sidered.

The fibrin of the former is blended with albumen, gelatin, etc.; in the latter we find starch, gluten, mucilage, etc., all combined together; saccharine blended with mucilaginous ingredients; oleaginous matter combined with farinaceous. The lower animals can no more endure food in which nutriment is reduced into the smallest compass than we can ourselves, as is proved by the condition of post-horses: to support the extraordinary exertions required of them, it is found necessary to feed them on corn alone.

4. The late developement of the teeth, is a sufficient indication that solid food is not designed for infancy; and their early removal, of the kind of diet that is best adapted for age. This is a point worth noticing, as the most serious mistakes are frequently committed; tending in the one case greatly to derange the system, and to lay the foundation of serious disease; and in the other, to shorten life. For the sustenance of the first seven or eight months a fluid aliment is prepared, which, for nutritive quality and adaptation to the necessity of the case, places it at an immeasurable distance from the utmost attainments of chemical science. That either fashion or caprice should ever be permitted to interfere with such an arrangement is deeply to be lamented; but there are instances in which it is inexpedient, or impossible, to comply with it. In such cases, the absurdity of loading the stomach with an aliment not analogous, is at once apparent. A direct law of nature is interfered with; and can it be a matter of wonder that disorder and disease should ensue? Asses' milk is, upon the whole, the best substitute; if this cannot be had, twothird parts of cow's milk, with one-third part of barley gruel or water slightly sweetened-but in general nothing else. The gradual developement of the teeth, from the appearance of the first incisor to the entire completion of the process, may likewise be looked upon as pointing out how gradual and cautious we should be in allowing food of a more and more solid texture, till fibrinous matter can at length be masticated. We find, accordingly, if animal food be given too early, or in too large a quantity, the system becomes excited and irritated, the ordinary

diseases of childhood are attended with much constitutional disturbance and dan ger, nutrition is actually impeded, the

child continues thin even while it is eating heartily, and a foundation is laid for the production of scrofula and other diseases. So again, in the decline of life, a substantial diet becomes more and more oppressive, and is in fact less and less needed. There is likewise a danger of the delicate vessels of the brain giving way, if a too stimulant chyle is prepared. It frequently happens in cases of healthy old age, when the appetite is vigorous, that life is terminated by an apoplectic seizure.

5. If, as we have seen, the gastric juice is the principal agent in digestion, it is of much importance that neither its secretion nor action should be interfered with. To effect its secretion, there is necessarily a very great temporary determination of blood to the inner coat of the stomach, distending the vessels; so much so, that, as was seen in the case of St. Martin, its colour changes from a pale pink to a deep red hue.* Of this we are usually made sensible by a degree of chilliness in the surface and extremities during the process. An equally increased supply of nervous energy takes place at the same time. If, then, this increased action be interfered with-as, for instance, by derivation to other parts, by either mental or bodily exertion, the gastric liquid cannot be secreted, and indigestion is the inevitable result. Hence the necessity of absolute rest after a full meal. If any one of the lower animals be driven immediately after eating, digestion never takes place, as has been proved when they have been killed under such circumstances. It is stated that in the United States of America, the practice of hastily swallowing dinner, and instantly returning to business, is almost universal, and among no nation does dyspepsia prevail to such an immense extent. "Of the number of our dyspeptics, says Dr. Caldwell, "no estimate can be formed— it is immense. Whether we inquire in cities, towns, villages, or country places, among the rich, poor, or those in moderate circumstances, we find dyspepsia more or less prevalent throughout the land." Too great dilution by the ingestion

* On one occasion, when this man dined on broiled

mutton and bread, without any liquids, the gastric secretion was so copious, that half an hour afterwards, it is said, the stomach was as full of fluids as

when he drank a pint immediately after eating. As the whole of this must have been derived from the blood circulating through the vessels of the stomach, we may judge how large a supply they

must have received to enable them to furnish it.

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of liquids, will again interfere with the action of the gastric juice. Hence the rule usually given to the dyspeptic, to abstain from drinking for an hour or two after dinner, is founded upon a physiological fact. From what has been said of the complicated action of the muscular fibres which embrace the stomach, whilst this secretion is effused from its entire internal surface, it may be inferred that some degree of bulk and consistency in the alimentary mass is a requisite to easy digestion. Some kinds of food, it is true, seem almost to require a liquid admixture; and it is well, in health, to attend to the sensations of the stomach in each individual case; but, for the most part, it is during the intervals of our more solid meals that liquids may most advantageously be taken.

