History
Grease from the early Egyptian or Roman eras is thought to have been prepared by combining lime with olive oil. The lime saponifies some of the triglyceride that comprises oil to give a calcium grease. In the middle of the 19th century, soaps were intentionally added as thickeners to oils. Over the centuries, all manner of materials have been employed as greases. For example, black slugs Arion ater were used as axle-grease to lubricate wooden axle-trees or carts in Sweden.
Read more about this topic: Grease (lubricant)
Famous quotes containing the word history:
““And now this is the way in which the history of your former life has reached my ears!” As he said this he held out in his hand the fatal letter.”
—Anthony Trollope (1815–1882)
“All history becomes subjective; in other words there is properly no history, only biography.”
—Ralph Waldo Emerson (1803–1882)
“What is most interesting and valuable in it, however, is not the materials for the history of Pontiac, or Braddock, or the Northwest, which it furnishes; not the annals of the country, but the natural facts, or perennials, which are ever without date. When out of history the truth shall be extracted, it will have shed its dates like withered leaves.”
—Henry David Thoreau (1817–1862)