A general review, covering: (1) principles of tanning; (2) dressing of raw hides; (3) tanning materials and tools; (4) primitive methods of tanning; (5) the coloring of leather; (6) basic types of leather; (7) preservation of skins and leather. It is pointed out that in damp ground a skin is robbed of its preservative substances and completely destroyed. Although oil tannage makes leather waterproof, oil tanned leather is decomposed by catalysis when it comes into contact with metal, and resinous viscous matter results such as covered many objects in the tomb of Tutankhamun. Tawed leather is not so easy destroyed. Bark-tanned leather is conserved in watertight clay, dry calcareous ground and peaty soil, whereas strong decomposition may ensue in sandy grounds or rich earth. Leather will keep in the ground just so long as the pH-value is more than 6.4. T. S. -- AATA