This section is from the book "The Home Cyclopedia Of General Information", by Charles Morris. Also available from Amazon: Home Cyclopedia of Necessary Knowledge.
An instrument for the withdrawal of air from a closed vessel, producing an empty space or vacuum; in ordinary air-pumps the vacuum is very far from complete, and in the most perfect of them some air remains. Many interesting experiments may be performed in the exhausted receiver of an air-pump, such as the boiling of water at a much lower than the usual temperature, and the extinguishing of a candle, a proof that air is necessary to combustion.
 
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