What did Newton observe about viscosity and temperature?

Isaac newton observed that the viscosity of fluids generally decreases as temperature increases. This is because higher temperatures provide more energy to the fluid molecules, allowing them to move more freely and reducing resistance to flow. Consequently, Newton formulated a relationship that described how the viscosity of a fluid is affected by temperature, which laid the foundation for understanding fluid dynamics. His insights remain fundamental in both theoretical and practical applications in physics and engineering.