The second is, the gauzes and ribbons being wetted, the ribbons are all attracted equally, and all the pieces of gauze equally intercept the action of electric bodies.

The third is, that the colors of a prism being thrown on a white gauze, there appear no differences of attraction.

Whence it proceeds that this difference proceeds, not from the color, as a color, but from the substances that are employed in the dyeing.

For when I colored ribbons by rubbing them with charcoal, carmine, and such other substances, the differences no longer proved the same." In connection with his experiments with his thread suspended on glass poles, Dufay noted that a certain amount of the current is lost, being given off to the surrounding air.

He recommended, therefore, that the cords experimented with be wrapped with some non-conductor--that it should be "insulated" ("isolee"), as he said, first making use of this term.
DUFAY DISCOVERS VITREOUS AND RESINOUS ELECTRICITY It has been shown in an earlier chapter how Von Guericke discovered that light substances like feathers, after being attracted to the sulphur-ball electric-machine, were repelled by it until they touched some object.