So we place them in hydrogen, it reacts with our amino acid, and then we basically heat it and we produce a mixture. Now, once we heat that, we can then take a sample out of that beaker, and we can place it into a special apparatus that essentially collects or determines how much light that solution can absorb. And we do that because after heating the solution of Ninhydrate and the amino acid, we can test the solution for light absorption, because the higher the concentration of that amino acid is inside that solution that contains ninhydrin, the more light our solution actually absorbs. For example, let's suppose we take this first beaker. We add the hydrant to it and we heat it. And so this will turn dark blue or dark purple.