ron base is peroxidized in the hide by means of the chromic acid, which is itself reduced to the state of sesquioxide, and remains with the iron and a portion of the alumina base, firmly united with the tissue.
3. The alum process consists in applying to the skins a saturated solution of alum and salt, followed by dressings of flour, yolk of eggs, oil, etc. See tawing.
For tanning in vacuo, see patents: —
23,360.Fergusson.Mar. 29, 185960,524.Johnston.Dec. 18, 1866
29,656.AldrichAug 21, 186075,391DotyMar 10, 1868
48,361.Brewer et al.June 27, 186584,190.HosmerNov. 17, 1868
Symonds' process for utilizing the useful matters which are not withdrawn from the bark by steeping, consists in burning the spent bark and conducting the products of combustion into a trough filled with water, where the solid and soluble portions are retained.
A vat with devices<