Stephen, who has just returned to the Surprise after having spent sometime marooned without supplies or fresh water, explains to Jack how he survived:
‘…Tell me Stephen, what did you drink on that infernal rock?’
‘Boiled shit.’ Stephen was chaste in his speech, rarely an oath, never an obscene word, never any bawdy: his reply astonished Jack, who looked quickly at the tablecloth. Perhaps it was a learned term he had misunderstood. ‘Boiled shit,’ he said again. Jack smiled in a worldly fashion, but he felt the blush rising. ‘Yes. there was one single pool of rainwater left in a hollow. The birds defecated in it, copiously. Not with set intent - the whole rock is normally deep in their droppings - but enough to foul it to the pitch of nausea. the next day was hotter, if possible, and with the reverberation the liquid rose to an extraordinary temperature. I drank it, however, until it ceased to be a liquid at all; then I turned to blood…’
H.M.S. Surpise, Patrick O’Brian, p. 129 (Published by Harper Perennial, 2007)
I don’t know whether to be more impressed by Stephens determined survival instinct or by the fact that Jack appears to make use of exactly the same method I applied to surviving university seminars.