PART I

SECTION I

The Synthesis of Vegetable Tannins

1. Tannin 2. Digallic Acid 3. Ellagic Acid 4. Depsides Carbomethoxylation of Hydroxybenzoic Acids Chlorides of Carbomethoxyhydroxybenzoic Acids Preparation of Didepsides Preparation of Tridepsides Preparation of Tetradepsides Tannoid Substances of the Tannin Type Chart showing the Decomposition of Products of Tannin

SECTION II

Synthesis of Tanning Matters

1. Aromatic Sulphonic Acids 2. Condensation of Phenols Condensation of Hydroxybenzene Condensation of Dihydroxybenzene Trihydroxy benzene Polyhydroxybenzenes Quinone Phenolic Ethers Nitro Bodies Amino Bodies Aromatic Alcohols Aromatic Acids 3. Condensation of Naphthalene Derivatives 4. Condensation of the Anthracene Group 5. Di- and Triphenylmethane Groups 6. Summary

Table

SECTION III

Tanning Effects of Mixtures and Natural Products

1. Mixture of Phenolsulphonic Acid and Formaldehyde 2. Mixture of Phenolsulphonic Acid and Natural Tannins 3. Tanning Effects of Different Natural Substances

SECTION IV

Methods of Examining Tanning Matters