BY DR. LAUDER BRUNTON. 533 



certain cases of disease, but which cannot positively be classed 

 among the normal constituents. 



The abnormal urine of man may contain albumin, irrape- 

 sugar, lactic acid and lactates (?), bile coloring matter and bile 

 acids, blood serum and blood cells, haemoglobin, pus serum 

 and pus cells, carbonate of ammonium, sulphuretted hydrogen, 

 oxalate of lime, xanthine, hypoxanthine, leucine, tyrosine, and 



The urine may contain, in addition to the substances which 

 have been previously named, others which have been intro- 

 duced into the body as drugs or poisons, and which, being 

 excreted by the kidneys, find their way into the urine ; this is 

 the case with many, although probably not with all the metallic 

 salts, with most alkaloids, and with organic bodies of different 

 constitution, as carbolic acid, alcohol, and various vegetable 

 coloring matters. 



183. Urinary deposits. Owing to deficiency in the quan- 

 tity of the urinary water, excess in the quantity of normal 

 ingredients, or presence of substances which are not normally 

 present, we are apt to have urinary sediments or deposits, some 

 of which are composed of structural elements, not usually 

 present, others of the normal or abnormal proximate princi- 

 ples. Amongst such sediments we find most frequently uric 

 acid, urates, ammoniaco-magnesian phosphate, calcium phos- 

 phate, calcium oxalate, blood corpuscles, mucus, epithelium, 

 pus, etc. 



** 184. Reactions of Urine treated with some com- 

 mon reagents. 



Before commencing a systematic account of the mode of 

 separating the chief constituents of urine, the student may 

 with advantage study the action on this fluid of a few of the 

 common reagents which indicate the presence of the chief 

 ingredients contained. Put about 15 cubic centimetres of 

 urine into a series of test-tubes, and try the following experi- 

 ments : 



1. Add about 5 cubic centimetres of strong nitric acid. No 

 precipitate will occur, either immediately or after standing for 

 some time. The color of the urine will, ho w 



darker. 



2. To a portion of fresh urine in a test-tube add an equal 

 volume of liquor potassa3. After some time a transparent 

 flaky precipitate will be observed, which separates on boiling, 

 leaving the supernatant fluid of its original color. 



By other experiments it may be shown that solutions of am- 

 monia and caustic soda likewise induce this precipitate, which 

 consists of earthy phosphates. 



3. Add to 15 cubic centimetres of the urine, about 5 c.c. of 

 a solution of silver nitrate (1-10) ; an abundant curdy precipi- 



