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Rh greater vividness than ever. The Memory of particular classes of Ideas is frequently destroyed; that, for example, of a certain Language, or of some other branch of Knowledge, or of the patient's domestic 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 suffered an injury of his head by a fall from his horse, on recovering from his insensibility gave minute directions in regard to his own treatment, 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 knowledge, 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 certain part of the Cerebrum; and the tracing of this malnutrition back to an interruption in the supply of Blood. In this curious Mental infirmity (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 knowledge 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 observation, 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 torrent 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 connection 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 disease 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