markedly deficient in intelligence.  Although in an asylum and partially paralysed, she was not really insane in the proper sense, but incapable of taking care of herself.  When other patients were getting into mischief this patient would give a warning to the attendants by the utterance of inarticulate sounds, showing that she was able to comprehend what was taking place around and reason thereon, indicating thereby that although stone deaf and dumb, it was probable that she possessed the power of silent thought.  I observed that during emotional excitement the pitch of the sounds she uttered increased markedly with the increase of excitement.  After having been discharged from Claybury Asylum she was sent to Colney Hatch Asylum.  Upon one of my visits to that institution I learnt that she had been admitted, and upon my entering the ward, although more than a year had elapsed since I last saw her, she immediately and from afar recognised me; and by facial expression, gesture, and the utterance of inarticulate sounds showed her great pleasure and satisfaction in seeing one who had taken a great interest in her case.  This poor woman must have felt some satisfaction in knowing that someone had interpreted her mental condition, for of course, her husband and friends did not understand why she could not speak.  I may mention that the first attack of loss of speech was attributed to hysteria.

This woman died of tuberculosis seven years after the second attack, and examination of the brain post-mortem revealed the cause of the deafness.  There was destruction of the centre of hearing in both hemispheres (vide fig. 17), caused by blocking of an artery supplying in each hemisphere that particular region with blood.  The cause of the blocking of the two arteries was discovered, for little warty vegetations were found on the mitral valve of the left side of the heart.  I interpreted the two attacks thus:  one of these warty vegetations had become detached, and escaping into the arterial circulation, entered the left carotid artery and eventually stuck in the posterior branch of the middle cerebral artery, causing a temporary loss of word memory, consequently a disturbance of the whole speech zone of the left hemisphere.  This would account for the deafness to spoken language and loss of speech for a fortnight, with impairment for more than a month, following the first attack.  But both ears are represented in each half of the brain; that is to say, sound vibrations entering either ear, although they produce vibrations only in one auditory nerve, nevertheless proceed subsequently to both auditory centres.  The path most open, however, for transmission is to the opposite hemisphere; thus the right hemisphere receives most vibrations from the left ear and vice versa.  Consequently the auditory centre in the right hemisphere was able very soon to take on the function of associating verbal sounds with the sense of movement of articulate speech