The peculiar degeneration of the coats of the vessels has been already stated to be the predisposing cause of aneurism; and the disease may be directly caused by over-excitement of the circulation, or by an over-exertion of the muscles. It is more frequent in males than females.[14] In men somewhat advanced in life the arteries get hard and rigid, whilst at the same time the muscles are strong, the general health good, and the whole frame stout and active; so that the patient is capable of violent muscular action, such as the arteries are ill able to bear, and consequently the internal coat of a vessel yields, and lays the foundation for an aneurism.[15] The lower limbs being chiefly subject to such exertions, aneurism in them is most frequent;[16] and for the same reason it is said to be common in those who ride much on horseback. Degeneration of the coats of the vessels in the superior extremity is extremely rare. This is another reason why spontaneous aneurism seldom assails them. _Treatment._—In internal aneurism the only indication which can be followed, with any chance of success, is to favour the occurrence of a spontaneous cure, by abstracting all stimuli, mental and corporeal, by enjoining complete rest, by keeping the patient on low diet, and by repeated bleeding. Thus the force of the circulation is diminished, and coagulation, it is said, promoted; by this practice aneurisms, the progress of which defies external means, are occasionally, though very rarely, cured. Ice and other cold applications to external aneurisms, or those which have made their way to the surface, have been recommended to induce coagulation, but their use is not unattended with danger; for they may, in some stages, so far diminish the vitality of the coverings as to cause sloughing, and fatal hemorrhage.