REMEMBERING JOHN DALTON .

Lalit Berry 

John Dalton, a renowned physicist, chemist and meteorologist was born on September 6, 1766 in England. He is best known for introducing the Atomic Theory and for his research into Colour Blindness also referred to as Daltonism.

In 1787, at the age of 21, Dalton began his metrological diary in which he entered more than 2,00,000 observations in his life time. He rediscovered George Hadley's theory of atmospheric circulation.

Until the advent of aeroplanes and weather balloons, the only way to make measurements of temperature and humidity at altitude was to climb a mountain. Dalton estimated the height using a barometer. 

In 1794, he communicated his first paper on ' Extraordinary facts relating to the vision of colours'. His research into visual problem was so broadly recognized that Daltonism became a common term for colour blindness. 

In 1800, he presented an important series of lectures entitled ' Experimental essays on the constitution of mixed gases.' 

The most important of all Dalton's investigations are concerned with the atomic theory. His name is inseparably associated with this theory which was a new concept for the world. 

He also published papers on diverse topics such as rain, dew, origin of springs, heat, colour of sky, steam, reflection and refraction of light. 

Dalton never married and had only a few friends. He lived a modest and unassuming personal life. On July 27, 1844, in Manchester, Dalton fell from his bed and was found lifeless by his attendant.