.*

to ventilate a room effectually, every person requires ten cubic feet of fresh air per minute a church, therefore, eighty feet long, fifty feet wide, and forty feet high, and containing one thousand persons, would require the whole atmospheric contents of the building to be renewed every sixteen minutes. A room containing a million cubic feet of air, in which were assembled ten thousand persons, would likewise require a total change every ten minutes; and an apartment twelve feet each way, with ten persons in it, would require an entire change of air every seventeen minutes.

also more to be guarded against, because persons can live in it without being aware of its danger, as far as their sensations are concerned. When we enter a crowded assembly on a cold day, the air is always at first repulsive and oppressive; but these sensations gradually disappear, and we then breathe freely, and are unconscious of the quality of the atmosphere. Science, however, reveals the fact, that the system sinks in action to meet the conditions of the impure air; but it does so at the expense of a gradual depression of the vital functions; and when this is continued, disease follows. No disease can be thoroughly cured when there is a want This quantity of ten cubic feet of air of ventilation. It is related, that illness per minute for each individual, is what is continued in a family until a pane of glass required to supply him with the amount was accidentally broken, and then it of oxygen necessary for the performance ceased: the window not being repaired, a of the functions of respiration; whilst the plentiful supply of fresh air was admitted. constant change of the atmosphere is imNearly all the churches in the empire re- peratively necessary to get rid of the proquire some artificial means of ventilation ducts of respiration, namely, the carbonic to render them physically fit receptacles acid and aqueous vapor, as well as the for the body during a prolonged service. effluvia from the body; for, disagreeable The Sunday-schools also, as a general rule, as it may be to refer to such a subject, are very ill ventilated; and lessons in the this is the most noxious cause of contasecond hour are far worse rendered than mination with which we are in the habit in the first, solely arising from a semi- of coming in contact. "We instinctively," lethargic coma that comes over the pupils says Bernan, "shun approach to the dirty, breathing a carbonic air, which has al- the squalid, and the diseased, nor use a ready done duty and been inhaled by garment that may have been worn by anothers several times. However much to other; we open sewers for matters that be regretted, it is still true that people will offend the sight and smell, and contamisometimes sleep during the sermon. Now, nate the air; we carefully remove impurithe minister must not be twitted with ties from what we eat and drink, filter this; for with the oratory of a Jeremy morbid water, and fastidiously avoid Taylor, or of a Tillotson, people could not drinking from a cup that may have been be kept awake in an atmosphere charged pressed to the lips of a friend. On the with carbonic acid, the emanations of a other hand, we resort to places of assemthousand listeners.* bly, and draw into our mouths air loaded with effluvia from the lungs and skin and clothing of every individual in the promiscuous crowd: exhalations, offensive to a certain extent from the most healthy individuals, but which, rising from a living mass of skin and lung in all stages of evaporation, disease, and putridity, and prevented by the walls and ceiling from escaping, are, when thus concentrated, in the highest degree deleterious and loathsome."

Instances innumerable might be pointed out in connection with our trades and professions, showing that no one can break with impunity the law of nature, which demands that the food destined to nourish and warm the body should be converted into heat, and vitalized by a constant supply of fresh and pure air. The importance of this subject becomes more evident if we turn to a few statistics. In a life of fifty years a man makes upward of five hundred millions of respirations, drawing through| his lungs nearly one hundred and seventy tons weight of air, and discharging nearly twenty tons weight of the poisonous carbonic acid. It has been also calculated that,

* Piesse.

*This is the minimum which should be allowed.

In the House of Commons, which is, perhaps, the most perfectly, as it is certainly the most scientifi cally ventilated building in the world, Dr. Reid minute for each member, when the room is never allows less than thirty cubic feet of air per crowded, and on many occasions sixty cubic feet have been allowed.

Another similar catastrophe is recorded by Blaine as having occurred in 1750. During the sessions a sickening, nauseous smell was experienced by the persons in court, and within a week afterwards many who had been present were seized with a malignant fever. Amongst those who died were the Lord Mayor, the two judges, an alderman, a barrister, several of the jury, and forty other persons. It was remarkable that the prisoners who communicated the infection were not themselves ill of fever; and it was still more remarkable that none of those who were ill of it (to the greater number of whom it proved mortal) communicated it to their families or attendants, which showed that persons who were treated in clean and airy apartments, as those were who fell victims to it, do not communicate the discase to those in the constant habit of attending upon them.

Historians relate with just indignation that nearly three hundred martyrs died at the stake in the reign of the bigot Mary. But how insignificant appear the number and sufferings of these victims of regal fanaticism when compared with the tortures of suffocation and death from stench, that were endured by thousands of persons in this and succeeding reigns, when every prison was a legal sepulcher.

