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

pains of rheumatism. That special condition of the body which gives rise to shifting pains which are sometimes seated in the muscles, (muscular hyperesthesia,) at others about the joints, (neuralgic rheumatism,) at other times in the joints, (rheuma- tism,) <frc, seems to favor this idea. It may be exactly true, or it may not, however, for as yet it is not further demonstrated. Dr. Alfred .Since, of England, and Dr. De la Rive, of France, are of the opinion that neuralgia arises from a material disturb- ance in the natural ncrvo-clectric state of those nerves affected, or of the whole nervous system, where is shown the neuralgic diathesis ; and that the disturbance is more usually at the pe- ripheric nerve pole ; but what that disturbance is, precisely, no one is able to define. If we comprehend under this head all those very painful affec- tions, wherever seated, which are apparently unconnected with inflammation, and which are not the result of some important or discoverable lesion, we shall find a large class, that doubtless arise from the encroachments or compressions of blood vessels upon the nerve trunks, just as they pass together through bony canals. This distention of the blood vessels may arise cither from an extraordinary flow of blood in the arteries, or from a faulty or sluggish return of blood through the veins; it may occur, then, where there is too much blood and too great a distention of the vessels from the quantity; bvt more frequently does it occur from the venous congestion, " stasis " or stagnation from atony, i. e., from impoverished blood, and from deficient enerva- tion and want of tone in the tissues. Exposures to sudden cold, as well as traumatic causes, also produce it. Since the commencement of the present century, neuralgia has been distinguished from rheumatism and gout. At first the study of this class of pains was limited to their occurrence in the face and lower extremities, and then the terms " tic doulou- reux " and " sciatica " were generally applied; but more re- cently the term " neuralgic affections " has been extended to all morbid exhalations of sensibility, or excruciating pains in parts not manifestly inflamed. Neuralgia may be defined as violent pain in the trunk or