Manufacturer and builder 1, 1873
Owing to the fact that water-glass is gradually dissolved out of the wood, while chloride of zinc is volatile at the temperature where wood ignites, Sieburger proposes the following: Two coats of a hot saturated solution of three parts alum and one part ferrous sulphate are first applied and allowed to dry. The third coat is a dilute solution of ferrous sulphate, into which white potter's clay is stirred until it has the consistency of good water-colors. Another method is to apply hot glu water as long as it is absorbed into the pores of the wood. A thick coat of boiled glue is then applied, and while fresh is dusted over with apowder composed of one part sulphur, one part ochre or clay, and six parts of ferrous sulphate.