tening has already been accomplished, and the starving scarcely is an applicable epithet, as the fattening is then merely turned to the use for which it was intended by nature. Mr Macnish, however, says, that it is just as rational to infer that the assimilative operation is at work in one leg, and at a stand in the other. But how will this illustration suit his own theory? The "nervous energy" has at least as general an influence as the process of assimilation; and he will find it as difficult to set it to work in one leg, and make it stand still in the other, as the task he is pleased to impose upon me. As far, there fore, as Mr Macnish's legs can contribute to the support of his argument, either of us may be right, or both of us wrong

I have nothing new to say as to the idiosyncrasies of General Elliot and Dr Reid; one of whom, it seems, acted on the principle of the chameleon, and the other of the boa constrictor. There is no very wide difference of opinion between Mr Macnish and me with respect to these gentlemen, their habits, and the result. Nor have I any farther objections now to adduce against" the sensorial power." Mr Macnish avers that he can shew" that one organ may have an excess and another a deficiency, with as much ease as that one body may be positively and another negatively electrified." I wish he could shew that these two powers were one and the same. This would be an undertaking worthy of his abilities. He will then have exchanged a mere word, a mere general term, comprising a variety of meanings, for a real, definite, acknowledged, substantial existence. I shall willingly admit its operation in all the phenomena which can be legitimately assigned to it; and if he can prove that it performs the office which I have ascribed to the process of assimilation, by such a concentration of facts as I have brought forward, I promise him faithfully to relinquish my hypothesis in favour of his new and improved one, even if there be in the balance but the weight of a feather against me.

I must, however, dissent from almost every word Mr Macnish has said, in contrasting "active-minded, deep-thinking, care-worn men, that sleep ill," with " men of dull, easy, contented minds, that eat like horses, and think of nothing but the next meal, and lay their stupid heavy heads upon a pillow, and instantly fall into a profound slumber." Neither of these classes can sleep well, unless they take a due portion of bodily exercise. If they do, Mr Macnish may be assured that they sleep equally well; unless, indeed, the latter be "a sluggish obtuse glutton, who devours more than is good for him," and in that case his nights are still more restless than those of his care-worn neighbour. His slumber, like Dr Reid's, is "a tor

Phrenological Journal, No. xlii. 178.

+ Id. ib.

por similar to that which falls over the snaky monster of the wilderness when gorged with food,"* and approaches the nature of apoplexy rather than of sleep: whatever of it is sleep, I would ascribe to the pressure of the assimilative particles; whatever of it is apoplexy, I would attribute to the pressure of the overswollen blood vessels. Mr Maenish, on the contrary, conceives that "the sensorial power which kept the brain awake is transferred by an easy process to the stomach, which, reinforced in this manner, acts vigorously, and enables the individual to fatten upon its labours. The two organs (he observes) are here, reacting upon each other; in the one case, the brain starving the stomach, in the other, the stomach starving the brain, and giving a practical vindication of the Shakspearian aphorism, that fat paunches make lean pates.

Shakspeare here was obviously metaphorical,--by “lean" he meant meagre of knowledge, not of flesh, for fat paunches are generally accompanied by fat pates, and both of them are unequivocal indications of the lymphatic temperament. The most usual accompaniment of this temperament is a large organ of Alimentiveness; and if this propensity overbalances the influence of the various intellectual powers, the organs of the latter will lie fallow and unproductive, acquiring neither size nor strength, while their more sensual companions will "fatten" on the nervous deposit, which, there is reason to presume, is abundant in proportion to the exercise of the organ, and thus contributes to the size of that fat contented ignorant brain, which entitles its lymphatic owner to the well-known sobriquet of " big head and little wit.",

Mr Macnish reserves his strong argument for the last, which he conceived would strike with fatal effect on my theory. He gives a consecutive detail of the whole process of digestion, observing that the drowsiness which takes place shortly after eating seldom lasts above an hour or two, and that " Mr C. would say that this arises from the brain being oppressed by the deposit within it of new particles, which must necessarily be derived from the food lately taken." But I have neither said so, nor would say so. What I have said on this point in my original essay is directly the reverse, and is as follows," It is true that sleep after meals is most irresistible while the food is still in the stomach, after digestion has commenced, and long before assimilation has taken its turn. But we are ignorant how far the arrival of new matter in the bloodvessels may instantly contribute to the deposition of the old, as an additional number of balls put into a tube at one extremity, will force out some of their predecessors at the other,"

• Phrenological Journal, No. xlii. 178.

+ Id. 180.

"I enter into no argument on the subject; I repose on the rational presumption that sleep is something more than rest after fatigue,that it is probably the consequence of an important vital process in the delicate and fragile instruments of the mind, and that no process can be more requisite to these instruments, or more likely to produce the effect, than the process of assimilation.”*

