II. London Air.—Carbonic Acid, Metropolitan Railway, November, 1869.
| Date. | Place. | Time of Day. | Carbonic Acid, per cent. | Oxygen, per cent. | |
| 1869. Nov. | 12. | Tunnel between Gower Street and King’s Cross Stations; specimen taken at the open window, first-class carriage. | 10 a.m. | ·150 | 20·60 |
| ” | 12. | Tunnel between Gower Street and King’s Cross Stations; specimen taken at the open window, first-class carriage. | 7·30 p.m. | ·078 | 20·79 |
| ” | 12. | Tunnel Praed Street; specimen taken at the open window, first-class carriage. | 10·30 a.m. | ... | 20·71 |
| ” | 15. | Specimen taken during journey between Gower Street and King’s Cross, first-class carriage, window open. | 10·15 a.m. | ·338 | 20·66 |
| ” | 15. | Same | 3 p.m. | ·155 | 20·70 |
| ” | 15. | Same | 11 p.m. | ·150 | 20·74 |
| Average | ·1452 | 20·70 |
Angus Smith.
The Air of Mines (Metalliferous).
| Name of Mine, and depth from surface, in fathoms. | Description of place, where taken and time when taken. | Thermometer, Fahr. | Number of Men working in it. | Oxygen, per cent. | Carbonic Acid, per cent. |
| Hurst | End, 300 ft. beyond a rise, 9 ft. high, 7 ft. wide. | ... | 2 | ... | 1·99 |
| Old Gang | End of level | ... | 2 | 20·58 | ·48 |
| ” | End of level | ... | 2 | ... | ·28 |
| ” | (a) Rise 7 ft. high, 132 ft. from current. | ... | 2 | 20·25 | ·39 |
| Grassington | (b) End of cross cut, 480 ft. from rise. | ... | 2 | 20·94 | ·06 |
| ” | End, 480 ft. from rise. | ... | 2 | 19·53 | 1·59 |
| ” | Rise 60 ft. high in shale. | ... | 2 | 19·52 | 1·72 |
| ” | End, 60 ft. from rise. | ... | 2 | 20·47 | 1·06 |
| ” | (c)End, 840 ft. from rise. | ... | 2 | 20·08 | ·94 |
(a) Air machine.
(b) Unusual amount of dust.
(c) Crystals were chiefly hexagons.
Angus Smith.
The following table, showing the amount of ammonia present in rain collected at the different places named, is from Dr Smith’s work, ‘Air and Rain.’
| Comparative. | Ammonia. |
| That of Valentia (Ireland) taken as 1 or 100. | |
| Ireland, Valentia | ·1 |
| Scotland, sea-coast, country places, west | 2·69 |
| Scotland, inland, country places, west | 2·96 |
| Scotland, sea-coast, country places, average | 4·10 |
| Scotland, sea-coast, country places, east | 5·51 |
| England, inland, country places, east | 5·94 |
| England, sea-coast, country places, west | 10·55 |
| German specimens | 10·61 |
| London, 1869 | 19·17 |
| Scotland, towns (Glasgow not included) | 21·22 |
| St. Helen’s | 25·33 |
| Runcorn | 25·72 |
| England, towns | 28·67 |
| Liverpool | 29·89 |
| Manchester, 1869 | 35·33 |
| Manchester, 1869 and 1870, average | 35·94 |
| Manchester, 1870 | 36·54 |
| Glasgow | 50·55 |
The effects resulting from breathing an impure atmosphere are necessarily dependent upon the extent of the pollution and other conditions. When the contamination is moderate the first effect is headache, accompanied with lassitude, and a general paleness of the face and skin, owing to a diminution of the red corpuscles of the blood or to their imperfect aëration; the pulse becomes lowered, and at the same time the breathing is accelerated. When in addition to breathing such air from day to day is superadded the misfortune of an insufficiency of food, scrofula and consumption very often follow. Dr Guy has demonstrated the great mortality that is caused by consumption in those trades in which workmen pursue their calling in hot, close, gas-lit rooms, in comparison with those who pass most of their time in the open air. The amount of air required by each person in a room is no less than 2100 feet per hour; when the ventilation does not supply this amount of fresh air, the apartment smells stuffy, the furniture becomes coated with a film of organic matter, unless constantly cleaned, and the carbonic acid becomes increased beyond its normal quantity.