open and reformed, by the efforts of a philanthropic agent, exclusively devoted to this subject; and our schools will, in our view, neither be examined, or extended, or improved as they should be, without some similar mode of action. In our busy country, the whole community have never been roused to attention or effort, on any subject, without similar means; and the benefit to be derived from them is obvious, in the feelings and the contributions called forth for every object to which they have been applied. The committee earnestly hope, that they will not cease to be applied to our schools, until every child, and every youth in our country, shall receive that education which is necessary to prepare him for duties as a man, and a citizen, and an heir of immortality.

On behalf of the Committee,

S. R. HALL, Chairman.

ART. VII.

ON THE SIZE AND VENTILATION OF SCHOOL

ROOMS.

To the Committee of the American Institute, on the Subject of School-Houses.

[The negligence of the comfort and health of children which is evinced by the carelessness of teachers and parents and the overseers of schools, in regard to the ventilation of school-rooms, is as dangerous as it is unpardonable; and we feel bound to urge it upon their attention again and again; and we beg those who read our pages to make the facts known to others. With these views we insert the following article, addressed to the Committee on School-Rooms of the American Institute of Instruction, and which is unknown to many of our subscribers. We hope they will apply it to practical purposes, for the benefit of their own children or pupils.]

GENTLEMEN, -The air we breathe is so common a blessing, that its value is not estimated; and the importance of preserving its purity in schools, by constructing rooms of sufficient size, and providing ample means of ventilation, cannot be appreciated, without considering the influence which it has upon life, health, and mental vigor. While I shall not attempt to offer an entire plan for a school-room, I have hoped to promote the general object you have in view, by collecting the principal facts in relation to the subject of air, which ought to be considered in its construction and arrangements.

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Effects of Air on the Blood. The heart of a healthy individual, of mature age, beats about sixtysix times a minute, or four thousand times an hour; that of a child, much faster. The whole mass of the blood is supposed to pass through it, fourteen times an hour, or once in four minutes. After it returns through the veins to the heart, and before it is again sent out into the body, it is made to pass through the lungs, where it comes in contact with the air we breathe, and undergoes several important changes.

1. Its temperature is raised several degrees. 2. Its color is

changed, from a dark red to a light crimson a change which the venous blood will undergo when drawn from the body and placed in the air; and it is found to contain an increased proportion of oxygen, or vital air. The whole mass of blood, thus altered every four minutes, conveys heat and nourishment and life to the extremities of the body; and if the process be interrupted, or imperfectly performed, for four minutes only, every organ and member of the body is of course more or less affected.

These changes cannot be produced without the presence of oxygen, or vital air; and they are produced in a healthy manner, only, by such a mixture, as we find in a pure atmosphere, consisting of 20 per cent of oxygen, and 80 of nitrogen. If an air less pure, or containing other gases, be breathed, these changes are not thoroughly produced; the lungs perform their task with difficulty; and the body and the limbs do not receive their due supplies of nourishment, and vital energy. They are even injured by the half corrupted state of the blood; and that weariness and languor are produced, which is always the consequence of spending some time in a bad air. Thus the person who attends a crowded assembly, where the ventilation is not complete, will find lassitude, and often chills extending through every limb, and languor invading every faculty of the mind; a feverish, unpleasant taste in the mouth; a restlessness through the following night, and often a degree of exhaustion in the morning, like that which succeeds a night spent in travelling. In order, therefore, to preserve the body in health, even after it has gained maturity, and especially to supply it when it is growing, and invigorate the constitution when it is forming, it is of the highest importance that the air should be preserved in that state of purity which the Creator designed. It is true, that disease and death do not immediately follow every deviation from this standard; but it is also certain that some degree of injury must be produced; and such a reason for neglect is as insufficient, as it would be to excuse ourselves for giving our friends or our children, food which was partially spoiled, or drink which was partially filthy, because it would not immediately. destroy their lives or health. How preposterous and inexcusable would every one regard it, to give them their food constantly mingled with poison, or their drink with pernicious and loathsome insects. Yet it is not less inexcusable to furnish them with half corrupted air, or that which contains poisonous gases! The food is given but three times a day; while the air is administered every moment. The child is at liberty to receive or reject the food; but he is forced to breathe the air in which we place him. To put our children or friends in a room, which does not contain that supply of vital air which is necessary for their health, is not only to offer them a poison, but to compel them to take it. Who can tell how much evil has been ignorantly done in this manner - how much health and enjoyment have been destroyed - how many constitutions have been enfeebled! The multitude of pale faces and meagre forms to be found on our school benches, and in our colleges, and our manufactories, will answer the question in part.

