- tate, giving the urine a turbid appearance; when the urine is neutral, they are still held in solution, to some extent, by the chloride of sodium, which has the property of dissolving a small quantity of the phosphate of lime. The Phosphates of Soda and Potassa are derived from the food and the disintegration of albuminous substances, and are held in solution by the water of the urine. The Chlorides are derived from the food and blood; the amount eliminated in health will greatly depend upon the amount ingested. 9 The Sulphates are found in large quantities in urine, and are held in solution like the alkaline phosphates. Urine thus composed constitutes healthy urine, which is an amber-yellow colored fluid, of an acid reaction, sometimes, how- ever, it is neutral, and occasionally slightly alkaline. The aver- age quantity of urine passed by a healthy adult per diem is be- tween thirty and forty ounces, and its mean specific gravity is 1024. Vogel gives the amount of urine passed per diem as fifty-seven ounces; but I am inclined to believe, since his expe- rience was chiefly limited to the male sex of Germany, who are for the most part beer or wine drinkers, that this average amount is by no means true of the adults in this country. The quantity and specific gravity of urine vary in health consider- ably ; the physician should therefore not be too hasty in sus- pecting trouble because the specific gravity is high or low; he should remember that there are certain circumstances and con- ditions of the .system (not at all pathological) which will tend to materially influence the quantity and density of the eliminated fluid; as for instance, if a less quantity of drink is taken into the system, or if the lungs, skin, or intestines perform their function with unwonted activity, a proportionately smaller amount of water will be eliminated by the kidneys; and as the solid ingredients of the urine remain the same in quantity, and are held in solution by the water, this solution becomes neces- sarily more concentrated, and its specific gravity therefore high. Then again we find, that if a large quantity of fluid is taken into the system, the temperature being low and the function of the skin diminished, the quantity of urine will be proportion- ately large and its specific gravity low. These changes in the specific gravity are not then produced by the quantity of solid matters, which under these circumstances remain the same in the twenty-four hours. The physician in examining urine should also bear in mind its diurnal variation, both in specific gravity and acidity, and that the quantity of each and all of its ingredients may vary to a certain extent, without any morbid condition of the sys- 10 tem. The urine which has collected during the night in the bladder and is voided early in the morning, is more dense, of a higher specific gravity, and more acid than that discharged in the forenoon, and the second discharge is often neutral or alka- line in reaction. During the middle of the day, it again be- comes denser, of a deeper color, and increases in acidity. All these properties become still more strongly marked during the afternoon and evening, and towards night the urine is again deeply colored and strongly acid, and has a specific gravity of 1028 or 1030. The urine as a general rule is discharged from the bladder five or six times in the twenty-four hours. The following tables, taken from Dalton’s Physiology, will serve to show the general character of the variation in reaction and gravity: Urine of first discharge, acid, specific gravity 1025. “ second discharge, alkaline, specific gravity 1015. “ third discharge, neutral, specific gravity 1018. fourth discharge, acid, specific gravity 1018. fifth discharge, acid, specific gravity 1027. OBSERVATION I.—MARCH 20. OBSERVATION II.—MARCH 21. Urine of first discharge, acid, specific gravity 1020. second discharge, neutral, specific gravity 1022. third discharge, neutral, specific gravity 1025. fourth discharge, acid, specific gravity 1027. fifth discharge, acid, specific gravity 1030. In examining urine, therefore, the physician should never be satisfied with the result of only one examination, but repeat the same, and then seek a conclusion. I observed before that normal urine reddens blue litmus paper, showing its acid reaction; often, however, it is neutral, and again slightly alkaline. If no food has been taken for hours, it becomes highly acid, whereas, after meals, or while digestion is still going on, it is but faintly so. Urine after being discharged from the bladder remains generally acid for a EE-ACTION OF UEINE. 