A Lot (formerly Loth) was an old unit of measurement for the relative fineness_ (1896), The Journal of Political Economy, Vol. 4, p. 190. to gross weight in metallurgy and especially in coinage until the 19th century. A Lot was thus a proportion of the precious metal content in a piece of metal.Geissler, Ewald and Josef Moeller (1886). Real-Encyclopädie der Gesammten Pharmacie, Volume 9, p. 264. It was used in the four main monetary systems of Germany: Austrian, South German, North German and Hamburg.

The lot was defined as the sixteenth part of a Mark.Bringucci, Vannoccio (1990), Pirotechnia. New York: Dover. p. 209.Kelly, Patrick (1821), The Universal Cambist and Commercial Instructor. Vol 1. 2nd edn. London. p. 169. For example, in silver, the total weight was divided into 16 (proportional) Lots until about 1857, according to which a "12-Lot" silver alloy (750 silver) contained 12/16 = or 75% by weight of silver and 25% of another metal (usually copper). A 14-Lot silver alloy (), on the other hand, corresponded to 875 silver. For refinement, a Lot was further divided into 18 grains. Thus 14 Lots, 4 grains fine then correspond to a fineness of 888.89 ‰ = (14 + 4 / 18) / 16 = (252 + 4)/288, i.e. 256/288 grains.

The German proportional measure, the Lot, was finally replaced on 1 January 1888 in the German Empire by the proportional measure, permille (thousandths).

See also Carat for gold.

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