putting on the cap and muffler, it was not convenient for removal, to ascertain whether or not the cheeks were bitten.

"The favourite cover of this cruise is even more simple, being composed of a kind of veil, made of sealskin or cloth, lined with flannel as before; it is attached to the cap outside, by buttons, and herein its utility consists, as the breath escapes without becoming solid.

"Another great inconvenience experienced whilst walking during intensely cold weather is the congelation of the eyelids, by the action of the cold on the exhalation of moisture from the eyes. It is then necessary to withdraw the warm hands from the recesses of the mittens, and apply them to the eyes, in order to melt the ice, and restore the sight.

"It is absolutely necessary, during the prevalence of very cold weather, that each person should have a companion when walking any distance from the ship; and a standing order to that effect should be issued, in order to avoid the neglect of frost-bites, and the more serious results arising from falls, cracks in the ice, &c., whereby a broken leg, or a sprained ankle, by preventing an immediate return to the ship, might possibly cost a man his life.

"It is therefore prudent always to have a companion; you are then enabled to inspect each other's faces occasionally, and perform the friendly office of removing frost-bite, which, if neglected, leaves an unpleasant scar, and renders the spot peculiarly sensitive for the future."

The privations and fatigues of Arctic life.

and travelling can scarcely be exaggerated. We give Mr. M'Dougall's description of a single march in the month of June:

"Thursday, June 23rd.-At 5 p.m. advanced to the eastward. Our track lay amongst continuous pools of water, knee-deep 'per mare, per glaciem.' About 7.30 we were abreast of the cairn on Cape Bounty. Here the floe was even worse than before, the men at times being obliged to extricate each other from the deep sludge, as well as to dig out the sledge, which often sunk below the bearers. We, however, managed to make a little progress in the right direction; and when, about 9.30 p.m., we encamped, many of the crew as well as myself were fast asleep before tea was announced.

"Friday, 24th.-At 2 a.m. we again started; the weather at the time was overcast and gloomy, with occasional showers, which penetrated to our shirts long before the march was over. About 4 we observed the ship; at 6 pitched tents on a patch of comparatively hard snow. At this time the weather had cleared off, and we were favoured by a warm sun and clear sky. We therefore took advantage of this promise of a fine day by undressing before bagging ourselves, and hanging our clothes outside the tent to dry.

"At 3 p.m. packed up and started for the ship. Our clothing had dried during the time we were encamped, but we were again soon wet up to our middles, and reached the ship in that state at 7 p.m., after four hours' march through one continuous pool of deep water."

HE striking resemblance between that wonder of modern invention the electric telegraph, and the system of nerves in the human frame, cannot fail to have been noticed by every one acquainted with the principles and mechanism of the two systems. Indeed, there have not been wanting theorists who have gone so far as to consider the vital principle and that of electricity identical, or nearly so; and who regard the subtle agency which is conducted along the galvanic wires as the same as that which travels along the delicate nerves of a living animal. More careful investigators treat such a proposition as a mere theory, not established by sufficient evidence. Still there are points of resemblance which render the comparison a curious and interesting one, and

may serve to convey some useful information in a manner likely to be retained easily in the

memory.

The nervous system consists of the brain as its centre. From this, and from a prolongation of the substance of the brain, in the form of a soft rounded cord, enclosed within the bones of the spine, and commonly called the spinal marrow, proceed a number of extremely fine and delicate threads, which are distributed to every part of the body. These are the nerves. The minute filaments of which the nerves are composed never unite together; but though they may lie side by side in the same band, remain distinct and separate, from their commencement in the brain, to their termination, it may be, in the most distant part of the body. This is precisely the case with the wires

of the electric telegraph. They are stretched side by side, but are never allowed to unite, or even touch one another.

The nerves have not all the same office. Some are distributed over the different muscles of the body; and their office is to convey the influence of the will from the brain to the fibres of the muscle, to cause those fibres to contract, or shorten, and thus to produce the voluntary movements of the body. Other nervous filaments have the property of communicating sensation.

The nerves are simply the media to convey impressions either to the brain or from it; and do not possess in themselves any inherent power of producing either motion or sensation in the parts to which they are distributed. Compare this with the electric telegraph. The wires have no electric property in themselves, but are merely lines of communication to convey the electric influence from one point to another.

