Chap. XIII. BLUSHING. 3-il 



can influence the nutrition of parts. Sir J. Paget has 

 given a curious instance of the power, not indeed of the 

 mind, but of the nervous system, on the hair. A lady 

 " who is subject to attacks of what is called nervous head- 

 ache, always finds in the morning after such an one, that 

 some patches of her hair are white, as if powdered with 

 starch. The change is effected in a night, and in a few 

 days after, the hairs gradually regain their dark brownish 

 colour." 43 



We thus see that close attention certainly affects 

 various parts and organs, which are not properly under 

 the control of the will. By what means attention — per- 

 haps the most wonderful of all the wondrous powers of 

 the mind — is effected, is an extremely obscure subject. 

 According to Miiller, 44 the process by which the sensory 

 cells of the brain are rendered, through the will, sus- 

 ceptible of receiving more intense and distinct impres- 

 sions, is closely analogous to that by which the motor 

 cells are excited to send nerve-force to the voluntary 

 muscles. There are many points of analogy in the action 

 of the sensory and motor nerve-cells; for instance, the 

 familiar fact that close attention to any one sense causes 

 fatigue, like the prolonged exertion of any one muscle. 45 

 When therefore we voluntarily concentrate our attention 

 on any part of the body, the cells of the brain which re- 

 ceive impressions or sensations from that part are, it is 

 probable, in some unknown manner stimulated into 

 activity. This may account, without any local change 

 in the part to which our attention is earnestly directed, 

 for pain or odd sensations being there felt or increased. 



43 ' Lectures on Surgical Pathology,' 3rd edit, revised by 

 Prof. Turner, 1870, pp. 28, 31. 



44 ' Elements of Physiology,' Eng\ translat. vol. ii. p. 938. 



45 Prof. Laycock has discussed this point in a very in- 

 teresting- manner. See his ' Nervous Diseases of Women,' 

 1840, p. 110. 



