226 PHYSIOLOGICAL CHEMISTRY. 



Appendix. Intestinal Conor ements. 



Calculi occur very seldom in human intestine or in the intestine 

 of carnivora, but they are quite common in herbivora. Foreign 

 bodies or indigested residues of food may, when for some reason or 

 other they are retained in the intestine for some time, become 

 incrusted with salts, especially ammonium-magnesium phosphate 

 or magnesium phosphate, and these salts form usually the chief 

 constituent of the concrements. In man they are sometimes oval 

 or round, yellow, yellowish-gray, or brownish-gray, of variable size, 

 consisting of concentric layers and containing chiefly ammonium- 

 magnesium phosphate, calcium phosphate, besides a small quantity 

 of fat or pigment. The nucleus ordinarily consists of some foreign 

 body, such as the stone of a fruit, a fragment of bone, or something 

 similar. In those countries where bread made from oat-bran is an 

 important food, we often find in the large intestine balls similar 

 to the so-called hair-balls (see below). Such calculi contain calcium 

 and magnesium phosphate (about 70$), oat-bran (15-18$), soaps 

 and fat (about 10$). Concretions which contain very much (about 

 74$) fat occur seldom, and those consisting of fibrin clots, sinews, 

 or pieces of meat incrusted with phosphates are also rare. 



Intestinal calculi occur often in animals, especially in horses fed 

 on bran. These calculi, which attain a very large size, are hard 

 and heavy (as much as 8 kilos) and consist in great part of concen- 

 tric layers of ammonium-magnesium phosphate. Another variety 

 of concrements which occurs in horses and cattle consists of gray 

 colored, often very large, but relatively light stones which contain 

 plant-remains and earthy phosphates. Stones of a third variety 

 are sometimes cylindrical, sometimes spherical, smooth, shining, 

 brownish on the surface, consisting of matted hairs and plant- 

 fibres, and termed hair-balls. The so-called " .EGAGROPILA," which 

 probably originate from the ANTILOPUS RUPICAPEA, belong to this 

 group, and they are generally considered as nothing else than the 

 hair-balls of cattle. 



The so-called oriental bezoar-stone belongs also to the intestinal 

 concrements, and probably originates from the CAPEA ^GAGRUS 

 and ANTILOPE DORCAS. We may have two varieties of bezoar- 



