worms, moths, etc., furnish examples. So, too, foxes, squirrels, groundhogs, snakes, eels, etc., are low-minded and inferior, and creep or run upon the ground, and accordingly burrow in the earth. Yet their habitations, like their characters, far surpass those of animals below them, while the beaver, higher in the scale of mentality, builds him a better habitation. So beasts of prey seek some dark hole or cavern in which to hide away from the sunlight, from which to steal forth in search of hapless objects of prey, and in which to deposit their plunder. Walking and swimming fowls build on the ground, while soaring ones build in trees. Innocent singing birds build in low trees, near the residence of man, while the hawk chooses the tall, thick forest, and the soaring eagle the towering cliff. Throughout all nature, the ABODES of all animals correspond perfectly with their characters, so that the latter can be safely predicated from the former.

This is equally true of man. The half-human, half-brute orangoutang, constructs a rude hut of sticks and bushes, while the more advanced Bosjowan builds a habitation a little better, but of the lowest class of human architecture, as he is at the bottom of the ladder. The Hottentot, Carib, Indian, Malay, and Caucasian, build houses better, and still better, the higher the order of their mentality.

This same law equally governs individuals. Those who are content to live in old rookeries, when they possess the means of building palaces, and perhaps erect splendid houses to rent, have sordid souls, and only need paws to make them woodchucks. So, too, those who build better barns for their cattle than houses for their children, are both unwise and inhuman. Those who are destitute of refinement, will build some outlandish tenement, as unsightly in looks as inconvenient in arrangement, while those who possess refinement and correct taste will build a neat, tidy, well-proportioned, good-looking edifice, and one as useful as it is beautiful. Lazy-minded, contented, easy souls, whose aspirations are low and weak, will build in hollows, and rear low houses, while those who are lofty, aspiring, and high in character and aims, will build on eminences, and erect high houses. The ruins of Pompeii show only two houses above one story, which coincides with our theory. Men with the eagle form of nose and physiognomy, like Tristram Burgess, of Rhode Island, called in Congress the "bald eagle,” will build on high ground, where they can have a commanding prospect; while those of a rabbit or squirrel form of teeth and face will dig their foundation in a bank, so that they can have a CELLAR KITCHEN; and thus of other subjects.

But especially will a man's INTELLECT show itself in the house he builds. If he lets the mechanic play with his fancy and his pockets, by persuading him to build after this or that gaudy fashion, because it is popular, and popular because it is expensive, he shows the absence either of independence of mind or clearness of perception. While those of im

matured tastes will build a try-to-be-extra exquisite monument of thetr weakness, those of well-balanced minds and good practical judgment will devise a comfortable and convenient mansion, which they will finish off in a higher and still higher order of taste, according to their several casts of mentality. Indeed, the more powerful a man's intellect, and the better balanced his mind, the more perfect mansion will he construct.

Of course this general rule has a great many exceptions, both ways. A man of a high order of mind may live in a poor house, from necessity, from habit, from an unwillingness to tear down the abode of his earlier years, or from sheer inattention; while others of poorer minds may build fine houses, yet owe them more to their carpenters, or to fortuitous circumstances, than to themselves. So a thousand other causes may prevent given individuals from carrying out their respective tastes; yet, as a general rule, a fancy man will build a fancy house, a practical man a convenient house, a substantial man a solid edifice, a weak man an illarranged house, a well-constituted man a good house, etc. And this diversity of tastes is well, for it gives a beautiful variety to our towns and villas. Yet this diversity is compatible with a high order of beauty and utility, and even promotive of both.*

ARTICLE XIV.

THE BEST HEAT GENERATOR IN THE WORLD.T

THE vital process requires large and perpetually-renewed quantities of OXYGEN. Without it all the materials of life furnished by digestion would be of no avail. They are the timber and the tools of the vital process, while oxygen is the master workman-the grand motive power of the animal economy, indeed, of universal nature. The vital process closely resembles combustion, of which oxygen is one great agent and instigator. As fire goes down with the scarcity of oxygen, and goes out with and in consequence of its disappearance, so the fire of life wanes in proportion as the supply of oxygen is diminished, and death supervenes almost immediately upon, and in consequence of its disappearance. It is this imperious demand of the system for oxygen which renders the requisition for breath so absolute, and its suspension so soon fatal. A demand for breath and oxygen thus imperious was not made in vain, but their office is as' important as their demand is absolute, else it would be capricious. God never trifles.

