NP just sorta ATD associated...Electrick Fluid and light

[Mark Kohut]

FROM ONE OF HENRY THOREAU'S TEXTBOOKS WHEN HE WAS ABOUT 12, IN 1829:

The earth, and all bodies with which we are acquainted, are supposed to contain a certain quantity of an exceedingly elastick fluid, which is called the electrick fluid. . . . 

Proposition I. The Electrick Fluid, being excited, becomes perceptible to the senses.
...
Experiment I. Let a long glass tube be rubbed with the hand, or with a leathern cushion; the electrick fluid, being thus excited, will attract light substances, and give a lucid spark to the finger, or any metallic substance, brought near it. 
The glass tube is called the electrick, and all those bodies which are capable, by any means, to produce such effects, are called electricks. The hand, or any other body that rubs an electrick, is called the rubber.