Waterskin

A waterskin is a receptacle used to hold water. Normally made of a sheep or goat skin, it retains water naturally and therefore was very useful in desert crossings until the invention of the canteen, though waterskins are still used in some parts of the world. Though it may have been used over 5,000 years ago by tribal peoples, the first pictures of it are from ancient Assyrians, who used the bladders as floats in 3000 BCE. It also was used by large ancient empires such as Rome before the advent of the canteen.

Modern waterskins are often made of various plastic- or rubber-impregnated canvases, or sometimes simply thicker transparent plastics, and are often called water-pouches, water bags, or water bladders. Such modern waterskins offer many features, such as detachable straw-hoses, valves, refill openings of various widths, various closures and handles, styles of covering or cases, and removable cases or carry pouches.

Historical accounts
The use of waterskins, or skin-bottles, to transport water is documented in a wide range of historical sources. In the 2nd century CE, the Mishnah (compiled in Judea in 189 CE) mentions their common use among the inhabitants of the land. These skins, after being flayed from the carcass, dressed and prepared to contain liquid, could hold as little as 7 kabs (the equivalent of 168 eggs in volume, or about 2.6 USgal), or far more.

Goat skin bottles used to transport water were typically found all throughout the Near East, including the Arabian Peninsula, where, in Yemen, it was common in the 18th century to see a slave carrying a waterskin on his back, or else 3 or 4 waterskins carried by donkey or by camel from the water source. Most waterskins could hold between 4 and 6 impgal of water.

Uses
In some societies, waterskins were used to churn milk into butter, by suspending the skin bottle with ropes between a tripod and two persons moving the waterskin violently back and forth between them. The Tosefta speaks of oil and wine also being stored in skin bottles.

The Bedouins of the Negev would occasionally store clarified butter (samen) and olive-oil in special skins called (ʿukkah). Their volume would be between 15 and 25 L.

Preparation
In the Negev, goat-skins were used in making waterskins ( = al-girbah), and for making churning bags ( = al-siʿin). After flaying the carcass and removing the hairs, the skins were prepared by submerging the goat-skin in a boiled, bath solution containing the bark of either Acacia raddiana or Pistacia atlantica, or else the root of sumac (Rhus tripartita), or the rinds of pomegranates (Punica granatum), and left in that state of immersion for 1 to 3 days.

In Arabic, ʻiṣām is the tie of a waterskin, which is bound round the head to confine the contents. It is also the name of the strap that is used for carrying the waterskin; the name of the cord itself.