Art. LVI.—On the Bromine Method of Estimating Sulphur in Gaseous Compounds.

Transactions and Proceedings of the Royal Society of New Zealand, Volume 29, 1896, Unnumbered Page

Art. LVI.—On the Bromine Method of Estimating Sulphur in Gaseous Compounds. By Dr. W. P. Evans. [Read before the Philosophical Institute of Canterbury, 30th November, 1896.] A Slight modification of the well-known Harcourt method of estimating sulphur in coal-gas seems capable of rendering-good service in the analysis of gaseous substances in general. For coal-gas a very simple form of apparatus gives excellent results. The gas is passed at the rate of about 25 litres per hour through any convenient form of absorption-flask; then through a combustion-tube packed for about 6in. of its length with platinised asbestos, and kept at a good red heat; and lastly through a second absorbing-flask (Winkler spirals or ordinary 10-bulb tubes answer extremely well as absorbing-flasks). The two flasks are charged with bromine water acidulated with hydrochloric acid. The first flask gives-those sulphur compounds -which are directly oxidized by bromine water, the second those which are only oxidized after passing the layer of heated platinum. In coal-gas this practically means that No. 1 gives the sulphuretted hydrogen and No. 2 the carbon-bisulphide. If, as is generally the case, only the total sulphur is needed, then the first absorbing-flask is, of course, to be omitted. The apparatus, once set up, needs no further attention. The only precipitate is the well-known barium-sulphate, and the results-obtained are more than accurate enough for. any technical purpose.