d

Such, therefore, are my observations on this subject in my original essay; but Mr Machish, in his theory of the sensorial power, appears to be a devoted disciple of the celebrated Darwin. In reference, therefore, to his master's authority. I might now remind him, that the process of assimilation frequently takes place by means of particles which have escaped the three hours' sojourn in the duodenum, and the common circuit through the lacteals, the thoracic duct, the left subclavian vein, the lungs, the heart, and the arteries. But I rest not on the cited experiments of Monro, who gave madder to some animals, having previously put a ligature on the thoracic duct, and found their bones and the serum of their blood coloured red;"† nor on those of Kratzenstein, Charles Darwin, Hughes, and others, in some of which nitre and asparagus, shortly after they were taken into the human stomach, gave evident proofs of their presence in certain secretions, while at the same time they could not be detected in the blood. Nor do I rest on the other instances in which similar evidence is derived from various other facts equally satisfactory, nor on any circumstance inconsistent with my original views. The nervous substance, before it is deposited on the brain, must undergo all the sublimation and refinement it can receive, in the most powerful and efficient laboratories of the frame, to fit it for its high and pre-eminent destination. This cannot, therefore, be the raw and unprepared material, hurried from the stomach to the head by any short and narrow by-way. It must be the highlywrought and elaborately animalized material, which has passed through every necessary process, and has advanced through the circulation to the very spot prepared to receive it. The nervous communication between the stomach and the brain may announce, with telegraphic despatch, that a new supply has arrived in the frame, and may stimulate, with the speed of electricity, the capillary terminations of the arteries, to deposit in abundance the congenial particles with which they have been furnished from a preceding supply of nutriment; and if the deposit be abundant, the sleep may be sudden and profound.

Transactions of the King and Queen's College of Physicians, ii.; or Tilloch's Philosophical Magazine, liv. 258.

+ Zoonomia, § 29-2, vol. i. p. 354.

+ Id. 359, 367, 371, 372. See the whole section.

Of the truth and justness of this simple view, the instantaneous slumber which sometimes follows a dose of morphia is at once an illustration, a proof, and almost a demonstration. 1

Mr Macnish, in his concluding paragraph, observes that there are other points in my essay which he thinks could also be made the subject of criticism." *I do not controvert the supposition; but perhaps, on a reference to my original essay, he would find many, if not all, of these points already disposed of I have not yet been assailed by an objection that I found too truculent or sturdy to encounter. So far my hypothesis wears the semblance of truth. It is not of sufficient moment to take any farther trouble with it. That it should be admitted by future physiologists as a conjecture, not to be rejected as unsupported and irrational, but one which may be considered as founded in nature and reason, explaining every circumstance and removing every difficulty connected with the subject, is the highest point of ambition to which I can aspire. To bring it to the test of experiment, and demonstrate it to be an incontrovertible fact, is not within the scope of any investigation which I know how to institute. I do not see, even if it were established, that it could lead to any higher result than the gratification of the careless curiosity of a few, upon a phenomenon about which a few only are curious; or if to a higher, it may perhaps convey the important instruction that we ought not to be satisfied with a shadow when we can grasp at the substance, nor with words when we may possibly attain to things. But even so I have done as much as the matter will justify. Other objections may be started; but, if my theory be true, they will be as easily dissipated as their predecessors. But I should be ashamed again to take the field, even in the cause of truth, where the truth at issue is of such puny import

ance.

As this is the last time I shall approach the public on the subject, I may be pardoned if I still linger to obtrude a short and comprehensive view of my whole hypothesis, as I am at present disposed to maintain it.

The absorbents and secerning vessels never remit their offices -those carrying off the old particles from every part of the frame, and these depositing new ones in their place; the absorbents being most busy with the muscular fibres which are most exercised by labour, or the nervous fibres most exercised by the operations of sensation, volition, and thought. Yet these fibres, so exercised, are always the strongest and most powerful of their kind in the frame: the secerning vessels must, therefore, be equally busy in restoring new particles in the Phrenological Journal, No. xlii. p. 135.

place of the old, or, during certain intervals, rather more busy, because more are restored than are taken away, as is proved by the increase of size, proportioned to the occasional or habitual exercise of the parts. Yet it is evident that it is not during the moments of exercise that the great mass of new matter is deposited, otherwise the muscular and nervous fibres in question would go on thickening and strengthening the longer the exercise of labour and thought was continued; and this, we know, is contrary to fact;fatigue ensues, and rest is necessary, and during that rest it is probable that the secerning vessels, though always depositing new particles, deposit much more, or the absorbents remove much less, than at other times. By rest, I mean a mere cessation from labour; and such rest is not sleep. The large mass of new particles deposited on the muscles cannot affect their tough and insensible fibres by any striking phenomenon; but when such a mass is deposited on the delicate, tender, and sensible structure of the brain and nerves, how different must be the effect. If small in quantity, and while these organs are in a state of active energy, it may be hurried unobserved into the existing activity of the living matter; but if large in quantity, and while these organs are resting from their labours, can it be that the extraneous and unassimilated mass does not press its increasing weight on their fragile machinery, and produce an EFFECT something like the pressure of the overswollen blood vessels, but natural, necessary, and healthful-the PARALYSIS, not of apoplexy, but of SLEEP? While the incumbent mass thus paralyses the encephalon, the body is powerless; there is no voluntary motion, no perception, no thought, no dream. But when the assimilation is complete in any one of the organs of the mind, then thoughts arise; but there is no perception until the assimilation is also complete in one or more of the organs of the senses; until then the simple current of our thoughts constitutes an ordinary dream.

If the nerves of motion continue invested in a newly deposited mass of nervous matter, while the mind anxiously desires and essays in vain to move the limbs-this is nightmare. If these nerves are extricated from their trammels, and those desires and efforts of the mind still continue-if they command and the nerves obey-this is somnambulism. But these dreams, whether ordinary and natural, or attended with the horrors of nightmare or the perils of somnambulism, vanish as our senses admit the impressions of the external world. We are then awake; but while thus awake, if the nerves of motion are still asleep-if their trammels still continue upon them-this is the daymare, so feelingly described by Mr Macnish. If through any idiosyncrasy the process of assimilation were never sufficiently considerable to paralyze, by the mass of new particles,