see, the ears hear, the tongue tastes, the nose smells, the stomach digests food, the heart circulates the blood, the liver secretes bile, &c. Even where the function is compound, as in the tongue, where a feeling, taste, and motion are all combined, we find a separate nerve for each function, and the same occurs in every part of the body. Now, as no nerve performs two functions, we may, reasoning from analogy, conclude, that it is so in the brain; different sentiments, different faculties, and different propensities, require for their manifestation different organs or portions of cerebral matter.

24. Again, the external senses have for their exercise, not only separate and external organs, but also as many separate internal organs. Hearing, seeing, smelling, &c., require different portions of cerebral substance for their exercise; may we not then from analogy, be justified in the conclusion, that there are as many cerebral, or nervous systems, or organs, as there are special internal senses, and particular intellectual and moral faculties? The legitimate inference then is, that each faculty does possess in the brain a nervous organ appropriated to its production, the same as each of the senses has its particular nervous organ.

25. The structure of the brain is not homogeneous, but differs greatly in different parts, both in composition, form, colour, consistence, and arrangement. But what object could there be in all this variety, if the brain acted as a whole, and there was but a single intellectual principle or faculty? A difference of structure shows that there must be a difference of function, and as the brain has been proved to be the organ of the mind, it follows that different portions or organs of the brain must be employed by the intellectual and moral faculties.

26. The faculties do not all appear at once, nor do they fail at once, but they appear in succession, and as a general rule, the reflecting or reasoning faculties are the latest in arriving at perfection. So also the organization of the brain is un

folded in a slow and gradual manner, and the intellectual faculties appear in succession only as the structure is perfected. For example, in infancy, the cerebellum forms one fifteenth of the encephalic mass; in adult age about one sixth. In childhood the middle parts of the forehead preponderate; in later life, the upper lateral regions are more prominent, which facts are also in accordance with the periods of unfolding the knowing and reasoning faculties.

27. Genius is almost always partial; that is, men generally have a taste or faculty, for one particular pursuit, or study, in which alone they have the power of excelling. One has a talent for poetry, another for mechanics, another for drawing, music, or mathematics, and that is often developed at a very early age, and without the advantages of educa tion, or particular instruction, and these persons may, in all other pursuits, be below mediocrity. Indeed, nothing is more common than to see in the same individuals some fac. ulties acute and powerful, while others are feeble and defective; having an extraordinary memory for dates, words, places, &c., while as to other things it is deficient. Such facts are not easily explained on the scheme of a single intellectual faculty, and a single organ devoted to its exercise.

28. It is an observation of common notoriety, that when the mind is fatigued with one kind of occupation or study, it can engage, with vigour, in one of a different kind, requiring the exercise of different faculties; and thus, instead of fatiguing, actually acts as a restorative. Could this happen, unless there were a plurality of faculties and organs of the intellect?

29. The phenomena of partial idiocy and partial insanity are at variance with the doctrine of a single organ of mind. We often see persons in a state of monomania, that is, they are rational enough on all subjects but one; but in relation to that, they are entirely mad. Now, if the brain be suffi ciently sound to manifest all the other faculties in their per fect state, why is it not also able to manifest this?

30. Numerous cases are contained in medical works where a wound of the brain was succeeded by the loss of a single faculty, and sometimes by exciting inflammation, bestowed unwonted energy on a single faculty. Larrey, in his surgical memoirs, mentions several cases of wounds made by bayonets and swords penetrating the brain through the orbit of the eye, which entailed the loss of memory for names, but not of things, &c.

31. Such are a few of the arguments adduced by writers on this subject, to prove that the brain is not only the organ of the mind, but an apparatus, a congeries of organs, each of which is the seat of a particular faculty, the organ of a particular function. The evidence to most minds will appear satisfactory and conclusive on this point, though other facts and more extended investigations are needed to place the science on a permanent foundation.

Questions. What was Aristotle's theory in relation to the size of the brain? How does its size compare with that of the body in man? in the dog, the horse? the elephant? the canary bird? the ape? What is now the received doctrine in relation to the size of the brain? How is it proved that the brain is the organ of the intellectual and moral powers? How do you prove that no other organ than the brain can be the seat of the mind? How does inflammation or injuries of the brain affect the mind? What cases prove this connection? What objections have been raised to the brain being the organ of the mind? What is said of the passions being situated in the viscera of the chest or abdomen? Does the affection of the heart by passion prove that it is the scat of the mind Why not? Does the brain increase in size by exercise? What was the opinion of the ancient Greeks on this subject? What is said of the functions of particular portions of the brain? Is much dependance to be placed on the experiments made on animals? Where is it supposed perception resides? What are the commisseurs of the brain? When the brain is injured on the right side, which side of the body is affected? What accident proves that the opposite side is affected? What is the office of the cerebellum? What effect do we see in animals when they have been wounded? Is man excelled by animals in the perfection of the senses ? In what respect does he excel all ani.

mals? What is Phrenology? What are its chief doctrines? What is said of locating the organs on the exterior of the skull? What facts show that the brain does not act as as a whole in the intellectual operations? Have the external senses separate internal organs? What may we infer from this? Is the structure of the brain homogeneous ? Do the faculties all appear at the same time? Is genius generally partial When the mind is fatigued, what effect is experienced by turning the attention to a different subject? What is monomania ? What do we infer from its existence? What is the general conclusion in relation to the chief doctrines of Phrenology?

CHAPTER XI.

THE SPINAL MARROW AND ITS FUNCTIONS.

1. We have seen, that of all animals, the brain of man has the greatest development, in proportion to the spinal marrow and nerves; if we descend to the lower animals, such as reptiles and fishes, we shall find that the brain presents merely a delicate, anterior termination of the spinal cord, not much larger in diameter than the cord itself.) In these animals, we find the instincts very limited, and the displays of sagacity extremely obscure; while they possess great tenacity of life. Frogs, for example, continue to jump about for many hours after their heart has been torn out; and the heart of the shark will palpitate as long after it has been removed from the body. Turtles have been known to live for months after the whole brain has been scooped out. These facts prove, that such an imperfect development of the cerebral mass, leaves the different systems of organs less intimately connected and more independent of each other.

2. If we descend still lower in the scale of invertebrate animals, we shall find the different parts still more independ ent of each other; for if we divide their bodies, so that each part will possess a nervous ganglion, it will become a separate individual, and exercise all the functions performed by the entire animal; and if we descend to zoophytes, we find that in cutting them into threads, however minute, each piece will retain life and continue to grow.

3. Medulla oblongata.-There is no distinct line of demar cation between the medulla oblongata and the spinal cord. For this reason, they are considered and described as one organ. The medulla oblongata, however, consisting of six columns, gives rise to several nerves of distinct function, and