| Nil Ratan Dhar | |
| Birth Date: | 2 January 1892 |
| Birth Place: | Jolkhada, British India (now Jessore, Bangladesh) |
| Death Place: | Calcutta, West Bengal, India |
| Nationality: | British India, India |
| Fields: | Physical Chemistry, Soil Science |
| Workplaces: | University of Allahabad |
Nil Ratan Dhar FNA, FRSC (2 January 1892 – 5 December 1986) was an Indian professor of soil science and chemistry at the University of Allahabad, known for discovering thermal and photo-chemical fixation of atmospheric nitrogen in the soil.[1] He was the brother of a freedom fighter Jiban Ratan Dhar. He was known as the "father of Indian physical chemistry."[2] [3] [4] Dhar was a founding member of many scientific organizations like The World Academy of Sciences,[5] the National Academy of Sciences, India and the Sheila Dhar Institute of Soil Science, Allahabad.
He was born on 2 January 1892 in Jolkhada, British India (now Jessore, Bangladesh) to Prassana Kumar Dhar, a lawyer, his grandfather, Prem Chand Dhar, was a Zamindar of the place. and his mother Nirode Mohini Dhar, the daughter of a local zamindar.
He obtained his DSc from University of London in 1917. In 1919, he earned a doctorate of science in France. He was awarded honorary DCs from Banaras Hindu University, University of Allahabad, Jadavpur University, Gorakhpur University and Visva-Bharati University.
Dhar was elected a fellow of the Chemical Society of London (FCS) and the Institute of Chemistry (later the Royal Institute of Chemistry) in 1919.[1] In 1935, he was appointed a Foundation Fellow of the National Institute of Sciences of India (FNI, now the Indian National Science Academy.[6] Dhar was a corresponding member of the Academy of Sciences, France and a foreign member of the French Academy of Agriculture. He was nominated for the Nobel prize four times. He was also a founding member of the Indian Chemical Society and the National Academy of Sciences, India, and the president of both organizations from 1933 to 1934 and 1935–1937 respectively. Though not a founding member, he also served as the president of the Indian Society of Soil Sciences. Dhar was also a member of the Society of Biological Chemists, India. In 1961, he became the General President of the Indian Science Congress Association.