The diseases and injuries of the radial and ulnar arteries scarcely offer peculiarities suffi cient to demand a special notice.
Aneurism as the result of disease, an ex tremely rare occurrence in the brachial artery, would appear to be here still more infrequent ; and this remarkable immunity as compared with the lower extremity has been differently ascribed to a supposed greater vitality, of the vessels nearer the heart, or with better reason to the less exposure of the arm to strains or shocks. Even this explanation, however, has so much imperfection about it, that it seems better to avoid theorising on the subject until more is known both of the physical relations of the different tubes to their central engine, and of the differences in the nature and ra pidity of the nutrition of their coats, which may be presumed to exist.
False aneurism may occur in any part of their course as the result of puncture or inci sion of their coats; the sac of the turnour being formed by the nearest investing fascia, and lined by the areolar tissue of the neighbour hood condensed by the pressure of the con tents. These consist of blood, which is usually in considerable quantities, and has experienced more or less coagulation subsequently to its discharge from the opening of the artery which occupies some part of the inner surface of the cavity. But neither in these points, nor in the treatment usually adopted is there any thing which requires particular specification.
The disease of the arterial system generally, which constitutes so frequent and important a part of the series of changes included in the term " old age," of course includes these ves sels. Ossification of the radial artery is by no means rare, although in this extremity it is very unusual to find it occluding. the tubes or leading to senile gangrene. Here, from the superficial position of this vessel, it is often a valuable index by which an insight is afforded into the condition of other and more important arteries. In this latter stage of the change the vessel is rather larger than normal, very hard, thick, and tortuous : while the impulse of the heart communicated to it by its contents, and tending to efface these abnormal curves, often almost lifts it from its situation at each stroke. In an earlier stage of the affection it is much less easily recognised, but even here the tactus eruditus may sometimes appreciate the change ; and though it is perhaps difficult to translate the sensation into words, such a pulse might. be paradoxically described as being at the same time hard to the touch, and comparatively soft and yielding to the pressure, while its beats are associated with unusually little ex pansion, though they strike the fingers with more force.
(William Brinton).