Jurins law, or capillary rise, is the simplest analysis of capillary action—the induced motion of liquids in small channels—and states that the maximum height of a liquid in a capillary tube is inversely proportional to the tubes diameter. Capillary action is one of the most common fluid mechanical effects explored in the field of microfluidics. Jurins law is named after James Jurin, who discovered it between 1718 and 1719.  His quantitative law suggests that the maximum height of liquid in a capillary tube is inversely proportional to the tubes diameter. The difference in height between the surroundings of the tube and the inside, as well as the shape of the meniscus, are caused by capillary action. The mathematical expression of this law can be derived directly from hydrostatic principles and the Young–Laplace equation. Jurin's law allows the measurement of the surface tension of a liquid and can be used to derive the capillary length.