Our science teacher Mr. Geoffrey had a science experiment which was about Evaporation to Dryness with his class P5. 
What is Evaporation to Dryness ?
When a solution containing dissolved solutes is heated, the solvent will evaporate. Only the solute (residue) will remain in the evaporating dish. Evaporation to dryness cant be use for solutions like sugar solution cause the Sugar will decompose upon heating. They have used salt for this experiment.