The evils produced by allowing the car-personal requirements necessary for avoidbonic acid from the breath to accumulate ing disease and preserving life. in the air, have been already mentioned; those engendered by inhaled animal effluvia are still more fatal in their results; for, according to competent authorities, it seems to be an invariable result that the accumulation and stagnation of the breath and perspiration of human beings crowded for a period in confined air, and neglecting personal cleanliness, produce plague or fever that may be communicated to healthy persons by contact or respiration. The most memorable example of this is the Great Plague of London, which was caused by the total absence of proper ventilation in the filthy and overcrowded hovels in which the greater part of the poorer population of London lived, together with the filth and putrefying abominations which habitually filled not only the streets but even the houses of the lower classes. According to Bernan, the jail-fever was another disease which, arising from a neglect of the vital necessity for fresh air, was, a few centuries ago, an object of dread to society. The unfortunate and the criminal alike were immured in damp, cold, ill-aired dungeons, and kept in a state of inactivity. They inhaled the pent-up noxious effluvia emitted from their own bodies; and, from the want of means for personal purification, their clothes and bedding during their incarceration became saturated with the fatal exhalations. In this condition the miserable prisoners engendered, and became victims to, a disease of deadly malignity. They sickened, and with little apparent illness they died. The prison-house was thus the focus of a contagion that spread far and wide beyond its walls, and spared few who were so unhappy as to come within its influence. It was remarked, that although a prisoner happened to escape the infection, his clothes, nevertheless, emitted a pestilence that scattered death around him wherever he went. The assizes held at Oxford in 1577 were long remembered, and were called the Black Assizes, from the horrible catastrophe produced on that occasion by the jail-fever. Baker, in his Chronicle, tells us, that all who were present in court died in forty-eight hours-the judge, the sheriff, and three hundred other persons! -so terrible was the retribution suffered by the community for its hardness of heart in denying to criminals even those

Equally striking are the good results which have followed a judicious application of ventilation where it was formerly absent. It is scarcely possible to conceive a more repulsive and abominable state than that in which our ships of war were during the latter part of the last century, owing to the disregard, or rather the studied opposition, with which those then in authority treated all proposals to improve their ventilation. We regard other nations with whom we happen to be at war as our enemies, but a few figures, eloquent in their simplicity, will convince any one that incapacity, narrowmindedness, or obstinacy in high places, are vastly more fatal in their results to our gallant sailors than the most formida ble enemy they ever faced. In the year 1779, there were 70,000 seamen and marines voted by Parliament; of these, 28,592 were sent sick to the hospitals, or 1 in 2.4. In 1784, of 85,000 men afloat, 21,371 were sent ashore sick within the

year, or 1 in 4. But in 1804, when ven- same causes, and our bodies may be left tilation was partially, if not thoroughly, lifeless as a snuffed-out candle; the food carried out in every ship, of the 100,000-the combustible matter men of which the navy that year consisted, 11,978 passed through the hospital, or only

one in 8.3.

The evils of inefficient ventilation have been strikingly shown in the case of the Custom House, where the difficulty of ventilating a large public room has been very manifest. There the atmosphere in some of the apartments was so defective, as to produce general symptoms of illhealth among the officers whose official seats were placed in it. The functionaries were described to have had "a sense of tension or fullness of the head, with occasional flushings of the countenance, throbbings of the temples and vertigo, followed not unfrequently by confusion of ideas," that must be very disagreeable to persons occupied with important and sometimes intricate calculations. A few were affect ed with unpleasant perspiration at their sides. The whole of them complained of a remarkable coldness and languor at their extremities, more especially the legs and feet, which became habitual. The pulse in many cases was more feeble, frequent and sharp, and irritable, than it ought to have been. The sensations in the head occasionally rose to such a hight, not withstanding the most temperate regimen of life, as to render cupping requisite, and at other times depletory remedies; and costiveness, though not a uniform, was yet a prevailing symptom.

The identity between the combustion of a candle and that living kind of combustion which is ever going on within us has thus been clearly exhibited. Like the candle, man depends for his life and vigor upon the chemical action exerted between the atmosphere and combustible matter; the combustion of the latter giving rise in each case to heat and vitality. Like the flame of a candle, too, man's health and strength languish and faint unless properly and uninterruptedly supplied with that mysterious breath of life oxygen; whilst the feeble hold which the flame, even under the most favorable circumstances, has upon the wick, and the ease and totality of its extinction by the most trivial circumstance - not only by a deprivation of air, but even by a puff of wind too much - should teach us, even in our pride of health and strength, that our spark of life may be extinguished by the

may be there all the same; the oxygen may be in waiting, ready to combine with it; but the spark of fire, that spirit of life which man receives direct from his Creator, is absent, and without this all else is as nothing.

