Licence: Public Domain Mark
Credit: The atmosphere in relation to human life and health. Source: Wellcome Collection.
Provider: This material has been provided by the Augustus C. Long Health Sciences Library at Columbia University and Columbia University Libraries/Information Services, through the Medical Heritage Library. The original may be consulted at the the Augustus C. Long Health Sciences Library at Columbia University and Columbia University.
111/166 page 99
![where there is much organic debris, rmich exceeds that in the atnioB- pheie, and would i)revent the sm-cess of such an experiment. (Iround air passes easily through earth, especially through gravel and sand, so that in the neighborhood of decoinx)osing organic inatter liouses built on such soil are liable to in\'asions ol poisonous gases. (Jarbon monoxide has been known to pass LM) or .50 yards through the earth into a house, causing severe illness. But the worst results follow the infiunous ]»iaetice which has been in vogue at the outskirts of large towns of selling turf and gravel on building sites, allowing the exca- vations to be filled in with rubbish aird refuse, and building dwelling* liouses over these sources of disease. Probably many houses in towns where fever persistently bi-eaks out owe their unwholesorneness to this cause. Even where the soil is natural and undisturbed beneath the foundations, there should always be a layer of impervious mateiial, such as good Portland cement or rock asphalt, between the house and the ground; or else a good space through which the outside air may freely How. Dwellings well raised above the ground escape many dan- gers associated with ground air, damp, and drainage. A damp base- ment is a frequent source of trouble. Hollow skirtings, casings for pipes, bell wires, etc., frequently give opportunities not only to rats and mice, but to deadly gases, to make their way into the apartments. Inquiry is needed to discover the actual quantities of vapor emitted from dift'erent soils and subsoils, at different temi)eratures of air arul soil, at different barometric pressures, at different times of day and night, and at different seasons, and at varying levels of subsoil water. An examination of the ditferent species of microbes or ama*ba like organisms emitted would also be of interest. EMANATION OF ORGANIC PARTICLES FROM EVAPORATING FLUIDS. The spread of infective organisms into the air from the surface of evaporating liquids is a subject worthy of investigation. It has been generally stated and assumed that an evaporating li(piid contaminated with impurities leaves behind it all foreign ingredients and passes into the air as pure vapor. This is very far from being universally true, if evaporation be understood not as a laboratory j^rocess carefully con- ducted, but as a process subject to the various interferences which must occur in natural conditions. Evaporation from the sea may give pure vapor into the air, so long as the sea is tranquil and no bubble breaks on the surface, but the breaking of waves on the ocean and on the shore, and the evolution of gases from animal and vegetable life and organic decay cause evaporation to be accompanied by a consider- able emission of sodium chloride, and of other substances in solution, into the air with the bursting of foam and bubbles and the tearing off of spray by the wind. Marshes give oft' various gases, especially in the drying process, besides vai)or. The upward movement of the air from the drying](https://iiif.wellcomecollection.org/image/b21208724_0111.jp2/full/800%2C/0/default.jpg)
