Experiment IX
We took a Leaf of Such Foliated Gold as Apothecaries are wont to Gild their Pills with; and with the Edge of a Knife, (lightly moysten’d by drawing it over the Surface of the Tongue, and afterwards) laid upon the edge of the Gold Leaf; we so fasten’d it to the Knife, that being held against the light, it conctinu’d extended like a little Flagg. This Leaf being held very near the Eye, and obverted to the Light, appear’d so full of Pores, that it seem’d to have such a kind of Transparency as that of a Sive, or a piece of Cyprus, or a Love-Hood; but the Light that pass’d by these Pores was in its Passages So Temper’d with Shadow, and Modify’d, that the Eye discern’d no more a Golden Colour, but a Greenish Blew. And for other’s satisfaction, we did in the Night look upon a Candle through such a Leaf of Gold; and by trying the Effect of Several Proportions of Distance betwixt the Leaf, the Eye and the Light, we quickly hit upon such a Position for the Leaf of Gold, as that the flame, look’d on through it, appear’d of a Greenish Blew, as we have seen in the Day time. The like Experiment try’d with a Leaf of Silver succeeded not well.