Experiments and observations tending to illustrate the nature and properties of electricity. In one letter to Martin Folkes, Esq, President, and two to the Royal Society / by William Watson.

  • William Watson
Date:
1746
Catalogue details

Licence: Public Domain Mark

Credit: Experiments and observations tending to illustrate the nature and properties of electricity. In one letter to Martin Folkes, Esq, President, and two to the Royal Society / by William Watson. Source: Wellcome Collection.

    60/68 (page 52)
    t S7- ] V- melted, and by that Means introduce the Originally-eledtric therein, you obferve the Eleftricity acfts in righfc Lines, and attracis powerfully. And here I muft beg Leave to remind you, not only oi the former Coroilary, but of forne of the former Experiments alfo; by which it appears, that although, to make a Non-elecfric exert any Power, we muft excite the whole Mafs thereof, yet we can excite what Part, and what only, of an Originally- elethric we pleafe. Thus we obferve, that Leaf-gold, and the Secd of Cot- ton-grafs, (which grows upon Boggs and is a very proper Subjeci for thefe Inquiries) are attrafted under a Glafs Jar made warm *, and turned Bot- tom *• I ha ve conftantly obferved, that the elecincal Attradtion through Glafs is much more powerfui, when the Glafs is made warm, than when cold. This Effebr may proceed from a two-fold Caufe* Firft, warm Glafs does not condenfe the Water from the Air? which makes the Glafs, as has been