This condition continues uninterruptedly for a period of five or six days (a sort of status epilepticus), persisting during the time the patient is awake, and ceasing only during the short intervals, or rather moments, of sleep. Throughout the whole period of the attacks the patient is troubled with insomnia. He sleeps restlessly for only ten or fifteen minutes at a time. On one occasion he was observed to be in a state of delirium as found in post-epileptic insanity and the so-called Dämmerzustände of epilepsy. This delirium was observed but once in the course of five years. The regular attack is not accompanied by any delirious states or Dämmerzustände. On the contrary, during the whole course of the attack the patient’s _mind remains perfectly clear_. During the period of the attack the whole right side becomes anaesthetic to all forms of sensations, kinaesthesis included, so that he is not even aware of the spasms unless he actually observes the affected limbs. The affected limbs, previously normal, also become paretic. After the attack has subsided, the paresis and anaesthesia persist (as sometimes happens in true idiopathic epilepsy) for a few days, after which the patient’s condition remains normal until the next attack. After his last attack, however, the anaesthesia and paresis continued for about three weeks. He has had every year one attack which, curiously, sets in about the same time, namely, about the month of January or February. The attacks have of late increased in frequency, so that the patient has had four, at intervals of about three or four months. On different occasions he was in the Boston City Hospital for the attacks. There was a profound right hemianaesthesia including the right half of the tongue, with a marked hypoaesthesia of the right side of the pharynx. All the senses of the right side were involved. The field of vision of the right eye was much limited. The ticking of a watch could not be heard more than three inches away from the right ear. Taste and smell were likewise involved on the right side. The muscular and kinaesthetic sensations on the right side were much impaired. The patient’s mental condition was good. He states that he has few dreams and these are insignificant, concerned as they are with the ordinary matters of daily life. Occasionally he dreams that he is falling, but there is no definite content to the dream.