INTESTINAL CONCRETIONS. 583 



combustible, composed of concentric layers, smooth, soft, and 

 finely polisbed. Fourcroy and Vauquelin have distinguished 

 two varieties ; the first o a pale-green colour, a slightly bitter 

 taste, almost completely volatile ; giving by heat a solid tenaci- 

 ous matter, soluble in alcohol, and separating in crystals as the 

 solution cools. This matter consists partly of bile, partly of re- 

 sin. The second variety has a brown or violet colour ; its taste 

 is not bitter ; it does not dissolve in alcohol, but is soluble in 

 alkalies. The solution becomes purple-red when allowed to dry 

 in the open air. When distilled it yields a yellow sublimate, 

 having the smell and taste of soot, and insoluble in water and al- 

 cohol, f 



6. Fungous. This species consists of concretions composed of 

 pieces of the Boletus igniarius, disposed in layers, and cemented 

 by an animal matter. These pieces had been doubtless swal- 

 lowed by the animals in whose intestines they were found. \ 



7. Hairy. Balls of hair felted together, sometimes pure, 

 sometimes covered with animal matter, and sometimes mixed with 

 vegetable remains, occur very frequently in the intestines of ani- 

 mals. J 



8. Ligniform, This eighth species must be added in conse- 

 quence of the experiments of Berthollet Among the presents 

 sent to Bonaparte by the King of Persia were three bezoars, which 

 were consigned to Berthollet for analysis. They all belonged 

 to this species. They had an oval shape, and a very smooth sur- 

 face. Their colour externally was greenish-black, internally 

 brown. They were formed of irregular concentric layers. In 

 the centre of one was found a collection of straws and other ve- 

 getable fragments ; in that of the other, small pieces of wood 

 about the size of a pin. Their specific gravity was 1/463. They 

 were insoluble in water, alcohol, and diluted muriatic acid. Po- 

 tash ley dissolved them readily, and they were thrown down un- 

 altered by muriatic acid. When distilled they yielded the pro- 

 ducts of wood, and left a quantity of charcoal in the retort, which, 

 when incinerated, gave traces of sulphate of soda, muriate of 

 soda, liine, and silica. Thus it appears that they possessed all 

 the properties of pure woody fibre. They must have been form- 

 ed in the stomach of the animals, and not in the alimentary canal. 



* Ann. de Mus. d'Hist. Nat. iv. 334. f Ibid. 335. \ Ibid. 336. 



Mem. d'Arcueil, ii. 48. 



