The introduction of the metric system in Dutch medicine 1820-1880 The Netherlands went metric in 1820 and the medical sciences were supposed to follow suit, except for apothecaries weight, which was very close to the Anglo-Saxon variant and was not abolished before 1870. Doctors and pharmacists had opposed metric weights in pharmacy in 1820 because they were afraid of errors that could lead to loss of life. On the continent old local and Paris units were used in general medical science. It took many decades for the metric system to become predominant in trade and daily life. The same slow acceptance was reflected in the medical sciences. Before it began to make tentative inroads, the metric system was entirely ignored for at least 15 years by the Dutch medical professions. Articles and other texts in medical magazines illustrate this. The slow advance of metric was also hindered by international, especially German influences. The other European nations began to go metric from 1840 onwards and France was the first to do so. Under Napoleon Bonaparte France had reverted to old units for daily life and retail trade in 1812. When Germany, a nation with a profound influence on Dutch medical science, went metric in 1870, the ultimate collapse of the old units began. Their presence in magazines dwindled and branches of medical science such as obstetrics and ophtalmology went metric; the former changed slowly and without planning, the latter went metric after an international agreement in 1866.