Of late years the Editor has been assiduously inquiring, How can our style of building houses be cheapened and improved? This inquiry he has attempted to answer in a work he has just published, entitled "Home, and its Architecture," which he trusts those who design to build will find of great value. We shall give a full account of it in future numbers.

This article was written for the last number, and designed to fulfill our promise in the December number, in reference to a heat generator, but was crowded over by a press of other matter.

Oxygen being thus essential to life, from what source is it obtained? From breath. Air always contains it-indeed, is composed of twenty-one parts of oxygen and seventy-eight nitrogen, the other hundredth being carbonic acid gas, and going to support vegetation. Air, wherever found, and under all circumstances, is composed of these substances always in the same proportion. Any variation destroys it, or makes it into something else.

Adapted to this demand for oxygen, air abounds wherever man can go, unless artificially excluded. Being highly flexible, it can penetrate the least possible crevice, and even what we call solid substances. It not only surrounds the earth, extending some forty-two miles-probably many more above it in all directions, but its great heaviness presses with immense weight upon every part of the surface of the body. Its quantity is, therefore, as illimitable as its demand is imperious. But, this oxygen being in the air, how is it introduced into the system?

a, the trachea, or windpipe.-b, its branch to the right and left lung.-c c c, the three lobes which compose each lung.-e e e, the air-cells of the lungs dissected.-d, the pulmonary arteries, or entrance and egress of the blood from and to the heart.

By the production of a vacuum by means of the contraction of the diaphragm, a thin, broad, and long muscle, located between the heart and lungs above, and the liver, stomach, pancreas, and abdominal organs below, attached across the back posteriorly, and to the abdominal muscles anteriorly (as seen in d d of the above engraving), the contraction of which hauls down all the organs below it, thus producing a

partial vacuum into which the great weight of the atmosphere, everywhere pressing into every accessible nook and corner, crowds the air nearest the mouth and nose, and thus inflates the lungs. By an arrange. ment of muscles stationed between the ribs, called intercostal, the ribs are hauled up, and thus thrown outwardly; hence that heaving and swelling motion of the chest seen in breathing, so as to increase this cavity and allow a still greater influx of air. Air is neither stringy nor ropy, and cannot, therefore, be pulled or sucked into the lungs, for we have no means of getting hold of it to draw it in. All we care or need to do is, to make that opening for it caused by hauling down the abdominal organs and heaving out the ribs. The air itself does the rest by running into the lungs spontaneously; or, rather, the pressure of the atmosphere is so great as to crowd that portion of air next the mouth and nose into this partial vacuum created by the diaphragm and intercostal muscles, the relaxing of which, and consequent letting up of the stomach and bowels, and letting down of the ribs, fills it up and thus expells the air, notwithstanding the resistance of that immense pressure of the atmosphere which forced it in. Yet the lungs do not empty out all the air, else they would collapse, as they sometimes do in crying children, so as to prevent inflation, the remedy for which is, to hold them by the heels, head downward.

The lungs are those two spongy lobes in the upper part of the chest which surround the heart, and together with the latter, fill up most of the cavity formed by the ribs. They consist of a very thin and light membrane, permeated by two sets of tubes, one set formed by the branching and re-branching, almost to infinity, of the trachea or wind-pipe, till their porous structure becomes too small to be traced with the eye, even when aided by the most powerful magnifying glasses yet invented. The other set of tubes is formed by the branching and re-branching to the same degree of capillary minuteness of the pulmonary arteries and veins-those ducts which convey the blood from the heart to the lungs and back again. Only a very thin, though tough membrane separates between these capillary air-cells and blood-cells, yet so minute are its ramifications, that an ordinary sized pair of lungs contain, or has folded up in them, a surface of about twenty thousand square inches! Nature is a great economist in every thing, space included; and by this folding up of the membranes of the lungs it is, that she contrives to present so large an amount of surface in so small a compass-a contrivance akin to that by which she has folded up the intestinal canal, and still further folded its mucous surface, so that a great amount of surface may be contained within a small compass. But for this folding arrangement, the size of the lungs must have been immense; just as, but for the similar folding structure of the intestines, mankind must have been six or eight times taller for the same weight than

now.

