Air electricity - the early studies
Electricity in the air - the science
Electricity has intrigued mankind for a very long time. Even the Ancient Greeks were able to produce "static" electricity by rubbing certain materials together.
During the 18th century there was a lot of interest in both "static" and "air" electricity:
In 1748, the French abbot, L'Abbe Nollet found that plants placed under charged electrodes grew faster. (He used a mechanical friction device to produce "static" electricity)
In 1752, Benjamin Franklin famously flew a kite in a thunderstorm to prove that lightning was a form of electricity. Always on the lookout for storms for his experiments, he built an "early warning" device which he called his "Lightning bells". Franklin then observed: "I found the Bells rang sometimes when there was no Lightning or Thunder, but only a dark Cloud over the Rod..." (indicating the presence of "air electricity" in the cloud)
And in 1775, Father Gian Battista Buccaira of the University of Turin, Italy, wrote: "It appears manifest that nature makes extensive use of atmospheric electricity for promoting vegetation ..... and we have also observed that artificial electricity has the same effect"
One of the first studies in the 20th century was made by Albert Einstein who, in 19l0 along with a colleague Conrad Harbicht, took as a Ph.D. thesis, the question of why the mountain air of Davos was renowned for its health-giving properties. They decided it was "Air Electricity". Einstein went on to consider other matters. And Harbicht later raised funds to continue his research.
We now know that "air electricity" is actually air ions. These can be either negatively or positively charged.
In 1932, Dr Hansell stumbled on the behavioural effects of artificially generated ions. He noticed a startling swing in the moods of a fellow RCA scientist who worked beside an electrostatic generator. Some days the scientist finished the day alert and in bubbling good spirits. On the other days he was rude, ill tempered and depressed. It turned out the machine was producing positive and negative air ions.
Dr Hansell investigated further and found that the scientist was happy when the generator was adjusted to produce negative ions but morose when it was producing positive ions. Soon after, results from European research confirmed these findings.
Since then advances in technology have enabled scientists to study the process in much more detail and thousands of scientific papers have been published on the subject.