Part 4 (1/2)

Another requisite to the well-being of the lungs, and to the free and salutary exercise of respiration, is a due supply of rich and healthy blood When, froestion, the blood is impoverished in quality, and rendered unfit for adequate nutrition, the lungs speedily suffer, and that often to a fatal extent The free and easy expansion of the chest is also indispensable to the full play and dilation of the lungs Whatever interferes with or impedes it, either in dress or in position, is obviously prejudicial to health On the other hand, whatever favors the free expansion of the chest equally proans Stays and corsets, and tight vests and waistbands, operateas they do the thoracic cavity, and interfering with the healthy dilation of the lungs

The admirable harmony established by the Creator between the various constituent parts of the aniard to the conditions required for the health of any one, or to infringe the conditions required therefor, without all the rest participating in the benefit or injury Thus, while cheerful exercise in the open air and in the society of equals is directly and e of the e does not stop there, the beneficent Creator having kindly so ordered it that the saeous to the important function of respiration Active exercise calls the lungs into play, favors their expansion, proh their substance, and leads to their coreatly facilitated by that free and vigorous exercise of the voice, which so unifor, and which doubles the benefits derived from them considered as exercise The excites which children experience while engaged in play is another powerful tonic, the influence of which on the general health ought not to be overlooked; for the nervous influence is as indispensable to the right performance of respiration as it is to the action of the ular supply of pure fresh air is another essential condition of healthy respiration, without which the requisite changes in the constitution of the blood, as it passes through the lungs, can not be effected To enable the reader to appreciate this condition, it is necessary to consider the nature of the changes alluded to

It is ascertained by analysis that the air we breathe is coen_, united in the ratio of four to one by voluly small and variable quantities of carbonic acid and aqueous vapor No other ases, will sustain healthy respiration To be ht per cent of nitrogen, twenty-one per cent of oxygen, and not quite one per cent of carbonic acid Such is its constitution when taken into the lungs in the act of breathing When it is expelled froreatly altered The quantity of nitrogen reht and a half per cent of the oxygen or vital air have disappeared, and been replaced by an equal aes, the expired air is loaded with moisture Simultaneously with these occurrences, the blood collected fros of a dark color and unfit for the support of life, assu life

Physiologists are not fully agreed in explaining the processes by which these changes are effected in the lungs All, however, agree that the change of the blood in the lungs is essentially dependent on the supply of oxygen contained in the air we breathe, and that air is fit or unfit for respiration in exact proportion as its quantity of oxygen approaches to, or differs froen, hydrogen, or any other gas that does not contain oxygen, the result will be speedy suffocation If, on the other hand, we breathe air containing too great a proportion of oxygen, the vital poill speedily suffer from excess of stimulus

The chief che to the presence of _oxygen_ Nitrogen, which constitutes about four fifths of its voluen

_Increase_ the proportion of oxygen in the atmosphere, and, as already stated, the vital poill speedily suffer from excess of stimulus, the circulation and respiration becohly excited _Dien, and the circulation and respiration become _too sloeakness and lassitude ensue, and a sense of heaviness and uneasiness pervades the entire syste each respiration a portion of its oxygen, and gains an equal quantity of _carbonic acid_, which is an _active poison_ When mixed with atuishes ani charcoal in a confined portion of common air Its effect upon the system is well known to every reader of our newspapers

It causes di, and ultimately _apoplexy_ and _death_[12]

[12] Since the text was prepared for the press, I have noticed from the Syracuse (New York) Journal of January 3d, 1850, mention of the death of General Rensselaer Van Rensselaer, of that city, fro ”the fumes of charcoal” burned in a ”portable furnace” This, it should be remembered, is but _one_ of the _ all over our country, in which _ient

Respiration produces the sa of charcoal does It converts its oxygen, which is the aliment of animal life, into carbonic acid, which, be it remembered, is an active poison

Says Dr Turner, in his celebrated work on chemistry, ”An animal can not live in air which is unable to support coain, ”An animal can not live in air which contains sufficient carbonic acid for extinguishi+ng a candle” It will presently be seen why these quotations are made

It is stated in several s at each inspiration of an adult varies from thirty-two to forty cubic inches To establish ht safely be based, I soo conducted an experiment whereby I ascertained the s ofmen was thirty-six cubic inches, and that respiration is repeated once in three seconds, or twenty times a minute I also ascertained that _respired air will not support combustion_ This truth, taken in connection with the quotations just made, establishes another and a _more important_ truth, viz, that AIR ONCE RESPIRED WILL NOT FURTHER SUSTAIN ANIMAL LIFE That part of the experiment by which it was ascertained that respired air will not support coive it with the hope that it may be tried at least in every _school-house_, if not in every family of our wide-spread country It was conducted as follows:

