MOTION IN THE ANIMAL ORGANISM. 



67 



a part of the organ in the form of lifeless 

 compounds, begins. 



The change of matter, the manfestation 

 of mechanical force, and the absorption of 

 oxygen, are, in the animal body, so closely 

 connected with each other, that we may 

 consider the amount of motion, and the 

 quantity of living tissue transformed, as pro- 

 portional to the quantity of oxygen inspired 

 and consumed in a given time by the 

 animal. For a certain amount of motion, 

 for a certain proportion of vital force con- 

 sumed as mechanical force, an equivalent 

 of chemical force is manifested; that is, an 

 equivalent of oxygen enters into combina- 

 tion with the substance of the organ which 

 has lost the vital force ; and a corresponding 

 proportion of the substance of the organ is 

 separated from the living tissue in the shape 

 of an oxidized compound. 



All those parts of the body which nature 

 has destined to effect the change of matter, 

 that is, to the production of mechanical force, 

 are penetrated in all directions by a multi- 

 tude of the most minute tubes or vessels, in 

 which a current of oxygen continually cir- 

 culates, in the form of arterial blood. To 

 the above-mentioned separation of part of 

 the elements of these parts, in other words, 

 to the disturbance of their equilibrium, this 

 oxygen is absolutely essential. 



As long as the vital force of these parts 

 is not conducted away and applied to other 

 purposes, the oxygen of the arterial blood 

 has not the slightest effect' on the substance 

 of the organized parts; and in all cases, 

 only so much oxygen is taken up as cor- 

 responds to the conducting power, and, con- 

 sequently to the mechanical effects produced. 



The oxygen of the atmosphere is the 

 proper, active, external cause of the waste 

 of matter in the animal body : it acts like a 

 force which disturbs and tends to destroy 

 the manifestation of the vital force at every 

 moment. But its effect as a chemical agent, 

 the disturbance proceeding from it, is held 

 in equilibrium by the vital force, which is 

 free and available in the living tissue, or is 

 annihilated by a chemical agency opposed 

 to that of oxygen, the manifestation of 

 which must be considered as dependent on 

 the vital force. 



In chemical language, to annihilate the 

 chemical action of oxygen, means, to pre- 

 sent to it substances, or parts of organs, 

 which are capable of combining with it. 



The action of oxygen (affinity) is either 

 neutralized by means of the elements of 

 organized parts, which combine with it, 

 (after the free vital force has been conducted 

 away,) or else the organ presents to it the 

 products of other organs, or certain matters 

 formed from the elements of the food, by 

 the vital activity of certain systems of ap- 

 paratus. 



It is only the muscular system which, in 

 this sense, produces in itself a resistance to 

 the chemical action of oxygen, and neutral- 

 izes it completely. 



The substance of cellular tissue, of mem- 

 branes, and of the skin, the minutest parti- 

 cles of which are not in immediate contact 

 with arterial blood, (with oxygen,) are not 

 destined to undergo this change of matter. 

 Whatever phanges they may undergo in 

 the vital process, affect, in all cases, only 

 their surface. 



The gelatinous tissues, mucous mem. 

 branes, tendons, &c., are not designed to 

 produce mechanical force; they contain in 

 their substance no conductors ot mechanical 

 effects. But the muscular system is inter- 

 woven with innumerable nerves. The sub- 

 stance of the uterus is in no respect different 

 in chemical composition from the other mus- 

 cles ; but it is not adapted to the change of 

 matter, to the production of force, and con- 

 tains no organs for conducting away the 

 moving power. Cellular tissue, gelatinous 

 membranes, and mucous membranes, are 

 far from being destitute of the power of 

 combining with oxygen, when moisture is 

 present ; we know that, when moist, they 

 cannot be brought in contact with oxygen 

 without undergoing a progressive alteration. 

 But one surface of the intestines and the 

 cells of the lungs are constantly in contact 

 with oxygen; and it is obvious that they 

 must be as rapidly altered by the chemical 

 action of the oxygen in the body as out of 

 it, were it not that there exists in the or- 

 ganism itself a source of resistance, which 

 completely neutralizes the action of the oxy- 

 gen. Among the means by which this re- 

 sistance is furnished we may include all 

 substances which are capablf of combining 

 with oxygen, or acquire that property under 

 the influence of the vital force, and which 

 surpass the tissues above mentioned in their 

 power of neutralizing its chemical action. 



All those constituents of the body which, 

 in themselves, do not possess, in the form 

 of vital force, the power of resisting the 

 action of oxygen, must be far better adapted 

 for the purpose of combining with, and 

 neutralizing it, than those tissues which are 

 under the influence of the vital force, al- 

 though only through the nerves. In this 

 point of view, we cannot fail to perceive 

 the importance of the bile in regard to the 

 substance of the intestines, and that of the 

 pulmonary cells, as well as that of fat, of 

 mucus, and of the secretions generally. 



When the membranes are compelled from 

 their own substance to furnish resistance to 

 the action of the oxygen, that is, when there 

 is a deficiency of the substances destined by 

 nature for their protection, they must, since 

 their renewal is confined within narrow 

 limits, yield to the chemical action. The 

 lungs and intestines will always simulta- 

 neously suffer abormal changes. 



From the change of matter itself, from 

 the metamorphosis of the living muscular 

 tissue, these organs receive the means of 

 resistance to the action of oxygen which are 

 indispensable to their preservation. Accord- 

 ing to the rapidity of this process, the quau- 



