Apothecaries' system countries. The weight of an apothecaries' pound was 345.1 g in Spain and 344.2 g in Portugal. As in Italy, some of the additional subdivisions of the Roman system, such as the "obolo", were still in use there. It was standard to use the "marco", defined as 8 ounces, instead of the pound. In 18th century France, there was a national weight standard, the "marc de Paris" of 8 ounces. The civil pound of 16 ounces was equivalent to 2 marks, and it was also used as the apothecaries' pound. With 30.6 g, the ounces were considerably heavier than other
Pound (mass) 6750 troy grains, or 9600 Tower grains, derives from this pound, as 25 shilling-weights or 15 Tower ounces, for general commercial use. Multiple pounds based on the same ounce were quite common. In much of Europe, the apothecaries' and commercial pounds were different numbers of the same ounce. The Tower system was referenced to a standard prototype found in the Tower of London and ran concurrently with the avoirdupois and troy systems until the reign of Henry VIII, when a royal proclamation dated 1526 required that the troy pound to be used for mint purposes instead of the Tower pound.