XXIV.] URINARY DEPOSITS, ETC. 147 



9. Pyrocatechin is sometimes found in urine. The method of obtaining it 

 requires too much time to be done in this course. 



Tests. 



(a.) To a dilute solution add ferric chloride = a green colour, which becomes 

 violet on the addition of sodic bicarbonate. 



(b.) Add ammonia and silver nitrate, which give a black precipitate of 

 reduced silver. 



LESSON XXIV. 



URINARY DEPOSITS CALCULI AND GENERAL 

 EXAMINATION OF THE URINE. 



1. Mode of Collecting Urinary Deposits. (i.) Place the urine in 

 a conical glass, cover it, and allow it to stand for twelve hours. 

 .Note the reaction before and after standing. With a pipette 

 remove some of the deposit and examine it microscopically. 



(ii.) Dr. Harris has published the following (Brit. Med. Jour., 

 1894, vol. i. p. 1356) : The urine is placed in a tube drawn to a 

 fine point, and fixed in a vertical position in a clamp. The pointed 

 end is down, and after being filled it is corked tight. After the 

 deposit subsides and collects in the lower pointed end of the tube, 

 a small quantity of it may be obtained by clasping the tube with 

 the warm hand or by pushing in the cork slightly. 



(iii.) Centrifuge. By means of a small hand centrifuge (fig. 75, 

 reduced to ^), as made by Muencke of Berlin, any deposit in urine 

 is readily collected at the bottom of a test-tube. The disc I, bear- 

 ing the tubes G, can be made to rotate 3000 to 5000 times per 

 minute. Fig. II. shows the disc in full rotation, and III. the form 

 of glass vessel used. 



There are two classes of deposits, organised and unorganised. 



ORGANISED DEPOSITS. 



1. Pus (p. 147). 



2. Blood (p. 140). 



3. Epithelium. 



4. Renal tube casts. 



5. Spermatozoa. 



6. Micro-organisms. 



7. Elements of morbid growths 



and entozoa. 



2. Pus in Urine (Pyuria) produces a thick creamy yellowish-white sedi- 

 ment after standing, although its appearance varies with the reaction of the 

 urine. If the urine be acid, the precipitate is loose, and the pus-corpuscles 

 discrete ; if alkaline, and especially from ammonia, it forms a thick, tough, 

 glairy mass. The urine is usually alkaline, and is always albuminous, and 

 rapidly undergoes decomposition. Pus is found in the urine in leucorrhfva 

 in the female, gonorrhoea, gleet, cystitis, pyelitis, from bursting of an abscess 

 into any part of the urinary tract, &c. 



