BLUSHING, a sudden reddening of the face. neck, and breast, owing to some mental shock, most commonly of the character of humiliation or shame. The muure and cause of this effect have been recently elucidated by phys:olognsal researches. It is produced by an increased flow of blood into the capillary vessels over the parts where the blush extends. Besides reddening, the complexion, it creates a sensible augn:cntation of heat in those parts. The feeling that uccompanies the state is of a distressing kind The phenomenon of B. is part of a general Influence exerted on the capillary circula tion by mental causes operating through the brain. experiments %thereby the exist ence of this influence has been established, may be described as follows: The small by which the blood is brought into proximity nth the various tissues of the body, are kept in a state of balanced distension between two forces, the one the propel sive power of the heart's action, which tills and distends them; the other, an influence derived from the nervous centers, and acting upon the muscular fibers so as to contract the vessels. The first of the two forces—the agency of the heart—is quite well under s nod: it is simply like the ease of the hose of a fire-engine by working the pump, and driving the water along. The t onnteracting force of the nerve-centers is proved by the following When the sympathetic nerve proceeding to the vessels of the head and face of an ;mime' is cut, there follows congestion of the blood vessels with augmented heat over the whole surface supplied by the nerve The car is seen to become redder; a thermometer inserted In the nostril shows an increase of tern• perature, the sign of a greater quantity of blood flowing into the capillaries. The infer ence front the experiment is that. from the withdrawal of a counterpoise. the force that distends the small blood-vessels—that is to say, the heart's action—has an umisna1 pre dominance. It is further proved that this nervous influence, acting upon the minute muscular fibers of the small vessels, proceeds from the nerve-centers lodged in the head. for, by cutting the connection between the brain and the ganglion in the neck. from
which the above-mentioned nerve is derived, the same restraining influence is arrested. and the congestion takes place. By stimulsting the divided nerve galvani!•ally, the suffusion disappears, the vessels shrinking by the galvanic contraction of their muscu lar coats.
The agency now described is of a piece with the action of the brain upon involuntary muscles ns the heart and the intestinal canal. and by it many organic func tions—digestion. nutrition. absorption, etc.—are affected by those changes in the cereb ral substance that neetimpany mental states. It is 'known that mental excitement has au immediate influence in all those functions; one set of passions. such as fear, tend to derange them, while joy and exhilaration operate favorably upon them.
To apply these observations to the ease in hand. Supposing a person in the average mental condition, and something to arise which gives a painful shock to the feelings a piece of ill news, a reproach from some one whose good opinion is much valued, an open shame, or the fear of it, a fit of remorse, an occasion of grief—the pain is accom panied with a sudden loss, or waste, or decrease of cerebral power; none of the func tions that the brain aids in maintaining is so strongly stimulated as before; and in particular, that stream of nervous energy which balances the heart's action in regulating the distension of the small blood-vessels, is abated, the abatement being made apparent in the redness and heat over the face and neck. In a great stroke of mental depression, the influence is of a much more extensive kind, though still of the same nature essen tially as regards the enfeeblement of the nervous energy. and may lower the action of the heart itself: in which ease there will be a wide-spread pallor, perhaps without a blush. In all probability, it is when the loss of cerebral influence extends only to the relaxation of the muscular fibers of the small vessels, leaving the heart in its usual vigor, that the state of B. is most fully manifested. Hence it is more apt to arise out of lute smaller modes of painful apprehension than from the more serious calamities that pros trate the system throughout.