Hay Test
Objective Hay Test is used to prove that bile acids reduce water surface tension. Base Theory Normal water have high surface tension that make difficult to forming misel in the gut, so our body secreted bile acids to reduce water surface tension. Activity of bile acids can help human body to transfer and absorb fats from food. It is possible to observe this by colloidal sulphur (sulphuric powder). Procedure Add 3 ml of water into two test tubes. To one of them add one drop of bile salt solution, next pour colloidal sulphur to both of them. Shake it once. In the tube with bile salt colloidal sulphur falls quickly, but in the other one, without bile salt, it stays on water surface.