Diseases of the Internal Senses. 745 



the paralysis of the nerve would be. Some of the plrases of this dis- 

 ease are fickleness, capriciousness, and instability of purpose, which are 

 due to fluctuation in the processes of the nutrition of the ganglia. The 

 ganglia are of fluctuating force, one moment spasmodically vigorous, 

 and the next relapsing into feebleness and inanition. (The remedy for 

 Irysteria is work at some outdoor manual toil. ) 



The decay of muscular vigor is shown in inability to sustain continu- 

 ous action. In like manner the degree of cerebral force is measured by 

 the vigor of attention. Hemiplegic patients, whose brains are partly 

 disorganized, and patients with dementia, quiekl}' tire of giving attention 

 to a speaker and can sustain a conversation only a short time. Esquirol 

 says, imbeciles und idiots have such very small power of attention, that 

 he often found it impossible to got them to keep their eyes shut long 

 enough to have plaster casts made, although they were as desirous as 

 he. On account of their defective attention their sensory impressions, 

 sight, hearing, feeling, &c. , are feeble, defective and inaccurate. The 

 construction of the cerebral organs is founded exclusively upon sensory 

 impressions. The delicacy of tactile impressions depends upon the del- 

 icacy and fineness of the skin. The muscular sense corresponds as to 

 delicacy with that of touch, the muscles, considered as organs of sense, 

 corresponding with the skin. The delicacy of the tactual sense is an 

 indication of the delicacy of all the other senses. Persons of coarse 

 skins are dull in their perceptions. Susceptible persons are called thin 

 skinned and vice versa. The delicacy of cerebral processes depend upon 

 the fineness of the sensibilities, that of the skin among the rest, and 

 they often rise or fall together. A case is reported of a young man of 

 good character and intelligent, who having become anesthetic in his skin, 

 suddenly became undisciplined and rebellious to the utmost extent, and 

 gave himself up to the worst tendencies even to the compromising of the 

 peace and honor of his family. When he recovered sensation he also re- 

 covered his usual rationalit}'. He had several relapses with the same effect. 



The eye is a ver}* important regulator of our movements, which are 

 very uncertain and insecure when deprived of its guidance ; and sight 

 forms the basis of an immense number of our internal sense organs. 

 By means of comparing new sight sensations with these standards, we 

 judge of distances, the direction of the movements of objects, their 

 forms, sizes, relative positions, &c. Sight also enters into acquirement 

 of knowledge by reading, by means of works of art, &c. So it is easy 

 to see what a hole would be made in the mind were it deprived of sight. 

 Hearing and the other senses are in the same way essential bases of 

 mental activit}- and cerebral organ construction. When the senses are 

 at fault, evil effects are sure to be entailed upon the cerebral organs and 

 the mental demonstrations arising from their action. 



