Staedel apparatus for the collection of nitrogen, on two stands

Staedel's apparatus, described in 1880, is an improved method for the collection of nitrogen in Dumas' method of analysis.

Gas produced from the combustion of the unknown compound passes into the bulb below the graduated tube by way of the side-arm. Carbon dioxide is removed by the caustic potash solution contained in this bulb then the stopcock is opened allowing the residual nitrogen to pass into the graduated tube for measurement. The reservoir is used to equalize the pressure on the gas.