CASE.—_Spontaneous cure of aneurism of ascending portion of arch of aorta, with death from bursting of aneurism of descending portion into the œsophagus._ Mr. H——, of this city, aged sixty years, while walking in his yard one day after a hearty dinner, was taken with a sudden sensation of faintness and nausea, which was soon followed by vomiting the contents of his stomach, with a considerable quantity of blood. After entering his house, the vomiting was frequently repeated, and at each effort large quantities of pale blood ejected. Sinking rapidly, in an hour he was dead. Twenty-four hours after, I made a post-mortem examination. Upon exposing the chest, found at the right border of the sternum, just below the clavicle, a hard, inelastic tumor beneath the skin, of the size of a small orange. While not adherent to the integument, it appeared firmly attached to the walls of the chest beneath. Upon turning aside the integument and pectoral muscles, the tumor was found connected by a long pedicle to parts within the chest; absorption of considerable portions of the sternal ends of the first and second ribs, with the side of the sternum, having resulted from pressure of the tumor upon those parts, and finally permitting its appearance beneath the skin. The removal of the sternum at once demonstrated the aneurismal character of the tumor by showing its connection with the ascending portion of the arch of the aorta, while a section of the same, exhibited the interior filled with dense concentric layers of fibrinous matter, separable from one another, the outer layers being dry and hard, while the inner portion was less firm and moist. This aneurism was plainly of the _false_ variety. The neck of the tumor was not much larger than the thumb, and of sufficient length to reach from the arch of the aorta to the dilated sac beneath the skin, outside the chest. A further examination of the aorta brought to light a second and _true_ aneurism of the descending portion of the arch, the dilatation involving all the coats of the vessels, and which, having _burst into the œsophagus_, explained at once the cause of the hæmorrhage and sudden death. Upon inquiring of the family, I learned that the tumor upon the chest had been known to have existed for fifteen or twenty years; that for some years the pulsations of the tumor were strong, but that for many years all beating had ceased; that he had never discontinued his work, that of a carpenter, and in fact, it had given him so little trouble that he had never consulted a physician in regard to it. For a year or so previous to death, he had been troubled with a cough, particularly upon exercising, but otherwise had been in good health.