Contraction

“ Let us now turn to the more complex and serially concatenated movements which oftenest meet us in real life. The object of our will is seldom a single muscular contraction; it is almost always an orderly sequence of contractions, ending with a sensation which tells us that the goal is reached. ”

“ Contraction does not seem to be an explanation of all or even the chief phenomena which we have briefly set forth. When this hypothesis was considered, flexion seemed to be the chief method of displacement ”

“ Dilatation & contraction suppose mutation of the smallest parts in respect of their situation. 11. Dilatation and contraction, as also all flexion, supposes necessarily that the internal parts of the body bowed do either come nearer to the external parts, or go further from them. For though flexion be considered only in the length of a body, yet when that body is bowed, the line which is made on one side will be convex, and the line on the other side will be concave ”

“ By muscular contraction he can create a pressure on an outward object, which, if sufficiently powerful, will set it in motion, or if it be already moving, will check or modify or altogether arrest its motion, and he can do no more. ”

“ That the notions of extension and external resistance, which are thus supposed to be acquired from the progressive contraction of muscles, and the difficulty opposed to their accustomed contraction, which introduces suddenly a new feeling, when all the antecedent feelings had been the same, should be directly combined, only with the sensations of touch, cannot appear wonderful, when we reflect, that it is only in the case of touch, there is that frequent coexistence or immediate succession, which is necessary to the subsequent union. ”

“ That the Nature of extension or dilation strives or endeavours to get space, ground, or compass, I mean those corporeal motions endeavour to make place and space by their extensions, that is, to spread their parts of matter into a larger compass or body. And when I say, That Contractions endeavour to cast or thrust out space, place, ground, or compass, My meaning is, That those corporeal motions endeavour to draw their parts of matter into a more close and solid body, for there is no place nor space without body. ”

“ There is a limit of Opakeness, and a limit of Contraction;
30In every Individual Man, and the limit of Opakeness,
Is named Satan: and the limit of Contraction is named Adam.
But when Man sleeps in Beulah, the Saviour in mercy takes
Contractions Limit, and of the Limit he forms Woman: That
Himself may in process of time be born Man to redeem
35But there is no Limit of Expansion! there is no Limit of Translucence. ”

“ If we increase this contraction, we draw over a little more in the same direction, until we come to lie completely on one side, and at this moment there supervenes a movement of rotation, almost instinctive, which makes us spasmodically take the normal position. ”

“ The sensible motion generated by the contraction can arise only from the transformation of insensible motion. This insensible motion suddenly yielded up by a contracting mass, implies the fall of its component molecules into more stable arrangements. ”

“ We have now seen how nerves and muscles may be irritated in a definite and precise way, and we have found that the irritation of its nerve causes a contraction of a muscle. In the case of a single twitch, however, the movement is too rapid to be appreciated, and still less analysed, by the unaided eye. We cannot tell, for example, whether the contraction occurs in a shorter time than the relaxation, and still less whether the contraction is at a uniform rate in time, or whether it contracts faster at the beginning and more slowly towards the end, or the reverse. ”

“ The relation between these stimulations and adjusted contractions must be such that increase of the one causes increase of the other; since the directions of the discharges being once established, greater stimulation causes greater contraction, and the greater contraction causing closer contact with the stimulating agent, causes increase of stimulus and is thereby itself further increased. ”

“ The general over-contraction may be small when estimated in foot-pounds, but its importance is immense on account of its effects on the over-contracted person's spiritual life. This follows as a necessary consequence from the theory of our emotions to which I made reference at the beginning of this article. For by the sensations that so incessantly pour in from the over-tense excited body the over-tense and excited habit of mind is kept up ”

“ A contracted muscle, according to this view, is like a strong band of india-rubber pulling on two pieces of wood and drawing them together. In like manner, when a muscle contracts, a similar elastic power is developed that pulls upon the bones and causes movement. When the contraction ceases, the muscle returns to its original length, again by elasticity, but acting in the opposite way.
What is this property of irritability by virtue of which the muscle responds to a stimulus and contracts? ”

“ The cases of this incapacity of the left hand to perform the acts which we perform habitually with the right are innumerable; and afford decisive illustration of the great fact which is now the subject of our attention. To perform the contractions of a number of muscles, the contractions of all of which must be combined in the action, the idea whereon each of the contractions depends must previously exist, and in the requisite order. That is to say, a certain association of Ideas must be performed. But we know, that no new 345 association of Ideas is easily or steadily performed. ”

“ When the nerve-current reaches the muscle, it sets up molecular changes in it, and these changes are expressed to our eyes by a contraction, heat at the same time being liberated. The electric current we call a stimulus. We use electricity for stimulating the nerve because it is a convenient method, but the nerve, as we shall see, might be stimulated in other ways, as by mechanical irritation, such as pricking, pinching, or beating, or by heating it suddenly. It does not matter, however, how we stimulate the nerve ”

“ The progressive contractions of the various muscles which move the arms, as affording similar successions of feelings, may be considered in precisely the same light, as sources of the knowledge of extension ”

“ Contractions and combinations are not merely frequent, but almost universal. There is scarcely an instance in which five consecutive letters are separately written, and there is no single line in which half a dozen contractions, often including from four to ten letters, do not occur. ”

“ This inseparable connexion between the Ideas, and the contractions, which we call the Power of the Will, is gradually formed. At first the hand of the infant is moved by sensations. If the inside of the hand is touched, so at least as to make the sensation considerable, the fingers bend; and perform more or less of the act of grasping. ”

