Robert Angus Smith

“ The amount of air wanted is wonderfully small; we do not know how much the carbonic acid may rise, but it must be very high. The organic matter is frozen, and is probably condensed on the ice; it may be inhaled as a solid, and in a form not to affect the smell. For a similar reason we require less ventilation in cold weather: it is not foolish, as some will endeavor to persuade us, to take less, but it is a natural instinct. We object to the cold, and we learn that heat is a more pressing want than even pure air, whether the organic matter affects our senses or not. ”

“ Yet the evil of small rooms is great, because rapid currents are required for ventilation; cold currents are hurtful, and the warm difficult to obtain. If, however, we could obtain warm-air currents, it would not be important for us to have the rooms so large. It is a question of price. I believe the warmth must be obtained as the first demand of Nature, and without it civilization will go back. When men are cold, they give themselves to physical exercise, and, if that is impossible, to discomfort, in which the mind refuses to do more than to complain, if it cannot forget. ”

“ We may next ask, Is there any advantage in rapid currents at any time? There is; in the case of infectious diseases, it would seem in the abstract to be of the greatest importance that the patient should be in a current, speaking as a chemist, and not a physician. The first reason is for his own sake. Even in health we poison ourselves, and in disease we tend more rapidly in the same direction. Infectious emanations may be collecting round a patient, and, if so, the still air will keep them more carefully near him. ”

“ It is, however, better for us to have what is called practically dry air—that is, air capable of containing much more moisture than it has. The amount of drying work done is according to the dryness, warmth, and speed of the air; with little of these qualities, a great bulk of air is required, where otherwise a small bulk might have sufficed. By warmth and dryness we have an advantage in requiring less rapid currents. I have said elsewhere that a climate has a certain advantage from being very rainy. To call dryness an advantage is not a contradiction. ”

“ Nature has employed them for disinfection more than any others. The whole soil of the earth is a great disinfectant, kept in constant activity, being constantly required, holding; in itself the most nauseous and unwholesome things, and still having healthy people living over it. However, the soil may be too full, and at times it becomes so, and therefore we run to places which cannot contain much impurity, such as bare rocks; and in such places we obtain pure air. If in houses we have too much organic matter for the porous substances to oxidize, we must resort to non-porous surfaces ”

“ If the day be warm, we may pass from a room having .06 in a hundred of carbonic acid to the air with .03, and feel refreshed. If the day is not warm, we do not feel the difference; at least, such persons as I have examined do not. The conclusion is that, in the early stages of the want of ventilation, the organic exhalations are the most injurious. Now, these increase with the temperature, while the acid does not. For this reason we ventilate in warm weather for the organic matter far more than for the sake of the acid. ”

“ If we could drive the impure air in a similar way in a narrow current toward its exit, we might manage ventilation with a very small amount of air. To do this is a matter of great importance, because the expense of building is becoming so great, that very few men can afford to pay for a large enough house, and, while rents are rising, the rooms of the middle classes have actually diminished in some places, and within these few years. ”

“ The moisture has organic matter in it which is not removed by mere drying, and the effects are very long in leaving. We may know this from breathing the air of any bedroom in a London hotel, or in most private houses in towns. People are afraid to keep their windows open, because of the smoke without, and so they retain the organic matter. We can readily smell this, even if arising from healthy persons, and it has ceased to be a matter of surprise. If unhealthy persons are present, unhealthy matter may be expected to diffuse. ”

“ In inhabited rooms the moisture increases as much as the organic matter, and the condition of the air is similar to that of the evenings of summer: whenever the temperature goes down a little, there is a deposit of dew; but, when the warmth increases, the air is laden with moisture, and the condition resembles that near a warm close vegetation. In both cases ventilation is wanted. Our walls become saturated with moisture if they are porous, if not porous they are covered with streams of water. ”

“ The world must be told every thing in ten thousand different ways before it learns, and it is wearisome to repeat the lesson. I am only saying, also, what every clean house-keeper carries out; and yet there is an apparent novelty in it when we compare it with the sayings and doings of many persons, intelligent and observing although they be.—Air and Rain. ”

