COMBUSTION CARBONIC ACID. 



a proportionate degree. As this gas is evolved in the flame 

 ef the lamps and candles in a heated and highly expanded state, 

 it will ascend to the ceiling of the room, and will float in a 

 stratum there for a certain time. If means are not provided for 

 its escape it will soon descend into, mix, with, and poison the air 

 of the room, and render it injurious to the health of those who 

 breathe it. 



27. In theatres and other large buildings, which are sometimes 

 illuminated by a central chandelier suspended from the ceiling, 

 an opening is provided over the chandelier, which permits the 

 escape of the carbonic acid, exactly as the chimney of a fireplace 

 or the flue of a stove receives that which is produced by the 

 combustion of the fuel. In all cases whatever, the healthiness of 

 apartments would be greatly increased if similar openings were 

 provided for the escape of the carbonic acid produced by lamps, 

 candles, and other causes. 



28. The effervescence of soda water, champagne, ale, beer, and 

 other similar drinks is produced by carbonic acid, which is fixed 

 in them, and suddenly liberated when relieved from the confining 

 pressure by the withdrawal of the cork. The agreeable pungency 

 of these liquors is in a great degree due to the presence of this 

 carbonic acid, which being allowed to escape by exposure in the 

 air, or by leaving the bottle uncorked, the drink becomes stale 

 and flat. 



AYater commonly contains more or less carbonic acid fixed in 

 it. This being expelled by the process of boiling, cold boiled 

 water acquires a peculiarly insipid taste, owing to the absence of 

 the acid gas. 



It appears that the reception of carbonic acid gas into the stomach 

 is not attended with the same deleterious effects as are produced 

 by its introduction into the lungs. There are few forms of food 

 or drink which do not include more or less of it. 



In general, fermentation is attended with the evolution of car- 

 bonic acid. The gas ejected from dyspeptic stomachs affected by 

 flatulency is carbonic acid. 



29. This gas is abundantly generated in all the spontaneous 

 changes which attend the corruption of dead animal and 

 vegetable matter. In autumn, after the fall of the leaf in woods, 

 forests, and gardens, and in all places where dead leaves are 

 allowed to accumulate, the air is more or less impregnated with 

 carbonic acid, which, by reason of its weight, remains long collected 

 in the lower strata of the air, rendering it unhealthy. 



30. This gas is often collected and retained in the bottom of old 

 wells, where it is known under the name of choke-damp. An 

 animal which descends in such a well dies. 



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