The end attained by this plating structure is, that a large surface may be provided for the juxtaposition of the air in the air-cells, side by side with the blood in the blood-cells. The right lung is somewhat larger than the left, and the two envelope the heart so that this juxtaposition may fa cilitate their combined functions.

We thus see in what manner the oxygen of the air is brought alongside of the blood, only a thin membrane separating them. Yet this membrane, while it prevents the blood from escaping, except when ruptured, does not intercept the passage of oxygen, a gas more subtle than the air itself, so

that it can pass in through this membrane, while blood cannot pass out through it, nor air pass in through it to the body.

All this done, by what means is the oxygen induced or coaxed through this membrane so as to unite with and vitalize the blood? But for some means of effecting this object, blood and air might lie side by side on a surface of twenty millions of inches instead of twenty thousand, and forever, instead of a few seconds, without the required passage of the oxygen -this indispensable ingredient of life-from the air which it loves, and from which it is loth to part-even cannot part without destroying the nature of that air-into the blood. How, then, is the blood oxygenated? As follows.

The globules of the blood contain iron so plentifully, that many of the French nobility are now wearing rings made from the iron extracted from the blood of their friends, for the same keepsake-purpose for which we wear rings inclosing a lock of our friend's hair. Now, though the oxygen of the air loves it mate, nitrogen, right well, yet it loves iron better, so that when the oxygen contained in the air in the lungs is brought alongside of the iron contained in the blood of the lungs, the two, loving each other devotedly, rush into each others arms; but the blood being unable to pass through this membrane which separates them, while the oxygen is able to do so, the oxygen leaves its mated nitrogen, and elopes with the iron into the blood, changes that blood from its dark venous, to a bright red color, thins it, and inspirits it with life and action, so that it is now all prancing with vitality, eager to be sent throughout the system on its mission of life. We say the oxygen in the air rushes into the arms of the iron in the blood; and as the powerful Achilles, having seized the beautiful Helen, carried her off from Troy, so the iron of the blood, having loaded itself with all the oxygen it can carry off, employs the heart as its coach-and-four to transport its new bride through the arteries into the capillary system, there to deposite this instrumentality of heat.

That oxygen is thus transferred from the air in the lungs into the blood, is rendered certain by the fact, that when air is inspired, it contains 21 per cent. of oxygen, while expired air contains only 12 per cent.; it having lost nine per cent. of its oxygen, but none of its nitrogen. Not till thus supplied with oxygen, is the blood COMPLETELY freighted with the materials of life. Though it had previously derived from food fibrine, bone, hydrogen, nitrogen, carbon, etc., yet they were of no avail until it could add to its cargo this grand moving principle of the animal economy. That oxygen thus obtained, goes frothing, and rushing, and bounding on its lifeimparting mission. What now takes place ? How are these materials deposited? And what end do they, especially oxygen, subserve in the animal economy ? The production of animal heat.

in

To effectually and thoroughly HEAT up the body and all its parts, is one of the first and most essential objects to be provided for. It so is, that a high temperature is indispensable to the vital process. Life, except some of the lower and cold-blooded species, cannot proceed except at a temperature far above that of surrounding objects. Though a snake may be frozen, so as to snap, when bent, like a pipe stem, and still live, yet man soon dies unless all parts of him are kept heated up to about 98° Fahrenheita temperature rarely reached by the atmosphere in the hottest climates in the hottest days in summer. And this tempertaure of the healthy human body is always about the same in summer and in winter;