I introduced a lighted taper into an inverted receiver (glass jar) which contained seven quarts of atmospheric air, and placed the mouth of the receiver into a vessel of water The taper burned with its wonted brilliancy about a radually, became extinct at the expiration of threeit, placed its mouth beneath the surface of the same fluid in another vessel I next re into it_ This was done by filling the lungs with air, which, after being retained a short tih a siphon (a bent lead tube) into the receiver I then introduced the lighted taper into the receiver of respired air, by which it was _iuished_ Several persons present then received a quantity of respired air into their lungs, whereupon the preiven, ensued The experireat care, and several times repeated in the presence of respectable members of the medical profession, a professor of cheentle further, I will make a practical application of the principles already established Within the last ten years I have visited half of the states of the Union for the purpose of beco acquainted with the actual condition of our common schools I have therefore noticed especially the condition of school-houses Although there is a great variety in their dimensions, yet there are cohteen feet on the ground, and fewer still larger than twenty-four by thirty feet, exclusive of our principal cities and villages Froe nuan, but east of the Hudson River and west of the great lakes, I conclude that, exclusive of entry and closets, when they are furnished with these appendages, school-houses are not usually larger than twenty by twenty-four feet on the ground, and seven feet in height They are, indeed, er School-houses of these dimensions have a capacity of 3360 cubic feet, and are usually occupied by at least forty-five scholars in the winter season Not unfrequently sixty or seventy, and occasionally more than a hundred scholars occupy a room of this size

A simple arithmetical computation will abundantly satisfy any person who is acquainted with the composition of the atmosphere, the influence of respiration upon its fitness to sustain anis at each inspiration, that a school-roo dimensions contains quite too little air to sustain the healthy respiration of even _forty-five_ scholars three hours--the usual length of each session; and frequently the school-house is imperfectly ventilated between the sessions at noon, and so particulars: 1 The quantity of air breathed by forty-five persons in three hours, according to the data just given, is 3375 cubic feet 2 _Air once respired will not sustain animal life_ 3

The school-room was estimated to possess a capacity of 3360 cubic feet--_fifteen feet less than is necessary to sustain healthy respiration_ 4 Were forty-five persons whose lungs possess the esti dimensions, and could they breathe pure air till it was all once respired, and then enter upon its second respiration, _they would all die with the apoplexy before the expiration of a three hours' session_

From the nature of the case, these conditions can not conveniently be fulfilled But numerous instances of fearful approxiht houses But in our latitude, comfort requires that rooms which are to be occupied by children in the winter season, be made very close The dimensions of rooms are, moreover, frequently narrowed, that the _warm breath_ may lessen the amount of fuel necessary to preserve a comfortable temperature It is true, on the other hand, that the quantity of air which children breathe is soereater than in the case of adults whose constitutions are matured, and who are hence less susceptible of injury It is also true ina rooreater than I have estireat proportion of the larger scholars will respire the estiain, all the air in a room is not respired _once_ before a portion of it is breathed the second, or even the _third_ and _fourth_ tied from purity to impurity--froe, being more perceptible, would be seen and _felt_ too, and a _reradual, it is not the less fearful in its consequences In a room occupied by _forty-five persons_, THE FIRST MINUTE, _thirty-two thousand four hundred cubic inches of air iling with the atmosphere of the room, proportionately deteriorate the whole mass_ Thus are abundantly sown in early life the fruitful seeds of disease and premature death

This detail shows conclusively sufficient cause for that uneasy, listless state of feeling which is so prevalent in crowded school-rooms

It explains why children that are amiable at home are mischievous in school, and why those that are troublesoh uncontrollable in school It discloses the true cause why so many teachers who are justly considered both pleasant and amiable in the ordinary domestic and social relations, are obnoxious in the school-roo there habitually sour and fretful The ever-active children are disqualified for study, and engage in mischief as their only alternative On the other hand, the irritable teacher, who can hardly look with conify thedeparture from the rules of propriety The scholars are continually becoovern them Week after week they become less and less attached to him, and he, in turn, becomes less interested in them

This detail explains, also, why so many children are unable to attend school at all, or beco to attend, when their health is sufficient to engage in other pursuits The nureater than most persons are aware of In one district that I visited a few years ago in the State of New York, it was acknowledged by coes to be emphatically true in the case of not less than _twenty-five scholars_ Indeed, in that same district, the health of more than _one hundred_ scholars wasan old and partially-decayed house, of too narrow dimensions, with very limited facilities for ventilation The evil, even after the cause was h the district orth more than three hundred thousand dollars And what _was_ true[13] of this school, is noith a few variations, true in the case of scores, if not hundreds of schools hich I aland to the Valley of the Mississippi

[13] In the district referred to there has since been erected a large and commodious union school house, which constitutes at once the pride and ornae

This detail likewise explains why the business of teaching has acquired, and _justly too_, the reputation of being unhealthy There is, however, no reason why the health of either teacher or pupils should sooner fail in a well-regulated school, taught in a house properly constructed, and suitably warmed and ventilated, than in almost any other business If this stateht be fraht clearly be shown that it is _policy_, nay, DUTY, to close at once and forever the four thousand school-houses of Michigan, and the hundred thousand of the nation, and leave the rising generation to perish for lack of knowledge

But our condition in this respect is not hopeless The evil in questionthe house, or, which is easier, cheaper, and h ventilation It would be well, however, to unite the two methods