I've heard of the Rajah of Dongala giving him fifty dollars' worth of trade goods and paying his passage in a prau only to get rid of him.

Fact.
And observe that nothing prevented the old fellow having Bamtz's throat cut and the carcase thrown into deep water outside the reefs; for who on earth would have inquired after Bamtz?
"He had been known to loaf up and down the wilderness as far north as the Gulf of Tonkin.

Neither did he disdain a spell of civilisation from time to time.

And it was while loafing and cadging in Saigon, bearded and dignified (he gave himself out there as a bookkeeper), that he came across Laughing Anne.
"The less said of her early history the better, but something must be said.

We may safely suppose there was very little heart left in her famous laugh when Bamtz spoke first to her in some low cafe.