492 DISEASES OF THE URINARY ORGANS. 



Kinds. — There are four situations in which calculi may 

 be formed, or rather in which they have been discovered, viz. 

 the kidney, the ureters, the bladder, and the urethra ; and 

 this has given rise to a distribution of them into renal, uretal, 

 cystic or vesical, and urethral calculi: a classification, be it ob- 

 served, having no reference whatever to their compositions. 



RENAL CALCULI. 



These are commonly lodged within the pelvis of the kidney ; 

 though both in horses and men the infandibula have been 

 found filled with them. Several of our veterinary museums 

 contain specimens of renal calculi. A very fine specimen was 

 in the possession of the late Mr. Ainslie, weighing twenty 

 ounces, and occupying the entire pelvis of the kidney : un- 

 fortunately, no history is attached to it, the late Mr. Youatt 

 having perchance purchased it from aknacker. One larger still, 

 weighing twenty-five ounces, was sent to the Veterinary As- 

 sociation by Mr. Bowles, V.S., Cambridge. " The subject 

 of it,'' Mr. Bowles writes, ^' was a post or coach horse, who was 

 frequently attacked with symptoms which were scarcely dis- 

 tinguishable from those of spasmodic colic : in fact, he was 

 always treated for that disease, and as frequently recovered. 

 The animal, at last, died suddenly, after a severe day's work, 

 when, on opening him, the existence of the calculus was dis- 

 covered. Of course, nearly the whole of the kidney had 

 become absorbed so that the other kidney, which appeared 

 usually healthy, now performed the functions of two." 



Eenal calculi, according to D'Arboval, exhibit two principal 

 varieties. One set are hard and compact ; have a mingled 

 yellow, green, and dirty white hue; with a form, not in- 

 variably but commonly, identical with that of the pelvis ; 

 are composed of regular layers ; and, when sawn through, 

 discover a central nucleus. The other set are areolated and 

 tuberculated, rough and grained upon their surfaces, and 

 not so hard, nor so compact or weighty, as the former, and 

 have an agglomerated composition. 



Symptoms. — We appear to be without any that can be 



