posed of any material of uniform specific gravity or weight, we can readily determine whether a line dropped from the centre of gravity in the cone, to the earth, will pass through the centre of any point within its base, or whether it leans in any direction, so as to carry the line to one side. In this judgment, we need to call in aid the organs of form and size, to take the dimensions of the cone; but these alone would not inform us of the condition of its balance. The organ of form might enable us to notice the angle it made with the surrounding earth. But we could not tell the position of the earth on the surface, in reference to the centre of gravitation. The faculty, which takes cognizance of this, is distinct from any other, and is called weight and resistance. The organ may be excited into action either through the sense of sight or of touch, or by the changing positions of our bodies when in motion.

FIGURE VII.

We have (Fig. VII.) two obelisks. The centre of gravity in each is supposed to be at A. In the first, a plumb line dropped from A to the ground, falls outside. of the base; but in the other it falls within the base. We should not need the plumb, to inform us, that one would fall, and that the other would stand; nor even that the one nearest erect, is not perfectly so. The organ of weight and resistance would soon make this discovery, and we might distinctly recollect their inclined position afterwards. And this power of recollection determines it to be something more than the work of the organ of vision. In the human body the centre of gravity is between the hips. The more erect we stand, the nearer a line dropped from the centre of gravity will fall to the centre between the feet. It is always necessary to support this centre of gravity. The quicker our perceptions of deviations in this centre of gravity are, the greater feats of agility we may be able to perform. Circus-riders have these perceptions remarkably quick, and are thus enabled to throw their weight where it is deficient.

It is this organ of weight and resistance, which takes cognizance of gravitation in general, and of the balance. of our own bodies in particular.

Were I to walk in the water, it would require muscular strength to overcome the resistance produced by the pressure of the water. This pressure, or resistance against my limbs, is communicated to the mind, through the nerves of sensation; and the effort to overcome it is made through the agency of the nerves of voluntary motion. But it is a particular organ, (viz. Weight and Resistance,) which gives a definite idea of the amount of this resistance, and the power of recollecting it after

wards. We thus see the function of the organ in question is to take cognizance of weight or gravitation, and also of resistance, and it thence derives its name.

The power exercised by this organ is necessary not only to man, but to the whole animated creation, else they would be victims to the laws of gravitation. In man it has a wide sphere of activity. "It is of use," says Dr. Spurzheim, "whenever weight or resistance are worked upon by the hands, or by means of tools, in carving, turning, polishing, in lifting, in resisting an opponent in boxing; in calculating the resistance of a current, the tide, or pressure of the wind; to direct a ship in certain directions; in using the bow with dexterity; in keeping the hands, arms, and body steady in shooting; in touching the strings or cords of any musical instrument with accuracy: it is therefore necessary to musical performers, be it on the harp, violin, violoncello, piano-forte, organ, &c.; to eminent engineers, as far as the knowledge of momentum, and of statics is concerned; to able printers, particularly of copper and lithographic plates; to clever workmen in mosaic," &c.

But for the organ in question, animal movements would be only staggering and tumbling. The intoxicated are disturbed in the exercise of this organ, and lose a steady gait,see the ground rise before them, and fancy themselves turned upside down, and grasp objects to save themselves from falling off of the surface. They sometimes feel lifted up, again they appear sinking down, - and again whirling round. It is thought that even sea-sickness may result from a disturbance of the organ of weight and resistance. I should rather suppose that eventuality, locality, and several other perceptive organs would be equally disturbed.

I have noticed the organ large in several gentlemen, among whom are J. N., Esq., of Portland, and N. G., Esq., of Boston, and a Rev. Mr. F. The two former excel in fencing, and the latter informed me, that he noticed very accurately whether an object stood plumb. I noticed the organ small in a portrait painter, and among his pictures I saw a defect in the air or position of the figures. The bust of Sir Isaac Newton, sold in the shops, shows the organ large.

The organ is situated in the superciliary ridge, directly outward of the organ of size. Owing to the large size of the corrugator muscle, at the internal corner of the eye-brow, it is not safe to judge of the size of the organ, without passing your thumb upward against it.

Dr. Spurzheim locates the organ "externally of that of size, above the orbit towards the superciliary ridge." When small, you may press your thumb upwards in the arch at this point, and you will notice the scull less prominent at that point than elsewhere along the arch. When large, it will be quite full there, and will seem to interfere with the position of the eye. I think it does not appear in the superciliary ridge as much as the other organs along the arch.

The last physical quality of objects, of which we obtain a knowledge through the agency of any of the external senses, is that of color; and the only sense that aids us in this is that of sight. But this does not enable us to see without light. Light is the medium by which the sense of sight performs its functions. It is composed of colors, and there can be no light without colors; that is,

without colors all will be black, which is the same thing as being of no color.

Every object, therefore, becomes visible only by the colored rays which it reflects. Bodies are so constituted by the arrangement of their particles, as to absorb some rays, and reflect others. Yet they are not so perfectly uniform in their arrangement, as to reflect only pure rays of one color, and perfectly absorb all others. But those rays, which are reflected in the greatest abundance, determine the color.

When all the different colored rays fall equally on a body, the rays reflected will be of the kind, and in the degree that the body is fitted in its particles to reflect, and from these proportions the body will take its color. But the rays of light may pass through bodies, and fall on others in different proportions from what they would, were it not for the bodies interposed. Hence the color of an object will depend on two considerations; 1st, the arrangement of its minute particles, and, 2d, the medium which the rays of light have passed through in reaching the object. An experiment made in a dark room with a prism will show this. Expose a rose to red rays, refracted through a prism, and it will appear more brilliant; but expose the green leaves to the same red rays, and the leaves will not appear green, but of a dingy brown, with a reddish glow. It would not be green, because no green rays have fallen on it. It would not be bright red, as was the rose, because bodies fitted to absorb green rays, will also absorb most of the red rays.

Now the power of discriminating these different rays, and thus of perceiving all the delicate shades of color, does not depend upon the acuteness of the organ of vision