He served for just three months, from 15 February to 27 May 1901, during a period of great instability in Western Australian politics.

The son of a Pensioner Guard, he came to Western Australia on board the Scindian in 1850 with his parents, and was educated at the Perth Public School.

In 1897 Throssell joined Sir John Forrest's government as Commissioner of Crown Lands, a key responsibility in a rapidly developing colony.

However, in the election of the following April, the "ministerialists" or former Forrest supporters failed to attain a majority of seats.

He did not contest the 1904 election for health reasons, but returned to parliament in 1907 after winning a by-election for the Legislative Council's East Province, the electoral region that included Northam.