length being determined by the depth of the vessel from the surface. The central point of this incision should correspond as nearly as possible to the part of the vessel to be included in the ligature. All the tissues must be divided to the same extent, important structures being pushed aside. As the vessel is approached, the tissues may be divided on a director.

When the sheath or areolar tissue contiguous to the vessel is reached, it is picked up by forceps and nicked; a director is introduced through the opening, and the tissue divided for a quarter of an inch. If the vessel is still enveloped in tissue, an opening is made into it as just described. Catch the edge of the wound in the sheath on the side toward the vein or other important structure by means of forceps. Roll, by means of a probe or director, the vessel away from the sheath thus securely fixed. The probe or director should be held at a right angle to the vessel, and be moved between the vessel and the sheath to an extent less than the opening in the sheath. It may be necessary to catch the opposite edge of the wound in the sheath to separate the vessel completely around its whole circumference.

An aneurism-needle carrying a ligature is passed under the vessel from the side on which the most vulnerable structure is situated. The sheath should be caught first on the side of the introduction of the needle by means of forceps, and then again on the side of exit, to make way for the point of the needle. If the vessel is deeply situated, the point of the needle is caught after it has passed beneath the vessel, and the handle of the instrument is unscrewed to allow the curved end of the needle carrying the liga

ture to be drawn under the vessel. One end of the ligature is held to prevent the whole ligature being drawn under the vessel.

The ligature being under the vessel, the first loop of the knot is applied at a right angle to the course of the vessel. Draw upon the knot by means of the fingers, which must press upon the ends of the ligature close to the vessel. The second knot is not to be drawn upon very forcibly. Do not allow the tightening of the knots to raise the vessel from its bed.

(Prove the operation by opening into the vessel to discover the thickness of its walls, etc.)

LIGATURE OF SPECIAL ARTERIES IN THEIR CONTINUITY.

RADIAL ARTERY.-Supinate the forearm and extend the wrist.

The surface guide is a line drawn from a point midway between the tips of the condyles of the humerus to a point about one half of an inch internal to the tip of the styloid process of the radius.

1. Lower Third.-Make an incision two inches long in the line of the artery, extending to within one inch of the wrist. Divide the integument and superficial fascia. Push aside any veins which appear, and divide on a director the deep fascia. Expose the artery between the tendons of the flexor carpi radialis and supinator longus. Nick the areolar tissue enveloping the artery, and pass the needle, avoiding the venæ comites. Ligate the vessel. Close the wound, providing for drainage.

2. Middle Third.-Divide the integument and fascia in the line of the artery. Look for the inner edge of the supinator longus, which is near the mid

dle line of the forearm. Retract the supinator longus outward to uncover the artery. Pass the needle from without inward, to avoid the radial nerve.

The radial artery may lie on the deep fascia, or on the supinator longus muscle.

ULNAR ARTERY.-Supinate the forearm and extend the wrist.

The surface guide to the vessel, for the lower two thirds of its course, is a line drawn from the internal condyle of the humerus to the radial side of the pisiform bone.

1. Lower Third.-Make an incision three inches long in the line of the artery, extending to within one inch of the wrist. Divide the integument and superficial fascia. Push aside any veins which may be present, and divide the deep fascia on a director. Flex the wrist and retract the flexor carpi ulnaris muscle toward the ulnar side to uncover the artery. Pass the needle from within outward, to avoid the ulnar nerve.

2. Middle Third.-Make an incision three inches long in the line of the vessel. Find the interspace between the flexor carpi ulnaris and the flexor sublimis digitorum. Avoid mistaking the palmaris longus or the supinator longus for the flexor sublimis digitorum. Separate the muscles and retract the sides of the wound. Pass the needle from within outward.

The artery may lie superficial to the muscles or deep fascia.

BRACHIAL ARTERY.-Abduct the arm and rotate it outward, also supurate the forearm.

The surface guide is a line drawn from the junc

tion of the anterior and middle thirds of the axilla to a point midway between the condyles of the humerus.

1. Bend of Elbow.-Make an incision two inches long in the line of the artery, at the bend of the elbow. Divide the integument and superficial fascia, pushing aside the median basilic vein. Divide on a director the deep fascia and the bicipital fascia. Slightly flex the elbow. Find the artery with the bicipital tendon situated externally and the median nerve internally. Pass the needle from within outward.

2. Lower Half of the Arm.-Make an incision three inches long in the line of the artery, dividing the integument and superficial fascia. Divide the deep fascia internal to the biceps muscle. Slightly flex the elbow, and retract the biceps muscle outward. Find the artery with the median nerve situated above, which is to be retracted outward with the muscle.

Pass the needle from within outward, avoiding the veins.

3. Upper Arm.-Make an incision three inches long in the line of the artery, dividing the integument and superficial fascia. Divide the deep fascia internal to the coraco-brachialis muscle. Retract outward the coraco-brachialis muscle, and find the artery with the median nerve situated above and externally, and the ulnar nerve internally.

Retract the median nerve outward, and the basilic vein and ulnar nerve inward. Pass the needle from within outward.

The brachial artery may divide high in its course or run superficially to the median nerve, etc.

AXILLARY ARTERY (third portion).—Abduct and rotate outward the arm.

The surface guide to the portion of the artery for ligation is a line drawn between the anterior and middle thirds of the axilla.

Make an incision three inches long in the line of the artery, extending an inch above the anterior fold of the axilla. Divide the integument and superficial fascia. Divide the deep fascia along the internal border of the coraco-brachialis muscle, and retract this muscle outward. Find the artery with the median and the musculo-cutaneous nerves situated externally and the ulnar and the internal cutaneous nerves internally. The axillary vein is posterior and situated more superficially. Pass the needle from within outward.

SUBCLAVIAN ARTERY (second and third portions). -Place a small block under the back of the subject. Turn the face to the opposite side and draw downward the shoulder.

The surface guide is a line four inches long, drawn one half inch above and parallel to the clavicle. The line should be drawn outward from a point two inches external to the sternal end of the clavicle.

Stand behind the shoulder. Draw the integument downward, and incise it against the clavicle. Allow the integument to retract so as to bring the incision above the clavicle. Divide the superficial fascia and platysma, pushing aside the external jugular vein. Partially sever the sterno-cleido-mastoid and trapezius muscles if necessary. Tease a way through the areolar tissue with its plexus of veins formed by the supra-scapular and transverse cervical veins until the omo-hyoid muscle is uncovered. Divide on a director the deep fascia, and retract the