| For the tannage of sole leather in the drum by the cutiloid process, about 120 per cent. |
| Thus the chrome tannage is reversible in solutions of ammonium or potassium oxalate and of ammonium acetate. |
| Another typical case of combination tannage is the Dongola leather produced by the use of gambier and of alum and salt. |
| His peat or humic acid tannage was patented by him about 1905, and is now worked on a commercial scale. |
| The second bath of the two-bath chrome tannage consists of a solution of sodium thiosulphate acidified with hydrochloric acid. |
| The possible combined tannages are numerous but are, in general, limited to the light leathers. Combination tannages are very ancient. |
