The diaries of Charles Darwin's wife have been published online, giving an unparalleled insight into the day-to-day life of the world's greatest naturalist.
Sixty pocket books are still in existence. They cover Emma Darwin's life from 1824, when on January 1 the 16-year-old girl records that she "played at charades", until her death in 1896.
"These books were found in a cardboard box in an old cupboard about 20 years ago," said the director of Darwin Online, Dr John van Wyhe. "People weren't really interested in the day-to-day Darwin then, just the Origin of Species."
This intimate record of Darwin's daily life, known to only a handful of scholars at Cambridge university until now, is in such a fragile state that academics could only use microfiche copies. Now it can be read in facsimile all over the world.
These little books record notes of intimate family and domestic matters, and chart the course of the illness that dogged much of Charles Darwin's adult life.
"Emma's diary is really special, really exciting," said Van Wyhe, "because it's daily coverage, right up close, for such a long time."
"Again and again the editions of [Charles Darwin's] letters are citing these diaries because they fill in the gaps. They tell us where Darwin was, who he saw and how he was."
The vivid detail of the diaries sometimes cuts across the major currents of Emma's life, and at other times is swept up in them. On the day of her wedding to Charles on January 29 1839 she writes only "came to town". Charles's "fatal attack" is recorded in a shaky hand the day before his death on April 19 1882. The family dog died, we learn, a day later.
Some of the entries use abbreviations or are in code.
"There's a system of exclamation points that we don't understand," explained Van Wyhe. "She also records her menstruation with a big X."