“ Action of a nerve—Rapidity of nerve-current—Nature of nerve-current—Analogy with electric current—Nerveless animals—Heat in muscle—Muscles liberate mechanical energy and heat—Chemical changes in muscle.
We have now seen that the living matter forming a muscle is irritable or excitable, that is to say, it responds or reacts to a stimulus. We have also learned that the muscle shows its response or reaction by a contraction. Lastly, we have found that the natural stimulus that sets the muscle into action is something that happens in a nerve. ”

“ Having thus discovered or supposed the two relations of contiguity and succession to be essential to causes and effects, I find I am stopt short, and can proceed no farther in considering any single instance of cause and effect. Motion in one body is regarded upon impulse as the cause of motion in another. When we consider these objects with utmost attention, we find only that the one body approaches the other; and that the motion of it precedes that of the other, but without any, sensible interval. It is in vain to rack ourselves with farther thought and reflection upon this subject. ”

“ If, then, we generalize from this particular instance, we may define a state of tension as follows: that a body is said to be in a state of tension when each of any two parts into which it may be divided tends to contract and to expand the other. You observe, then, that the tendency of one part to extend the other is the criterion of a state of tension; and I will now show you a couple of experiments which will, I think, enable me to prove that it exists in the surface of a liquid. ”

“ Is it to cause a body to act in such a manner that the reaction shall be greater than the action itself, and by that means generate force by the accumulation of the surplus? Or, can the motion communicated be greater than that lost by the agent? ”

“ So we perceive, in the first place, contractility explains innervation; and then, that something more is wanting. And as nervous contractility is nothing but a mental fiction (a nerve never moves, never contracts, when it is touched) the whole matter tapers down to this something more, or to that other thing. ”

“ Cohesion of solid parts and impulse, the primary ideas peculiar to body. The primary ideas we have peculiar to body, as contradistinguished to spirit, are the cohesion of solid, and consequently separable, parts, and a power of communicating motion by impulse. ”

“ And when, by a power existing in B, A is drawn towards it without any other exciting cause; thus, if nothing else in the world existed but A and B in a state of rest, and A move towards B by some influence which is as much a part of its nature as its thirst or inclination, then would be created what is called physical attraction. And now, for a trifle, I will give you the most convincing demonstration of the modus operandi of all these phenomena. ”

“ Contractility is, then, a common and general property, inherent in all animal textures, but which, according to the manner that it is brought into action, presents essential differences, which divide it into many species, that have no analogy. ”

“ Is the bare idea of a movement's sensible effects its sufficient mental cue (p. 497) , or must there be an additional mental antecedent, in the shape of a fiat, decision, consent, volitional mandate, or other synonymous phenomenon of consciousness, before the movement can follow?
I answer: Sometimes the bare idea is sufficient, but sometimes an additional conscious element, in the shape of a fiat, mandate, or express consent, has to intervene and precede the movement. The cases without a fiat constitute the more fundamental, because the more simple, variety. ”

“ Have not the small particles of bodies certain powers, virtues, or forces, by which they act at a distance? .... What I call 'attraction' may be performed by impulse, or by some other means unknown to me. I use that word here to signify only in general any force by which bodies tend toward one another, whatsoever be the cause. ”

“ If I or you touch a man or woman with a finger, or clasp their hand, or embrace them more completely, the tendency is at once set up, and the force seeks to flow, and, according to certain conditions, does flow, from one to another, evermore seeking to find a common level,—always, that is, in the direction of the greater need, or the greater capacity. ”

“ When several forces act upon a line, a plane, or a solid, they produce an effect equal to that one force alone, which is called the resultant: this force has a determinate direction and a point of application, as though it were simple or had not emanated from others; why cannot this be applied to thought? Why may not a thing, although it is simple, be the product of the concurrence of various agents? ”

“ But we are wholly ignorant of the medium of communication of one with the other. Hence, why, in my division of the vital forces, I have avoided a systematic basis. The distinction of the two kinds of sensibility, of the three215 kinds of contractility, rests wholly upon the observation of facts. Such is the obscurity of the phenomena of life, that I doubt if we shall ever be able to establish divisions from a knowledge of the nature and essence of the vital forces. ”

“ The conception of force as the originator of motion in matter, without bodily contact or the intervention of any intermedium, is essential to the right interpretation of physical phenomena;... its exertion makes itself manifest to our personal consciousness by the peculiar sensation of effort;... and it [force] affords a point of contact, a connecting link between the two great departments of being—between mind and matter—the one as its originator, the other as its recipient. ”

“ That property of mutual attraction became at some time a fixed condition of all matter, but it will not account for the formation of a system of bodies so adjusted that the attracting force will act among them by a specific law, by the operation of which they will be prevented from exerting on each other an excessive amount of such force, or any amount but that which is exactly needful to preserve their relative distances from each other. ”

“ And when such cases occur, we are to compute the attractions of the bodies by assigning to each of their particles its proper force, and then collecting the sum of them all. I here use the word attraction in general for any endeavour, of what kind soever, made by bodies to approach to each other; whether that endeavour arise from the action of the bodies themselves, as tending mutually to or agitating each other by spirits emitted ”

“ And just as all particular things are evolved by the force of attraction and dissolved by the force of repulsion, a state of concentration or aggregation in the individual perpetually alternating with a state of diffusion or segregation, so it is also with the material universe as a whole. ”

“ A moving force, by which matters can directly act upon one another only in the common surface of contact, I call a superficial force; but that whereby one matter can directly act on the parts of the other beyond the surface of contract, a penetrative force. ”