Immediately connected with the foregoing principle is this-that the integrity of a nerve is essential to its action. If a nerve be divided, the parts below the division to which that nerve was sent are paralysed. Both the sensibility of the parts, and the power of moving them, are lost. Here, again, the parallel holds good. Let an electric wire be broken, or cut asunder, and it becomes utterly useless, so far as the purposes of the telegraph are concerned. It ceases to convey the galvanic charges beyond the part divided.

The effect of dividing or cutting across a nerve, in producing paralysis, proves that the power of the will and the faculty of sensation have their seat in the brain.

With regard to the influence of the will on the various muscles of the body, among many other wonderful results, it may not be uninteresting, though a little out of course, to mention one curious circumstance the difficulty we often experience in moving one muscle, without at the same time involuntarily, or against our will, moving others. For example, moving one eye, and keeping the other steady; turning the two eyes in opposite directions; closing one lid, the other remaining open; or frowning without dilating the nostril. We must also all have noticed the grimaces people are apt to make in violent efforts of the body, particularly where the muscles of respiration are concerned. The difficulty here is to keep the muscles of the countenance at rest while those of the chest and limbs are forcibly ex

erted. Again, try to extend or straighten the two middle fingers separately, and not at the same time unbend the other fingers, and without practice it will be found impossible. Or attempt to turn round one arm in one direction, and the other arm in the opposite, and we may venture to predict that the first experiment will be a ludicrous failure. The explanation of these and similar examples is this. In some of the actions referred to, it is necessary to move part of a muscle only, while the remainder is at rest. To do this the will must act on particular nervous filaments without affecting others close beside them. In the other instances, the muscles simultaneously contracted are supplied with nervous fibres which have their origin in the brain, either near each other, or in exactly similar situations of the two sides; and it is difficult for the will to excite one fibre, or set of fibres, without at the same time stimulating those that are contiguous or corresponding. To render this clearer, take an illustration. An unpractised player on the pianoforte, in attempting to strike one note, will often hit an adjoining key at the same time; or if he is playing with both hands, he finds it difficult at first to prevent his right hand from imitating the example of his left. After a time, however, the manipulation becomes easy, and he is able to execute the most difficult and rapid movements with the greatest ease and accuracy. Reflect on the complicated processes in operation, and few things will seem more wonderful than the performance of a skilful pianist or organist, especially when we recollect that, while the fingers and feet are tripping it so nimbly, the presiding will, with corresponding rapidity and precision, is striking the chord of a still more beautiful and delicate instrument in the brain and nerves.

Thus much in illustration of the connection of the brain and nerves in our voluntary movements. It is not so easy to admit that the brain is also the source of sensation. Such is, however, the fact. Divide the nerves whose terminations are spread over the hand and arm-separate them, that is, from the brainand the sensibility of the parts is entirely lost. Divide the spinal chord itself, and all parts below the division are paralysed and insensible. In the nerves of motion, the influence is sent from the brain to the other end of the nervous fibre. In the nerves of sensation, on the contrary, the impression is conveyed from the far extremity of the thread upwards to the brain.

We do not, however, refer the sensation to the brain, but to the end of the nerve on which the impression was made. Even when the end of a nerve is removed, if the portion still connected with the brain be irritated, the resulting sensation is still referred to the natural and original termination of the nerve -as is strikingly exemplified in the case of persons who have happened to lose a limb. The impression of cold, or a blow on the stump, is referred by such persons to their amputated fingers or toes for years even after the operation.

Besides our sensations and voluntary movements, there is another class of functions over which the nervous system presides, viz., involuntary actions established for the continuance and defence of life-such as respiration, coughing, swallowing, winking, and all sudden instinctive movements to avoid a threatening danger. The manner in which they are performed is this: an impression or irritation is made on the end of a nerve; this impression is immediately propelled to the brain or spinal cord, and is communicated through it to other nerves, either springing from the same place or connecting the one with the other by some peculiar sympathy. For example, a strong light falls on the iris, or coloured curtain surrounding the pupil of the eye, and no effect is produced; but let the rays of light pass through the open pupil, and fall on the retina or nerve of vision, the impression is instantly conveyed along the optic nerve to the brain; thence some peculiar influence, not the will, is transmitted along another nerve to the iris, which immediately contracts, to shut out the too dazzling glare. Again: let any pungent particles irritate the nostril or throat, the irritation is communicated by one set of nerves to the brain; thence another set of nerves immediately conveys an involuntary stimulus to the muscles of respiration, and these are forced to sudden and violent effort to expel the intruding substance by the forcible passage of the breath. In this way coughing and sneezing are effected.

