Acts primarily upon the cerebrospinal system, giving rise in the motor sphere to profound prostration (neurasthenia), as well as paralysis and convulsions, and in the nervous sphere to neuralgic pains. It also acts prominently upon the respiratory mucous membrane, producing catarrhal inflammation, and profuse muco-purulent expectoration, with dilatation of the bronchi, together with excessive prostration of the respiratory nerves. Tin also ranks as an important vermicide, acting, according to Hahnemann , as a narcotic to the parasites, so that they may readily be dislodged by appropriate purgatives. It has also proved of excellent service for the removal of those symptoms of the digestive sphere which usually accompany vermicular affections, whether the parasites be actually present or not. Characteristic symptoms.