11 day or more. The normal acid or alkaline reaction of urine seems to depend upon the state of the blood. Under ordinary circumstances, the kidneys secrete an acid urine from an alka- line blood, showing that they have the power peculiar to their cells to separate the acid salts from the blood. When, however, the blood after the entrance of newly digested food becomes strongly alkaline, the acid reaction of the urine ceases, and it becomes neutral or slightly alkaline. The alkaline reaction of urine may also be due to the presence of a fixed alkali, like the carbonate of potassa or soda, or a volatile alkali, due to the decomposition of urea into carbonate of ammonia. In the first instance, if red litmus is dipped into the urine, it turns blue and remains so after drying. In the second instance, it becomes also blue, but its original red tint returns after the paper has been dried. Alkalinity of urine from a fixed alkali, the result of fruits, certain articles of food and medicine, is not indicative of a mor- bid condition of the system. I may mention here that the salts of the organic acids, as the lactates, malates, acetates and tar- trates of soda, potassa, etc., when taken into the system, are re- placed in the urine by the carbonates of the same bases, and of course render the fluid alkaline. Dr. Bence Jones found that two drachms of tartrate potass, dissolved in four ounces of water and taken into the circulation, rendered the urine alka- line in thirty-five seconds; after two hours, the alkaline reaction ceased. Lehman found in one instance by experimenting upon a person with congenital extroversion of the bladder, in whom the orifices of the ureters were exposed, that the urine became alkaline in the course of seven minutes after the injection of half an ounce of acetate of potassa. I shall speak of this sub- ject under abnormal urine in a subsequent paper, and point out the extent of alkalinity and its continuance as consistent with health. The alkalinity of urine depending upon a volatile alkali is always to be viewed as pathological. Urine in its healthy and recent condition is affected by chem- ical and physical reagents in the following manner: Boiling the 12 urine of an acid reaction produces no visible change; if it be neutral or alkaline, the mixture becomes turbid, particularly so when the earthy phosphates predominate, since these salts are less soluble at a high than at a low temperature. The addition of mineral acids will first alter the color of the urine, which assumes a brown color by the use of sulphuric acid, and determines thereby the presence of the coloring urhcematin. The hydrochloric and nitric acids decompose the urates and deposit uric acid in a crystalline form upon the sides and bottom of the glass tube; these crystals are most frequently transparent rhomboidal plates, or oval laminae with pointed ex- tremities. The microscope shows them very clearly; frequently the crystals are tinged of a yellowish hue by the coloring mat- ter of the urine, which unites with them when they are depos- ited. Not unfrequently they are arranged in radiated clusters, or small spheroidal masses, so as to present the appearance of minute calculous concretions; the variance in size and form de- pends upon the time occupied in their formation. If potassa or soda be added to urine, so as to neutralize its acid reaction, it becomes immediately turbid, owing to a deposit of the earthy phosphates, which are insoluble in alkaline fluids. The solution of chloride of barium precipitates a deposit solu- ble in free acids [the phosphates], and a deposit insoluble in acids [the sulphates']. Nitrate of silver precipitates a yellow deposit soluble in nitric acid and ammonia [the alkaline phos- phates], and a white precipitate insoluble in nitric acid, but soluble in ammonia [chloride of sodium.] Urine contains certain organic substances, which possess the power of interfering with the mutual reaction of starch and iodine, and even of decomposing the iodide of starch after it has once been formed. This peculiar action of urine was first noticed and described by Professor Dalton. The interference occurs in all cases in which iodine exists in the urine. When it has been administered as a medicine, it exists in the form of an organic combination; and in order to detect its presence by means of starch, a few drops of nitric acid must 13 be added at the same time, so as to destroy the organic matters; after which, if iodine is really present, the blue color imme- diately appears. Urine also possesses the property, which depends upon some of its organic ingredients, of interfering with Trommer s test for grape sugar. If clarified honey be mixed with fresh urine, and sulphate of copper with an excess of potassa be afterwards added, the mixture takes a dingy, grayish blue color. On boil- ing, the color turns yellowish or yellow-brown, but the sub- oxide of copper is not deposited. In order to remove organic matter and detect the sugar, the urine must be first treated with an excess of animal charcoal and filtered. By this means the objectionable organic substances are retained upon the filter, while the sugar passes through in solution, and may then be detected as usual by Trommer’s test. ACCIDENTAL INGREDIENTS IN URINE, Often medicinal and poisonous substances, after having been introduced into the system, are found in the urine. This is of importance to the physiologist and chemist, and in many cases to the physician. From the presence of certain medicines in the urine, we may know whether to continue them or not. For instance, if nitre, digitalis, or strychnine be given, they should be detected in the urine; their absence would prove their accu- mulation in the system, and the timely discovery of such a con- dition will sometimes prevent a fatal result. Substances which tend to unite strongly with the animal matters, and to form wfith them insoluble compounds, such as the preparations of iron, lead, silver, arsenic, mercury, etc., are least liable to ap- pear in the urine. They may occasionally be detected in this fluid when they have been given in Targe doses, but when ad- ministered in moderate quantity are not usually to be found there. Most other substances, however, accidentally present in the circulation, pass off readily by the kidney, either in their original form or after undergoing certain chemical modifica- tions. 