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DEGREE OF VENTILATION REQUIRED.

withered to the roots.

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Their arms are weak, their

bodies wasted, and their sensations embittered by privation and suffering. Half the life is passed in infancy, sickness, and dependent helplessness. In exhibiting the high mortality, the diseases by which it is occasioned, and the exciting causes of disease, the abstract of the registers will prove, that while a part of the sickness is inevitable, and a part can only be expected to disappear before progressive social amelioration, a considerable proportion of the sickness and deaths may be suppressed by the general adoption of hygienic measures which are in actual but partial operation. It may be affirmed without great risk of exaggeration, that it is possible to reduce the annual deaths in England and Wales by 30,000, and to increase the vigour (may I not add the industry and wealth?) of the population in an equal proportion; for diseases are the iron index of misery, which recedes before strength, health, and happiness, as the mortality declines."

Supposing, as appears to have been proved, that man respires, on an average, twenty times in a minute, and that at every respiration he inhales 16 cubic inches of air, of the 320 cubic inches thus passed through the lungs, 32 cubic inches of oxygen are consumed. Of every 22 grains of carbonic acid expired, about 6 grains may be said to be carbon, the remainder being oxygen; and it has been inferred, by simple calculation from these premises, that a man inhales during the 24 hours about 266 cubic feet of air, weighing 20 lbs.,-that he consumes 27 cubic feet

of oxygen, weighing about 24 lbs.,-that the carbonic acid expired weighs at least 24 lbs., of which 11 ounces are carbon and the remainder oxygen. Some have computed the weight of carbon expired daily to be considerably less than this: as little as 7 ounces; but it seems probable that 11 ounces of carbon are not more than are expired daily from the lungs, on an average of the whole population. To this account must be added, the disengagement of upwards of half a pint of water in the air expired. The amount of ventilation necessary for the purposes of health, must be such as will secure to the system the proportion of oxygen required to maintain the elevated temperature of the body, and to carry off the carbonic acid, and as will serve to remove the aqueous exhalation from the lungs. The amount of ventilation, the rapidity of the change of the air, must be greater, in direct proportion to the quickness with which the air is vitiated, either by the number of people occupying a given space, or by the consumption of oxygen by means of fires or otherwise. The importance of ventilation is likewise greater when the air is warm, than when it is cold, for the reason that warm air is by so much rarefied, and contains a correspondingly smaller proportion of oxygen in a given volume. It is quite evident how important the question of ventilation must be in the between-decks of ships of war, where as many as 500 men are sometimes crowded together on the same deck, the hammocks being slung as close to one another as can by possibility be accomplished. The importance of ventilation is great

EFFECT OF VENTILATION ON HEALTH.

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in such a case as this, where, from circumstances, the other conditions of life are for the most part peculiarly those of health: where the diet, and the temperance, and the cleanliness, and the regular exercise, and the freedom from mental anxiety, and the excitement of duty, are all so strongly in the favour of the individual. The importance of ventilation is great, and very great, in the crowded barrack-room of the West Indies, where heat and malaria contribute so fearfully to the amount of liability to disease, that the average proportion of cases of illness is double that which obtains among the troops employed in these temperate regions, and the general fatality of the cases is found to be no less than trebled. And, even in these fearful circumstances, ventilation ofthe dormitories has done much,and might, if carried out fully, do more,―to lessen the amount of the sickness and mortality. But, at home, in the United Kingdom, in the classes of people that are less subject to the wholesome controul and kind superintendence of those above them in the social scale,-where the day's wants are not so statedly ministered to, and their supply is perhaps subject to much vicissitude, and is often and for long periods reduced below the physical requirements of the system, where intemperance so often helps to derange the organism,—the value of ventilation, as a means of public health, becomes even more conspicuous and important, and strikingly deserving of the attention of the philanthropist. Free ventilation may be the single means within the gift of

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the public, by which the physical lot of our poorer fellow-subjects may be ameliorated; and it may be the efficient means by which fever, with all its suffering and its fatality, is kept away,-the means by which the energies of the system are maintained in the best state for the maintenance of health and life, on a minimum of food. spiring an impure atmosphere deranges the functions of the economy,-interferes with the processes of assimilation and expenditure,-prevents the best use being made of the alimentary supplies, be they small or great,-depresses the nervous energies,— and predisposes to disease from any exciting cause, whether calculated to induce sporadic, endemic, or epidemic disease. It may occur to any one who thinks on this subject, how much more good, real lasting good, might often be done to the wretched inhabitants of the crowded room by an improved ventilation, than by the eleemosynary charity which is so often and so grossly misused.

In the evidence as to the workshops, those used by tailors especially, the strongest proofs were given in the parliamentary inquiry, as to the extent and the evil influence of deficient ventilation; the shops being thus rendered so close and so hot, by the animal heat, the uncarried off pulmonary and other exhalations, the high temperature of the stoves for heating the irons used in the business and of the irons themselves, that, even in summer, the temperature of the shop has been ascertained to be twenty or thirty degrees higher than that of the

REFERENCE TO PARLIAMENTARY INQUIRIES. 91 external air, that the men have been covered with a profuse perspiration,—that, in a large shop, forty or fifty pounds' worth of light-coloured goods have been damaged by the damp hands of the men in a single season,-that so much exhaustion has been induced, that numbers have been unable to stay out the hours, and been obliged to leave earlier,—that the appetite became impaired,-that the use of stimulants, to an extent destructive of health, became gradually more and more necessary, or seemed to be so, that ardent spirits were taken the first thing in the morning before food could be eaten, and drams of spirits were taken at three stated times afterwards during the day. It appeared, that the expectation of life was thus diminished by at least one-third. Moreover, in the case of milliners and dress-makers, from the same cause in a great degree-deficient ventilation of the work-rooms, although partly, no doubt, from late hours, and deficient sleep, and defective or improper nourishment, and neglected out-of-door exercise, the probable duration of life was curtailed to the same extent. Add to these great instances, that of the wretched weavers, whose habits or prejudices lead them to exclude purposely as much air as possible, from the work-room, from the opinion that it damages the costly fabrics they are doomed to manufacture at the cost and sacrifice of earth's chiefest blessings,-or that of the miner, not only robbed of the light of day, and to some degree of the free ventilation of the air, during his hours of labour

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