Device featured in Newton's "Opticks"

PRISM

["**Hint:** This triangular tool bends light to reveal a rainbow.\n\n*(This hint alludes to the prism's shape and its famous effect on light without directly repeating the original clue or giving away the answer.)*"]

**Explanation:** The clue "Device featured in Newton's *Opticks*" leads to the answer **"PRISM"** because Isaac Newton famously used a prism in his experiments on light and optics, as detailed in his 1704 work *Opticks*. A prism is a transparent optical device that refracts light, splitting it into its component colors (the visible spectrum), which Newton demonstrated to study the properties of light. The clue directly references this historical and scientific context, making "PRISM" the clear and correct answer.