It was instinct.

Like a desperado giving up the ghost, I desired to gasp by myself.
From being cast away with a brother, good God deliver me! The four days passed.

And on the morning of the fifth, thanks be to Heaven, there came a breeze.

Dancingly, mincingly it came, just rippling the sea, until it struck our sails, previously set at the very first token of its advance.

At length it slightly freshened; and our poor Chamois seemed raised from the dead.
Beyond expression delightful! Once more we heard the low humming of the sea under our bow, as our boat, like a bird, went singing on its way.
How changed the scene! Overhead, a sweet blue haze, distilling sunlight in drops.