ON ACQUIRED PSYCHICAL HABITS. 309 



greater vividness than ever. The Memory of particular classes of 

 Ideas is frequently destroyed ; that, for example, of a certain Lan- 

 guage, or of some other branch of Knowledge, or of the patient's do- 

 mestic or social relations. Thus a case was recorded by Dr. Beattie, 

 of a gentleman, who, after a blow on the head, found that he had lost 

 his knowledge of Greek, but did not appear to have suffered in any 

 other way. A similar case has been recently communicated to me, 

 in which a lad, who lay for three days insensible, in consequence of a 

 severe blow on the head, found himself, on recovering, to have lost all 

 the Music he had learned, though nothing else had been thus " knocked 

 out " of him. Again, Dr. Abercrombie relates a curious case, on the 

 authority of an eminent medical friend, in which a surgeon who suf- 

 fered an injury of his head by a fall from his horse, on recovering from 

 his insensibility gave minute directions in regard to his own treat- 

 ment, but was found to have lost all remembrance of having a wife 

 and children ; and this did not return until the third day. Similar 

 losses of particular Languages, and other kinds of acquired knowl- 

 edge, have been noted as the results of Fevers. 



One of the most remarkable results of recent Pathological research 

 has been, the discovery of the dependence of the condition termed 

 Aphasia, or " loss of memory of words," upon malnutrition of a cer- 

 tain part of the Cerebrum ; and the tracing of this malnutrition back 

 to an interruption in the supply of Blood. In this curious Mental in- 

 firmity (which often begins to show itself before there is any other 

 evidence of Cerebral disorder, but which is now recognized as a most 

 serious indication of impending mischief), the subject either forgets 

 the words he wants for expressing his ideas, or he uses inappropriate 

 words in their place. It is obvious that he knows what he wants to 

 express, but cannot recall the words in which to convey that knowl- 

 edge to others. There is no paralysis of speech, for his articulation is 

 quite unaffected ; so that he can repeat the words he wants, if they 

 are suggested to him by others. In a case formerly under my obser- 

 vation, the Aphasia went on gradually but very slowly increasing for 

 three or four years ; showing itself at first as to only a few out-of-the- 

 way words, but gradually increasing until no intelligible language 

 seemed to be left, except that of swearing, which came forth in a tor- 

 rent when any restraint was put on the patient's bodily activity, which 

 continued very energetic until near the close of life. In another case 

 recently mentioned to me by a medical friend, who was a near con- 

 nection of the patient, the disease ran its course in a few months. 

 Cases of this kind almost invariably terminate in Apoplexy. Now, it 

 may be said that we have here only the evidence of synchronous dis- 

 ease of the Brain and disorder of the Mind ; so that the dependence 

 of the latter upon the former is not made out. But the very curious 

 discovery was made a few years ago, by Dr. J. Hughlings Jackson, 

 that the locally-impaired nutrition of the Brain in these cases is usu- 



