The Leatherworker in Eighteenth-Century Williamsburg / Being an Account of the Nature of Leather, & of the Crafts Commonly Engaged in the Making & Using of It.

THERE'S NOTHING LIKE TANNING

Homer’s Iliad contains what may be the earliest surviving literary reference to leathermaking. Describing the swaying fight for possession of Patroclus’s corpse, the author (in Pope’s translation) wrote:

As when the slaughter’d bull’s yet reeking hide,

Strain’d with full force, and tugged from side to side

The brawny curriers stretch; and labour o’er

The extended surface, drunk with fat and gore....

The untidy process here alluded to as currying was doubtless one of man’s first methods of making leather. It consisted of laboriously working into a hide or skin such greasy and albuminous substances as animal fats, brains, blood, milk, and so forth. The product, although technically not “leather,” had many of leather’s characteristics; this is a paradox that calls for some definitions. In the terminology of the trade:

Hides are the pelts of the larger animals—cattle, horses, buffalo, elephants, and so on;

Skins come from smaller animals—calves, sheep, goats, pigs, deer, beaver, etc.—and from birds, fish, and reptiles;

Leather is any hide or skin after it has been tanned.

As the legislature of colonial Virginia put it in 1691 (in an act that will shortly engage our attention again):

And for the avoyding of all ambiguities and doubts, which may and doe grow and arise upon the difinition and interpretation of this word leather, Be it enacted and declared, that hydes and skinns of oxe, steer, bull, cow, calfe, deer, goats and sheep being tann’d shall be, and ever hath been reputed and taken leather.

The key word is “tanned.” Like any organic matter, skins and hides will soon begin to decay unless they receive some kind of preservative treatment. They may be simply scraped and sundried—or salted or smoked or soaked in brine or in slaked lime. From some of these processes may come extremely tough and durable products—rawhide, parchment, and vellum are limed—but they are not leather because they have not been tanned.

Taneur This illustration from Diderot’s great eighteenth-century French encyclopedia shows the essential operations in a tannery: A) washing hides in a stream; B) scraping hair or flesh from a hide on the “beam”; C) soaking hides in a series of lime pits; D) bedding hides in a tanning vat with a layer of shredded bark between each hide; E) stirring lighter hides in a hot water tanning solution.

Tanning brings about within the fibrous structure of a pelt certain chemical and physical rearrangements that are still imperfectly understood. Their effect, however, is to render the pelt permanently imputrescible, pliable when dry, and capable of sustaining repeated wetting without hurt. The agents responsible for the transformation, known as “tannins,” are found in almost all plants, in certain minerals, and in various readily oxidizing oils.

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