Lessons In Electric Circuits, Volume I – DC By Tony R. Kuphaldt Fifth Edition, last update October 18, 2006….1.1 Static electricity
It was discovered centuries ago that certain types of materials would mysteriously attract one another after being rubbed together. For example: after rubbing a piece of silk against a piece of glass, the silk and glass would tend to stick together. Indeed, there was an attractive force that could be demonstrated even when the two materials were separated…..

The table of electric currents and their various bodily effects was obtained from online (Internet) sources: the safety page of Massachusetts Institute of Technology (website: (http://web.mit.ed /safety)), and a safety handbook published by Cooper Bussmann, Inc (website: (http://www.bussmann.com)). In the Bussmann handbook, the table is appropriately entitled Deleterious Effects of Electric
Shock, and credited to a Mr. Charles F. Dalziel. Further research revealed Dalziel to be both a scientific pioneer and an authority on the effects of electricity on the human body. The table found in the Bussmann handbook differs slightly from the one available from
MIT: for the DC threshold of perception (men), the MIT table gives 5.2 mA while the Bussmann table gives a slightly greater figure of 6.2mA. Also, for the ”unable to let go” 60 Hz AC threshold (men), the MIT table gives 20 mA while the Bussmann table gives a lesser figure of 16 mA…..

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