14 Perrocyanide of potassium, when introduced into the circu- lation, appears readily in the urine. Bernard* observed that a solution of this salt, after being injected into the duct of the submaxillary gland, could be detected in the urine at the end of twenty minutes. lodine, in all of its combinations, is found in urine after it has been given. Dalton found, after the ad- ministration of half a drachm of the syrup of iodide of iron, iodine in the urine at the end of thirty minutes, and it contin- ued to be present for nearly twenty-four hours. Quinine, ether, chloroform, tannin, and carbolic acid have been detected in the urine after having been introduced into the system. While it would be very interesting for the physician to ex- amine the urine for these substances, it is to be regretted that the process of analysis is not always simple. Poisonous substances have been detected in the urine, and may be of importance in the treatment of the individual, or in legal medicine. The presence of albumen, oxalate of lime, sugar, blood, bile, fats, and abnormal pigments are generally considered as indica- ting disease. I shall speak of these hereafter, and point out the exceptional conditions in which some of these substances may appear in the urine without the existence of any morbid condition of the system. CHANGES IN THE URINE DURING DECOMPOSITION. The urine, like any other animal fluid after its discharge from the system, and when exposed at an ordinary temperature, is decomposed, and this decomposition is characterized by cer- tain changes which take place in a regular order of succession. I have already intimated that mucus plays an important partin the decomposition of urine. Physiology has taught us that or- ganic substances, when beginning to putrefy, induce in certain other substances all the phenomena of fermentation. The mucus in the urine being an organic substance, soon becomes changed, particularly when exposed to a temperature between * Le?ons de Physiologie Experimental, 1856, p. 111. 15 60° and 100° F., and communicates these changes more or less rapidly to the supernatant fluid. This first change is called add fermentation, and produces a free acid, usually lactic add, from some of the undetermined animal matters contained in the urine. This fermentation takes place very early, within the first twelve, twenty-four, or forty-eight hours, according to the elevation of the surrounding temperature. Perfectly fresh urine, as has been stated before, contains no free add. Lactic acid, nevertheless, has been so frequently found in nearly fresh urine as to lead some eminent chemists (Berzelius and Lehman) to regard it as a natural constituent of the excretion. It has been subsequently found, however, that urine, though entirely free from lactic acid when first passed, may frequently present traces of this substance after some hours’ exposure to the air. The lactic acid is undoubtedly formed, in these cases, by the decomposition of some animal substance contained in the urine. Its production in this way, though not constant, is sufficiently frequent to be regarded as a normal process. It is, in consequence of this change, or the presence of this acid [lactic acid C 3 H6 O3 (C6 H6 O6)], that the urates are par- tially decomposed, and the deposit of crystalline uric acid takes place in the same manner, as if a little nitric or muriatic acid had been added to the urine. Urine, therefore, if abounding in the urates, frequently shows a deposit of uric acid a few hours after it has been passed, though it may have been perfectly free from deposit at the time of its emission. During the period of add fermentation, Dalton believes that oxalic add [C3 ED N2 O4 (C6 H4 N2 O6)] is also sometimes pro- duced in a similar manner with the lactic acid, and that the presence of oxalate of lime in urine, after a day or two of expo- sure to the atmosphere, is not at all a dangerous or morbid symptom; “ for whenever,” he goes on to say, “ oxalic add is formed in the urine, it must be necessarily deposited under the form of oxalate of lime, since this salt is entirely insoluble both in water and in urine, even when heated to the boiling point.” It is difficult to comprehend how the deposit of oxalate of 16 lime in the urine was held previously in solution. The explana- tion of Dalton is, 11 that its oxalic acid is, in all probability, formed, as stated above, in the urine itself, and that it unites as fast as it is produced with the lime previously in solution, and thus appearing as a crystalline deposit of oxalate of lime.” It is much more probable that this is the true explanation, since, in the cases to which Dalton alludes, the crystals of oxalate of lime grew, as it were, in the cloud of mucus which collects at the bottom of the vessel, while the supernatant fluid remains clear. The crystals of oxalate of lime are of minute size, and appear under the microscope in well-defined octahedra of various sizes, and dumb-bell-like bodies (the latter are not frequent), double quadrangular pyramids, united base to base, and prismatic crys- tals, are