Cambridge university publishes surviving Charles Darwin correspondence online

A member of staff walks under a portrait of Charles Darwin on show at an exhibition at Darwin's former home Down House, in Kent, southern England, on February 12, 2009. REUTERS/Tal Cohen (BRITAIN) - LM1E52C17DP01

The University of Cambridge in England has published all of Charles Darwin's surviving correspondence online for others to enjoy.

Darwin was an English naturalist, geologist and biologist who is famously known for his Theory of Natural Selection that would ultimately serve as the basis for the Theory of Evolution.

The 15,000 letters in the collection detail his time between 1822 and 1882, ranging from his time aboard the HMS Beagle to his end of life.

This will serve as a companion piece to the forthcoming print edition that is due out in 2023. The university notes that the online collection also has letters that were discovered too late to be included in the physical copies.

Many letters also include footnotes for added context. The centerpiece of the collection is undoubtedly the Origins of Species correspondence, and includes 400 letters that have come to light only in the last six years.

The set also includes letters from the final few months of Darwin's life in which he says "My course is nearly run". Darwin passed away at home on 19 April 1882 due to a heart attack and wrote those lines in February.

He also writes that he could not find any young researcher who "is not as deeply convinced of the truth of Evolution as I am."

The collection also has his wife Emma Darwin's final letter to Darwin's friend Jospeh Dalton Hooker informing him of his death.

"I cannot realize what life will be without him but I do feel through it all that with my children it is worth having," an excerpt from the letter read.