I went to see divers gardens about London: returning, I saw at Dr. Joyliffe's two Virginian rattlesnakes alive, exceeding a yard in length, small heads, slender tails, but in the middle nearly the size of my leg; when vexed, swiftly vibrating and shaking their tails, as loud as a child's rattle; this, by the collision of certain gristly skins curiously jointed, yet loose, and transparent as parchment, by which they give warning; a providential caution for other creatures to avoid them. The Doctor tried their biting on rats and mice, which they immediately killed: but their vigor must needs be much exhausted here, in another climate, and kept only in a barrel of bran.