XCII. Observations on catechuic acid
Memoirs and Proceedings of the Chemical Society
Waldie, Esq., were elected Members ; and Rllessrs. Robert Hunt and John Mercer, Jun., as Associates of the Society. The following communications were then read :- XCII. Observutions 012 Catechic Acid. By JOHN THOMAS 4 SHORT time since I was requested to visit a tannery I- where the principal tanning ingredient employed was catechu, and among other matters my attention was directed to a whitish substance which made its appearance on the external surface of the leather when the tanning process
... tanning process was completed, and the uniform appearance of this substance over the whole surface is considered by the proprietors as the test of the perfection of their process of tanning, which is usually accomplished in about fourteen days. T h e tanning liquor is prepared by making an imperfect solution of the catechu in warm water, or in the liquor that has been previously partially exhausted of its tannin by a former operation; the depilated hides in their usual state are sewn up so as to form water-tight bags, into which the tanning liquid, prepared as above, is placed, so as to completely fill them; they are then placed on floors and turned once or twice a day into every C O O P E R , ESq.