all occasionally observed. Considerable difference of opinion is evinced as to the pro- duction of oxalic acid and to what extent a deposit of oxalate of lime in urine is consistent or inconsistent with the health of the individual. There can be no doubt that oxalic acid is also found in the system, since it has been found in the blood; its true source is not known. I take the following view : If oxalate of lime is found imme- diately after urine has been voided, it is either the result of fermentive action in the urinary passages, or the formation of oxalic acid in the system; the history of the case will generally guide us in our opinion. The oxalate of lime found in urine after a day or two of its exposure to the atmosphere is (I adhere to Dalton) the result of acid fermentation. Of the pathology, etc., of oxalate of lime, I shall speak more fully in a subsequent paper. At the end of some days the changes above described come to an end, and are succeeded by the process known as “ alka- line fermentation.” This is nothing more nor less than the decomposition or transformation of the urea into carbonate of ammonia. As the alteration of the mucus advances, it loses the power of producing lactic and oxalic acid, and becomes a 17 ferment, capable of acting by catalysis upon the urea, and ex- citing its decomposition as above. It has been already men- tioned that urea may be converted into carbonate of ammonia by prolonged boiling, or by contact with decomposing animal substances. In this conversion, the urea unites with the ele- ments of two equivalents of water, and consequently it is not susceptible of the transformation when in a dry state, but only when in solution or supplied with a sufficient quantity of mois- ture. The presence of mucus, in a state of incipient decompo- sition, is also necessary to act the part of a catalytic body. Consequently, if the urine, when first discharged, be passed through a succession of close filters so as to separate its mucus, it may be afterwards kept for an indefinite time without alter- ation. But under ordinary circumstances the mucus, as soon as its putrefaction has commenced, excites the decomposition of the urea, and carbonate of ammonia begins to be developed. According to von Tieghen, the alkaline fermentation is not dependent upon the mucus, but a peculiar torula, which is found in every urine. [See Vogel’s Anbeitung, p. 130.] The first portions of the ammonia will begin to neutralize the biphosphate of soda; the acid reaction of the fluid diminishes in consequence of this change, and the production of carbonate of ammonia still going on will soon render the fluid neutral and alkaline. It will be seen that these changes are dependent upon the presence of mucus, or, if you please, torulce, since, if they are present, they are intimately mixed with the mucus, and it has been found that they increase in quantity, in the same affections, in which mucus increases; an increased quan- tity of either the mucus or torulse, therefore, in combination with a high temperature will greatly influence the rapidity of the decomposition. Urine of a neutral or slightly acid reac- tion, when passed, will, of course, become sooner alkaline than that of intense acidity. The fermentive process may be going on in the bladder, thus we have alkalinity of urine, due to the decomposition of urea into carbonate of ammonia, in paralysis of the bladder, simply 18 from the fact that the fluid is retained for many hours, and that there is nothing to antagonize the changes; on the contrary, many circumstances will favor this process—such as a high temperature, a large amount of mucus, etc. The first effect of the alkaline condition of the urine thus produced, is the precipitation of the earthy phosphates. These salts, as I hinted in the course of their description, are held in solution by the acid biphosphate of soda, and are totally insol- uble in neutral and alkaline urine. The precipitate begins to fall as soon as the natural acidity of the urine has fairly disap- peared, and settles upon the sides and bottom of the vessel, or is partly entangled with certain animal matters which rise to the surface and form a thin, opaline scum upon the urine. There are no crystals to be seen at this time, and the deposit is entirely amorphous and granular in character. The next change consists in the production of two new double salts by the action of carbonate of ammonia on the phosphate of soda and magne- sia. One of these is the “ triple phosphate,” phosphate of mag- nesia, and ammonia—(2 Mg 0N H4 0P O5 -f 2 H 0). The other is the phosphate of soda and ammonia—(Na 0 N H4 0 H 0P O5 +BH 0). The phosphate of magnesia and ammonia is formed from the phosphate of magnesia in the urine by the re- placement of one equivalent of magnesia by one of ammonia; the crystals of this salt are very elegant and characteristic. They show themselves throughout all parts of the mixture, growing gradually in the mucus at the bottom, adhering to the sides of the glass, and scattered abundantly over the film which collects upon the surface. By their refractive power, they give to this film a peculiar glistening and iridescent appearance, which is nearly always visible at the end of six or seven days. The crystals are perfectly colorless and transparent, and have the form of triangular prisms, generally with beveled