hope yet to take the subject up again in relation to the organ in the forehead, which on proofs, aliunde, as patent to the senses as those of the functions of a nerve, we concluded to belong in extreme size to engineers and mechanicians, who have an obvious superiority in the application of their mus cles, and of instruments used in aid of their muscles, to dis turb and restore equilibrium in mechanical operations. We at once acknowledge, that Mr Bell's nerve is not traced into this convolution of brain in the superciliary ridge; but this, as an objection, is logically removed by a plain analogy; for the optic nerve is not traced into the organ of Colouring, nor the auditory into that of Tune; yet how essentially do these faculties depend upon these two senses respectively. Tune and Colouring, as organs, are demonstrated by evidence as good as that which proves the optic and auditory nerves to be the organs of seeing and hearing, as senses. But, on the new view, that the power in question, in so far as Mr Bell has thrown light upon it, is a sense, we are farther aided by the analogy of Colouring and Tune. The senses of seeing and hearing minister to these faculties; but the faculties work up higher the raw material of light and sound, into all the combinations of tints, melodies, and harmonies. So may, and probably so does, this new sense of resistance* minister to a higher faculty which can combine forces, and estimate their harmonies, as Sir George Mackenzie has happily expressed it, in complicated equilibrium. But we must crave time, both to observe and think, on this difficult subject. In the mean time, we see, in the hypothesis, for it is yet no more -of a sense and a higher faculty both existing, an answer to the objection, that some animals, as the common fowl, when

Sir George Mackenzie, in a paper in this Journal, No X. vol. III. page 211, and in another paper lately read to the Phrenological Society (vide next article), suggests Force as the generic term. This new sense may yet throw light on the origin of our notions of Force, as the external cause which excites the particular sensations of the sense, but which sensations are, therefore, not force. It is extremely probable, that, without the sensations of the muscular frame, we never could have perceived force at all.

the whole cerebral hemispheres are removed, still make an effort to walk and balance themselves. Although we have no reliance on observations made on these violent cerebral mutilations, we must admit, supposing these efforts of the fowl to balance the body quite unequivocal, that there could be no aid in such a case to the perception of equilibrium from an organ in any part of the hemispheres which were removed. But the sense may exist in what remained of the brain,—more than a third,—after the hemispheres were re, moved; and any higher function it is certainly not pretended is manifested by the mutilated animals.

In giving a name to the new sense, as a sense, we must distinguish, as in the other senses, the passive sensation from the positive perception of its external cause. The latter, we are, so far as we yet see, inclined to think with Sir George Mackenzie, is Force; but the former is the sensation of the muscular frame, as in equilibrio with impressing forces. The other senses are named from the sensation, not from the perception; we have the senses of seeing, hearing, smelling, and tasting; not of light, sound, odour, and flavour; on which analogy we are at present inclined to denominate this new sense, not the Sense of Force, but the SENSE of EQUILIBRIUM.

ARTICLE VIII.

LETTER FROM SIR GEORGE S. MACKENZIE, BART. ON THE PERCEPTION OF FORCE.

To the Editor.

SIR, The reviewer of my "Illustrations of Phrenology," in your Journal,* has taken notice of my suggestion of Resistance as the perception of that faculty hitherto marked Weight, and which Mr Simpson has called the Instinct, or Sense of Equilibrium; and I hope I have to thank my re

Vol. iii. page 451.

viewer for having led me to some more precise notions on the very interesting subject. On farther reflection, I am satisfied that Resistance is too narrow an expression, yet, for the perception in question; although Resistance must be included in any more extensive term, just as Weight is included in Resist ance. In a former communication,* I stated some reasons for thinking that the more general perception in question is Force. I now offer you some farther considerations in sup port of that conclusion.