This connexion between the muscles of respiration and those of the face explains in part the simultaneous disturbance of the breathing and the countenance, under the influence of the passions.

Our limited space will not allow of further illustrations; and we must now revert to the comparison with which we started, and in a few words draw the parallel between the entire nervous system and the machinery of a government carried on by means of the electric telegraph.

The brain is the seat of power. The nerves are the telegraphic wires to transmit communications to and from this central station. In the brain are seated the presiding Will and its consort in dominion, the sensitive Vital Principle. On all sides they are surrounded and protected by a perfect system of surveillance in the Senses, and a most obedient and prompt executive in the Muscles. From the eye, the watchman looks abroad, and communicates by the fibres of the optic nerve, as by so many electric wires, the condition and movements of the world around. From the ear, the listening sentinel catches the most distant sounds, and reports them, through a similar medium, to the same centre of government; while the sense of touch, a sort of universal coast-guard, transmits to head-quarters, with equal fidelity, intelligence of a still more varied character.

The several muscles of the body may be regarded as the executive power. Between them and the brain is another series of gal vanic wires-the nerves of motion-by means of which the ready forces receive and implicitly obey the mandates of the sovereign will.

Let an enemy attempt an entrance through the open portal of the nostril or the throat, information is instantly conveyed to the presiding powers, who despatch their peremptory orders along the nerves to the muscles of respiration, and by their vigorous efforts the intruder is speedily expelled. Let wholesome airs and friendly odours seek admission, they are received and welcomed. Let a reasonable supply of food be offered, it is admitted, duty free; and in a thousand other ways this most efficient telegraphic system is employed to command the means of enjoyment or of sustenance, and in case of sudden emergency or threatened danger, to rouse the protecting powers of the body to take up arms and defend the citadel of life.

C. A. H. B.

THE ANT.

LXXII.

In further noticing the apertures of some ant-hills, I fully ascertained the nature of the labour of their inhabitants, of which I could not before even guess the purport; for the surface of the nest presented such a constant scene of agitation, and so many insects were occupied in carrying materials in every direction, that the movement offered no other image than that of confusion.

I saw then, clearly, that they were engaged in stopping up passages. For this purpose they at first brought forward little pieces of wood, which they deposited near the entrance of those avenues they wished to close; they placed them in the stubble, and then went to seek other twigs and fragments of wood, which they disposed of above the first, but in a different direction, and appeared to choose pieces of less size as the work advanced. They at length brought in a number of dried leaves, and other materials of an enlarged form, with which they covered the roof, an exact miniature of the art of our builders when they form the covering of any building. Nature, indeed, seems everywhere to have anticipated the inventions which we boast, and this is, doubtless, one of the most simple.

Our little insects, now safely in their nest, retire gradually to the interior, before the last passages are closed. One or two only remain without, or concealed behind the doors on guard, while the others repose or engage in different occupations in the most perfect security.

I was impatient to know what took place in the morning upon these ant-hills, and therefore visited them at an early hour. I found them in the same state in which I had left them. The ants were wandering about on the nest; some others issued from time to time from under the margin of the little roofs found

at the entrance of the galleries; others afterwards came forth, who began removing the wooden bars that blockaded the entrance, in which they readily succeeded. This labour occupied them several hours. The passages were at length free, and the materials with which they had been closed scattered here and there over the ant-hill.

Every day, morning and evening, during the fine weather, I was a witness to similar proceedings. On days of rain, the doors of all the ant-hills remained closed. When the sky was cloudy in the morning, or rain was indicated, the ants, who seemed to be aware of it, opened but in part their several avenues, and im mediately closed them when the rain com

menced.

Could the most enlightened reason, which ascribes such procedure to mere animal instinct, have done more ?

THE ASS.

LXXIII.

"As stupid as an ass," has grown into a proverb; yet the ass is, like all other animals, capable of appreciating kindness. A poor ass in our neighbourhood comes on a Sunday to certain houses to beg. He looks in at the window first, and when he finds that he is seen, he goes to the door and waits there patiently until he is sent away or rewarded with a potato or two, or a crust of bread. There are about two hundred houses in the street, but he never calls where he is not in the habit of getting something. Should a policeman come up while he is waiting, he immediately leaves the flags and stands on the road, but as soon as the man is out of sight, he comes back to the door; the police have been in the habit of beating him when they found him on the footpath. Having visited all his friends, he then picks up what he can on the piece of waste ground behind the houses.