The tourniquet is a less manageable and not more certain compressor of the arterial trunk than is the hand of an intelligent assistant. At every region of the course of an artery where the tourniquet is applicable, a sufficient compression by the hand is also attainable with greater ease to the patient; and the hand may compress the vessel at certain regions where the tourniquet would be of little or no use, or attended with inconvenience, as in the locality of the subclavian artery, passing over the first rib, or the femoral artery, passing over the pubic bone, or the carotid vessels in the neighbourhood of the trachea, as they lie on the fore part of the cervical spinal column. DESCRIPTION OF PLATES 11 & 12. PLATE 11. A. Subclavian vein, crossed by a branch of the brachial plexus given to the subclavius muscle; a, the axillary vein; a *, the basilic vein, having the internal cutaneous nerve lying on it. B. Subclavian artery, lying on F, the first rib; b, the axillary artery; b *, the brachial artery, accompanied by the median nerve and venae comites. C. Brachial plexus of nerves; c*, the median nerve. D. Anterior scalenus muscle. E. Subclavius muscle. F F. First rib. G. Clavicular attachment of the deltoid muscle. H. Humeral attachment of the great pectoral muscle. I. A layer of fascia, encasing the lesser pectoral muscle. K. Thoracic half of the great pectoral muscle. L. Coracoid attachment of the lesser pectoral muscle. L*. Coracoid process of the scapula. M. Coraco-brachialis muscle. N. Biceps muscle. O. Tendon of the latissimus dorsi muscle, crossed by the intercosto-humeral nerves. P. Teres major muscle, on which and O is seen lying Wrisberg's nerve. Q. Brachial fascia, investing the triceps muscle. . R R. Scapular and sternal ends of the clavicle. S. Cephalic vein, coursing between the deltoid and pectoral muscles, to enter at their cellular interval into the axillary vein beneath E, the subclavius muscle. [Illustration: Right arm and upper chest, showing blood vessels, muscles and other internal organs.] Plate 11 PLATE 12. A. Axillary vein, cut and tied; a, the basilic vein, cut. B. Axillary artery; b, brachial artery, in the upper part of its course, having h, the median nerve, lying rather to its outer side; b*, the artery in the lower part of its course, with the median nerve to its inner side. C. Subclavius muscle. C*. Clavicle. D. Axillary plexus of nerves, of which d is a branch on the coracoid border of the axillary artery; e, the musculo-cutaneous nerve, piercing the coraco-brachialis muscle; f, the ulnar nerve; g, musculo-spiral nerve; h, the median nerve; i, the circumflex nerve. E. Humeral part of the great pectoral muscle. F. Biceps muscle. G. Coraco-brachialis muscle. H. Thoracic half of the lesser pectoral muscle. I. Thoracic half of the greater pectoral muscle. K. Coracoid attachment of the lesser pectoral muscle.