214 STUDIES IN LIFE AND SENSE. 



We understood 



Her by her sight ; her pure and eloquent blood 

 Spoke in her cheeks, and so distinctly wrought 

 That we might almost say her body thought. 



The natural blush is thus the offspring of. the mind. Its physio- 

 logical explanation is simple enough. A larger quantity of blood 

 than usual is sent into the minute blood-vessels of the skin, these 

 vessels being in a state of temporary relaxation, and having had 

 withdrawn the natural stimulus to moderate contraction, which is part 

 of their ordinary duty. In what way has the head of the department 

 interfered with the ordinary routine of the body? The answer is 

 supplied by the knowledge we have already gained respecting the 

 control of the forces which provide for the due circulation of the vital 

 fluid, and also by experimentation upon the rabbit's ear. When the 

 sympathetic nerves are affected, the heart's action, as we have 

 noted, is quickened, and a greater amount of blood is sent through 

 the vessels. When we divide the sympathetic nerve which supplies 

 the blood-vessels of the ear, these vessels become dilated, and the 

 rabbit's ear exhibits the same phenomena seen in the blushing coun- 

 tenance of the human subject. On the sympathetic system, then, 

 we must lay the burden of any complaints we have to make respecting 

 the " damask cheek " of every-day life. And conversely, to the same 

 lines of nerve which speed the heart's action we must give the credit 

 of causing the pallid countenance of fear or despair. When the cut 

 end of the sympathetic nerve in the rabbit's ear is irritated, we 

 perceive the ear to become pale, and its temperature to decrease. 

 This result arises from our conveying to the nerves of the blood 

 vessels some stimulus resembling that we have deprived them of, 

 so that they contract overmuch, and thus expel the blood from the 

 surface over which they are distributed. But the slowing of the 

 heart in the ordinary course of life is probably a matter with which 

 the inhibitory nerves have to do, and thus upon the pneumogastric 

 fibres we may rest the pale cast of the human face divine. Not to 

 be passed over without remark, are the consequences to our health 

 and physical well-being which flow from such overriding by the 

 nervcus system of the ordinary processes and acts of life. When an 

 influenza, or some still more serious internal disturbance of our 

 healthy equilibrium, occurs, we may trace the affection in question to 

 the influence of cold on the skin (as in a chill) acting upon nerves 

 which regulate the blood-vessels and their contraction. Thus, to 

 descend from philosophy to broad utilitarianism, it is not the least 

 important effect of studies dealing with the mechanism of body and 

 mind, that they may explain to us with equal facility the rationale of 

 the emotions or the reason why we " catch a cold." 



The ordinary relations between body and mind may thus be 



