How can you use a heating curve to find the melting and boiling point

Explanation:

A heating curve graphically represents the phase transitions that a substance undergoes as heat is added to it. ... The first change of phase is melting, during which the temperature stays the same while water melts. The second change of phase is boiling, as the temperature stays the same during the transition to gas.

the old alchemists made significant contributions to science even though there starting premises were off a bit. their conclusions after failure would steer them into better directions for investigation. science is no more than close observation and the initial mistakes result in rethinking and retrying experiments.