thimble holder/chamber is directly suspended inside the solvent flask (having a vertical large opening) above the boiling solvent. The thimble is surrounded by hot solvent vapour and maintained at a higher temperature compared to the Soxhlet extractor, thus allowing better extraction for compounds with higher melting points such as bitumen. The removable holder/chamber is fitted with a small siphon side arm and, in the same way as for Soxhlet, a vertical condenser ensures that the solvent drips back down into the chamber which is automatically emptied at every cycle. History William B. Jensen notes that the earliest example of a continuous extractor is archaeological evidence for a Mesopotamian hot-water extractor for organic matter dating from approximately 3500 BC. The same mechanism is present in the Pythagorean cup. Before Soxhlet, the French chemist Anselme Payen also pioneered with continuous extraction in the 1830s. A Soxhlet apparatus has been proposed as an effective technique for washing mass standards. References External links The Soxhlet Extractor explained Royal Society of Chemistry: Classic Kit: Soxhlet extractor Soxhlet apparatus used as a replenishing source of solvent in chromatography Extracting the Spicy Chemical in Black Pepper video demonstrating the use of a Soxhlet extractor to extract piperine from black pepper. thimbles used for Soxhlet extraction Laboratory glassware Laboratory techniques Analytical chemistry Articles containing video clips Laboratory equipment