6. Once more, we have seen that the gastric juice is not always present in the stomach, but is secreted in consequence of the application of a stimulus. We may hence learn a lesson of much practical value, especially to those who have feeble powers of digestion, namely, to allow the stomach sufficient repose, by taking food | at regular intervals, as nearly as possible always at the same hours, and observing total abstinence during these intervals. There cannot be a more mistaken direction than to take little, but to take it fre- | quently, or a more ridiculous adage than that the "stomach of an invalid is, like a school-boy, always at mischief unless it be employed." To keep the stomach constantly in action, is as absurd as it would be perpetually to maintain that of the brain or the voluntary muscles. Nor is this all. The ulterior processes which convert chyme into chyle, and chyle into blood, and which also require an expenditure of nervous energy, cannot be efficiently carried on at the same time with the digestion of the stomach. We find that appetite does not return, in a state of health, till these changes are completed, although all the chyme may long before have passed out of the stomach. If, therefore, this organ be again set to work before these latter processes are completed, the secretion of the gastric fluid and the contraction of the muscular fibres of the stomach will be alike imperfect. If a person be interrupted in his meal for a quarter of an hour, he finds, on resuming it, that his appetite is gone, although he may not have eaten half the quantity required, simply because these ulterior

changes have commenced. So that it is laid down by Dr. Paris, as a proposition of much importance in relation to the theory of diet, "that the several processes by which food is converted into blood cannot be simultaneously performed without such an expenditure of vital energy as weak persons are unable to sustain without mischief." We may, therefore, consider it as a direct physiological deduction, that, to insure health, meals should be taken as nearly as possible at the same time every day, and regular intervals allotted between them. They should not be taken too frequently, neither should they be too far apart. There can be no question that the custom of our ancestors of taking three meals a day-an early breakfast, dinner at noon, and an early evening meal, in connexion with their early habit of rising-was the most natural, and by far the most conducive to health. If, however, modern hours must be observed, it will be best to take as early a breakfast as possible, for much exertion either of body or mind before the first meal is manifestly injurious; a substantial lunch; and nothing after dinner. No habit can well be more injurious than that commonly adopted by men of business, of taking perhaps an early breakfast, abstaining from all food during the greater part of the day, and then coming home to a late dinner, at which they eat to repletion, or at least indulge in that stimulant kind of food or drink, which the exhausted system seems to require, which produces a temporary feeling of comfort, but is sure, sooner or later, except in the very robust, to bring on permanent indigestion. A somewhat different, but equally mischievous practice, prevails among the lower orders-that of improvidently and sensually regaling themselves with a more than plentiful meal on one or two days at the commencement of the week, and then remaining in a state of semi-starvation during the remainder. Such habits are among the most common causes of dyspeptic complaints in both classes. D. W.

OLD HUMPHREY ON LAUGHTER. It is an old observation, that mankind have three marks set upon them, whereby one person is known from another. We know our friends when we see them, by their appearances; when we do not

see them, by their voices; and when they are at a distance from us, by their handwriting. I am half tempted to add a fourth mark; for most of our friends might, I think, be identified by their laughter.

Laughter is mirth in convulsions, and while some express the lightness of their hearts by their Ha, ha, ha's! or their He, he, he's! others are equally emphatic in their Hi, hi, hi's! and their Ho, ho, ho's! Some men, by their continual giggling, seem to take the laughing philosopher for their model, who held that there was nothing in the world worth crying for; while others, adopting the opposite opinion, appear to consider a laugh as next neighbour to a sin. For my own part, I cannot but regard the faculty of laughter as one of the goodly gifts of our almighty and indulgent Creator, enabling us, at the same moment, to make our hilarity audible, to relieve our joy-oppressed hearts, and to communicate the same pleasurable emotion to others. An ill-natured laugh is a reproach to any one; but a kind-hearted, good-natured laugh is so good a thing in my estimation, that I regret it should ever be indulged unreasonably or unseasonably.

There is as great a variety in laughter as in other things. Some laugh till the tears roll down their cheeks. Some hold their sides, as if under no small apprehension of their ribs giving way; while others indulge, amid their paroxysms, in the expression, "Oh, my back! my back!" as though pleasure and pain, ecstacy and agony, were mingled together in such an unbearable degree of intensity, that enjoyment and endurance were equally afflictive. I remember an instance of a fit of laughter continuing for several hours, with very slight intermission. Wearied and exhausted beyond measure, the unhappy laugher could not restrain her emotion; if for an instant her excitement subsided, a recurrence to the cause of her extravagant mirth instantly reproduced it.

audible giggle, which consists of spasmodic motion, and not of sound; yet never has a laugh regaled my ears like the spirit-stirring Ha, ha, ha, ha, ha! of my German neighbour.

