In the dysphagia or dyspncea caused by its pressure, which serves in naany instances first to call our attention to its presence, it does not differ from other forma of tumor : but from the position of the aorta they are perhaps more common and earlier in their appearance, the cough in particular having a remarkable metallic clang. Aneurism is much more liable to interfere with the arte rial circulation, morbid growth with the venous ; in the one a difference can frequently be observed between the pulse at the two wrists, in the other we are more likely to find tortuous veins over the neck and thorax : but it may be worth mentioning that oedema of the arms, when the circulation is obstructed, sometimes renders the observation of the pulse fallacious. It would seem, too, that relief from the pressure, by change of posture, is more decided in the case of aneurism than of other thoracic tumors ; but in all cases it is usually found at some period of their history that a prone position is preferred to any other.
The situation in which aneurism is commonly found, towards the upper and front part of the chest, may lead to its being de tected by percussion and auscultation ; the dulness is limited, and is not complete ; and though greater on one side than the other, unlike the consolidation of tubercle, it is most distinct close to the sternum. Solid growth in the anterior mediastinum is not limited to the upper part of the sternum, but the dulness extends all the way down ; it is also more complete. The earliest auscultatory phenomenon is a jogging sound, which can be heard, and seems to be felt, when listening over the site of the tumor : it is probably produced by its actually. impinging on the parietes. In other instances an arterial bruit or whiz is heard there much more dis tinctly than elsewhere : it is not unfrequently audible also in the pra3cordial region ; and hence, with the natural accompaniment of hypertrophy, may be wrongly attributed to valvular disease of •the heart.
In its further progress the aneurism causes absorption of the intervening tissues, becoming gradually more superficial ; the bony structures soften, and the pulsation is readily observed externally. Pain is necessarily excited by this action, and has a gnawing character : the whizzing sound is rarely wanting. It is not easy to determine what circumstances give rise to the pro duction of bruit in some cases and not in others; probably they are connected with the form of the tumor and the condition of its interior. An artery pretty evenly dilated will only give rise to
the jogging sound already spoken of in consequence of its contact with the ribs; while one in which a distinct pouch has formed, or which is lined in its interior by uneven layers of lymph, will throw the blood into sonorous vibrations as it enters or leaves the enlarged portion.
§ 3. Abdominal Aneurism.—Abdominal pulsation has a very vague significance, and the student cannot be too careful to avoid the mistake of supposing it to be constantly or even frequently an evidence of aneurism. It is of common occurrence among nervous, hysterical, and dyspeptic patients, and means nothing generally, when unaccompanied by the evidence of disturbed circulation which is afforded by the existence of hypertrophy of the heart. On the other hand, simple hypertrophy very often communicates its pulsation through the diaphragm to the abdo minal viscera, when there is no enlargement of the descending aorta; and in such cases if anemia lead to the development of bellows-murmur, the mistake of supposing both pulsation and bruit to be dependent on aneurism is very likely to be made.
The decided indications of abdominal aneurism are the follow ing : The tumor corresponds in position and direction to the known course of the aorta or iliacs ; its attachments are firm, and it is but slightly movable ; pulsation is felt in a lateral direction as the patient lies on his back, and this pulsation does not disappear on change of posture ; a local bruit is audible which cannot be heard over the pra3cordial region.
Any tumor lying upon arteries of the size of the aorta and iliacs must necessarily convey a sense of pulsation in an upward direction—from the artery, through the tumor, to the finger placed opposite to it; but it does not pulsate laterally, and when a finger is placed on each side the difference is unmistakable. It is also to be remarked that in change of posture the altered relations of the tumor and the vessel will cause the pulsation to disappear in the one case, while it remains unaffected in the other. The arterial bruit cannot be much relied on, especially if there be concomitant anemia.