INTESTINAL CONCRETIONS. 581 



cretion voided by a labouring man in Lancashire.* These con- 

 cretions on the outside are covered with a thin, whitish, smooth, 

 earthy crust, but when cut open they exhibit a velvety, conir- 

 pact, brownish surface, alternating with concentric lamina of the 

 white earthy substance. The white laminae consist of a mixture 

 of phosphate of lime and ammonia -phosphate of magnesia. The 

 velvety substance resists the action of chemical reagents, and 

 burns with the smell of straw. Dr Wollaston, by a microscopic 

 examination of it, found that it consisted of the minute needles 

 or beards which are seen constituting a small brush upon the oat 

 seed when deprived of its husk. It is obvious from this that 

 these concretions can only be formed in the intestines of those 

 persons who use oatmeal as an article of food. Dr Monro used 

 to state in his lectures that when these concretions reached a cer- 

 tain size they blocked up the intestines and proved fatal. 



In the London and Edinburgh Journal of Medical Science for 

 September 1841, there is a very interesting case of a man aged 

 41, who passed fourteen large intestinal concretions similar to 

 those in Dr Monro's collection, together with an excellent and 

 instructive analysis of them by Dr Douglas Maclagan of Edin- 

 burgh. 



In 1829, M. Colombot, a physician at Chaumont, sent to the 

 Academy of Medicine of Paris, an account of several intestinal 

 calculi voided by stool and of a peculiar kind. M. Caventou re- 

 ceived from M. Bourdois other intestinal calculi of the same 

 kind, and subjected them to a chemical examination. When 

 voided they were light, greenish, and translucent, without any 

 regular shape but of a considerable size. When kept for a fort- 

 night in a box they became opaque, grayish white, and exhaled 

 the smell of rancid butter ; they reddened tincture of litmus. Hot 

 alcohol dissolved them immediately but left empty vesicles, in 

 which the matter dissolved had been contained. The portion dis- 

 solved possessed the characters of stearin,f Lassaigne had long- 

 before 'examined intestinal concretions containing a great quan- 

 tity of stearin ; but they differed from those examined by Caven- 

 tou in wanting the membranous cyst in which the stearin was 

 confined.} 



Fourcroy and Vauquelin analyzed a great number of intesti- 



* Marcel's Essay, p. 129. f Jour, dc Pharm. xv. 73. 



Ibid. p. 184. 