This laugh was made up of five sonorous Ha's! uttered rapidly in the same tone. It had no preparatory announcement; no unnecessary appendages; no lingering accessories: but came forward by itself, and stood alone, based on its own merits. It was a full-bodied, proud, and princely pouring out of a mirthful heart. Most laughers give notice of the coming clap, which dies away by degrees, and after it has passed, they require some time to compose themselves; but not so with my neighbour. He withdrew from his mouth his cigar or his ornamented hookah, just long enough to peal out his Ha, ha, ha, ha, ha! in parenthesis, and then resumed his whiffing occupation, as though insensible that any interruption had taken place. If a friend entered the house, he was received with the royal salute, Ha, ha, ha, ha, ha! When he left it, the same noble discharge did honour to his departure. At all times, and on all occasions, morning, noon, and night, spring, summer, autumn, and winter, the Ha, ha, ha, ha, ha! of my neighbour was ever ready.

A change came over his worldly affairs, and my German neighbour left his habitation. Days, weeks, months, nay, years flew round, and I knew not whether he were on this or on the other side the seas. This is, indeed, a world of change, and when for a protracted season we lose sight of our friends or neighbours, we with some reason speculate on their departure, and number them among the dead. They "that dwell in houses of clay, whose foundation is in the dust, which are crushed before the moth," are not expected to have here an abiding dwelling-place. "Ah!" thought I, "my poor neighbour is, most likely, in his narrow house."

We are told in the book of Proverbs that "even in laughter the heart is sorrowful;" and now and then instances occur wherein the truth of the text is painfully set forth. As there is no peace to the wicked, so it follows that their outward mirth is mingled with inward care. How hollow must be the mirth of one who is in continual fear; and how heartless the laughter of him who, on account of his crimes, has ever in prospect before him the loss of life or liberty! In looking back on the past, many a laughing friend rises to my remembrance. The time, the occasion, the family group, or friendly gathering, with the various attitudes of the mirthful guests, are all before me, and the laughter-loving playmates of my youth are strangely mingling with the less numerous companions of my age. "There is a time to laugh;" and happy is he who enjoys it, without ever mistaking or abusing the occasion.

How it may be with you I know not, but of late, my laughs have been "few and far between." Not that my heart is disposed to be less joyous than it used to be, when fit opportunities call it forth, but that mournful occasions have more frequently abounded.

Mirth may not trespass on the place Where silent sadness reigns; Nor rudely laugh in sorrow's face, Nor smile where grief complains! Laughter, to be lawful, should observe two points: it should neither give pain to another, nor bring after-sorrow on ourselves. He who cannot call to mind the laughter of yesterday without feeling remorse or self-reproach on account of it to-day, has been merrier than he ought to have been.

More than once have I stated my opinion, that the very peculiarities of our friends are dear to us, for they form a part of themselves. A change in the cut of their clothes, or an alteration in their gait would be a loss to us. Unless a peculiarity be something worse than whimsical, I cannot spare it in a friend. He must look, move, speak, cough, and laugh,

Give me the spare, angular form of one friend, and the broad back of another, with the spindle leg, the round face, the bare head, the furrowed brow, and the limping foot, as the case may be, of the rest of them, for I could hardly spare the crutch of the cripple I esteem. Take away at your peril so much as a freckle off their faces, or a knee buckle from their attire. I claim them as they are in their manner, mien, voice, and general behaviour; in their gaieties and gravities, their laughter and their tears.

The cares of the world are so many, and find their way so readily into almost every hour of almost every day of the year, that we require a degree of cheerfulness to counteract them. As a new broom cleans away the dust and cobwebs of an unswept apartment, so does a burst of buoyancy sweep away the dust and cobwebs of a beclouded mind. Cheerfulness is to us, when inclined to be careworn, as a cool clear draught to the traveller; it recruits our strength and spirits, and we start afresh in the path of duty, more able to bear the toil of our pilgrimage.

If you gather nothing more from my remarks, you will at least gather this, that I regard the faculty of laughter as one of the goodly gifts of God, for which we are all bound to be thankful. how I love to hear the cheerful laugh of a kind-hearted man among a group of merry children!

