would leap forward to exertions, the thought of which is often despair!

Few things are more distressing, more heartbreaking, than the amount of sickness, and even of death, that is due to causes now ascertained to be preventable. We all lament bitterly the slaughter of war; but nothing is more certain than that the number of soldiers who are slain by preventable disease is immensely greater than the number who fall in battle. In the late Russian war, no fewer than 20,800 of our countrymen lost their lives. But of these only 5000 fell in the field or died of their wounds; no fewer than 15,800, mostly men in the prime of life, died of diseases, of which, humanly speaking, far the greater part might have been prevented, had proper means been taken. Even in times of peace, the proportion of deaths in the army has till lately been far greater than elsewhere. One of the chief causes of this mortality has been ascertained to be the want of sufficient ventilation in the soldiers' barracks. Where due arrangements have been made of late years for giving the soldiers fresh air, the death-rate has been very considerably diminished.

But out of the army, too, and especially among the working classes, there is an amount of preventable sickness and death, which is very terrible.

In a General Sanitary Report published some years ago by the Poor-Law Commissioners, it was stated that in Manchester the average age at death of professional men, gentry, and their families, is 38 years; tradesmen, 20; mechanics and labourers, 17. In Liverpool, gentry 35, tradesmen 22, workmen 15. In the rural districts of Rutlandshire the corresponding ages are 52, 41, and 38 respectively. In the district of Bethnal Green, London, gentry 45, tradesmen 26, workmen 16. The low average in the case of tradesmen and workmen, is chiefly owing to the number of deaths among children of a tender age. Among the gentry, on an average only one death out of five occurs among children under five years; among tradespeople the proportion is one in two and a quarter; and among working men one in two. That is, among the working classes of such districts, there is the same number of deaths below the age of five as above it. It is difficult to state with any approach to precision, how many lives are lost in this country through causes that might have been prevented. We have seen the number estimated variously at from 50,000 to 100,000. We believe that the larger number is no exaggeration. It is very singular that so little horror is felt at this prodigious slaughter. For the most part, human life is very properly regarded with great sanctity in

our country. We are indignant at any needless sacrifice of life. We cry shame when a crew is drowned because a miserly shipowner sent them to sea in a rotten craft. When an explosion occurs in an ill-ventilated mine, we can hardly refrain from regretting that the reckless proprietor was not himself shattered by the catastrophe. Yet for the most part little horror is felt at the far more extensive and frightful loss of life that takes place above ground from similar causes. We all remember the horror that thrilled every bosom in the land, when 200 imprisoned colliers were believed to be suffering the agonies of suffocation, and the intense anxiety that prevailed to learn their fate. Yet we can be told that ten times that number of lives are lost weekly in Great Britain through preventable causes, and fold our hands in indifference. What would be the feeling of the community if some Nana Sahib were roaming through the country, and if every week brought the revolting news of a fresh massacre of 2000? It was no palliation, but a hideous aggravation of that fiend's barbarity, that a large proportion of his victims were children. It should be no palliation of the evil which filth, bad air, and similar agents are causing, that probably one-half of their murders are those of little children. Infanticide has usually been counted the crowning barbarity of

savage nations; culpable ignorance and neglect of the laws that promote the health and prolong the lives of children, is the disgrace of the most civilized.

It being admitted, then, that there is a vast amount of preventable sickness and death, especially among the working classes, the great thing is, to get at the reasons of this, and, having found the cause, infer the remedy. What are the chief of the subtle agencies that penetrate the frames of young and old, that poison the blood and undermine the strength, that breed consumption and fever and scrofula, that nip the young blossoms of the tree of life, that send so many little ones to sleep in the cemetery, when they might have gladdened their parents' homes with their smiles and prattle, and grown up to be comforts at home and blessings abroad? What are the enemies to health whom we must try, when young, to hold out, that when old we may not have to try to put them out? It is but a few of the principal that we can specify; and these only in a very cursory and imperfect way.

The first we mention is polluted air. The necessity of a constant supply of fresh air for the health of the body can only be thoroughly appreciated where there is some acquaintance with the process of respiration or breathing, and the ends which that process serves. Why are we made to breathe? Why

does our chest heave night and day, and our mouths and nostrils perpetually draw in air from without, and pour out air from within? The process is most intimately connected with the preservation of health and life. The blood that flows through our bodies, carrying, when it is healthy, fresh life and strength to every part of them, is continually gathering up in its passage a substance that is destructive, and is continually demanding a fresh supply of another substance, which is wholesome and life-giving. The process of breathing is designed for at once getting rid of the one and supplying the other. The chamber of exchange, where the blood throws out the hurtful substance, and takes in the wholesome, is the chest, the cavity of the lungs. The brokers that make the exchange are the lungs themselves. The medium of conveyance by which the one substance is carried out, and the other carried in, is the breath. The hurtful substance which is thrown out is called carbonic acid; the wholesome which is drawn in, is called oxygen. To keep the blood healthy (and that is much the same thing as to keep the body itself healthy), a certain amount of oxygen must be supplied to the blood. When this amount of oxygen is not supplied, the consequences are most serious. It may be withheld to such an extent, that death is immediately or rapidly the consequence.

It was