extremi- ties, or resemble feather-down. Frequently, also, their edges and angles are replaced by secondary facets. They are soluble in acids, but never in alkalies. [See plate 2, fig. 3 and 5.] The phosphate of soda and ammonia is formed by the union of 19 ammonia and the phosphate of soda, which latter is one of the normal constituents of urine. Its crystals resemble very much those of the triple phosphates, except that their prisms are of a quadrangular form, or some figure derived from it. They are intermingled with the preceding in the putrefying urine, and are affected in the same way by chemical reagents. The carbonate of ammonia, after converting all the other in- gredients with which it is capable of entering into combination, is now given off in a free form. The urine acquires at this time a strong ammoniacal smell, and a piece of moistened test- paper held a little above its surface will have its color imme- diately turned by the alkaline gas escaping from the fluid. This is the source of the ammoniacal vapor which is so freely given off from stables and from dung-heaps, or wherever urine is allowed to remain and decompose. This process continues un- til all the urea has been consumed, and until the products of its decomposition have either united with other substances, or have finally escaped in a gaseous form. ABNORMAL URINE AND ITS DIAGNOSTIC VALUE, I shall now consider the character of urine which has been changed during disease in quantity or quality, together with the pathological indications of these changes. Some physicians shrug their shoulders, and to use the lan- guage of Bedford, are disposed to smile with something less than contempt, when they hear of the importance attributed to urine in diagnosis; but no independent and progressive mind will ever heed these insinuations. The educated physician can no longer scorn the idea of “ urinary diagnosis,” provided the examinations are conducted scientifically and with the intention on the part of the physician to study the character of disease and alleviate the suffering of mankind. The enlightened laity, when they know his motives and see that these examinations are valuable aids in diagnosis, and that they are conducted without ostentation on the part of the physician, will appre- ciate his skill and regard the subject as a part of the progress 20 of medical science. What more need be said to induce every physician to make, now and then, an examination of the urine of his patients, than to assure him that a study of the changes which take place in this excretion, during disease, will guide him in his diagnosis, prognosis, and treatment ? In examining urine, the physician should always first look and test for what he expects to find. In obscure cases of diag- nosis, he ought carefully to consider and weigh all the striking points, and from repeated examinations he will arrive at a con- clusion dictated to him by the language of nature; for she speaks to him not only through the symptoms in general, but also through the character of the excreta, particularly of the urine. I may add that nature never deceives, but the observer may deceive himself. Before proceeding to discuss in detail urine in its abnormal conditions, it will not be amiss to acquaint the student with some of the principal requisites for its exami- nation. He should have at hand accurate test solutions, the strength of each of which is exactly known; be provided with graduated pipettes for sucking up and measuring the fluid to be examined prior to its transfer to a convenient vessel; and with graduated glass instruments, or burettes, from which exact quantities of the test solutions may be dropped. Graduated flasks, also, for the preparation of the solutions for the reagents are very useful, and beaker glasses to hold the urine. A microscope is the most essen- tial instrument in urinary diagnosis. He must also bear in mind that in the quantitative analysis, it is customary to' use the French system of measures, and to employ instruments on which cubic centimetres are marked. One thousand cubic centime- tres are equal to one litre, or 61.028 English cubic inches, or to a thousand grammes of water; and one gramme is equal to 15.434 troy grains. [Da Costa.] In examining urine, the following are the details of the facts to be determined and recorded: I. —Record the age and weight of the patient. 11. —Collect all the urine passed in twenty-four hours, meas- 21 ure it in cubic centimetres, and record its absolute amount. lll.—Observe and record the following general properties— viz.: 1. Specific gravity; 2. Urohsematine, as determined by Vogel’s color table; 3. Clearness or turbidity on emission or after rest; 4. Determine the absolute weight, by multiplying the quantity passed, expressed in c. c., by the figures expressing the specific gravity; the result is the weight in grammes. IV.—Set aside the following quantities of the urine for the volumetric determination of— 1. Urea, 40 c.c. 2. Uric acid, 300 to 500 c.c. 3. Phosphoric acid, 40 c.c. [The precipitate from the urea estimation is sufficient.] 4. Chloride of sodium, 40 c.c. 5. Sulphuric acid, 100 c.c. 6. Degree of free acidity. 7. Sugar, 20 c.c. 8. Albumen. 9. Solids, 20 grammes. V.—Collect and examine the sediment. Vl.