Nux Vomica acts preeminently upon the spinal cord, including the motory and sensory centers at the base of the brain ; affecting chiefly that portion of the spinal tract which presides over reflex functions. The condition produced is one of excessive irritation and excitability, giving rise to incoherent muscular action, which, in the extreme, constitutes violent tetanic contractions, and which finally may end in entire cessation of muscular movement, or paralysis. These tetanic convulsions affect particularly the limbs and trunk ; the former being rigidly flexed, and the body arched as in opisthotonos, the respiratory muscles rigidly contracted, rendering breathing laborious, even to asphyxia, while at the same time there are present spasmodic conditions of the face, jaws, throat, oesophagus, and of the intestinal and urinary tracts. The entire condition thus presents a horrible aspect, but through it all the mind is unaffected, though it is probable that little pain is experienced. The paroxysms are usually interrupted " by periods of calm, from which, however, the least noise, a breath of air, or the lightest touch, may act with the suddenness of lightning to renew the scene." ( Stram .) Death finally results, either from asthenia or asphyxia. In addition to this remarkable action upon the muscular system, Nux Vomica affects profoundly the organs and functions of nutrition, the secretions being altered, the functions perverted, and the organic substance changed, giving rise to a long train of symptoms, presenting accurate pictures of gastric, hepatic, and intestinal affections, which may be only appreciated and understood by a careful study of the pathogenesis of the drug. The same character of irritation which, in the mucous membrane of the alimentary tract, gives rise to dyspeptic symptoms and aids in the production of constipation, produces in the respiratory sphere a dry catarrhal condition, giving obstruction in the nasal passages, and dry cough. Nux Vomica also affects prominently the genito-urinary sphere, producing at first an increased activity of these organs, followed by depression and relaxation. The chief peculiarity of Nux is its adaptation to disorders of digestion, especially when resulting from long-continued errors of diet, from highly seasoned foods, stimulating drinks, hot medicines, and drug mixtures in general, and especially when occurring in persons of sedentary habits. Characteristic symptoms.