The sample should be loaded into a relatively cool apparatus with the closed end of the sample tube down. Most melting point apparati can hold up to three samples.
Why should the melting point apparatus be cool prior to the experiment?
Answer
The machine must be cooled to a temperature well below the
expected melting point before the experiment is begun. If the
melting point apparatus is warm when the sample is put into it, the sample may
melt immediately. Then, you will have to allow the sample and the apparatus to cool. When the solid re-solidifies, it will be more difficult for you to observe when the solid begins to melt.
Why should the melting point apparatus be cool prior to the experiment?