From CNN (11 Aug 2010):
Online database reveals estates of Marx, Darwin
London, England (CNN) — A collection of wills reveals Karl Marx died a poor man and Charles Darwin left behind a large estate, an ancestry website said Wednesday.
The England and Wales National Probate Calendar, 1861-1941, reveals the value of more than 6 million estates, including some left by famous people.
It was published online Wednesday for the first time by Ancestry.co.uk.
……
Darwin, by contrast, left a personal estate worth 146,911 pounds (around 13 million pounds today) — $232,000 ($20.5 million today) — when he died in 1882, the website said.
The Dispersal of Darwin 