Melting point apparatuses determine the melting point of a substance. Most melting point apparatuses have a unique exterior look, but the interiors all house a melting point capillary. The solid sample is sealed inside the capillary and placed inside the apparatus. The sample is heated by an oil or heating block. As the temperature increases, the sample turns from a solid to a liquid. The melting point apparatus records the temperature range of the melting procedure and allows you to review the process.