Henry Cavendish

            Henry Cavendish was an English chemist and physicist. He was born on October 10, 1731 in Nice, France. Henry was the son of Lady Anne Gray and Lord Charles Cavendish. He was born into the aristocracy, with both the Duke of Devonshire and the Duke of Kent as grandfathers. At the age of 11, Henry Cavendish was a pupil at Dr. Newcome's School in Hackney. At the age of 18, he entered Cambridge in St. Peter's College. He left four years later and did not graduate. .
             He performed many experiments on gases, and that formed the majority of his chemical researches. He was the first to recognize hydrogen, which he called inflammable air. Henry also made contributions to chemical theory. Cavendish approached most of his investigations through quantitative measurements. He established that hydrogen gas was a substance entirely different from ordinary air; he calculated their densities as well as the densities of several other gases. He established that common air and the air from a balloon from the upper atmosphere, is made up of nitrogen in a 4:1 ratio.
             Not all of Henry's work was in pure science. He also got into meteorology and other applied sciences. At one point he served as member of a committee that had a task to devise the best method of protecting a powder magazine at Purfleet from lightning. At another moment he helped investigate the physical properties of gold alloys, because of the government's concern over the loss of gold in coins.
             Cavendish spent numerous years studying electrical phenomena but published only two papers on the subject, in 1772 and 1776. He was also known for the person who calculated the mass of the Earth accurately. He used a torsion balance to measure the gravitational attraction between lead spheres in 1798, from which he calculated Newton's gravitational constant, "G" which he used to calculate the Earth's mass.
             Henry was a shy and quiet man, and he never married.