THE URINE. 787 



invariably accompanies the severe forms of nephritis, and larger 

 quantities of pus and blood in the urine. Albumen, on the con- 

 trary, may be absent in grave cases of catarrhal nephritis and 

 cirrhosis of the kidneys. In very rare cases of so-called chyluria, 

 cloudy urine is secreted of a high specific gravity, so rich in 

 albumen that it coagulates into a thick jelly upon being boiled. 

 In addition to tl^e albumen, which is always held in solution, 

 unless acids be added or the urine boiled, numerous fat-granules 

 are present in chyluria, which render the freshly passed urine 

 opalescent. Lastly, a small number of plastids, of the aspect of 

 lymph-corpuscles, may be found. The disease in most cases 

 terminates fatally, and the kidneys, it is maintained by good 

 pathologists, are found normal. 



Determination of the Specific Gravity. According to Hofmann and Ultzmann, 

 we ascertain the exact specific gravity by means of the urinometer, as fol- 

 lows : Fill a standing glass cylinder four-fifths full of urine. The froth being 

 removed by filtering-paper, the urinometer is placed in the urine, never being 

 allowed to come in contact with the walls of the vessel. Bring the eye on a 

 level with the surface of the urine, and read the corresponding division of the 

 urinometer, but not the upper rim of the fluid raised a little by attraction. 

 Touch the stem, causing the urinometer to sink slightly in the fluid, and, 

 after it has come to rest, read again. In all such observations the urine 

 should have a temperature of at least 62o F. (17 C.); otherwise consid- 

 erable error may result. If the amount of urine is small, dilute with even 

 three or four volumes of water ; test as directed, and multiply the number of 

 the division mark by the number of volumes used for dilution. For example, 

 if three volumes of water be added to one volume of urine, and we read 

 1.008, to obtain the real specific gravity of the original fluid 1.008 is 

 multiplied by 1+3 = 4 (1.008X4 = 1.032). The solid materials, on which 

 the specific gravity depends, which were dissolved in one volume, are, after 

 the dilution, dissolved in four volumes ; the specific gravity is therefore only 

 one-fourth of that of the original. By multiplying the decimal of the specific 

 gravity by the coefficient of Haser (2.33) we have the result in grammes of 

 the weight of solids contained in 1000 c. c. of urine. Hence, if we have the 

 entire amount passed in twenty-four hours, we can easily estimate the weight 

 of solids of the whole. For example, we have 1500 c. c. passed in twenty- 

 four hours, of specific gravity 1.020; to estimate the weight of solids in 

 1000 c. c. we multiply the decimal 20 the last two figures by the coeffi- 

 cient 2.33 (20X2.33=46.60), and the product, 46.60, is the weight in 

 grammes of the solids in 1000 c. c. of the urine. Valuable conclusions may 

 be drawn from the amount of solids and the specific gravity ; but each case 

 requires special consideration. For example, we may have to deal with dis- 

 eased kidneys, the amount of urine being normal or diminished, of a low 

 specific gravity. We may conclude, since urea composes nearly the half of 

 the solid constituents, that urea has not been excreted in a sufficient quan- 

 tity, and we may consequently expect uraemia very soon. 



