Apothecaries' system measure precious metals and stones. (The troy pound was already declared illegal for most other uses by the Weights and Measures Act of 1878.) In the US, the metric system replaced the apothecaries' system in the United States Pharmacopoeia of 1971. Apothecaries' system The apothecaries' system or apothecaries' weights and measures is a historical system of mass and volume units that were used by physicians and apothecaries for medical recipes, and also sometimes by scientists. The English version of the system is closely related to the English troy system of weights, the pound and grain being exactly the same in
Reuse of excreta Black Soldier Fly larvae with feces. The mature flies would then be a source of protein to be included in the production of feed for chickens in South Africa. It is known that additions of fecal matter up to 20% by dried weight in clay bricks does not make a significant functional difference to bricks. A Japanese sewage treatment facility extracts precious metals from sewage sludge. This idea was also tested by the US Geological Survey (USGS) which found that the sewage sludge generated by 1 million people contained 13 million dollars worth of precious metals. Debate is ongoing about