The following is one fearful example of the effects of negligence on this point. In the Dublin Hospital, during the four years preceding 1785, two thousand nine hundred and fortyfour children, out of seven thousand six hundred and fifty died within a fortnight after their birth; or thirtyeight out of every hundred. The physician, Dr Clarke, suspected the cause, and introduced air, by means of pipes six inches in diameter. The consequence was, that during the three years following, only one hundred and sixtyfive died out of four thousand two hundred and fortythree, or less than four in a hundred. The fair conclusion, therefore, was, that two thousand six hundred and sixtyfive children, of the previous years, died for want of pure air!!* We shudder at the history of the black hole of Calcutta ;'† but here was a sacrifice of life, eighteen times as great, in an institution of charity!

Quantity of Air Consumed. A man in health, is supposed to breathe, on the average, twenty times in a minute, and to take in forty cubic inches of air at one inspiration; or eight hundred cubic inches, equal to three and one fifth gallons per minute. Of this, one fifth only, or one hundred and sixty cubic inches, is vital air, or oxygen; and thirtytwo cubic inches, or one fifth of the whole vital air contained, is consumed in the minute, in order to produce the changes in the blood which are necessary to health. In five minutes, therefore, the vital air of the whole three and one fifth gallons would be consumed; or, in one minute, the vital air of two-thirds of a gallon. In one hour, the whole vital air of nine thousand six hundred cubic inches, or fortyone gallons, would be destroyed, and respiration could no longer be performed.

But in addition to this, an amount equal, or nearly equal, to that of the oxygen consumed, is produced of carbonic acid, formerly called fixed air (which often destroys life in wells); and this poisonous gas is breathed in place of vital air. At the end of half the time mentioned, therefore, we shall have an air composed of only half the proper quantity of oxygen, and corrupted by an equal quantity of a ' poisonous gas. In this view of the subject, we can hardly doubt that double the supply we have stated, i. e. twenty thousand cubic inches, or eightytwo gallons per hour, would leave a person to faint and die. Facts confirm this estimate.

Particular experiments were made on this subject by two English philosophers, Dr Henderson, and Mr Kite. Dr Henderson breathed six hundred cubic inches for four minutes; or nine thousand cubic inches, equal to thirtysix gallons, an hour; and was compelled to stop, after suffering much oppression and distress for breath.

Mr Kite breathed five hundred and ninetyone inches, for a minute;

*There are many examples which show that typhus fever is often the result of neglecting ventilation; and it is rendered contagious in the same way.

In a dungeon, so called, at Calcutta, 18 feet square, 146 persons were confined; and although there was one window for the admission of air, 123 of the number died in agony, in ten hours!

equal to seventeen thousand seven hundred and thirty inches, or one hundred and fortyone gallons per hour, and was greatly oppressed for breath. He breathed the same quantity one and a half minutes, and the oppression became intolerable; and in two minutes use of one third gallons of air, (equal to seventy gallons per hour) he became giddy, his face swelled, and he fell back in his chair.

Halley says, that it requires at least one gallon per minute to sustain life, or sixty gallons an hour; but this was the air compressed by being in a diving-bell, at the bottom of the sea; and the quantity must be estimated higher at the surface of the earth. Lavoisier says, that, according to his experiments, a man would die in 5 cubic feet, or eight thousand six hundred and forty inches, in an hour.

It would appear, then, that when a person is confined to three hundred cubic inches, 1 gallons of air a minute, or to eighteen thousand cubic inches, or seventytwo gallons an hour, he will be in danger of oppressed breathing, and fainting. He will not receive the supplies necessary to maintain his vital energies without much more air. The question, 'How little can be afforded without immediate danger to life?' is one which should never be asked by a kind, or even faithful educator, concerning that which God bestows in unlimited abundance, and which can only be excluded by inexcusable parsimony, or cruel neglect, towards those under our care. We are not merely bound to keep children alive, but to give them all the air which is necessary to invigorate their constitutions, to produce comfort, and cheerfulness, and activity, of body and mind. We must therefore resort to the instructions of experience as to this point.

