Electro-physiology and electro-therapeutics : showing the best methods for the medical uses of electricity / By Alfred C. Garratt.

line, which will be verified by experience in this department of practice. It will be noticed that if only the anterior fibres of this muscle are touched by the current, the arm is started for- ward and inward, and carried to an elevated posture. But if directed only to the posterior fibres, then the humerus is started backward, and if the current be pretty strong, the hand will also be carried back, and even raised, and retained high up the back When aided by the serralus magmas, the deltoid not only lifts, but sustains, the arm elevated ; and when aided also by the joint action of the middle portion of the trapezius, it, — or rather they, — elevate the arm to the head, and to all postures above the hori- zontal line of the shoulder. The deltoid is exceedingly prone to pains and palsy, and occasionally suffers from atrophy. The rhomboideus major arises from the spinous processes of the four upper dorsal vertebra?, and is inserted into the posterior border of the scapula. Its action is to draw the scapula hori- zontally back upon the spine, and the spine laterally to the scapula. The rhomboid minor arises from the last cervical ver- tebra, and is inserted into the edge of the triangular surface of the posterior border of the scapula. The action of this muscle is to draw the scapula obliquely upward, — i. e., towards its cer- vical origin; and these two muscles especially influence the dorsal " curvature " of the spine. But there is the levator an- guli scapula also, that goes to make up the second layer of mus- cles on the shoulders and back, which arises from the transverse processes of the four upper cervical, and is inserted into the upper angle and posterior border of the scapula. The action of this muscle is to draw the scapula upward towards this cervical region, and the spinal column of that region downward towards the scapula. If, then, the rhomboid be electrized, as where the trapezius is destroyed by palsy or atrophy, the scapula is raised and also rotated on its axis, so that the inferior angle is nearly in the same line with the external angle ; and by the tonic con- tractility of this muscle, it fixes the base of the scapula firmly against the walls of the thorax. If the rhomboid is also atro- phied or palsied, then the base of the scapula projects from the thorax, and becomes very prominent under the skin, so that a remarkable cavity is formed between it and the spine.