A white crystalline compound melts at 111°–112°C and the melting-point capillary is set aside to cool. Repeating the melting- point analysis with the same capillary reveals a much higher melting point of 140°C. Yet repeated recrystallization of the original sample yields sharp melting points no higher than 114°C. Explain the behavior of the sample that was cooled and then remelted.