Many of us can trace our first interest in the hygiene of ventilation to reading of the ghastly incidents of the Black Hole of Calcutta on a night in June of 1756. The "Hole" was a room, 18 or 20 feet square, having two small windows obstructed by a verandah. One hundred and forty-six Europeans were confined over night in this dungeon. In the morning but twenty-three were taken out alive.
The physical conditions endured by these victims of close air must have included: diminished oxygen tension in the air and corresponding excess of carbon dioxid; excessive heat, combined with humidity; pollution of the air with organic exhalations from the lungs and skin. The effect of this physical environment must have been aggravated by the associated psychic factors of fear and rage.
It would seem to be a very simple problem in this experimental age for a jury of laboratory
SEWALL H. ON WHAT DO THE HYGIENIC AND THERAPEUTIC VIRTUES OF THE OPEN AIR DEPEND?. JAMA. 1912;LVIII(3):174-177. doi:10.1001/jama.1912.04260010176008