Abstract
A brief survey is given of the physical and chemical characteristics of celluIose ethers, which is gaining importance in industry. On the strength of patent literature, reference is made to the technological uses of cellulose ethers in the tobacco industry. A microscopical method of establishing the presence of cellulose ethers in reconstituted leaf and in new smoking products is described and reference is made to differences between methyI celluloses and carboxymethyl celluloses as they appear during the investigation. Other qualitative reactions and possibilities of quantitative determination are also summarised.