It is probable that the primary function of every knowing faculty is to cognise something that is constant or invariable in nature, and that the subordinate functions apply to varia tions and combinations. Space is constant ; so is Time, Num ber, Order, Light, Sound. We have distinct notions of Force, Resistance, Weight, Equilibrium, &c.; and if we inquire into what is constant in nature in reference to them, we may arrive at the faculty by discovering its primary functions.

Force, as a general term, is constant in nature. My reviewer may be right in saying, that the only idea of Force is derived from resistance and counter-resistance; but this re fers only to the first excitement of the perception of Force, through the medium of Touch.† Experience carries us a great deal farther; and we see the effects of Force when there is neither resistance nor counter-resistance. A body in the act of falling does not appear to resist, nor to meet with resist ance, at least (if we are to go minutely into the matter) in vacuo. Motion is the result of force overcoming resistance; or, as stated in my former communication, already referred to, Motion may be called Force in action, after having overcome resistance. It is the visible or sensible exhibition of the effect of Force. Resistance is not felt, nor its effects seen, until Force be applied; nor is it constant, because it is not always applied. If it be called a force, it is subordinate.

Vol. iii. page 211.

+ Mr C. Bell has demonstrated, that Touch is not the medium of this perception. This was evidently unknown to Sir George Mackenzie.-EDITOR.

Experience tells us that Force is constant, because we find all nature in motion. No body is at rest, except relatively to other bodies. The earth is constantly revolving round the sun, and turning on its axis, and kept in its orbit by the exertion of Force applied in different directions. Force, as my reviewer says, doubtless addresses itself to Causality, as a cause of motion. But he does not mean by this, that the cognisance of Force is a function of Causality, or any cause that this faculty may discover. Two sounds may make a discord; Causality discovers the cause, but the perception of the discord belongs to another faculty. Before it could address itself to Causality, Force must have had a previous existence recognised by another faculty.

Equilibrium is a word denoting, in the allusion of my reviewer, a reference to a particular force, that of gravitation; a certain effect of which is resisted by particular management. It is the effect of resistance applied to a constant force in such a way as to prevent motion in some particular direction; in other words, to preserve a body in a desired position, whether when at rest or in motion. It seems evident, that the knowledge of equilibrium is first acquired by its loss. I should be inclined to say, that intoxication rather promotes than destroys the perception of the body being in equilibrio; for it is observable of persons in that state, that they are exceeding

anxious about keeping their feet, as we say. They make many efforts, however unsuccessful; and sometimes are greatly offended by proffers of heip. The effect of intoxication is to deprive a person of the power to exert the force necessary to enable him to stand steady; and when liquor is swallowed in sufficient quantity, all efforts to preserve equili brium cease, and all the organs are as if dead. I consider equilibrium in connexion with force, as I do concord in connexion with tune. Concord is the harmony of sounds; equilibrium the harmony of forces. The forces are combined with resistance in such a manner as to be equally divided around it. Being then an effect arising out of combined

causes, and discovered to us after we acquire a knowledge of force and resistance, the perception of it appears to me a subordinate function.* I give up my notion, that resistance is cognisable by a distinct faculty. It is not peculiar to the sense of touch, for we know resistance by seeing its effects as well as feeling them. We also hear its effects; and indeed cognise it in the interruption of the functions of each of the senses. I now consider it as subordinate, and including various qualities of matter, as will be seen in the following arrangement:

In all these Force is the index.

If the views thus taken shall contribute to the farther elucidation of the subject, or have led me to stumble on error so as to warn others of the obstruction, the service rendered we owe to the reviewer. He has paid me a high compliment in supposing I might think to purpose on the point; higher than is merited. It is earnestly requested he will keep in mind, that I offer these views to his consideration, not, presumptuously, for his adoption.

I have only now to remark, that my work on Phrenology was intended for those who had a slight acquaintance with its

• In the preceding article we have offered our own view of the relation between Force and Equilibrium in relation to the animal body. We have supposed Equilibrium the Sensation, and Force the Perception.—EDITOR.