STRUCTURE AND HABITS OF BIRDS.

Oh,

THE varied hues which adorn the plumage of birds, however pleasing to man's senses, were not given merely for his gratification. That, we have no inclination to deny, was one object; but there were other, and, to the birds themselves, more important purposes to be served. Some species required especial means of protection from the piercing ken of their stronger enemies, while others had to be provided with especial means of procuring their food. Both these objects have been effected by peculiarities of colour.

The best mode of protecting an animal from the attacks of the carnivorous or raptorial tribes, is obviously to render it as little conspicuous as possible. Imagine a lark, whose habit is to be much

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on the ground, coloured scarlet, and it would be an object to which the attention of every passing hawk would be immediately and fatally directed. Resembling, however, the clod of earth on which it sits, the lark rests in comparative security. For the same reason, most species of animals resemble in colour their indigenous locality. "The wood snipe," says Mr. Blyth, in his excellent edition of White's Selborne," ""is of the exact tint of the dead leaves over which it runs; the snipe, that of the marsh; and the rail, that of coarse and decaying vegetation in the ditch." The colour of the ptarmigan in summer closely resembles the hue of the locality in which it is placed; but in winter, when the ground is covered with snow, the same colour, so far from being a protection, would render the bird a very conspicuous object. Nature has provided for the emergency, and in autumn the plumage of the ptarmigan gradually changes, so that, when winter clothes the fields in white, the bird may vie, in unsullied purity, with the snow on which it treads. It might be difficult, perhaps, for one, who had been admiring in a museum the brilliant plumage of a number of the tropical species, to believe that their variegated feathers could furnish means of concealment; yet such is undoubtedly the case. In our own inclement country, the vegetation is comparatively plain and unvariegated in its hues, and the same character marks the birds whose haunts are amongst our copses and trees. But the face of nature wears a very different aspect in warmer climes; there the earth brings forth in abundance its richest treasures, the trees are laden with golden fruit; flowers, whose loveliness surpasses our highest conceptions, strew every path, and the entire vegetable kingdom is decked in its brightest ornaments. If we can imagine a scene such as this, and the whole glistening beneath the rays of a vertical sun, we shall then understand how the ornaments which render tropical birds so remarkable in our museums, act in the midst of surrounding splendour and brilliancy as means of concealment.

That certain peculiarities of colour are of great importance in enabling some species to obtain their food, will, we think, be evident from a few examples. Professor Rymer Jones relates that a piscatorial friend of his, when dressed for his favourite amusement, always appeared in

a sky-blue coat and white trowsers, which he termed "sky-fashion," and was of opinion that this dress was the best adapted to conceal him from the fishes. The professor states, that "shortly after this conversation, walking through a collection of aquatic birds, I was rather startled to find that they almost all wore blue coats and white waistcoats; almost all of them were dressed 'sky-fashion.' If you look at the heron and sea gull, you will find blue coats and white waistcoats upon them. What could induce the fish to come within reach of the heron? Were it visible, they would go in all directions; but, on account of its colour, they are not able to perceive its presence.' The fishes look up to the heron, which, having the sky for its background, is best concealed from their observation by its plumage being "skyfashion." The extract which we have given from professor Jones's observations, is taken from a report of an interesting course of lectures, which that gentleman has recently delivered in various parts of the country.

The bee-eaters (meropida) furnish us with some very curious adaptations of colour to their mode of capturing prey. A Brazilian species, which we had the pleasure of inspecting in the noble museum of lord Derby, has the plumage entirely dark, with the exception of some white feathers on its breast, bearing a sufficient resemblance to the white petals of a flower, to decoy the bees in their search for honeyed blossoms. The bird, thus provided with admirable powers of attraction, rests quietly on some twig, until its winged prey, darting towards their supposed booty, are seized with sudden velocity. Another instance of a similar character is afforded by the bluebellied bee-eater of Africa, whose bright crimson throat, surrounded by the herbage of the tree on which it is perched, presents the appearance of a most lovely flower. Some species are provided with beautiful crests, evidently for the same object. Thus in the royal tody, of Brazil, (megalophus regius,) the feathers are so disposed, that they radiate from the hinder part of the head, and form a semicircle, resembling the half of a full blown syngenesius flower; the size of the crest being enormous in proportion to that of the bird, and having a very splendid appearance. The ground colour of the feathers is of the richest chestnut red,