88 



PRODUCTS, ADVENTITIOUS. 



which have a white and silvery look (choles- 

 terin). In the third stage depressions with a 

 smooth surface, (except in the points where 

 the lining tunic has undergone fissure for the 

 evacuation of the matter described,) mark the 

 previous seats of this matter. The fourth stage 

 is distinguished by the disappearance of the 

 lining membrane in the affected points, and 

 hence by actual excavation. Neither suppura- 

 tion nor injection attend the changes reviewed. 



When the atheromatous matter undergoes 

 the calcareous change, a hard but minute point 

 commonly appears in its centre; this gradually 

 increases, especially in breadth, the middle 

 coat being earlier implicated than the lining 

 tunic, which is occasionally covered with con- 

 crete fibrin. Eventually the lining coat is de- 

 stroyed, and the concretion brought into con- 

 tact with the blood ; the middle coat rarely 

 becomes affected through its entire thickness. 

 The deposition may commence in a multitude 

 of minute points simultaneously, whence the 

 atheromatous matter acquires a gritty feel. 



The white and cartilaginiform patches are 

 not in any instance the nidus of the saline 

 deposit, according to M. Bizot ; at least he 

 has never succeeded in tracing the early pro- 

 cesses of deposition in those patches. Nothing, 

 however, he admits is more frequent than the 

 deposition of atheromatous and subsequently 

 of calcareous matter underneath the " cartilagi- 

 nous " patch, which is occasionally perforated 

 by the calcareous substance, and an appear- 

 ance produced easily explaining the current 

 opinion that the patch in question is the ori- 

 ginal seat of the saline particles. We agree 

 with M. Bizot that the " cartilaginous" patch 

 is altered plastic matter exuded on the inner 

 surface of the vessels. Mr. Gulliver has, it 

 is true, discovered fat-globules and crystals of 

 cholesterin in the " white patch" of vessels ; 

 but the circumstance appears explicable in the 

 manner just referred to as resulting from the 

 French author's inquiries. 



In the arteries of the limbs calcareous depo- 

 sition may likewise commence in the middle 

 coat itself, which becomes harder and thinner 

 as the disease advances. 



It is important to observe that the close 

 examination of calcareous plates through their 

 various phases of development demonstrates, 

 as we have seen, their independence of inflam- 

 mation. 



Calcareous deposition is remarkably depen- 

 dent upon age. Bichat calculated that the 

 arteries of seven of every ten persons beyond 

 the age of sixty were thus affected ; while its 

 existence is extremely rare in early youth. 

 Writers have indeed maintained the perfect 

 immunity of the vessels of youthful subjects 

 from this change : but Mr. Young found the 

 temporal artery of a child fifteen months old 

 converted into a calcareous cylinder; Otto* 

 once discovered incipient ossification of the 

 aorta in a girl of seventeen ; Wilson met with 

 a similar condition in a child three years old; 

 Andral in a girl aged eight; and numerous 



* Patholog. Anat., by South, p. 333. 



other instances of the kind are recorded. Cal- 

 careous deposition is more common in vessels 

 of a large than of a small calibre, and espe- 

 cially in the aorta; rarer in the upper than 

 the lower extremities ; it sometimes extends 

 through the entire arterial system of the trunk 

 and lower limbs, we have before us the ves- 

 sels of a subject in this condition, who died 

 with gangrrena senilis.* Such disease never 

 occurs, according to Otto, in the arteries of 

 the thoracic and abdominal walls, and perhaps 

 those of the alimentary canal and liver ; and 

 is, on the contrary, common in those of the 

 pelvis, of the brain, of the thyroid gland, the 

 heart, the spleen, the kidneys, &c. The pul- 

 monary artery is, comparatively speaking, con- 

 sidered exempt from calcareous deposition : 

 several instances, however, are referred to by 

 Otto, in which it was more or less completely 

 "ossified;" it is not unfrequently so where 

 the right and left cavities of the heart com- 

 municate, (but here the vessel is placed in re- 

 spect of its contained fluid in the state of on 

 ordinary artery). Hope -j- attended a lady, aged 

 60, in whom the " pulmonary artery was found 

 quite ossified where it plunged into the lungs ;" 

 and from our own records of cases we know 

 that slight alteration is not very uncommon. 



The close comparison of corresponding ves- 

 sels on the two sides of the body has led M. 

 Bizot to the discovery that not only the same 

 vessels, but the same parts of these, are, with 

 the rarest exceptions, affected with the same 

 alterations of structure, that a law of sym- 

 metry regulates the development of these. 

 Upon this point much curious information will 

 be found in M. Bizot's admirable essay. 



Calcareous deposition is common in the ar- 

 teries of syphilitic subjects, and of those who 

 have taken mercury to excess. Much fanciful 

 hypothesis has been indulged in respecting the 

 influence of certain kinds of diet on its pro- 

 duction. 



This morbid state destroys the elasticity of 

 the arteries, renders them fragile, and inter- 

 feres with the circulation ; we have known it 

 lead to rupture of the aortic valves. The cal- 

 careous matter protruding more or less into 

 the vessel affords a centre for the blood to 

 coagulate around, and may lead to its com- 

 plete obliteration, a result which it would 

 appear may be produced by mere thickening of 

 the coats ; in either case suspension of the 

 circulation and gangrene are the results. 

 " Ossification " of the coronary arteries of the 

 heart has been met with in cases of angina 

 pectoris (recently by ourselves) and of sudden 

 death, probably rather acting as the occa- 

 sion, than the cause, of both. 



(2.) Central. (Arteroliths.) Calcareous 

 concretions, free in the interior of the arteries, 

 are as rare as the conditions which we have 

 just described are common. OttoJ saw in the 

 Copenhagen Museum " a round stone as large 

 as a pea," said to have been taken from the 



* Univ. Coll. Mus. 



f Diseases of the Heart, 3rd ed., p. 589. 



j Path. Anat., by South, p. 335. 



