Acts especially upon the cerebrospinal system, affecting particularly the sensorium and the muscular system, in the former producing perversion of the perceptive and intellectual faculties-illusions and hallucinations, and also causing a distinct mania partaking of the quarrelsome or obscene character. While in its action upon the cerebral functions, Hyoscyamus has much in common with Belladonna and Stramonium , there is yet an essential difference, in that it does not produce the cerebral hyperaemia so characteristic of the former, nor the intensely high degree of maniacal excitement caused by Stramonium . Its functional excitement is moderate, and the circulatory disturbance never goes on to inflammation. Hence its cerebral manifestations partake more of a purely nervous excitability, and resemble more particularly the type of cerebral disorder occurring in typhoid conditions, typhus fever, and delirium tremens. On the muscular system, through the motor nerves, it acts with great power, producing paralysis, spasmodic affections of single parts, and convulsions, but more especially paralysis of the involuntary system. The most essential feature of the drug is its increased sensorial activity and nervous excitement. Characteristic symptoms.