And that is what causes precipitation crystallization out of the solution. And this is known as salting out. So an application of salting out is basically purification. So purifying our proteins, as we'll see in just a moment. Now, this can be done because different proteins are composed of different amino acids, and different amino acids contain different hydrophilic and hydrophobic nature. So, because proteins consist of different variation of amino acids, they have different solubilities in water.