Laudanum by pharmacists in preparing Paregoric from Laudanum, and to note that the dosages in this article refer to Apothecaries weight and fluid measure. In particular, "the difference between a minim and a drop should be borne in mind when figuring doses. A minim is always a sixtieth part of a fluidrachm regardless of the character of the substance, while a drop varies from a forty-fifth to a two-hundred-and-fiftieth part, according to the surface tension of the fluid." Tincture of Opium (Laudanum) and Camphorated Tincture of Opium (Paregoric) each have 50.9 drops per gram; 50.0 drops per cc; 185.0 drops per
Laudanum other such drugs continued to be legally available without prescription as long as they were labeled. It is estimated that sale of patent medicines containing opiates decreased by 33% after labeling was mandated. In 1906 in Britain and in 1908 in Canada "laws requiring disclosure of ingredients and limitation of narcotic content were instituted". The Harrison Narcotics Tax Act of 1914 restricted the manufacture and distribution of opiates, including laudanum, and coca derivatives in the US. This was followed by France's "" in 1916, and Britain's Dangerous Drugs Act in 1920. Laudanum was supplied to druggists and physicians in regular