19-year-old Helena Muffly wrote exactly 100 years ago today:
Monday, April 20, 1914: There wasn’t much coming this way except the rain.
Her middle-aged granddaughter’s comments 100 years later:
This was the second rainy day in a row. According to a book published in 1914, The Principles of Hygiene by D.H. Bergey, MD, there was a relationship between weather and health.
The Influence of Precipitation on Health
The immediate effect of a fall of rain is to cleanse and purify the air from dust of all sorts, organic and inorganic, and from micro-organisms. So far the influence of rain is decidedly beneficial to health; but when rainfall is so excessive as largely to increase the humidity of the air, its hygienic effect becomes merged in that of humidity.
The Influence of Humidity on Health
If the relative humidity be increased, there will be a hindrance to the escape of water from the body; and when this condition is combined with a high temperature the heat is far more oppressive than when the atmosphere is dry and allows free evaporation. On the other hand, a moist, cold atmosphere is far more distressing than when the air is dry, and there is but little movement.
The Effects of Wind Upon Health
It is complex and not well defined how wind affects health. All wind favors evaporation, and therefore loss of heat from the body. Winds that are and moist are mild and relaxing; dry, cool winds are bracing; but cold winds are penetrating, and considered dangerous to persons of delicate constitutions.
Sunlight as a Disinfectant
Sunlight is an efficient disinfectant. This agent is constantly acting and, no doubt, removes most of the detrimental agents on surfaces exposed to the sun. Most bacteria grow best in the dark.