Two Hope's eudiometers
Named after the Scottish chemist Thomas Charles Hope, this eudiometer was primarily used for analysing atmospheric air in lecture-demonstrations. It is in two parts: the tube containing the air sample was inserted in the neck of a small bottle filled with an alkali sulphide solution for absorbing the oxygen slowly. Next, the amount of absorption was measured by placing the bottle under water, removing its side stopper and noting the level of water rising into the graduated tube. Hope succeeded Joseph Black as Professor of Chemistry in Edinburgh in 1799.