mal to be found in proportion to the size of its brain in comparison with its collected nerves, and thus expressed, it will be found tolerably accurate: but even this rule is insufficient; we must have recourse to a consideration of the distinct parts of the brain, and then we shall find that the animal is advanced in intellect, in proportion to the size of the hemispheres of the cerebrum. This is confirmed by comparing the brain of man with that of other animals. On the contrary, those parts of the brain which seem to be devoted to the lower functions of organic andsensitive life, viz. those which are at the basis of the cerebrum and the cerebellum, are often found in a state of greater perfection in various animals than in man.

Against the assertion that the brain is the organ of the soul, several objections are advanced.

1. The case of hydrochephali, those whose heads have been filled with water, and who have yet retained their faculties. This objection supposes that the brain is macerated and dissolved in the water; and falls away if the supposition be refuted. The brain being,`as has been shewn, nothing but a folded skin or membrane, is susceptible of being unfolded without being destroyed. This takes place

in Hydrochephali interni, in whom water, being collected in the ventricles of the brain, by its expansive power unfolds the membrane of the brain, and presses against the internal surface of the skull. Dr. Gall attended several years a woman who had all the symptoms of water in her head, yet she retained her faculties; on her death he found four ounces of water in her skull, and it was on her that he first discovered, to his entire satisfaction, the expanded membrane. of the brain. Gall considers the hydrops externus as comparatively rare, and advises physicians, in sawing the skull, to use the greatest precaution lest they cut the membrane at the same time; and it is to the want of this precaution, that he ascribes the mistake concerning this disease. He states as a symptom of the hydrops internus, the protrusion of the eyes out of the sockets, arising from the same expansion occasioned by the water. Life, therefore, may subsist for a certain time, though the brain is thus forced out of its place; for no substance is lost. Having, in a state of disease, discovered the membrane of the brain, G. then proceeded to seek it in the fresh brain of a subject free from any disease in the head; and he declares that on repeated trials he has found it. In the only

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only experiment which the writer of this account witnessed, a pipe was put into different parts of the circumvolutions or gyri of the brain, and by blowing, a sort of bladder was occasionally produced. The subject on which the experiment was tried had been taken from the body several days before, and was allowed to be unfit to give the experiment a decisive trial.

2.) A second objection is founded on the fact, that very considerable parts of the brain may be destroyed, either by an external wound, or from internal disease, and the powers of the mind yet remain unhurt.

This objection is satisfactorily removed by the duplicity of the organs in the brain; the sound organ on the one side being sufficient to fulfil its function, notwithstanding the detruction of that on the other side. It is found that the organs of sense and animal life are double, as eyes, ears, the muscles, &c.; while those which maintain what more resemble a vegetative or organic life (as stomach, liver, &c.) are single. It is true, the lungs, kidneys, &c. may seem to be an exception, yet they are not, from their inequality, to be considered as completely double, and these organs form a transition from the lower and organic, to the higher and animal life.

Among

Among the cases which G. stated to shew the possibility of life continuing after a partial destruction of the brain, was that of a clergyman who was under his care, and who complained that one half of his head was good for nothing, he could not think on that side, &c. He preached three days before his death, and on examining his brain, the side complained of was found actually mouldy; the other side was in an inflamed state. Analogous to this are the well known cases of Hemiplegy.

Against this notion of a duplicity of organs in the brain, the unity of perception and consciousness has been brought forwards. But the analogy of the external senses is a sufficient reply to this objection; the organ is not in the one case, any more than in the other, considered as the principle of sensation or perception, it is but the material condition of their exercise.

G. digressed here concerning the use of the double organs; it is enough briefly to observe that he is of opinion only one eye, one ear, &c. is employed at a time; and that these succeed each other in their operation. Probably, he said, the right side of the brain is the more active, as the right side of the body throughout, head, breast, eye, hand, arm,

foot,

foot, &c. are generally the stronger. Eight tenths of those, he says, who have a hump, have it on the right shoulder, as the muscles on this side are the most active and strong. He carried these remarks (without laying any stress on them) so far as to observe that, when a boy, he used to ask himself how it came that men seldom walk quite straight; and that he imputed it to the successive use of each eye, by means of which the point of vision is changed.

3. The argument derived from the cases of petrifactions in the brain needs no particular answer.

CHAP.