On This Day In Chemistry

August 4th

French painter Nicolas-Jacques Conté was born on this day in 1755

He developed a method for making pencil leads, by mixing powdered graphite with clay and firing the mixture in a kiln. This method is still used to make pencils today. Until this point, pencil leads were made from pure graphite sticks that could only be imported to France from Cumbria in the UK. By varying the ratio of clay and graphite powder, the hardness of the pencil lead could also be changed.
 

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