INTESTINAL CALCULI AND CONCRETIONS 



several together, and the writer has removed as many as sixty from the 

 large bowels of a horse. Where the bowel contains a number, their 

 rubbing action upon each other prevents them from developing to any 

 considerable size, but we have known a single one to reach as much as 

 65 lbs. weight. 



The origin of intestinal calculi is clearly shown by dividing them 

 through the middle with a saw, when it will be found that the centre 

 is occupied by a nucleus of foreign matter, such as a nail, a button, a piece 

 of wire, or particles of grit, &c. &c. If the cut surface of the stone be 



examined, and especially after having been roughly polished, it will be seen 

 to be made up of a number of layers of earthy matter placed one outside 

 the other in widening circles. Radiating lines are also seen extending from 

 the centre to the circumference, marking out the calculus into triangular 

 blocks. The outer surface is usually smooth, and in this respect they 

 contrast with similar formations known as " concretions ". Calculi are 

 almost invariably found in the large bowel, where their formation and 

 retention are favoured by the peculiar pouched arrangement of the organ. 

 Their composition is expressed in the following analysis by Giradin : — 



Ammonio-phosphate of 

 Calcic phosphate . . . 

 Water 



Animal matter 

 Soluble salts, &c. . . . 

 Extractive matters 

 Fatty matter 



48 00 

 19-0Q 

 14-00 

 •80 

 0-60 

 4 00 

 7-00 