—Determine the amount of the excretion normal to the individual by the following empirical formula (Parke’s); Mul- tiply the following figures by the weight of the person in pounds, avoirdupois; the result is the excretion in grains in twenty-four hours of the several ingredients of the urine : In men be- In women In children between In yonng tween 20 bet. 20 and men & wo- and 40. 40. “ men bet. 3 and 8. 8 and 16. 16 and 20. Urea, - - 3.53 2.96 6.83 5.20 4.39 Chlorine, - 0.875 0.817 1.44 1.097 0.926 Sulphuric acid, 0.214 0.25 0.414 0.315 0.266 Phosphoric acid, 0.336 0.336 0.65 0.495 0.418 The following corrections are required: 1. If the person be between forty and fifty, calculate according to columns 1 or 2, and then deduct 10 per cent.; for ages between fifty and sixty, 22 deduct 20 per cent.; for ages between sixty and seventy, de- duct 30 per cent.; for ages upward of seventy, deduct 50 per cent. 2. If the person has been starving for two or three days (as in some fevers), deduct one-third from the calculation made according to the table; if the diet be meagre, deduct one-eighth or one-sixth; if pretty plentiful, yet still below that of health, deduct one-tenth. 3. If there be a total inactivity, deduct one- tenth; if there be merely quietude, deduct one-twentieth. [Aitken’s Practice, vol. ii., p. 899.] COLOR OF URINE. I shall first speak of the color of urine, for even the laity are apt to draw conclusions from this physical sign. Much infor- mation may be obtained from a thorough examination. The normal color of urine, which varies from an amber color t® a yellowish-red, depends upon the pigment known as Heller’s Urophsein [Urohsematin], or Thudichum’s Urochrome, etc. It is to be remembered that articles of diet, drinks, and medicine will greatly affect the normal hue. Strong coffee darkens the urine; a greenish-yellow or brownish tint is observed when rhubarb has been taken; but this hue is also indicative of the presence of bile. Turpentine produces a dark color and im- parts the odor of violets to the fluid. Senna produces a yellow- ish color; indigo, chincaphilia, hsematoxylon, and beet-root will tint the urine deeply. Tar and creosote, and the external and internal use of carbolic acid render the fluid black, so will dis- integrated blood or inhalations of arseniuretted hydrogen. A red color is generally owing to an admixture of blood; a very light color is indicative of an increase of water, found in dia- betes, hysteria, and similar nervous affections. A dark urine is found in fever patients ; a light-colored fluid is always indi- cative of the absence of fever. How, since the physician is aware of the many causes which may be productive of changing the color of this excretion, he will know the necessity, at the bedside of the patient, of reason- ing, by way of exclusion. If we can not account for the' abnormal color by articles of 23 diet or medicine introduced into the system, we must endeavor to determine its cause. The change may depend upon the col- oring pigment urophcein (urohsematin). This substance con- tains iron, and resembles closely the pigment of the blood. In- deed, it is believed by many physiologists to be the product of retrograde metamorphosis of the red blood corpuscles. Many reasons would seem to point to the correctness of this theory. The blood corpuscles certainly undergo changes like all organic substances, and no other excreted material corresponds so well to the product of the changed red blood corpuscles, particularly their haematine, than the urophsein in the urine and the biliver- dine in the bile. The increase of this pigment in all acute febrile affections, but more especially in typhus fever and other diseases depend- ent upon a morbid condition of the blood, such as is associated with septic poisons, would give support to this theory. Should it become an established fact, the physician will have every rea- son to place importance upon this particular pigment in his diagnosis and prognosis. Urophcein is detected in the urine by adding to a specimen double the quantity of sulphuric acid; the result is a brown color, if the mixture become dark, the quantity of urophsein is shown to be increased, which is the case in diseases of the liver, as well as in the affections already indicated. For the purpose of estimating with accuracy the quantity of this pigment, Vogel has proposed a method of comparing the hue of the urine with a table of fixed colors, which serve as starting points, and each shade of which represents a defi- nite proportion of the pigment. Urine to be thus compared, must be clear (if not so, it is to be filtered) and should be put in a glass beaker of four or five inches diameter. It is to be remembered that all specimens of urine in which the color has been changed by bile pigment, articles of food and medicine, must be excluded from this examination. The shades of urine have been arranged under three groups, as follows: 24 I.— Yellowish Urines: 1. Pale yellow, like a weak solution of gamboge. 2. Bright yellow, like a medium solution of gamboge. 3. Yellow, like a strong solution of gamboge. II.—Reddish Urines: 1. Reddish yellow, like gamboge with a little carmine. 2. Yellowish red, like gamboge with more carmine. 3. Red, like carmine with a little gamboge lll.—Brownish Urines: 1. Brownish red, red with an admixture of a little brown. 