PRODUCTS, ADVENTITIOUS. 



common in the coecum, large intestines, and 

 stomach, and in rare instances have been dis- 

 charged by the mouth. 



There is a very obvious distinction between 

 intestinal calculi, seized by almost all writers 

 on the subject, in regard of their origin : (1.) 

 some originate elsewhere, and make their way 

 into the alimentary canal ; (2.) others are the 

 result of the deposition within the intestines of 

 certain materials around some substance acting 

 as a nucleus, itself either introduced from 

 without or from some other part of the system; 

 (3.) others are wholly formed in the alimen- 

 tary canal. 



(I.) a. Biliary calculi, to be presently de- 

 scribed, form the great majority of those be- 

 longing to the first class. They present pre- 

 cisely the same characters as while still in con- 

 nection with the biliary system, b. Calculi 

 sometimes pass into the intestine from the 

 urinary passages. Dr. Marcet found a calculus, 

 mainly composed of a mixture of phosphate of 

 lime and triple phosphate, in the rectum of an 

 infant with imperforate anus. A communica- 

 tion existed between the bladder and rectum. 



(2.) Calculi belonging to the second class 

 vary much in respect of their nucleus ; the 

 matter found in the intestine, constituting the 

 cortex of the calculus, is generally composed of 

 phosphates, applied in layers or not, and mixed 

 or not with additions of the vegetable or other 

 substance which served originally as the nu- 

 cleus ; the mass is solid and compact, or softer 

 and more porous, and mixed with the mucous 

 secretion of the bowel. The division into layers 

 is sometimes very indistinctly marked ; gene- 

 rally a slight difference of colour exists in the 

 different strata. Yellowish brown is the most 

 common hue. 



The nucleus in this class of calculi may be 

 animal, vegetable, or inorganic. 



(a.) Animal. Under the name of egagro- 

 piles, or hair-balls, have been described masses 

 of not uncommon occurrence in the intestines 

 of the lower animals (especially of calves), 

 composed of hairs in their central part, in 

 their outer parts of concrete animal and saline 

 matter. The hairs forming the nucleus are 

 swallowed by the animals when licking them- 

 selves. Laugier* has very carefully described 

 a felly-looking mass of some size found in the 

 human rectum, the cortex of which consisted 

 of faeces, hydrochlorate of ammonia and lime, 

 phosphate of lime, silica, and oxide of iron ; 

 the nucleus, prismatic in shape and covered 

 immediately with a brown crust, consisted in 

 its central part of gelatin, in its more external 

 of blood. Probably, as has been suggested, 

 the mass originated, in consequence of a vessel 

 being wounded by a piece of bone, blood 

 being effused round this, and saline matters 

 subsequently accumulated round both. 



(b.) Vegetable. Nuclei of vegetable matter 

 are more common, In graminivorous animals 

 intestinal calculi of this kind sometimes acquire 

 vast size. - In a horse (aged 17 years) a mass 



* M&n. de 1'Acad. Roy. de Med. t. i. 



was found having a nucleus of oat-grains, and 

 so huge as to measure 28 inches round, and 

 weigh 19 pounds (Breschet). Laugier and 

 Lassaigne, in a similar mass, collected round 

 bits of straw, found the cortex composed of 

 earthy phosphates. In the duodenum of the 

 human subject Andral discovered a calculus of 

 the size of a small egg, consisting of earthy- 

 looking matter externally, and having a plum- 

 stone for its nucleus. 



But the most interesting calculus of this 

 species is endemic in Scotland, and for its full 

 history we are chiefly indebted to the investi- 

 gations of Wollaston and Dr. Monro Tertius.* 

 The vegetable substance acting as the nuclear 

 basis of the mass (which looks like felt or 

 coarse sand) is the husk of the oat-seed in 

 fragments, along with the minute fibrils, form- 

 ing a velvety mass at one end of the seed un- 

 derneath the husk. The abundant use of oat- 

 meal in North Britain, as an article of food, 

 explains the frequent occurrence of these 

 calculi among the population ; they are said 

 by Dr. Maclagan-f- to be growing less common, 

 in consequence of the greater care now be- 

 stowed in the north in separating the husky 

 matters in preparing grain for the market. 

 The inorganic constituent associated with the 

 vegetable fibrous matter is mainly phosphate 

 of lime (20 per cent, in two specimens ana- 

 lyzed by Dr. Maclagan), associated with silica, 

 evidently derived from the oat (6 and 4 per 

 cent.). 



(c.) Inorganic. Certain medicines, magne- 

 sia (Monro) and chalk especially, have occa- 

 sionally collected into calculous masses in the 

 large intestine of persons in the habit of swal- 

 lowing large doses of either for a considerable 

 time : the saline matter being hardened into a 

 solid ball with mucus and faecal matter. Croc- 

 kelt | relates the case of a child who swallowed 

 a pin, and at the age of 18 voided per anum 

 a calculus of spheroidal shape and earthy com- 

 position. The head and half the stem of the 

 pin were enclosed in the mass. A piece of 

 wood accidentally forced into the rectum has 

 been known to form the nucleus for phos- 

 phatic deposition. Females who chew and 

 swallow the ends of threads used in sewing, 

 or indulge in the singular habit of eating their 

 curling-papers (hysterical pica), occasionally 

 become the subjects of intestinal calculi. 



(3.) Calculi formed wholly in the digestive 

 passages are comparatively rare. They may 

 consist of faeces and inspissated secretions 

 wholly (under which circumstances the name, 

 calculus, is not in strictness applicable to 

 them), or these may serve as a nucleus for the 

 deposition of the ordinary phosphatic salts. 

 White discovered, near the ilio-ccecal valve of a 

 tuberculous subject, two masses (one weighing 

 two, the other one and a-half pounds) com- 



* Morbid Anatomy of the Human Gullet, &c. 

 1811. 



f Lond. and Edinl>. Month. Journ. of Med. Sci- 

 ence, Sept. 1841. 



t North American Journal, 1827. 



Dahlankamp, Archives Ge'n. de Me'd. t. xxiii. 



