Concremcnt Poniiatioii. ■ 221 



masses and favoring", as do protein chimps, the adhesion of any 

 precipitate, and, too, perhaps causing ammoniacal fermentation. 

 A high proportion of sahnes in the nrine is, as pointed out hy 

 Klininier. an important feature. This authority questions whether 

 the presence of albuminoid or mucoid substances, such as are occa- 

 sioned in the urinary tract l)y inflammation, provides any means of 

 cohesion, as a sort of paste. .Some such organic stroma is uniformly 

 found, especially because the concretions determine a catarrhal pro- 

 cess at times, as a result of which layers of mucus and albuminous 

 material are found between the mineral deposits ; such viscid matter 

 is, however, also found in loose sediments and perhaps may in 

 reality interfere with calculus formation by preventing [approxima- 

 tion and] cohesion of the particles. Such organic framework is not, 

 as pointed out by Moritz, peculiar to calculi, but is, too, an 

 important feature in any 

 urinary crystal, whatever 



it ma\- be. The size and ^■\<^^'v^'^>-<S^- \ 



shape of urinary concre- 

 tions varies widely with ' /<.■*-'/ -CC^lNV^^^^$^W<0 -" « , ^ 

 the species of animal, the 

 site of formation and the 

 composition. Renal cal- '''"^i;^^.-? 



culi are usually round, '^ 



•^ Fig. 35. 



pearl-shaped, like writing y^^.^^^^ calculus from a horse, 



sand, millet seed or hemp 



seed : those of the renal pelvis are irregular, warty, or correspond to 

 the shape of the pelvic cavity, crcscentic, and may reach a size nearly 

 that of a fist. Tn the bladder the urine throws down a slimy, sandy 

 material which forms a thick, soup-like urine or masses which 

 may attain several pounds in weight and assume the shape of 

 half of a pear (corresponding to the interior of the bladder and 

 flattened on one side by the passage of the urine). When com- 

 pact, vesical calculi are lentil shaped, oval, flattened or faceted 

 from pressure, polished or sometimes rough and mulberry-like, 

 gland shaped, and range in size from that of a millet seed to the 

 size of a double fist. Small concretions met with in the ureters or 

 urethra, and often impacted in these passages, are not formed in 

 this situation, but are swept from the kidneys or bladder. The 

 color of urinary calculi is usually brown, metallic, bronze-like ; 

 some concretions are, however, gray, ye^lo^^•ish or piu'c white, anc| 

 occasionally reddish ones are met. 



