Xanthan is a gummy substance produced by a bacterium that takes its full scientific name—xanthomonas, Greek for yellow one—from the colour of the mould it produces. Xanthan has two uses: in the food industry it is used to stabilize emulsions—that is, it stops certain beverages or ready-made sauces from separating into a thick part that sinks to the bottom and a thin part that rises to the top; in the oil-well industry it is used as a lubricant in drilling-muds—that is, it makes the sludge surrounding a drill bit more slippery, so that the bit turns more easily as it chews through the earth. Xanthan was first commercially produced in the 1960s.