April 7th is World Health Day. World Health Day is sponsored by the World Health Organization to promote awareness of a specific theme of concern for WHO. The 2010 theme is '1000 Cities, 1000 Lives'. They are collecting 1000 stories of people contributing to health awareness and profiling 1000 cities around the world that promote health or cleanup campaigns.
Find out what else occurred on this day in science history.
1823 - Jacques-Alexandre-César Charles died.
Charles was a French physicist and inventor who described the relationship between the volume and absolute temperatures of ideal gases known as Charles's Law. He also built the first hydrogen filled balloon and the first manned hydrogen filled balloon.
1817 - Francesco Selmi was born.
Selmi was an Italian chemist who was a pioneer in colloid chemistry. He also coined the term 'ptomaine poisonoing' while studying putrification and poisons.
1816 - Christian Konrad Sprengel died.
Sprengel was a German theologian and botanist who was the first to describe the mechanics of pollination in plants. He observed how insects would transfer pollen from the stamen of one flower to the pistil of another. He also coined the term dichogamy to describe the process of maturation of the male and female parts at different times.
1795 - France adopts the metre as the standard unit of length.
France officially adopts the metre as the standard unit of length for the new metric system. They produced a standard length of brass that would represent the meter until one of platinum was constructed in 1799.