PHYSIOLOGY. 155 



by impressions made upon that organ ; and one of these, which 

 surely has more effect than all the rest, is the change of temper- 

 ature, which powerfully acts upon all our organs of sense, but to 

 which the surface of the body is especially exposed. And it is 

 remarkable that impressions made upon one part of the surface 

 are very readily communicated over the whole. We are made 

 to shiver by any part of the body touching a cold body, and 

 heat is in the same manner communicated over the whole. 



" ' The uterine and genital system in females.' Here I 

 must adhere to the fact, without assigning the cause or particu- 

 lar purpose. 



" These communications of motion have been called, in gen- 

 eral, consent or sympathy. I need not tell you that they have 

 been very much spoken of, as you will see in Dr. Hoffmann's 

 Works, in the Tract.Med.de Sympathia of Dr. Rega, and in Dr. 

 Whytt's Essay on Nervous Diseases. Every term which is like 

 establishing a power exerted between bodies at a distance with- 

 out contact and motion, and therefore a term for an occult 

 quality, is properly rejected : I would wish, therefore, that the 

 terms sympathy and consent were rejected from our system. 

 Our modern physiologists have sought for a mechanical com- 

 munication by deriving the nerves of the parts from the same 

 common fasciculus, or supposing that they have an origin in the 

 brain near to one another, but this is to be rejected." 



CXLIV. The communications of motion between the sever- 

 al parts of the nervous system which have been mentioned as 

 instances of a particular sympathy between these parts, are 

 very seldom to be explained by any contiguity or contact, either 

 in the origin or course of the nerves of the communicating parts. 

 " It seems to have been the intention of the economy, that 

 the nerves tied up in the same common membrane should have 

 no lateral communication, but that the nervous power should 

 proceed along one single fibre to the brain, in order to produce 

 the sensation, so that we might be able to refer the sensation to 

 the place of impression, as otherwise there could be no distinct 

 sensation ; nor when the will determines the action of a single 

 muscle, should we have any single separate action, but the ac- 

 tion of all the separate muscles would follow, to which these 



