corundum, synthetic corundum.7, gems

An account of Edward Daniel Clarke’s experiments with the gas blowpipe, an apparatus producing an intensely hot flame through the combustion of mixed gases. Clarke describes the construction and operation of the instrument and its application to experiments on minerals, metals, earths, and other substances exposed to very high temperatures. The work records observations on fusion, alteration, and related reactions and is significant in the development of blowpipe analysis as a technique for identifying and investigating minerals, including gem materials.