Observations placeholder

As described in Illustrations Of The Influence Of The Mind Upon The Body In Health And Disease, Designed To Elucidate The Action Of The Imagination - Daniel Hack Tuke, M.D., M.R.C.P.,

PART II. THE EMOTIONS.
CHAPTER X. INFLUENCE OF THE EMOTIONS UPON THE ORGANIC OR VEGETATIVE FUNCTIONS.

Dr. Wilks (Medical Times and Gazette, Feb. 1, 1868) observes,

" We hear sometimes of fear turning the whole mass of the blood. I believe this is literally correct. I have seen now so many cases of anaemia, some of them fatal, occurring upon a severe shock of the nervous system, that I have no doubt of the fact."

He then refers to the modus operandi, but frankly confesses his ignorance until physiologists will inform us in what part of the body the blood is manufactured.

Those who explain everything by the varying calibre of the blood vessels, would fully admit that mental states influence, not only the amount of the blood in a vessel during a given period of time, but also thereby its chemical composition.

CI. Bernard tries to prove, experimentally, how the nervous system controls (and therefore how Emotion may influence) the absorption of oxygen by the blood in the lungs, and its combination with the histological elements of the tissues. As his experiments on the relation of secretion to the blood prove that, during this process, the blood in the veins of the glands, which is usually dark in colour, becomes of a bright arterial scarlet, and as he accounts for these phenomena by the opposite action of the two classes of nerves — the contracting and dilating — which supply the vessels ; — results which may be artificially induced by section and galvanism — it follows that even if we go no further than Bernard's mechanical views, varying emotional states would readily affect the relative amount of oxygen and carbonic acid gas in the blood.

As the transformation of the effete materials of the tissues, taking place in the capillaries, requires time, and therefore a certain stagnation of blood for the operation, if the emotions interfere with this condition, it is easy to see that there will be a tendency for arterial blood to pass unchanged into the veins, as actually occurs when the sympathetic nerve is divided.

Changes of psychical origin in the quantity and quality of the blood, and consequently in secretion and nutrition, may thus receive at least a partial explanation by our application of Bernard's experiments. Increase of temperature, and thereby of certain chemical phenomena, must also be included. That changes in the chemistry of the blood may, however, be produced in a more direct manner is, to say the least, very probable. The knowledge of Bernard's experiments did not prevent Brodie remarking that the influence of nervous power "in causing the blood to undergo changes in its chemical composition," as well as in "affecting the secretions," is very analogous to the effects produced by the voltaic battery.