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.
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![are still warm and the air is rapidly cooling. When the microbes are dense in the humid and misty low stratum of air, and when the human body is being ([uickly chilled, tliey are able to attack successfully. The microbe is probably a very common and widely diffused one, and may be ijresent in comparatively small projxjrtion and in less vigor in the lower air generally over the land. At sea it would be absent, and indeed there is good evidence tluit it does Tiot bear long transport in a virulent state in the free air. Colds are scarcely ever caught on the o])en sea, even if the clothes be Avet with salt water, and breezes straight from the Atlantic do not seem ca[)able of inducing sore throat or cold. But, of course, to make an experiment crucial, i)revious life in the oi>en air, disinfection of clothes and if ijossible of the breathing organs, would be necessary. It is not improbable that the microbe of colds, like that of pneumonia, may be freipiently present in the mouth. The experience of St. Kilda,' which used to be absolutely free from colds until the annual boat arrived from the mainland, points to the ordinary presence of the infective particles on clothes or in the breath. The islanders were nearly all struck down with severe colds within a day or two after welcoming their visitors. Probably a similar dose of infection would be quite insufficient to prostrate jiersons on the mainland who were accustomed to the petty assaults of the microbe, and protected by scarcely noticed symptoms of catarrh. An exactly similar thing occurs in the case of influenza. Hundreds of instances were observed in which the proximity of persons who had had inlluenza or had been near cases of influenza gave it to others, and often persons lately arrived in a place which had passed through the epidemic were struck down while the great majority of the resident population remained protecte<l, at least for some months. Colds protect against their own recurrence in most people for some months. Severe colds go through a house after the manner of an infec- tious disease, and can be similarly guarded against by isolation. The air certainly conveys a cold for several feet through confined air, and in a closed railway carriage susceptible persons who have been free from colds for some time are easily infected. An attack is often attrib- uted to a chill felt at the beginning of the infliction, but in reality the cold has usually been caught some hours or a day or two before, and the feeling of chill is simply the beginning of the disorder, as in other infectious maladies. On the other hand, there may be a real chill, which gives opportunity to the microbe to make its attack and produce a feverish cold in a day or two. Foul air and crowded rooms are emi- nently conducive, especially if combined with drafts, to disseminate colds. Persons arriving in town from the pure air of the. country or from a sea voyage are very apt to catch cold. They have been living aj)art 'Anil other islands. See Darwin's Naturalist's Voyage. Report of the Local Goverumeut Board; Ei)idemic luUueuza, Loudon.](https://iiif.wellcomecollection.org/image/b21208724_0083.jp2/full/800%2C/0/default.jpg)
