3J:2 BLUSHING. Chap. XIII. 



If, however, the part is furnished with muscles, we 

 cannot feel sure, as Mr. Michael Foster has remarked 

 to me, that some slight impulse may not he unconsciously 

 sent to such muscles; and this would probably cause an 

 obscure sensation in the part. 



In a large number of cases, as with the salivary and 

 lacrymal glands, intestinal canal, &c, the power of atten- 

 tion seems to rest, either chiefly, or as some physiologists 

 think, exclusively, on the vaso-motor system being af- 

 fected in such a manner that more blood is allowed to 

 flow into the capillaries of the part in question. This 

 increased action of the capillaries may in some cases be 

 combined with the simultaneously increased activity of 

 the sensorium. 



The manner in which the mind affects the vaso- 

 motor system may be conceived in the following man- 

 ner. When we actually taste sour fruit, an impression 

 is sent through the gustatory nerves to a certain part of 

 the sensorium; this transmits nerve-force to the vaso- 

 motor centre, which consequently allows the muscular 

 coats of the small arteries that permeate the salivary 

 glands to relax. Hence more blood flows into these 

 glands, and they secrete a copious supply of saliva. Now 

 it does not seem an improbable assumption, that, when 

 we reflect intently on a sensation, the same part of the 

 sensorium, or a closely connected part of it, is brought 

 into a state of activity, in the same manner as when we 

 actually perceive the sensation. If so, the same cells 

 in the brain will be excited, though, perhaps, in a less 

 degree, by vividly thinking about a sour taste, as by 

 perceiving it; and they will transmit in the one case, as 

 in the other, nerve-force to the vaso-motor centre with 

 the same results. 



To give another, and, in some respects, more appro- 

 priate illustration. If a man stands before a hot fire, 