Proper size of school-rooms. Unfortunately, we have few particular observations in regard to school-rooms.

The French writers on hospitals, deem it indispensable that each patient (even in the private sick room of a school), should have 6 cubic toises of air, equal to fourteen hundred cubic feet; and such is the plan of the best European hospitals. Sir Gilbert Blane says, six hundred cubic feet are necessary in England (with a climate much colder, and an air generally purer than ours) for each patient; and that with a less quantity it is impossible to maintain the requisite purity of the air.' If we take but half the quantity required by the French (allowing the rest on account of disease), it will probably be a better rule for our climate; and when we recollect the superior means of ventilation in the immense rooms of a hospital, (in many cases 70 feet long and 14 feet high) this will by no means be too much for a small, close school-room. We shall then have a space of seven hundred cubic feet for each pupil; or, supposing the room to be eight feet high, each child should have eightyseven square feet, or a space of 8 feet by 11. It appears from the facts collected by Mr Adams, that the smallest allowance, in several distinguished schools which he visited, was 7 feet; and the largest, sixteen to a scholar;

*See Adams's Lecture, in the collection of Lectures delivered before the American Institute in 1830.

or, if the room were ten feet high, (as we believe those referred to are) seventytwo to one hundred and sixty cubic feet. Lancaster, whose rooms in England were 15 or 20 feet high, in many cases allowed nine square feet to a pupil, or from one hundred and thirty to one hundred and eighty cubic feet to each; and this where the most rigid economy was demanded. Supposing the ceiling to be ten feet high, at only the allowance of one hundred and fifty cubic feet to an individual, the smallest dimensions of a room for thirty pupils should be 22 by 20 feet; of one for fifty pupils, 30 by 25- for seventy pupils, 35 by 30— and for one hundred 44 by 34 feet. A liberal allowance would require at least one third more; and double the space is highly desirable. But if we reduce the space occupied by each child to less than that here allowed, we hazard his health and constitution, as well as his immediate comfort, in order to avoid an expense comparatively of no moment. And with this amount of space, nothing but frequent and careful ventilation, and great attention to cleanliness, in the persons of the pupils as well as in the room, will prevent their suffering from the constant exhalations, (often loaded with disease) which arise from the skin, the stomach, and the lungs; and which cannot be weighed and measured, except by the baneful effects they sometimes produce, when they are suffered to accumulate. These exhalations, let it be remembered, are thrown off by the organs, because they are injurious to the person himself. But without due ventilation they must be respired by others; and not only that, they are mingled with the saliva in the mouth, and pass with it into the stomach. Who can wonder at the loss of appetite, and diseases of the lungs and stomach, which are so commonly connected with ill-ventilated school-rooms! Such places are literally nurseries of disease, and open sepulchres for health, and happiness!

Ventilation of school rooms. · In regard to the mode of ventilating school-rooms, it should be remembered, that the gases and exhalations in a crowded assembly are of two kinds; 1st, those which ascend on account of their heat or lightness to the upper part of the room, and are perceived by those who sit in elevated galleries, or whose heads are in any way raised towards the ceiling; and 2d, the carbonic acid or fixed air, which is heavier than the atmosphere, and therefore descends, and occupies that part of the room next the floor, in the same manner as it is found to settle in wells and cellars. To favor the escape of the lighter exhalations, it is indispensable to have openings over the tops of the windows, or in the upper part of the room; and scarcely any degree of ventilation below will supply their place.*

* I presume many have noticed a fact illustrating this remark, which I have more than once observed in travelling; that when a room which has been closed during the day in warm weather, is aired at night by windows opening only from below, the air will appear for a short time quite fresh; but on shutting the windows, will become, in half an hour, as close as ever. In this case, the warm exhalation and lighter gases remained undisturbed at the top of the room; and as soon as the lower air, which has been cooled, becomes heated, and ascends, they are again brought down, and become perceptible.