A Soxhlet Extractor is a type of laboratory instrument invented in 1879. It was named after its inventor Franz von Soxhlet. The device was originally designed for the extraction of lipid from a solid material. However, a Soxhlet extractor is not confined to the extraction of lipids only. Typically, a Soxhlet extractor is only required where the desired compound is not completely soluble in a solvent, and the impurity is insoluble in that solvent. If the compound in question is substantially soluble in a solvent then a simple filtration is good enough to separate the compound from the insoluble substance.