One-page installment of a serial article on fabric analysis from Posselt's Textile Journal, January 1916. It covers physical tests for identifying the raw materials in yarns and fabrics, concentrating on use of the compound microscope. It describes the microscope's parts, lighting, and how to tell dyed wool fibres from natural coloured ones. It also covers examining vegetable fibres and making cross-sections to distinguish silk from artificial silk. A line drawing of a microscope is included.