_Electrics._ │ _Qualities._ │ _Rubbers._ │ │Every substance with “The back of a cat │Positive │ which it has hitherto │ │ been tried. ───────────────────────┼───────────────────────┼─────────────────────── │ │Every substance Smooth Glass │Positive │ hitherto tried, │ │ except the back of a │ │ cat. ───────────────────────┼───────────────────────┼─────────────────────── Rough Glass │Positive │Dry oiled silk, │ │ sulphur, metals. │ │Woolen cloth, quills, „ │Negative │ wood, paper, sealing │ │ wax, white wax, the │ │ human hand. ───────────────────────┼───────────────────────┼─────────────────────── Tourmaline │Positive │Amber, or air blown │ │ upon it. „ │Negative │Diamond and the human │ │ hand. ───────────────────────┼───────────────────────┼─────────────────────── White silk │Positive │Black silk, metals and │ │ black cloth. „ │Negative │Paper, hand, hare’s & │ │ weasel’s skin. ───────────────────────┼───────────────────────┼─────────────────────── Black silk │Positive │Sealing wax. │ │Hare’s, weasel’s and „ │Negative │ ferret’s skin, │ │ load-stone, brass, │ │ iron, silver, hand. ───────────────────────┼───────────────────────┼─────────────────────── │ │Metals, silk, Weasel’s skin │Positive │ load-stone, leather, │ │ hand, paper, baked │ │ wood. „ │Negative │Other fine furs. ───────────────────────┼───────────────────────┼─────────────────────── Sealing wax │Positive │Metals. │ │Hare’s, ferret’s and „ │Negative │ weasel’s skin, hand, │ │ leather, woolen │ │ cloth, paper.