FOUL AIR AND DISEASE OF THE HEART. 191 



From these effects it is certain tbat confinement to an atmosphere 

 impregnated with carbonic acid, even to the extent of one per cent, 

 only, quickly deranges the function of the heart, and ultimately dete- 

 riorates the tissues themselves of that organ. 



The greater the percentage of carbonic acid in the air respired, 

 the more quickly and the more profoundly are these effects produced. 

 The constant breathing of air containing one per cent, only of car- 

 bonic acid proves fatal to life ; but, if it is respired for a short time 

 only, functional disturbance alone is then and there produced. It is, 

 however, certain that in this functional disturbance lie the germs of 

 organic mischief, and that frequent repetition of the cause will un- 

 doubtedly end in organic disease. Hence the impure atmosphere of the 

 bedrooms of the poor, and, indeed, of many of the middle class, proves 

 a sharp spur to the degenerative tendency manifested by the heart, and 

 especially by the right side of the heart, after the age of forty. Such 

 bedrooms are generally small in their superficial area, low-pitched, 

 and often lighted by a diminutive window, which at night is kept 

 constantly closed; and having a door which opens to the interior of 

 the house, but which is also closed during the occupation of the rooms. 

 Nay, to prevent the slightest admission of fresh air, the crevices of 

 both window and door are most carefully stopped ; and, to render the 

 matter still worse, a fire is not unfrequently kept burning during the 

 winter nights. 



What must be the effect produced upon the air of such rooms un- 

 der the conditions named ? I take, for example, an average-sized bed- 

 room in the cottages of the poor say, a room twelve feet long, ten 

 feet wide, and eight feet high. This gives a cubical space of 960 feet, 

 which is not more than half the cubical space allowed each patient in 

 our best-arranged hospitals. In this room, with its diminutive win- 

 dow and door constantly closed, three, four, and frequently a greater 

 number of persons pass the night of eight or ten hours' duration. 

 No provision has been made for the admission of fresh air none for 

 the escape of the carbonic acid exhaled during respiration. What lit- 

 tle provision did exist in the crevices formed by the badly-fitting door 

 and window has been carefully abrogated by sand-bags, rolls of rags, 

 and stuffing of every description. Thus the air of the room becomes 

 poisoned with carbonic acid, and in this condition it is breathed and 

 rebreathed, to the manifest injury of the heart. 



A simple calculation will enable us, if not to determine with ex- 

 actitude, at least to approximate to the amount of carbonic acid ex- 

 haled by each sleeper, and consequently to the degree of vitiation 

 which the air of the apartment undergoes. I fix the number of respi- 

 rations at its minimum 14 per minute ; the quantity of air exhaled at 

 each expiration at 20 cubic inches ; the quantity of carbonic acid con- 

 tained in the expired air at 4 per cent. ; and the duration of the night 

 at 8 hours. Hence, 14x20x8x60=134,400 cubic inches, or 77.77 



