PRODUCTS, ADVENTITIOUS. 



spermatic artery ; but he believes it to have 

 probably been of venous origin. Eight loose 

 stony concretions have, he observes, been met 

 with in an aneurismal sac*; the largest of 

 these was as big as a plum. Landerer has 

 recently analyzed an aortic concretion, which 

 contained 14 per 100 of uric acid.f 



Veins. Parietal concretions are as rare in 

 the veins as common in the arteries ; central 

 concretions as frequent in the former as rare 

 in the latter vessels. 



(1.) Parietal. These are in truth of ex- 

 treme rarity in the veins. That they do occur, 

 however, and with somewhat greater frequency 

 than is admitted by speculative writers, is cer- 

 tain. An example of " ossification" of the co- 

 ronary veins is related in the Ephem. Nat. 

 Cur. Dec. iv. An. x. Obs. 175; Cruveilhier J 

 once found the popliteal veins studded with 

 ossifications similar to those existing in the 

 accompanying arteries ; not a few examples of 

 " ossification" of the vena porta are on re- 

 cord $ ; Morgagni and Baillie found the vena 

 cava inferior in a similar state, 8cc. In many 

 cases of the kind there appears to have been 

 calcification of the parts immediately adjoining 

 the vessels. 



The sort of antagonism existing between the 

 arteries and veins, in respect of parietal con- 

 cretions, has been referred by Bichat to differ- 

 ence of structure of the lining membrane in 

 the two classes of vessel ; by Bizot to the dis- 

 similar properties of the blood circulating in 

 them ; by others, who regard the deposition 

 as evidence of decay, to the greater activity 

 and consequent earlier exhaustion of the arte- 

 rial tubes. None of these notions are unopen 

 to objection. 



(2.) Central. Central concretions in the 

 veins (pheboliths, from <f>A.e^, a vein, and \idos, 

 a stone,) are generally of ovoid or rounded 

 shape ; vary in size from a pin's head to a pea 

 and upwards, in rare instances attaining the 

 bulk of a hazel-nut, and in weight average 

 about a grain or a little more at most ; are of 

 low specific gravity; occur singly or in num- 

 bers varying from two to ten and upwards ; 

 are either perfectly free, or adherent to the 

 internal surface of the vessel either directly or 

 by means of a slender peduncle (these three 

 conditions may be observed in the same vein) ; 

 are smooth on the surface, and (whether partly 

 sanguineous or wholly calcareous) invested 

 with a delicate membrane of serous aspect. 



These concretions are unquestionably by far 

 more common in the veins of the pelvic viscera 

 (the spermatic, the ovarian, the vesical, the 

 haemorrhoidal,) than in others. They are not 

 unusual in the splenic veins, and have been 

 met with in the renal, mesenteric, prostatic 

 (thirty were found in the latter by Ehrmann ||), 

 and pubic veins ; they have been seen twice 



* Biermayer, Mus. Anat. Path. p. 101, No. 360. 



t Med, Gazette, July, 18-17. 



j Essai sur 1'Anat. Path. t. i. p. 70. 



Ruysch, Thes. Anat. viii. No. 58 ; Meckel 

 Path. Anat. Bd. ii. Abth. ii. S. 190. 



|| Compte Rendu des Trav. Anat. &c. p. 38. 

 Strasb. 1827. 



by Cloquet in the vena cava inferior. They 

 occur sometimes in varices of the lower ex- 

 tremities*; Dupuytren found them in the 

 anterior and posterior tibial veins ; but they 

 have not, so far as we are aware, been seen in 

 the veins of the arms. 



Gmelin -j- found them composed of 



Animal matter 27.5 



Phosphate of lime 53.5 



Carbonate of lime 15.5 



Magnesia and loss 3.5 



100.0 



The part of the vein containing a phlebolith 

 is sometimes much dilated, and eventually the 

 vessel may become obliterated above and below 

 the obstruction. Lobstein conjectures that the 

 new formation with its investing portion of 

 vein may be altogether separated from its con- 

 nections ; and, in the case of the haemorrhoidal 

 veins, passed bv stool. 



Hodgson supposed that these bodies were 

 first formed external to the vessel, and subse- 

 quently made their way into its interior ; An- 

 dral that their original seat was the substance of 

 the walls of the vein. The occasional existence 

 of a peduncle does not, as has been presumed, 

 really warrant these notions ; as it may no doubt 

 be formed either of fibrin or of plastic matter 

 (thrown out by the tunics from secondary in- 

 flammation) coated with epithelium. Besides, 

 the absence of marks of rupture of the surface 

 further confutes them. It was suspected bv 

 CruveilhierJ, taught by Lobstein, and proved 

 by Carswell || , that phleboliths originate in clots 

 in the interior of the vessels. The following 

 is the series of changes observed : stagnation 

 occurs; a clot forms; loses its red colour; 

 becomes concentrically stratiform ; acquires 

 fibrous consistence, and gradually grows calca- 

 reous and indurated, stratum by stratum, from 

 the centre outwards, until the whole mass ac- 

 quires almost stony hardness. Dr. John Reidf 

 regards the process of induration as one " re- 

 sembling the formation of osseous tissue in 

 other parts of the body ;" a view invalidated 

 by the absence of true cartilaginous matrix, 

 or of osseous texture at any period of the 

 evolution of the bodies in question. 



(e.) Lymphatic and lacteal. Although it is 

 possible that the extreme rarity with which the 

 lymphatic and lacteal vessels have been found 

 to contain calcareous matter may in part de- 

 pend upon those vessels being seldom ex- 

 amined, yet it is certain that such condition 

 is really singularly uncommon. Cheston 

 Browne** refers to a casein which the entire 

 thoracic duct from the receptaculum upwards 

 was "ossified" and obliterated. J.D. Scherbff 



* Bouillaud, Rev. Med. Avril, 1825. 



f Tiedemann's Zeitschrift, Bd. iv. H. i. 1831. 



j Essai, t. i. p. 71. 



An. Path. t. i. p. 505. 



|| Fascic. Anal. Tissues. 



f Ed. Med. and Surg. Journ. No.' 123. 



* Phil. Trans, vol. Ixx. p. 323, 1780. 

 tf De calculo in due. thorac. 1729 ; Haller's 

 Dif?s. Path. 