One more lesson from our candle, and we have done. What becomes of the human soul when it has left the body? What becomes of the flame when the candle is extinguished? Must our philosophy halt here? or will it turn round upon us, and attempt to prove, in scientific jargon, that there is no such thing as a future? We think not. We believe that, as the relationship between the candle and man bears strict analogy from the first kindling of the mysterious vitalizing principle, through the varied phenomena of life, in sickness and in health, and even in the more mysterious phenomena of extinction, so can the analogy be carried further into the dim, shadowy realms beyond.

If there is one question more than another which has occupied the attention of modern philosophers, it is that relating to the conservation of force, or, as it sometimes is called, of energy. It has long been admitted that matter can neither be created nor destroyed, and the whole tendency of modern discovery is now directed to show that energy is equally incapable of extinction. So long as it is exerting its action in a definite way, shining and glowing as a candle-flame, evolving the forces of heat and light, we take note of it by means of our outward senses; but, when the flame goes out, are these forces annihilated? Assuredly not. The energy which hitherto was occupied in the production of heat and light has only changed its immaterial form; it still exists in undiminished quantity, though it is now incapable of appreciation by our material senses. For just as the forces evolved by burning fuel are transformed into mechanical motion in the steam-engine; and just as mechanical motion is equally capable of being re-transformed into heat, light, electricity, or chemical action-just as every word we utter, acting on the material atmosphere around us, resolves itself into aërial waves of sound, which forever afterward vibrate with diminishing intensity, but expanding

but become absorbed into that vast reservoir of energy which is the source of all life and light upon this globe.

area, from one extremity of the atmosphere to the other, retaining always the same amount of energy as it did when the mechanical motion of the breath and And shall we then suppose that the soul lips first gave it birth-so do the forces of man is of less account than the flame of once born to activity when the candle is a candle? If philosophy can thus prove lighted live to the end of time undiminish- that the latter never dies, shall not faith ed in intensity, although changed in char- accept the same proof that our own spiritacter. When the flame is naturally ex-ual life is continued after the vital spark is tinguished, these living forces do not die, extinguished?

From the Edinburgh Review.

TROYON'S LACUS TRINE

ABODES OF MAN.'

memory history contains no record whatever. It tells us of entire populations, with their arts, customs, and languages, buried and forgotten before Troy town was besieged, or the oldest piles of Cyclopean masonry were massed together by their mysterious architects:* with annals far antecedent to the memory of Spenser's Eumnestes, who

"All the wars remembered of King Nine,

And old Assaracus and Inachus divine."

NOTHING in the history of scientific in- | history began-peopled by a race of whose vestigation is more remarkable than the singular manner in which the labors of various inquirers, acting without apparent concert, seem frequently to take at the same time a common direction. Phenomena of deep interest or importance exist around us unrevealed, like the gold in Australian gravel, until the hour suddenly arrives when light, thrown on them from one quarter, is answered by corresponding lights from all parts of the heavens. Then the system of which these phenomena form a part, their relation to each other, From the mounds and dikes of farthest and their bearing on some general subject, Scandinavia-from limestone caves and disclose themselves little by little, with all turf deposits scattered over Western Euthe freshness of discovery. Twenty years rope-from the bogs of Ireland and the ago, or little more, it was the commonly lake shores of Switzerland-nay, from the received doctrine that there were not any gravel and sand strata of past geological traces of Man to be found in Europe at-periods, in Picardy and in Suffolk-the tributable to any age earlier than that very evidence accumulates upon us of the existrecent period known, or, at all events, inence, and long continuance, of successive dicated to us through history. And now, 66 pre- historical" races of men; smaller simultaneously, and from various corners men than ourselves; a "feeble folk," apof Europe, a new school of inquirers, pro-parently, who must have had a difficulty ceeding, as we shall see, by a method ut in maintaining their existence against the terly different from any adopted before, inclemency of climate and the incursions inform us that this quarter of the globe was peopled for uncounted ages before

*The present King of Denmark, however, contributed to the Annual Meeting of the Society of *Habitations Lacustres des Temps Anciens et Northern Antiquaries, (1857,) a memoir in which Modernes. Par FRÉDÉRIC TROYON. Lausanne : reasons are given for believing that these Cyclopean 1860. structures (or the "Halls of the Giants," which anProceedings of the Royal Irish Academy, Vol. swer to them in the North) might have been erected by men to whom the use of metals was unknown,

VII.