The ventilation of hospitals has received much attention in France and other parts of the Continent. Dr. Van Eck6 introduced a system in Belgium, which has been copied in some of the French hospitals, on the recommendation of a commission presided over by Dr. Grass6. A btoTo called a ealorifire is placed In the basement story. Air from the garden of the hospital descends a shaft, passes horizontally into the basement, and thence through the stove. The air warmed in the stove passes over a pan of water to imbibe moisture, and then ascends to the wards above. In warm weather the air from the garden is made to paw ue into the wards without passing through the calorifbre, by simply turning a regulating valve. Thus all the air admitted to the wards is derived from thb garden. The warmed air enters each story at the centre of the floor, through small holes. Some of the warm air is in an icier tube, and ascends to the next highest story ; and so on, up to the top range of rooms. The foul air rises from the four corners of each ward, up pipes to the loft., and then to a central drum or shaft. A small steam-engine works a fan to draw out the foul air more quickly. The smoke from the engine fire and from the calorif6re is made to warm a mass of air carried up to the drying-room of the laundry. In England, Dr. Arnott has ventilated the York County Hospital in a peculiar way. There is an air-cylinder with a capacity of 125 cubic feet, moving up and down eight times in a minute, and connected with a beam having a central pivot. A column of water, CO feet high, produces a pressure which forces air into the cylinder, and from the cylinder 2900 cubic feet per minute is forced into the building.
This subject, the ventilating of hospitals, is connected medically with a recent proposition by Dr. Stenhouse to use charcoal as a ven tilating filter for ships and sick rooms. The antLsepjdo properties of charcoal are well known. Dr. Storehouse proposes to employ two sheets of wire-gauze, enclosing a thin layer of powdered charcoal; and to place this apparatus wherever foul air is likely to pass. In some cases it would be well to employ a ventilating fan, to force a passage of the air through the filter. Dr. Stenhouse remarks, that if a layer of coarsely-powdered charcoal were placed under the floors of kitchens and basement rooms, it might prevent, by a sort of filtration, the ascent of offensive sewer odours from beneath.
We may advert, lastly, to an inquiry made in 1859, at the instance of the General Board of Health, by a commission consisting of Mr.
Fairbairn, Mr. Glaisher, and Mr. Wheatstone. Dr. Lyon Playfair was also appointed; but as he could not assist in the investigation, he did not sign the report The inquiry was generally into the modes of warming and ventilating buildings. Experiments were made in the board-room of the General Board of Health, on the temperature of the air, walls, and floor, and on the hygrometric state of the air. Then at the Wellington Barfracks, in different soldiers' rooms, heated by differ ent kinds of open fires. Other experiments were made to determine the effect of duplicate panes of glass; and to determine the chemical and general state of the air.
Among the results at which the commissioners arrived were the following :—Smoke from almost all fires for warming rooms may be avoided. All fire-places ought to be constructed to prevent the forma tion of smoke at all. The ventilation of rooms ought not to be attempted by any peculiar form of grate; the grate ought to be devoted to the due burning of the fuel, leaving the ventilation to be achieved by other means. In all open fire-gratee reflecting surfaces should be used, to increase the amount of heat radiated into the rooms. Chimney flues should be of much smaller dimensions than is customary. The flue should not be situated in the outer wall of the house, so as to become chilled by the external air; it should be provided with a closing aperture, placed far back to increase the intensity of the com bustion. Fire-brick linings should be used. Sunken ash pits and hidden ash should be provided. The grate is best placed when visible from the greatest number of places in the room ; and the burning mass in it should be broad rather than deep. The commissioners agreed with Dr. Arnett, that the grate should not be so near the floor m is now customary in the better kind of houses.
The ventilation of mines is noticed under Mims°.
To those who wish to study this subject in detail, we refer to the volumes on Warming and Ventilation by Tredgold, Hood, Richardson, Arnett, Sutton, Jebb, Lloyd, Burn, Bernan, Reid, and Perkins. The parliamentary Blue Books relating to the new Houses of Parliament, and to the proceedings of the Board of Health, also contain much information on the matter. A cheap, useful, and well-illustrated com pendium of the whole subject will he found in Tomlinson's Treatise on Warming and Ventilation,' forming part of Woale's Rudimentary Series.