DR. ARNOTT TO THE AUTHOR, ON THE SUBJECT OF VENTILATION.
Bedford Square, January, 1845.
my dear sir,
To aid the memory of persons inquiring about the means of preserving health, I have elsewhere endeavoured to mark clearly, that the four things, fit air, temperature, aliment, and exercise, are all that need to be secured, and the two things violence and poisons all that need to be avoided, by men of sound constitution, that they may enjoy uninterrupted health and long life;—and consequently that the causes of all other disease than the decay from age are to be looked for in errors committed in regard to these four necessaries, or in the direct influence of these two kinds of noxious agents. The tabular view on the opposite page [282], now to be examined, exhibits the subject to the eye.
In some moderately warm and uniform climates of the earth, such as the Azores or Western Isles in the Atlantic, the two first mentioned necessaries, viz. fit temperature and pure air, are so constantly present that the inhabitants no more think of them as necessaries to be laboured for than they think of the gravitation which holds their bodies to the earth as such a necessary. But in colder, or changing climates, to procure house-shelter, clothing, and fuel, for cold weather becomes a very considerable part of the necessary business of life. And where food is dear, that is to say, obtainable only as the reward of much labour, as is true in England, the amount
of labour which individuals can perform with safety to their health, is often not sufficient to supply all the urgent wants.
Exposure to temperature lower than what suits the human constitution is so severely felt, that persons, even before fixed disease has arisen as a consequence, cannot remain indifferent to it; and how little soever some minds are disposed to reflect or speculate on such subjects, there are few who are not aware that all the diseases which in this and other climates are called winter diseases, as catarrhs, quinsies, pleurisies, croups, rheumatisms, &c. &c. are consequences of error in regard to temperature. But only persons whose attention has been specially directed to the subject become fully aware of the fatal influence of that want of fresh air which the closeness or otherwise faulty construction of dwellings occasions. The immediate effect is little felt, although the insidious enemy is unfailingly producing diseases perhaps more destructive even than those from cold, above enumerated. Impaired bodily and mental vigour, and the scrofulous constitution which renders persons more liable to many diseases and among these to consumption, the destroyer at present of about a sixth part of the inhabitants of Britain, may be cited as part of the effects.
In England, as yet, many singular and hurtful misconceptions prevail on the subjects of both warming and ventilating. The object of a little work which I published some time ago on these subjects, was to substitute for the misconceptions correct knowledge, and to describe some new and simple means of obtaining the objects sought. A considerable change, however, in common opinions and habits is not easily effected, and the co-operation of many labourers will be required to accomplish
all that is here wanted. In a new edition of the book, now in preparation, I have attempted to convert some remarkable errors that have been committed in public situations into useful warnings or lessons for the future. It is but recently that even the members of our Houses of Parliament became aware that many of their body formerly had lost health, and even life, from want of a complete ventilation of the Houses, easy to be effected. And at present the havoc made in the crowded workrooms of milliners, tailors, printers, &c. and the injury done to young health in many schools, from similar want of knowledge, are most painful to contemplate. Without the requisite knowledge very expensive attempts are made with little or no benefit; with that knowledge, the desired ends may be completely attained at little cost.
The great error committed in regard to ventilation has been the want of an outlet in or near the cieling of rooms, for the air rendered impure in them by the breathing of inmates and the burning of candles, lamps, gas, &c. At present the only outlet of English rooms is the fire place or chimney opening near the floor. But all the impurities above referred to rise at once towards the cieling, because of the lessened specific gravity of air when heated, and there they would at once escape by a fit opening. Where there is no such opening, however, they become diffused in the upper air of the room, and can escape only slowly by diving under the chimney-piece as that air is changed. Thus the air of a room above the level of the fire-place, whenever there are people or lights in the room, must always be loaded, more or less, with impurity. The purest air of the room is that near the floor, being the last that entered, and the coolest, therefore and heaviest specifically;