782 OF THE FUNCTIONS OF THE NERVOUS SYSTEM. 



pressed at the time or are subsequently remembered, although the individual 

 cannot himself retrace them as having ever before been present to his conscious- 

 ness ; they being yet proved to have been so at some long antecedent period. 

 A very extraordinary case of this kind has been recorded, in which a woman, 

 during the delirium of fever, continually repeated sentences in languages un- 

 known to those around her, which were found to be Hebrew and Chaldaic ; of 

 these she stated herself, on her recovery, to be perfectly ignorant; but on trac- 

 ing her former history, it was ascertained that, in early life, she had lived as 

 servant with a clergyman, who had been accustomed to walk up and down his 

 passage, repeating or reading aloud sentences in these languages, which she 

 must have retained in her memory unconsciously to herself. Of the nature of 

 the change by which sensory impressions are thus registered, it seems in vain 

 to speculate ; there can be little question, however, that it is in some way de- 

 pendent upon the nutrition of the Cerebrum, since we see that alterations in 

 that function have a marked effect upon the Memory. Thus, in the case just 

 cited, we can scarcely doubt that some alteration either in the circulation of the 

 blood through the cortical substance of the Cerebrum, or in the quality of the 

 fluid, was the cause of changes, which, transmitted downwards 'to the Sensorium, 

 reproduced the former sensations; just as a disturbance of the circulation in the 

 retina produces the sensation of flashes of light or other visual phenomena. 

 Again, it is certain that disease or injury of the Cerebrum may destroy the 

 Memory generally, or may affect it in various remarkable modes. Thus we not 

 unfrequently meet with cases, in which the brain has been weakened by attacks 

 of epilepsy or apoplexy in such a manner as to prevent the reception of any 

 new impressions ; so that the patient does not remember anything that passes 

 from day to day ; whilst the impressions of events which happened long before 

 the commencement of his malady, recur with greater vividness than ever. On 

 the other hand, the memory of the long since past is sometimes entirely de- 

 stroyed ; whilst that of events which have happened subsequently to the malady, 

 is but little weakened. The memory of particular classes of ideas is frequently 

 destroyed ; that of a certain language, or some branch of science, for example. 

 The loss of the memory of words is another very curious form of this disorder, 

 which not unfrequently presents itself : the patient understands perfectly well 

 what is said, but is not able to reply in any other terms than yes or no- not 

 from any paralysis of the muscles of articulation, but from the incapability of 

 expressing the ideas in language. Sometimes the memory of a particular class 

 of words only, such as nouns or verbs, is destroyed ; or it may be impaired 

 merely, so that the patient mistakes the proper terms, and speaks a most curious 

 jargon. So, again, a person may remember the letters of which a word is com- 

 posed, and may be able to spell his wants, though he cannot speak the word 

 itself ; asking for bread (for example) by the separate letters b, r, e, a, d. A 

 very curious affection of the memory is that in which the sound of spoken words 

 does not convey any idea to the mind ; yet the individual may recognize in a 

 written or printed list of words, those which have been used by the speaker ; 

 and the sight of them enables him to understand their meaning. Conversely, 

 the sound of the word may be remembered, and the idea it conveys fully ap- 

 preciated ; but the visual memory of its written form may be altogether lost, 

 although the component letters may be recognized. For this class of pheno- 

 mena, in which there is rather a severance of the associative connections that 

 have been formed between distinct states of consciousness, than an actual an- 

 nihilation of the impression left by any of the latter, the term " dislocation of 

 memory" has been proposed by Dr. Holland; 1 but, as he justly remarks, " no 

 single term can express the various effects of accident, disease, or decay, upon 



1 See his " Chapters on Mental Physiology," p. 146. 



