Note 116 — Chapter XV · IRON AND CHROME TANNAGES.
Reading edition
Acid of S.G. 1·16 (32° Tw.) contains 31·5 per cent. of HCl by weight or 36·6 grm. per liter, and therefore is practically 10 × normal strength. Acid of S.G. 1·2 (40° Tw.) contains 39·1 per cent. or 469 grm. per liter.