Diseases of the Internal Senses. 737 



:unl unconscious. Even the patchwork may have been performed by 

 the ganglia below the cerebrum. 



In old age the cerebral cells become ' ' more or less infiltrated with 

 fatty granular matter ; they cease to be transparent and shrivel up. 

 They lose their susceptibility to be moved by stimuli, and if moved they 

 relapse easily, that is, they soon forget. Early memories are retained 

 by the aged, but recent impressions fade. They find it hard to learn 

 and retain new things, as names, new words and their meaning, as in a 

 foreign language ; or to acquire a technical education. This decay of 

 the ability to learn new things, makes the passage of time seem more 

 rapid to the old. Each new sensation registered in the brain, is a sort 

 of time-keeper, and if no sensation were to be registered for a period 

 of years, we should not know that such a period had elapsed. When 

 people constantly dwell in the past, it is an indication that present 

 events are not making lasting impressions on their brain. Demented 

 persons who have spent many years in an asylum, will constantly dwell 

 upon the ideas they had before their entrance, and having little power 

 to remember sensations of events during their stay, imagine the time to 

 be much less than it really is. 



It frequently happens that where there is an injury to the cerebrum 

 the memory of the events which happened just preceding the accident 

 are permanently obliterated. In such case it is probable that the blood, 

 which is directed by the stimulation to the organ under its influence, is 

 by the shock of the accident driven away with the plastic materials it 

 carries ; so that the constructive process upon the organ is instantly in- 

 terrupted before its completion. 



Sir H. Holland in company with a German inspector explored two 

 deep mines in the Hartz mountains one day and became greatly fatigued 

 and exhausted, so much so that he lost the power of speaking German. 

 Every German word and phrase escaped him, and it was not till he had 

 taken food and wine and been at rest for some time that he recovered 

 them. 



A gentleman who suffered a blow upon the head, in consequence of it, 

 lost the memory of the Greek language which he had acquired, but his 

 memory was not affected in any other way. 



A case is related by Carpenter of a lad who received a blow on the 

 head by which he lost the recollection of all the music he had ever 

 learned, but nothing else. 



In another case a surgeon was injured in the head by a fall from his 

 horse. On recovering from insensibility he gave minute directions for 

 his own treatment, but was found to have lost all recollection of having 

 a wife and children, but this memory returned after three days. 



There are various conditions in which the power of the will to operate 



