380 Internal Closure of the Intestines. 



and chloride of calcium (Fiirstenberg). The most frequent 

 cause of calculi formation in the intestines is the continued 

 abundant feeding of wheat and rye bran (the disease is fre- 

 quently found among the horses of millers and bakers), which 

 contain an abundance of phosphate of magnesia. The latter dis- 

 solves in the acid contents of the stomach and of the small in- 

 testines, and is precipitated in the alkaline contents of the large 

 bowel; it combines with the ammonia formed during putrefac- 

 tive processes, and gives rise to phosphate of annnonia and 

 magnesia, crystallizing around bodies which may have acci- 

 dentally gotten into the large intestine (grains of oat, pebbles, 

 splinters of iron, swallowed tooth [Fobelot]). Zschokke, how- 

 ever, claims that intestinal disturbances play a considerable 

 role in the production of intestinal calculi. The latter are 

 formed in the large intestine, as a rule preferably in the stom- 

 ach-like dilatation of the colon. We here usually find one cal- 

 culus, variable in size, generally more or less spherical, some- 

 times weighing over twenty pounds; there may exceptionally 

 be several calculi, even many of them; in the latter case they 

 are irregularly formed. Colin examined horses for calculi; he 

 found them 23 times (2.5%) in 900 cases examined, always in 

 the stomach-like dilatation of the colon, only once in the cecum. 

 Calculi have exceptionally been found in the small intestine; 

 their mode of origin could then not be explained; in some of 

 these cases the calculi were probably gallstones, as pointed out 

 by Lewin. 



Acfordiiig to Fiirstciilierg a new layer is formed around intestinal calculi after 

 each meal of l)ran. A calculus of 14 pounds with a diameter of six inches on section 

 showed 720 concentric layers; it would, therefore, have required 3(iO days for its 

 formation. In a case of Pastore a calculus of the size of a fist had been formed 

 in less than a year. 



Aside from the true calculi we find in the large bowel 

 pseudo-calculi (phytoconcrements) and other concrements 

 which lack a definite structure and which owe their formation 

 to pasturing on sandy, marshy meadows, or to marshy feed ; 

 also to the habit of some horses to swallow and to nil)ble on 

 wooden partitions, or to drinking water from shallow brooks or 

 pools, or from wells containing much sand. The latter may form, 

 in the large intestines, mortar-like conglomerated masses with 

 the feces. In the formation of the latter (partictdarly if much 

 l)ran is given), phosphates and carbonates of lime, swallowed 

 hairs, dry vegetable parts or swallowed foreign bodies, take a 

 consideral)le part. (Deysine has reported a case in which he 

 found a swallowed sponge incrusted with lime salts.) The sur- 

 face of pseudo-calculi and concrements is usually uneven; Ihey 

 often have sharp corners or may be covered by a crust of phos- 

 phate of ammonia and magnesia. They are much lighter than 

 genuine enteroliths. 



In a case of Grimnie several hair balls were found in the large colon of a l.orse 

 which had been fed for nine weeks with oat meal ; they were up to the size of a fist 



