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Many students know P.C. Ray only as "the father of Indian chemistry". The phrase hides a specific story: a laboratory discovery, decades of teaching and a company. This post sets out what reliable sources record about him, explains his most famous compound in Class 12 terms, and ends with what a student can take from his way of working.
Who was Prafulla Chandra Ray?
An ACS Publications article records that he was born on 2 August 1861 in Raruli, in Khulna district, now in Bangladesh, and died on 16 June 1944. He studied at the Metropolitan Institution in Calcutta and attended chemistry classes at Presidency College under Alexander Pedler, then went to the University of Edinburgh on a Gilchrist scholarship, where he took his BSc and DSc. A 2020 letter in the Indian Journal of Surgery dates the DSc to 1887 and notes that he taught at Presidency College.
What was special about mercurous nitrite?
Mercury forms two kinds of salts. In mercuric salts the ion is Hg²⁺. In mercurous salts it is the unusual double ion Hg₂²⁺, two mercury atoms bonded together. So mercurous nitrite is written Hg₂(NO₂)₂.
The ACS article records that in 1896 Ray discovered stable mercurous nitrite, which led to years of further work on nitrites and hyponitrites of different metals and earned him the nickname "Master of Nitrites". His later papers in the Journal of the Chemical Society show that programme in action, for example Decomposition of mercurous nitrite by heat (1903, with Jatindra Nath Sen) and Theory of the production of mercurous nitrite and of its conversion into various mercury nitrates (1905). Chemists still study why the compound behaves as it does, as in a 2020 Resonance article on its stability.
How did he build Indian chemistry?
Ray's influence went well beyond his own papers. The ACS article says he authored more than 150 original research articles and was loved by his students, and that he was founder president of the Indian Chemical Society.
He also believed Indians should make their own chemicals and medicines. The Department of Pharmaceuticals states that Bengal Chemicals and Pharmaceuticals was established in 1901 by Acharya P.C. Ray, and the Indian Journal of Surgery letter adds that he started the business in 1892 as an individual initiative. The same government page records that the company was nationalised in December 1980.
He was a historian of science as well. His A History of Hindu Chemistry appeared in 1902, and his autobiography, Life and Experiences of a Bengali Chemist, in 1932.
In 2011, the Royal Society of Chemistry honoured him with its Chemical Landmark plaque, the first awarded outside Europe, according to the Indian Journal of Surgery letter. The same article corrects a common social media claim: Ray had no connection with the discovery of hydroxychloroquine.
How this connects to your syllabus
Mercury's two oxidation states and the Hg₂²⁺ ion come up in Class 12 chemistry under d-block elements. Our guide to d- and f-block elements covers them. Ray's younger colleague in this story is Shanti Swarup Bhatnagar, whose textbook on magnetochemistry Ray praised in a letter.
If oxidation states and unusual ions like Hg₂²⁺ feel confusing, the Fermi Concept Library has a lesson for each concept in chemistry, so you can work through them one at a time.
What can a student take from his way of working?
Follow one result as far as it goes. A single unexpected compound became a whole research programme.
Teach and build. He taught for decades and set up a company that made chemicals and medicines in India.
Learn the history of your subject. He wrote a history of chemistry in India while doing laboratory research.
Check claims. Even about Ray, false stories circulate. Go to sources.
This week, write the formulas of mercurous chloride and mercuric chloride side by side, and explain in one line why the mercurous one is written Hg₂Cl₂.
