254 INTESTINAL CONCRETIONS. 



proper exercise and sufficient water, constipation need not be 

 feared, and impactions are very rarely witnessed. 



Intestinal Concretions. Not only do we find indigestible 

 materials accumulate in the intestine, but if any foreign ob- 

 ject, such as a small pebble, a nail, &c., penetrates the large 

 intestine, it acts as a nucleus around which materials of 

 different kinds agglomerate, and concretions of large size 

 are formed. Sometimes the food may clog, and adhere to 

 the mucous membrane, constituting a stercoral concretion. 

 I have seen a solid deposit of excrement perforated through 

 its centre, so as to admit of the passage of faeces, but which 

 clogged and incapacitated a considerable portion of the intes- 

 tinal tube. 



Occasionally a calculus forms in the stomach of the horse 

 from the accumulation of calcareous salts phosphates of 

 ammonia and magnesia around a piece of metal or other 

 substance. The deposit is at first crystalline, and after- 

 wards amorphous the external surface, however, being 

 smooth and polished. Mr Stanley, of Leamington, found 

 two large calculi in the stomach of a horse, weighing respec- 

 tively 4 and 5 Ibs. ; the latter being wedged at the opening 

 of the duodenum, causing death. 



The intestinal concretions have been classified according 

 to their composition. Thus we have phosphatic calculi, oat- 

 hair calculi or dust balls, and mixed calculi. These are dis- 

 tinct from the simple stercoral masses which consist alone of 

 hardened fgeces. Gurlt has classified the calculi according 

 to their colour, but Professor Morton's classification is best. 



The phosphatic calculi vary in size from a pea to a mass 

 twenty pounds in weight. They have a smooth, polished 

 external surface, and approach the spherical form. If several 

 are formed together, they are flattened on their sides. A 

 section proves the presence of a nucleus, around which strati- 



