| VOLUMES OF CARBONIC ACID IN 10,000 VOLUMES OF AIR. | |
|---|---|
| On the mountains and moors of Scotland—mean of 57 analyses | 3·36 |
| In the streets of Glasgow—mean of 42 analyses | 5·02 |
| London, N., N.E., and N.W. postal districts—mean of 30 analyses | 4·384 |
| London, E. and E.C.—mean of 12 analyses | 4·745 |
| Manchester streets, ordinary weather | 4·03 |
| During fogs in Manchester | 6·79 |
The effects of carbonic acid gas alone must be carefully distinguished from those of the same gas plus the organic impurities from respiration, with which it is commonly associated. Dr. Angus Smith found that air containing 3 per cent. of carbonic acid produced difficulty of breathing, but he was able to breathe comfortably an atmosphere containing 0·2 per cent. carbonic acid. Other observers have found they could breathe without discomfort air containing 1 per cent. carbonic acid. When the carbonic acid is derived from respiration, headache and giddiness are produced in many persons when the carbonic acid amounts to 0·15 per cent. A fatal result has occasionally occurred from the inhalation of the carbonic acid at the bottom of brewing vats, or about lime-kilns. The gaseous impurity at the bottom of wells is more commonly nitrogen than carbonic acid (page [102]).
The presence of an excess of carbonic acid diminishes the elimination of carbonic acid from the lungs, nutrition and muscular energy being consequently impaired. This is seen in workshops where the air is confined and gaslight is commonly employed; though the air here also contains carbonic oxide, sulphurous acid, and organic impurities, and these probably have a large share in producing the evil results.
(2) Carbonic Oxide in the proportion of more than 1 per cent. is rapidly fatal, and has poisoned when under ½ per cent. Poisoning by its means occurs where charcoal stoves are used, and especially when the charcoal is burnt in rooms with no chimney flue. This is an occasional mode of suicide on the continent. Carbonic oxide is a much more deadly poison than the dioxide (carbonic acid); it forms a stable compound with the hæmoglobin of the red blood-corpuscles, displacing oxygen from them, and is got rid of with great difficulty. Lace-frame makers place a coke stove under their work, and thus inhale the invisible gas. Headache, giddiness, irregular action of the heart, and depression of the general health result. Carbonic oxide is the most poisonous constituent of coal-gas, and is present in much larger quantity in carburetted water-gas with which coal-gas is now commonly mixed, than in pure coal-gas (page [115]).
(3) The inhalation of Sulphuretted Hydrogen produces headache, nausea, and diarrhœa; but in manufactures involving the inhalation of a small proportion of this gas the symptoms are much slighter.
(4) Sulphurous Acid is always present in small quantities in the air of towns, derived from the combustion of coal and coal-gas. Straw-bleachers and the bleachers in cotton and worsted manufactories, often suffer from severe cough and bronchitis due to inhaling its irritating vapours.
(5) Carbon Disulphide when vaporised and inhaled produces headache, general muscular pains, and nervous depression. It is used in the manufacture of waterproof coats, toy balloons, etc.
(6) Ammonia produces irritation of the eyes and bronchial irritation. Hat-makers commonly suffer from its effects, being generally pale and feeble. It is difficult to say how much is due to the ammonia, and how much to the high temperature at which they work.
(7) Acid Fumes are very irritating to the lungs, and in the case of alkali manufactures, they destroy all vegetation for considerable distances. Hydrochloric acid produces great irritation, and chlorine even more so. The fur-dyer is not only subject to the dangers of dust, but also of the fumes of nitric acid, used to remove fat and give certain shades of colour to the fur.
(8) Other Vapours evolved in various processes produce special symptoms. House-painters suffer from the inhalation of turpentine vapour, headache and loss of appetite commonly resulting. The symptoms from the commonly coexistent lead-poisoning are distinct. Brush-makers have a persistent cough, due to the inhalation of resinous fumes, evolved in making brushes.