London: Thousands of personal letters by 19th-century naturalist Charles Darwin, including an unpublished account of watching his beloved daughter-in-law die an agonising death in childbirth, will be released to the public online for the first time.
The Cambridge University project will begin with a correspondence - some 1,400 letters - with his closest friend, the botanist Joseph Hooker.
It was to him that a devastated Darwin wrote in 1876: "I am sure you will pity us, when you hear that Amy was seized with convulsion which lasted for several hours, she then sunk into a stupor and I saw her expire at 7 o`clock this morning."
Digitising the historic papers of the celebrated British naturalist best known for his theory of evolution, follows the university`s online success with the archive of another scientist, Sir Isaac Newton, which has attracted millions of hits worldwide, The Independent reported.
Cambridge University Library houses the world`s largest and most significant collection of Darwin`s personal papers. The archive, some 9,000 letters, includes correspondence with leading thinkers of the day.
There are also notes from the famous Beagle voyage, and the earliest manuscripts outlining his theories, which scandalised Victorians by suggesting animals and humans had a common ancestry.
But no correspondence was more important to Darwin or to scholars than the Darwin-Hooker collection, according to Alison Pearn, Associate Director of the Darwin Correspondence Project.
The letters span 40 years from 1843 until Darwin`s death in 1882, and offer insight into their friendship.
"In perhaps his most famous letter of all, Darwin wrote to Hooker in 1844 of his growing conviction that species `are not ... Immutable` an admission he likened, half-jokingly, to `confessing a murder`. It was also to Hooker that Darwin sent the manuscript of On the Origin of Species for comment," Pearn said.
Of their letters, 300 have not been published before.
In another letter to Hooker, Darwin poured out his grief at the death of his daughter-in-law aged 26. She was the wife of his son, Francis.
Darwin wrote: "Thank God she never knew that she was leaving Frank and all of us for ever. I cannot think what will become of Frank. She helped and encouraged him in his scientific work and whether he will ever have heart to go on again. I cannot conceive. My dear old Friend I know that you will forgive me pouring out my grief."
"I don`t know of another letter [like it]. I don`t think there are many people to whom [Darwin] would have written in this way. This is unique insight into his attachment to his daughter-in-law," Pearn said.