Read this sentence from the passage: "i could tell, by their quicksilver speed, that the littlest creatures were accustomed to the approach of larger predators." what does the word quicksilver mean? frightening valuable unpredictable dangerous

Ce some of your french crowns have no hair at all, and then you will play bare-faced. but, masters, here are your parts: and i am to entreat you, request you and desire you, to con them by to-morrow night; and meet me in the palace wood, a mile without the town, by moonlight; there will we rehearse, for if we meet in the city, we shall be dogged with company, and our devices known. in the meantime i will draw a bill of properties, such as our play wants. i pray you, fail me not. who is quince making fun of in this speech?