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.*-In the winter season, an opening into the upper part of the chimney, when the draft is good, will answer the purpose. Where this is wanting, and especially in rooms where lights are used, a very excellent means of ventilation is found in an artificial chimney, formed by a pipe issuing from the upper part of the room, with a large funnel at the opening, in which a lamp is kept burning. By means of the strong draft here produced, Sir Humphrey Davy, the celebrated English chemist, cleared his laboratory in a very short time, after having filled it with noxious gases.

But it is not less necessary to guard against the effects of the carbonic acid which settles in the lower part of the room. In caverns and wells, it often rises only to a certain height; so that above this level an individual may breathe and a light may burn, perfectly well; while a light would be extinguished and the respiration obstructed, or stopped, on descending below it. Thus, in the celebrated Grotto del Cane, in Italy, in which this gas issues from the ground, and although it is invisible, can be found by its effects to flow along the ground, a dog will die, while a man whose mouth is elevated above the level of the gas, suffers no inconvenience. The teacher, therefore, especially if he is elevated on a platform, will not always

* 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 exhalations 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 made perceptible.

be sure that the air of that part of the room in which the smaller children are breathing is good, merely because he perceives no want of purity in that which surrounds him; and, like the man in the Grotto, may be surprised to find that one who breathes below him suffers from the badness of the air. On this account it is of great importance that no part of the room should be below the level of the doors; and that regular pro-. vision should be made for opening the doors frequently and for a sufficient time, to allow this deleterious gas to flow off. These circumstances seem to me very decisive arguments against making a school-room descend, as I have sometimes seen, towards the centre, producing a kind of "black hole" for the smaller children; and they show the importance of employing rooms above the level of the ground, for schools, as well as other assemblies of people. The immediate evil effects are imperceptible perhaps; but seeds of disease and debility may be planted, which no subsequent care can eradicate.

The best mode of securing regular ventilation as well as uniform heat in a school-room, during the season when the windows must be closed, undoubtedly is, to introduce the external air from the side, and not from the cellar, of the building, through a stove or furnace, so that it may enter the room warm, diffuse the heat equally throughout, and prevent the current of cold air which presses in at every crevice. In this way also, the doors and windows may be opened at any time, without cooling the room too much, as the air usually presses outward.*

* Several excellent plans have been discovered for this purpose, of which I trust the Committee will furnish some account. I have found, that a common stove might be made to answer the same purpose, in some degree, in the following way :-Let a close case of sheet-iron be made of such dimensions as to rise from the floor to the top of the stove, or a little above it, on three sides; and so large that there will be a space of two inches on all sides between the stove and the case. The stove should be raised on legs, or bricks, a few inches from the

The facts and principles presented in this paper, have been collected with care, from the best and most recent authorities in Chemistry and Physiology within my reach;* in the hope that they might serve to impress more deeply on the minds of parents, and of the guardians and visitors of our schools, the importance of providing the indispensable means of bodily health and intellectual vigor, for teachers and their pupils. It can scarcely admit of a doubt, that the premature decay, or sudden destruction of many a faithful teacher, and the debility of constitution of many a pupil, is brought on by the insidious but poisonous influence of the corrupt air in which they spend their days. The economy, which hazards such results, by providing small school-rooms, can only be compared to that infatuated avarice, which destroys life, in striving to obtain or to hoard the means of existence. In no single mode, probably, could the American Institute be more useful, than in establishing and circulating correct views on this important subject; and I cannot but hope that their efforts will be the means of extensive good, on this and many other subjects of vital importance to the interests of education, and therefore, to the prosperity of our country.

I am, Gentlemen,

Repectfully yours,

WILLIAM C. WOODBRIDGE.

floor, and the opening beneath closed in front with brick-the other three sides being closed by the case. Introduce the air from without, by a wooden trough, and let it rise under the bottom of the stove, and it will pass out between the stove and its case in a pleasant state of warmth. The trough should be furnished with a slide, to regulate the amount of air, according to the warmth of the stove and of the room; and the case should be so constructed that it may be removed, in order to clean the space around the stove when necessary.

* Among these are Hare's, Gorham's, Henry's, and Silliman's Chemistry; Richerand's, Magendie's, and Bostock's Physiology; Londe's Hygiene; The Paris Dictionary of Medical Sciences, and Rees' Cyclopedia.

ON THE

CONSTRUCTION

OF

SCHOOL-ROOMS.

[The Censors have been favored with a communication "On the Construction of School-Rooms," from the Rev. WILLIAM WOODBRIDGE, which was not offered for the prize of the Institute. On this subject, Mr. Woodbridge speaks with the voice of experience; and the following extracts from his communication, contain an exposition of principles which are well worthy of attention. The Censors would not be understood, however, to approve of the plan proposed in this communication, in all its details.]

THE subject proposed by the Institute, requires attention to the best modes of constructing, warming, lighting, and airing school-rooms. The construction of a room necessari'y depends on the objects to which it is destined, and the ends to be obtained; and these must first be considered. No man ought to build, without counting the cost: viz.-For what purpose he builds as well as at what expense; whether of money, or TIME, HEALTH, or LIFE. What millions have been wasted for want of the first! What losses follow miscalculations in the last.

Before stating any particular plan, I would make some general, but essential remarks.

1. The intent of all theoretical and practical education is, to form the sound mind in the sound body. This is the central point to which all means are to be directed. How are the powers of genius to be developed in a sickly child? What are the public uses of theology, in a dyspeptic divine? the energies of wisdom in a consumptive habit ?—in a walking corpse? Health then, and wisdom, are the great objects of education: "United they flourish-divided they die." For this the church-the nation-is in mourning.

or

2. Fresh air, and cleanliness in every form, are absolutely and imperiously essential in our common schools.

3. Clear light, easy and convenient seats and benches, that favor easy attitudes of body, appear to be important, if not essential points in the structure of school-rooms. Uneasy bodies render the mind uneasy and restless. Clear images of truth cannot be reflected from turbid and agitated water.

4. To prevent is easier than to rectify disorders in a school. In order to do this, no scholar should be out of his teacher's eye five minutes in a day.

Such vigilance is essential to order; as it convinces the scholar that nothing can be done, even slily, without detection, nor can study be neglected without notice: it is a first principle in the teacher's art, the first in school tactics. Therefore every school-room ought to be so constructed as to render this great and incessant duty convenient.

5. The "non-naturals," to use the Physician's term, have great effect upon the mental temper, as well as the physical system. A village fiddler takes great care of his violin, keeps it carefully from wet and dampness and too much heat, which affect the tone of its strings, and render them too tense or too lax; surely then the nervous and muscular system requires attention. Mental habits are formed under the hand of the teacher. Passions are to be regulated into proper discipline, for self-command, and social order, and regular sub