Career
He was elected at a by-election in May 1851, after the sitting Liberal Member of Parliament John Simeon had resigned his seat. The election was extremely unruly, with a violent mob causing damage and the death of one voter from a heart attack. The Times reported "The constituency of the isle has been in a perfect ferment during the whole of the election and broken panes and broken heads have been among the results".
Dawes (running on a policy of free trade) defeated his Conservative challenger Captain Hammond (who advocated protectionism) by 46 votes.
However, at the general election in July 1852 he was defeated by the Conservative Party candidate, Francis Venables-Vernon-Harcourt, who secured a majority of 101 votes. Dawes did not stand for Parliament again, but devoted himself to the study of agricultural chemistry.
He was the author of a number of tracts on the subject. Dawes suffered from heart disease, and died while on a visit to the health resort of Sidmouth, Devon in January 1856.
He was buried in the family vault at Street Helens, Isle of Wight.