« ForrigeFortsæt »
far, the healthy composition of the blood, and consequently impairs, in a greater or lesser degree, its Nutritive properties.
Then the velocity of the circulation is also subjected to fixed laws, influenced to a considerable extent by, or rather acting in conformity with, individual organisms and constitutions. The rapidity of the circulation is certainly astonishing. Each ventricle of the heart is estimated as capable of containing two ounces of blood which is ejected at each contraction. "The number of contractions of the Heart in a given time," says Carpenter, "is liable to great variation within the limits of health, from various causes," but from a table which he gives we take the following as an approximation to the average of male pulses at the several ages specified.*
If, then, we take the pulsations of the heart in the average of healthy manhood at 75 per minute, and that at each stroke or beat two ounces of blood are ejected into the circulation, we arrive at the conclusion that 150ozs. of pure arterial blood, or 9lbs. is propelled through the aorta in a minute. And taking 30lbs. as the quantity of blood in a healthy man of average size, it follows that the whole circuit of the circulation is completed by every drop of blood in the body in less than 2 minutes; and as after each circuit the blood undergoes purification in the lungs, we have all the blood in the body purified and circulating afresh about 28 times in an hour!
But even this estimate of the rapidity of the circulation, extraordinary as it may appear, is held by some Physiologists to be far under the truth. In the arteries the blood is calculated
* The pulse of the adult Female exceeds in frequency the pulse of the adult Male, at the same mean age, by from 10 to 14 beats in a minute.Human Physiology, third edition, par. 727.
to travel at the rate of 12 inches per second, and in the veins at 8 inches, but in passing through the capillaries, from the arteries to the veins, its rate of progress is much slower. However, it is affirmed, as the result of experiment, that the whole circuit of the circulatory system is traversed and completed in half-aminute! But it is sufficient for our purpose that the rapidity of the circulation should be generally understood, and we shall see what an important bearing this rapidity has, as a remedial agency, in correcting defective Nutritive action, and affording relief in congested states of the organs.
The reader will now understand that Pure Blood is the mainspring of Nutritive Life, and that blood impurities, no matter how produced, are either the exciting or predisposing cause of all diseased bodily conditions. He will also understand that every part of the human organism is perpetually undergoing a process of decomposition and decay, and that an appropriation or assimilation of nutritive particles by each part to supply this waste is a necessary condition of Life and Health. The blood is the medium through which this incessant supply of reproductive material is conveyed to every part of the system, and it is also the principal channel by means of which the decomposed effete matter is collected and conveyed from the system. This function the blood performs by means of secretions which it deposits for expulsion through the organs of excretion-the skin, lungs, liver, kidneys, and intestines. The excretions are thus the products of the decomposition and waste of the organism, and of the excrementitious products of digestion, and their regular elimination from the system is essential to blood purity; for, if not eliminated, they corrupt the blood, poison the whole circulation, and become fruitful sources of disease.
Thus will be understood how intimate and material the relationship is between all the organs of the body, and their mutual dependence, the one upon the other, for the performance of the functions of perfect Life, and the fulfilment of its grand design. The organism working concurrently and harmoniously together is the perfection of Life; and any derangement of the
parts-no matter how caused-produces a disturbance and confusion that may result in a multiplicity of ills. As Shakspeare says of degree
"Take but degree away, untune that string,
And, hark, what discord follows! each thing meets
So with our organism. Take one link away-impair an organ, derange a function, and discordant action follows to the greater or less injury of the whole.
Now, of all the organs of excretion, by which the poisonous waste matter of the system is eliminated, modern physiologists and pathologists, also, are now inclined to regard the skin as comparatively the most important. There is no other organ co-extensive with it. It possesses secretive, eliminative, absorbent, and respiratory functions in a higher degree of combination and power than any other of the excretory organs. Not only so, but it supplies a ready medium by which the whole internal organism can be reached and acted on. This is an established truth, while equally important and true it is, that no means have yet been discovered at all comparable to the Hot-air Bath for stimulating the functions of the Skin, which our artificial habits of life are constantly endeavouring to derange and impair.
Imperfect skin-action implies disease in some form or other. The inevitable tendency is for the blood to become impurethe circulation irregular-for the digestive powers to act languidly-for the secretions and exudations of the body to be imperfectly performed, and, consequently, for some part of the internal organism to become overloaded or congested—in short, for the Nutritive functions to become completely deranged. Such a condition of body is preliminary to the development of localised disease.
The reverse is Health, which follows from, and is dependent on, perfect skin-action, while medical art has no contrivance, drug, or compound equal to, or comparable with, the Hot-Air Bath for maintaining the skin in a condition of healthy activity.
We will now proceed to show that the Bath so acts by giving vitality to skin functions, which our ordinary modes of life have a direct tendency to deaden-by promoting healthy secretions and eliminations-by preventing the congestion of internal organs and maintaining the vital fluid, the blood, in a pure normal state, attracting it to the surface there to deposit its poisonous matters for exudation, thence to return with replenished vitality into healthy circulation-in a word, by giving, as nothing else can give, vigour and tone to Nutritive Life through the purity of the blood.
The Skin-Its structure and uses—Its functions essential to Life. THE vital functions of the Skin, in their relation to the animal economy, were formerly greatly underrated, because not properly understood. The investigations, however, of modern physiologists, aided by powerful miscroscopic agency, have clearly revealed its truly wonderful organism, and demonstrated how all-essential its sound and active vitality is to the due performance of the functions of healthy life, and also how it is designed as a medium through which, in cases of disease, the internal organism can be safely reached and acted on.
The Skin, in the popular acceptation of the term, is considered as only one simple substance, but in reality what in ordinary language is called the skin, is to the physiologist known as the epidermis, the outer, or scarf skin, underneath which lies the cutis vera, or true skin. Thus, properly speaking, the skin consists of two layers, the inner layer, and, immeasurably, the more sensitive and delicate being known as the cutis vera, the derma or true skin, and the outer layer, by which the cutis is protected, as the epidermis or scarf skin. Between these two layers, or strata, there is a soft granular or cellular substance called the rete mucosum, which contains the particles that give colour to the skin.
Some physiologists hold that the matter which gives colour to the skin is situated in the rete mucosum, while others are of opinion that it lies in the inner or flocculent surface of the epidermis. According to Dr. Beddoes, chlorine gas will extract the colouring matter from the negro; and Fourcroy verified this experiment, but in a few days the black colour returned again with its former intensity.