slow boat to china

[Sam Clements]

Supposedly Frank Loesser wrote the song of this name in 1948.

I can find a Washington Post column by Bill Gold in December, 1947 which
says:

"As the old proberb says, I'd like to get him on a slow boat to China."

I can find nothing earlier using Proquest or Newspaperarchive.

Was there truly an earlier proverb, or perhaps the song actually came out in
very late 1947 but has a publishing date of 1948.

Sam Clements