URINARY CONCRETIONS. 



507 



(a) Ammonia-magnesium phosphate (Figs. 173, 160, 154): Large coffin-lid 

 crystals, immediately soluble on addition of acids. 



(6) Small globules, yellowish in reflected light, dark in transmitted light, 

 often provided with points; thorn-apple or morning-star shaped, together with 

 amorphous granules (Figs. 154 and 175). These consist of acid ammonium urate. 



(c} Calcium carbonate: Small whitish globules, biscuit-shaped or arranged 

 side by side in irregular masses, together with amorphous granules. Efferves- 



ft %.* 



FIG. 173. Ammonio-magnesium Phosphate. 



V # 



FIG. 174. Imperfectly Developed Crystals of Am- 

 monio-magnesium Phosphate. 



FIG. 175. Acid Ammonium Urate (after v. Jaksch). FIG. 176. Basic Magnesium Phosphate. 



cence takes place on addition of acids, also in the microscopic preparation (Fig. 

 172, a). 



(d) Leucin and tyrosin are extremely rare (Fig. 163). Crystals of neutral 

 calcium phosphate (Fig. 172, c), with their spear-shaped extremities in contact, 

 are also rare, as well as plates of basic magnesium phosphate (Fig. 176). 



Organic sediments may occur both in acid, as well as in alkaline, urine. Among 

 them, pus-corpuscles are present especially in alkaline urine, and the lower forms 

 of vegetable organisms likewise predominate under such circumstances. 



URINARY CONCRETIONS. 



Urinary concretions vary in size from that of a grain of sand or a pebble to 

 that of a fist. They are encountered in the bladder, also in the pelvis of the kid- 

 ney, in the ureters, and in the prostatic sinus. All urinary concretions contain a 

 framework of organic structure uniting the particles of the formation into a 

 coherent mass. They are divided, according to Ultzmann, as follows: 



1. Concretions whose nucleus consists of the sediment formed in acid urine 

 primary calculus-formation. All of these arise primarily in the kidney and pass 

 thence into the bladder, where they undergo enlargement in accordance with the 

 development of the crystals in the urine. 



2. Calculi that have for a nucleus either the sediments found in alkaline urine 