2. Reddish brown, more of the brown than in the last. 3. Brownish black, almost black with a touch of the reddish-brown. The following table, prepared by Vogel, gives an estimate of the quantity of pigment contained in a certain amount of urine of a fixed shade, and also indicates the relative amount of pig- ment contained in different specimens of urine, of equal quan- tity, but of various shades. I* II III IV V VI VII VIII IX *EEMARKS. 1 2 4 8 16 32 64 128 256 *1. Pale yellow. 1 2 4 8 16 32 64 128 II. Bright yellow. 1 2 4 8 16 32 64 III. Yellow. 1 2 4 8 16 32 IV. Reddish yellow. 1 2 4 8 16 V. Yellowish red 1 2 4 8 VI. Bed. 1 2 4 VII. Brownish red. 1 2 VIII. Reddish brown. 1 IX. Brownish black. For the purpose of making these approximative comparisons, Vogel has fixed the quantity of coloring matter contained in 1000 c. c. of pale yellow urine at one. Example.—lf a certain quantity of pale yellow urine (as com- pared with the color table), say 1000 c. c., contains one part of coloring matter, the same amount of yellowish red will contain 16 parts, and of brownish black 256 parts. One volume of yellow urine contains as much pigment as four volumes of pale yellow urine. One volume of red urine contains as much as four volumes of reddish yellow, or 52 volumes of pale yellow urine. If one individual discharges 1000 c. c. of yellow urine 25 in 24 hours, another during the same length of time 4000 c. c. of a pale yellow color, both will have eliminated the same amount of coloring pigment. The following may serve as an example to determine the proportion of coloring matter con- tained in 1800 c. c. of urine of a “ yellow ” color. 1000 c. c. of pale yellow urine equals one part of pigment. Yellow urine, however, contains, according to the above table, four times more pigment, we receive, therefore the following proportion: 1000:4 = 1800: x 7, 2; is the total amount of pigment contained in 1800 c. c. of yellow urine, provided the amount in 1000 c. c. of pale yellow urine is fixed at 1. The other coloring matter named by Heller “ uroxanthine ” or uindiean” by Schunk, is decomposable by strong acids and heat, into a red pigment “ urrhodine” and a blue pigment “uro- glaucine ” the former identical with indigo-red, the latter with indigo-blue. Uroxanthine is detected by mixing thirty drops of urine with five or six times as much of strong hydro-chloric or nitric acid; the fluid after agitation becomes red or faintly violet; if the fluid contains more than a very small amount of this pigment, the mixture becomes decidedly violet or blue from the development of the indigo. Exposure to air also evolves this pigment; its composition is very similar to that of hsematin and the coloring matter of the bile. It is found in small quan- tities in normal urine, and increases in the febrile affections, in ail concentrated urines, in diseases of the nervous system, kid- neys and serous membranes, in cholera, etc. The urine of per- sons afflicted with melanotic cancer, whether seated in the urinary passages or elsewhere, becomes on exposure to the air gradually brown or even black (like porter); this change may be hastened by the addition of nitric or chromic acid; the color is evidently due to the melanine in the pigment cancer, and may be regarded as diagnostic of that affection. [For particu- lars see Eiselt in 11 Prager Vierteligahrschrift ” 1858, p. 190, and Priban in the same journal, 1865, p. 16.] The pink color of urine is in most cases attributable to the 26 coloring matter “ uroerythrin.” Golding Bird has described a similar pigment as ‘‘purpurine"; it is this substance which im- parts to the deposit of urates or uric acid the brick-red or pink color. In febrile and liver affections, in acute rheumatism and gout, the quantity of uroerythrin is increased, and gives the urine a reddish hue. A solution of acetate of lead produces a pinkish precipitate, which is its test. Thudichum supposes this pigment to be a product of oxidated urochrome, which latter he believes to be the normal coloring pigment of the urine, and that Harley’s urohcßmatin, Heller’s urrhodin, and Schunk’s indigo-rubia, are nothing more than products of decomposed urochrome. Thudichum says “ uro- chrome yields by chemalysis various remarkable products of decomposition—viz., uromelanine, uropittine, and omicholine. Schunk states that the color of the urine is not dependent upon only one pigment, and since new coloring matters will form, by spontaneous decomposition of either the original coloring prin- ciple or some other substance contained in the fluid, it is not at all surprising that those pigments are increasing both in name and number. The same observer, as already mentioned, has proven that the uroxanthine of Heller, and the product of its decomposition, uroglaucine and uropodine, are identical with the substance named by him indican and its product of oxida- tion, indigo-blue and indigo-red; and when it is considered that Thudichum’s urochrome is the source from which many of the above-named coloring matters are derived, the study of these pigments is much simplified. I shall now consider the tests for indican (uroxanthine) and urochrome. Indican itself does not impart any color to the urine, but by its decomposition, to which it is very prone (as observed above), it yields indigo-blue, indigo-red, and glucose. Schunk finds it in normal urine, and Carter has proposed the following test: (Da Costa, 3d edit., p. 592). Into a test tube pour urine to the depth