“ Disease seems to creep along the ground; the causes may be at a considerable height, but we are compelled to suppose them very thinly disseminated there; and the action seems to be according to quantity as well as intensity; toward the surface they congregate and are active. This we see from the evening air, especially in marshy places; it is only after a certain repetition of the attack of the more thinly diffused wandering substances falling down from the atmosphere and accumulating, that men yield to the influence. ”

“ As to the imperfect mixing, it is so various and characteristic that we cannot reduce it to rules; we may hold a smoking substance in the midst of an apartment, and find the smoke go directly to an opening without mixing with the air of the room. It goes, too, with a velocity greater than that of the air of the room, otherwise an opening must be supposed sufficient to change the whole air of the room in a few seconds, that being the time required for the smoke to reach the opening. ”

“ We ventilate to remove smoke and ordinary dust; these are easily seen; and we use ventilation to procure dryness. Moisture rises constantly from the skin, and, if an inhabited apartment is not ventilated, that moisture accumulates. By opening the windows we cause floors to dry sooner, and we remove moisture from all the apartments, and that moisture has generally organic matter with it. If we ventilate with very moist air, we shall dry nothing; if we have very dry air, we may dry too thoroughly. ”

“ Perhaps we cannot have rapid currents in large rooms very easily, so much air is required; but we can have frequent changes of air. It is clear, however, that the rapid removal of the air collecting around patients with infectious diseases, and probably also non-infectious, is most likely to promote health, both in the patients and in the attendants. Few people can stand the rapid motion of cold air, and, if we must have rapid currents, they must be heated. ”

“ To purify rooms the air must blow long into them, or every part must have the organic matter rubbed off by the hand. This is a sufficient rule for both hospitals and private houses. Good rubbing will purify furniture, and this our housewives know; long-continued currents of air are also known to be good, but better as a supplement to rubbing. ”

“ The first is certainly the dislike to organic-smelling substances evaporated from living beings. As some of them are very volatile, a very little rise of temperature increases their amount; and, in warm weather, we require a change of air so frequently, that we cannot make any use of the carbonic-acid test. The amount of change is infinite; we require it for every breath, and we do not consider whether a door is sufficiently open ”

“ Which is cheapest for us? Is it to build large rooms and to have less warmth with slow currents, or to build small rooms and to have more warmth with rapid currents? It is to be wished that the former should be the rule for private houses; more comfort and convenience are promised, and mechanism is not required; if it were, it could not be obtained. For hospitals, the use of mechanism is more within possibility. The expense of large rooms, when the architecture is of a kind intended to ornament a capital city, is very great. Should we not gain by a judicious system of warming? ”

“ It furnishes, however, one of the most important and probably the most important of the reasons in every-day life, because carbonic acid is the most rapidly hurtful to animal life of all the emanations from the person. It lowers the vitality rapidly, and kills with indefinite warning. The best warning is the organic matter, which acts for both. The warning by carbonic acid is called indefinite, because people lose vitality, but do not observe that the cause is in the atmosphere, there being no smell connected with that gas. ”

“ The source of the air with which we ventilate ought probably to be high in all cases, but even here we must move slowly. We are not quite sure that any infectious disease ever sends its emanations high into the air. ”

“ IT is often asked how much fresh air we must allow to come into a room in order to keep it wholesome. The amounts vary so much that we shall never be able to answer the question as it arises in all its changes, unless we consider our reasons for ventilating. ”

“ The knowledge of the smell cannot be taught, but it may guide us to much that can be taught. Ventilation for this class of bodies will be probably much more attended to in future; care must be taken to drive them to the nearest opening, and not to allow them to diffuse themselves through the room in which they may be produced. ”

“ The leather of the bookcase was said to show the inorganic bodies; the books themselves are covered with the organisms when care is not taken, so that one small room gives an epitome of the whole subject. ”

“ About five times that amount affects a candle sensibly, a photometer being used, and it is extremely probable that less affects it also. Are human beings affected as readily? I rather avoid this question at present; we have not facts enough. We will now speak of the gas in conjunction with organic matter. ”

“ Such substances absorb moisture in some seasons, and give it out slowly at others. Our clothes are of this kind. It is not possible to have warm coverings not porous. Porous bodies hold also a good deal of air, and they cause oxidation more readily. ”