PHLEBOLITES. 439 



Cruveilhier,* would afford some countenance to Andral's 

 opinion, were it not at variance with accurate observation ; 

 and we may suppose that this appearance was produced by 

 the presence of the foreign body causing irritation and effu- 

 sion of coagulable lymph. 



" Tiedemann,f and, following him, Lobstein, suppose them 

 to be formed by a mechanical deposition of the calcareous 

 matter contained in the blood, intermixing itself with the al- 

 bumen of the blood. It appears to me that this opinion is 

 unable to explain the manner of their formation in many 

 cases, and consequently, can scarcely be regarded as the pro- 

 bable cause of their formation in these cases which seem to 

 agree with this supposition. Mechanical deposition of the 

 matters contained in the blood cannot, I think, explain their 

 formation in those J cases, where we find an osseous-looking 

 deposit taking place in the centre of a coagulum, around 

 which the fibrin arranges itself in concentric laminae, increas- 

 ing in density as we proceed to the centre, and where appar- 

 ently those nearest the centre gradually assume this osse- 

 ous appearance, which extends itself towards the cir- 

 cumference. 



" If these bodies resulted from mechanical deposition, could 

 the earthy salts pass through the several dense laminae of 

 fibrin, and deposit themselves, apparently in certain propor- 

 tions, in the innermost laminae? If the presence of the earthy 

 salts was the result of a deposition, would they not rather 

 l)e found upon the outer surface of the most external lamina, 

 instead of penetrating through it to reach the innermost? 

 We cannot, at least in the present state of our knowledge on 



* Cruveilhier's Anatomie Pathologique, tome il p. 71. 

 t Journal Complementaire du Diction, des Sciences Medic., tome iii 

 + Cloquet's Pathologie Chirurgicale, and Observations of Dr Carse- 

 well in article " Veins," Cyclopcedia of Practical Medicine. 



