[127] PAGE 48, LINE 34. Page 48, line 38. _Sed vt poteris manifestè experiri...._ Gilbert's experimental discoveries in electricity may be summarized as follows: 1. The generalization of the class of _Electrics_. 2. The observation that damp weather hinders electrification. 3. The generalization that electrified bodies attract everything, including even metals, water, and oil. 4. The invention of the non-magnetic _versorium_ or electroscope. 5. The observation that merely warming amber does not electrify it. 6. The recognition of a definite class of _non-electrics_. 7. The observation that certain electrics do not attract if roasted or burnt. 8. That certain electrics when softened by heat lose their power. 9. That the electric effluvia are stopped by the interposition of a sheet of paper or a piece of linen, or by moist air blown from the mouth. 10. That glowing bodies, such as a live coal, brought near excited amber discharge its power. 11. That the heat of the sun, even when concentrated by a burning mirror, confers no vigour on the amber, but dissipates the effluvia. 12. That sulphur and shell-lac when aflame are not electric. 13. That polish is not essential for an electric. 14. That the electric attracts bodies themselves, not the intervening air. 15. That flame is not attracted. 16. That flame destroys the electrical effluvia. 17. That during south winds and in damp weather, glass and crystal, which collect moisture on their surface, are electrically more interfered with than amber, jet and sulphur, which do not so easily take up moisture on their surfaces. 18. That pure oil does not hinder production of electrification or exercise of attraction. 19. That smoke is electrically attracted, unless too rare. 20. That the attraction by an electric is in a straight line toward it. [128] PAGE 48, LINE 35. Page 48, line 39. _quæ sunt illæ materiæ._--Gilbert's list of electrics should be compared with those given subsequently by Cabeus (1629), by Sir Thomas Browne (1646), and by Bacon. The last-named list occurs in his _Physiological Remains_, published posthumously in 1679; it contains nothing new. Sir Thomas Browne's list is given in the following passage, which is interesting as using for the first time in the English language the noun _Electricities_: