By far the most frequent forms of aneurism of the brachial artery are those which are the result of injuries inflicted upon the vessel, as in the operations of venisection at the bend of the elbow. When the artery has been unfortunately wounded, the following results may happen : the blood may escape freely from the wound in the artery, and may pass into the areolar tissue of the limb to a greater or less extent: in some cases the extravasation of arterial blood is so considerable as to reach nearly as high up as the folds of the axilla, and for a certain distance also below the elbow-joint; this has been termed a diffused false aneurism. This form of aneurism may occur also, from too great an amount of pressure having been applied to the sac for the cure of the next variety we shall speak of, namely, the circumscribed false aneurism, the sac gives way and the blood becomes diffused through the limb. An instance of this kind is recorded by Mr. Ellis, one of the surgeons to Jervis Street Hospital; he observes, " the pressure having been too forcibly applied, the sac gave way and a diffused aneurism became established."*

* Lecons Orales, vol. i. p. 265.

Prac. Surg. p. 206.