Henry+Cavendish

= = =HENRY CAVENDISH [1731-1810]= = = ==

=== //“A small bubble of air remained unabsorbed... if there is any part of the phlogisticated air [nitrogen] of our atmosphere which differs from the rest, and cannot be reduced to nitrous acid, we may safely conclude that it is not more than 1/120 part of the whole.// ===

**Cavendish’s Life And Achievements** Henry Cavendish was an English chemist and physicist. He was born in Nice in October 1731. He was the first to see hydrogen gas as a distinct substance. He also described the composition of water and made the first accurate measurement of the density of the Earth. He was a bright child, and at the age of 11 he became a pupil at Dr. Newcome's School in Hackney. In 1749 at the age of 18, he entered Cambridge in St. Peter's College which he left in 1753, without taking a degree. His father helped him conduct experiments on electricity, heat and magnetism. Later when his father died, he used the house to conduct most of his electrical research and his chemical experiments. He did many scientific studies but didn't publish and of his important discoveries. He was quiet, shy and was only sociable with his scientific friends. He showed that water is composed of oxygen and hydrogen and he also measured heats of fusion and evaporation as well as specific heats and those of the mixing of solutions in water. His measurements of the freezing points of different solutions showed the existence of compositions that yield minimum and maximum freezing points. Cavendish's experiments also consisted of capacitance. In his experiments, he measured the strength of a current by shocking himself and estimating the magnitude of the pain. He was the eldest son of Lord Cavendish. He went up to Cambridge, but, quit the place after three years without receiving a degree; He also inherited a fortune. He spent his whole life on scientific investigations. He discovered Hydrogen gas, and he determined the density of the Earth. He also observed that the gas obtained during the solution of copper in muriatic acid was rapidly absorbed by water.

**Notable Work Of Cavendish** Cavendish made many notable discoveries in chemistry. [mainly between 1766 and 1788, and in electricity, between 1771 and 1788] In 1798 he published a single notable paper on the density of the earth. At the time Cavendish began his chemical work. Cavendish reported his own work in "Three Papers Containing Experiments on Factitious Air." These papers added greatly to knowledge of the formation of hydrogen. He discovered the reaction between calcium carbonate and carbon dioxide to form calcium bicarbonate, the cause of temporary hardness of water. He also found out how to soften such water by adding lime (calcium hydroxide). This is important because now we have soft and hard water; one we drink and we do not.



The Apparatus: This a llowed the first determination of the mass of the Earth and allowed people to determine the masses of all the other planets. The torsion pendulum: He pioneered a ridiculously precise technique for measuring tiny forces, and really set the standard for precision tests of gravity. -1797

In 1784 Cavendish determined the composition of water, showing that it was a combination hydrogen and oxygen. He experimented a lot with water and the density of the air. He only published a small amount of the experimental evidence he had available to support his theories, but his peers were convinced of the correctness of his conclusions. Cavendish was an awkward and unusual man; this pushed people away because he was extremely timid. He is known for his exactness and accuracy with his calculations. **Henry Cavendish Award: discovering “chemistry”**

**Wanted Henry Cavendish**


During Cavendish’s his lifetime he made notable discoveries in chemistry. In 1798 he published a single paper on the density of the earth, but interest in this subject was evidently of long standing. No one despised Henry, but he was an unusual fellow and this turned people away from him. He was never married, and very scared of the opposite sex. He had odd habits such as obsessive compulsive disorder. He was intimated by woman, and was often known to “run away” and became embarrassed which put a damper on his reputation. He became a little more social, especially with his scientist friends which helped with learning and sharing information. **Dead or Alive**