In the following year potato blight brought famine which impinged on the Darwins' servants and workmen, and led to overthrow of the Corn Laws. Darwin welcomed this, but as a landowner now found that it affected his income from rent and he wrote to his agent that "Although I am on principle a free-trader, of course I am not willing to make a larger reduction than necessary to retain a good tenant." Despite his own illness recurring, Darwin pressed on with "South America", having to jointly subsidise it with the publisher when the Treasury grant ran out, and it was completed by October 1846.