In acute cocainism Kraepelin[232] finds an increased pulse rate, a lowering of blood pressure and the appearance of an excitement of the intoxication type with an agreeable sensation of warmth and well-being. There is an initial motor excitement followed eventually by weakness. This is a somewhat similar reaction to that caused by alcohol, but it is more marked. Small doses cause the habitué to feel elated, talkative and inclined to prolific writings. He feels a greatly increased efficiency but does not show a corresponding productivity. Larger doses cause delirious excitement with a tendency to sudden collapse. After a prolonged use of the drug a condition of nervous excitement ensues, with an increasing susceptibility to intoxication, a mild flight of ideas, a diminished capacity for mental exertion, loss of will power and failure of memory. The patient is busy with entirely useless activities, quite voluble, and writes incessantly. He becomes unreliable, forgetful, disorderly and careless in his conduct. The mood alternates between one of well-being, irritability, suspicious anxiety and emotional dulness. Kraepelin speaks of the great loss of weight, increased reflexes, dilated pupils, rapid pulse, etc. Insomnia is a common symptom. The characteristic psychosis of cocaine, however, in his opinion is a paranoid condition somewhat resembling the alcoholic forms. The onset is usually sudden, with irritability, suspicion and anxious restlessness, together with the sudden development of hallucinations of various kinds. Auditory hallucinations are particularly numerous and are very active. The patient's surroundings appear strange and unreal. He sees all kinds of pictures of the most realistic type. Tactile hallucinations are very common. The patient often shoots at his imaginary persecutors or attempts suicide to escape them. A typical symptom is the appearance of delusions of jealousy. With all of this the patient is usually well oriented. Only occasionally is there a clouding of consciousness and confusion. Insight is, however, always lacking. Even with a clear sensorium the delusional ideas are firmly retained. The mood is excited, irritable, sometimes angry and exasperated, but most frequently depressed and suspicious. The conduct is characterized by restlessness and uncertainty. There is usually a marked volubility suggesting a conscious delirium at times. The whole development of these conditions is rapid, often within a few weeks. They disappear as quickly in many instances. Chronic cocainism is very similar to the alcoholic conditions. From a symptomatic point of view, however, the paranoid cocaine psychoses occupy relatively an intermediate position between alcoholic delirium and the paranoid states. In experiments on dogs Nissl found a stainability of the achromatic substance in the neurones, a beginning shrinkage of the cell nuclei and a slight increase of leucocytes in the pia and vessels.