FUNCTIONS OF THE CEREBRUM. 373 



of Recollection. In either case, the Memory of them is probably due to the 

 operation of the principle of Association ; by which sensations and the ideas 

 they excite become linked together, in such a manner that the recurrence of 

 one shall be the means of the recal of others which are connected with it. 

 There seems much ground for the opinion, that every Sensation actually ex- 

 perienced may become the subject of a Perception at any future time, though 

 beyond the voluntary power of the memory to retrace ; and the phenomena of 

 dreams and delirium, in which these sensations often recur with extraordinary 

 vividness, afford much support to this doctrine. Some of the instances upon 

 record are remarkable, as proving that the sensations may be thus remembered, 

 without any perceptions being attached to them ; these sensations having been 

 of such a nature as not to excite any notion or idea in the mind of the indi- 

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

 woman, during the delirium of fever, continually repeated sentences in lan- 

 guages unknown to those around her, which proved to be Hebrew and Chal- 

 daic ; of these she stated herself, on her recovery, to be perfectly ignorant ; but 

 on tracing her former history, it was found that, in early life, she had lived as 

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

 the 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 sensations are thus registered, it is in vain to 

 speculate ; and it does not seem likely that we shall ever become acquainted 

 with it. This is certain, however, that disease or injury of the brain will 

 destroy this power, or will affect it in various remarkable modes. We not un- 

 frequently 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 

 neiv 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 destroyed ; 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 is not unfrequently to be met with : the patient 

 understands perfectly well what is said, but is not able to reply in any other 

 terms than yes or wo, 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 de- 

 stroyed ; or it may be impaired merely, so that the patient mistakes the proper 

 terms, and speaks a most curious jargon. These cases have a peculiar interest, 

 in reference to the inquiry into the functions of different parts of the Cere- 

 brum. 



492. To the formation of vivid ideas of sensible objects, whether these have 

 actually presented themselves in the same form at some previous time, or are 

 modifications of the forms which had a real existence, the term Conception is 

 applied ; and this designation, like Perception, is also applied to the result of 

 the operation, that is, to the idea which is thus formed. The novelty of the 

 Conception may depend upon the new combination or correlation of the 

 objects it includes; or it may result from a sort of decomposition of former 

 complex ideas', and the re-assemblage of their elements under a different form. 

 These processes', like the Memory, of which they are modifications, may be 

 either spontaneous or voluntary; and in both forms they are continually em- 

 ployed by almost every one, the tendency to the exact reproduction of former 

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