of half an inch; add one-third of its volume of commer- cial sulphuric acid of the specific gravity 1830, by allowing it to trickle down the side of the tube, so as to form the lower 27 stratum. The fluids should then be intimately mixed by agi- tating them together. There is produced, according to the amount of indican present, a cplor varying from the faintest tinge of pink or lilac to the deepest indigo-blue. Unless due regard be paid to these minutiae, the reactions mentioned will not be observed. A tolerably correct estimate of the share taken by the different coloring matters in the production of a given tint may be made by neutralizing the sulphuric acid, added as above, with caustic ammonia, then agitating the mix- ture with one-third of its volume of ether and allowing it to re- main at rest for a few minutes. The ether rises to the surface, holding the indigo-red in solution, and the blue in suspension (if any have been generated), leaving the ordinary urine pig- ment dissolved in the aqueous fluid below. The following is a test recommended by Thudichum for the detection of uroehrome. 1. Fresh urine is treated with excess of milk of lime or ba- ryta, allowed to stand, and filtered. To the filtrate, lead acetate with a little ammonia is added till colorless, and the precipitate well washed and digested with cold dilute sulphuric acid, till a filtered sample shows an excess of sulphuric acid when tested with barium chloride and hydrochloric acid. At this point filter the whole, shake the filtrate with barium carbonate to re- move the sulphuric acid, add a little baryta water, pass carbonic acid through the liquid, and filter again. Precipitate the solu- tion with mercuric acetate, wash the precipitate of uroehrome mercury very thoroughly with cold and hot water, decompose it by sulphuretted hydrogen, filter, shake the filtrate with a little fresh silver oxide to remove hydrochloric or kryptophanic acid, filter; again decompose by sulphuretted hydrogen, and evaporate the filtrate to dryness in vacuo over sulphurir acid. A yellow uncrystallizable mass of uroehrome remains. 2. Uroehrome is easily soluble in water with a yellow color, very little soluble in alcohol, soluble in ether, and can thereby be separated from krytophanic acid, which is insoluble in ether. 3. To the solution in water, add lead or mercuric acetate; a flaky yellowish precipitate will fall. 28 4, Add silver nitrate; a gelatinous precipitate soluble in nitric acid will form. 5. Add mercuric nitrate; a white precipitate, pale, flesh col- ored on boiling will be produced. 6. The aqueous solution on standing becomes red and depos- its resinous flakes, containing uromelanine, uropittine, omichol- ine, and omicholic acid (q. v.). This decomposition is hastened by boiling and by acids. 7. Treat acidified extract of urine by ether, and distill the latter. Precipitate the residue by basic lead acetate, decompose by hydrothion, and treat urochrome as above. 8. Separate kryptophanic acid by dissolving its lead salt in excess of lead acetate, in which urochrome lead is insoluble. The colors produced by an admixture of bile or blood will be considered under separate heads in subsequent papers. The odor may also be taken into consideration in the exami- nation of urine, depending as it does upon its normal or abnor- mal constituents. Medicines may impart their odor to the fluid, as saffron and cubebs, for instance. After the internal use of turpentine, the odor of violets is perceived. Several French pathologists (Deßeauvais, etc., etc.,) assert that the odor of these articles is not observed in the urine of patients suffering from an organic lesion of the kidneys. This would be a valuable aid in differentiating organic lesions from mere func- tional disturbances. But Vogel advises us to be chary with this diagnostic sign, as he found the characteristic odor of tur- pentine in a case which afterwards terminated fatally, and in which examination revealed disease of the parenchyma of the kidney. In cases where but one kidney is affected, the test, in my opinion, would be equally unreliable. Asparagus and garlic, when taken into the system, produce a most disagreeable odor of the fluid, particularly when in- dulged in for a succession of days. The laity not knowing this fact, may seek medical advice, fancying a loathsome disease of the kidneys. An instance of this kind occurred last summer in the practice of Professor Morgan, of this city. When urine 29 has been long retained in the bladder, the odor of ammonia may be perceived. The smell of stale fish is occasionally no- ticed, and is owing to a slow decomposition of the organic con- stituents of the urine. A strong urinous smell indicates a large amount of urea or its product, carb. of ammonia; a sweetish odor, like whey, is indicative of diabetes mellitus. SPECIFIC GRAVITY. To ascertain the density or amount of solid matters contained in urine, the physician generally employs the urinometer—al- though not being the most exact mode, it answers very well. To insure a more reliable result1, the fluid should be brought to the temperature at which the urinometer was graduated (gen- erally 60° F.). Mr. Uckland calculated the following table, by which this objection is partly overcome : Ot) Ot) Oi Ot) Ot) Ot) Ot) CO^JQOl^WtOHO Temperature. - Ol OOOOtO^QGoO Number to be added to the indication. *