4*54} SYMPATHY. 



may become painful, and even secrete milk, when the uterus or 

 the ovaria are only diseased. 



The influence of mental emotions is an example of sympathy. 

 The affection of the nutritive functions of the brain such 

 affections as are common to it and all other organs the state of 

 its circulation, the degree of its general excitement and of its 

 strength, the state of its structure, all may sympathetically 

 influence other parts, and may be influenced sympathetically in 

 turn. But, besides these, the condition of the peculiar functions 

 of certain parts of the brain exercises very powerful influence 

 upon every part of the body. When grief, fear, anxiety, despair, 

 terror, or contentment, hope, enthusiasm, joy, love or hatred, 

 sexual passion, &c. &c. occur in the brain, certain sympathetic 

 effects take place in certain other parts of the body, as in the cir- 

 culating organs at large, in the genitals, &c. ; and the effect may 

 be violent, even to destruction of life and perhaps laceration of 

 structure, or continued so as, if agreeable, to remove disease, 

 or, if unpleasant, to occasion functional or structural derangement 

 in any part that may be the most predisposed. Now blushing 

 under anger or shame, paleness, polyuria, and diarrhoea, under fear, 

 erections under desire, all called effects of the passions, can be 

 but so many changes occurring sympathetically from certain states 

 of certain parts of the brain, as peculiar states of other functions 

 of other organs affect different organs sympathetically. 



It must be obvious that the sympathising part is not always 

 that which appears to sympathise. When a voluntary muscle 

 contracts sympathetically, it is not the muscle but the nerves 

 moving the muscles, and indeed generally the ultimate fibres in 

 the encephalon or chord, that are sympathetically excited; and the 

 contraction of the muscle is the result of their excitement, just 

 as it would be if their excitement occurred in any other way. 

 The sympathy is not between the excited part and the muscles, but 

 between it and the nerves of the muscles : wherefore, if the nerves 

 of the muscle are divided, the sympathy still exists, but ceases to 

 be manifest, because the muscles are no longer influenced by the 

 sympathising nerves. Hence Bichat k , who divided sympathy 



k Anatomic Genfrale, t. i. p. 183. sq. 



John Hunter divides sympathy into general and partial ; such as pyrexia 

 from a wound, and vomiting from irritation of the fauces. Partial sympathy he 

 subdivides into remote, contiguous, and continuous, Where there is no evident 

 connection between the sympathising parts sufficient to account for the circum- 



