"KimDalkin" wrote in message
...
I just finished ready Jack London's "South Sea Island Tales".

In it he descibes Islanders preventing dehydration by sitting in sea
water. A hurrican had just destroyed the islands drinking water. He
describes it relieving thirst, though not getting rid of it entirely.

I spoke to a doctor friend of mine, and he thinks its pluasible. The
density of salt in the body is just slightly less than sea water. If
severely dehyrated, then reverse osmoosis would occur, and water would
pass through the skin back into the body.

Does reverse osmosis occur?
If so, should the Ancient Mariner of jumped into the sea, instead of
watching the boards shrink?

Kim



I suppose that
1. remaining cool and eliminating water loss in sweat and

2. breathing in more humid air and so reducing so-called insensible loss
(the amount of moisture needed to humidify air, about 500 mls per day, in
the nasopharynx before entering the lungs- the air that you breathe out is
fully humidified which is why it mists up mirrors)

would reduce water requirements.

I doubt that water transfer through the skin would be much as the skin is
designed to be water impermeable, otherwise we would leak all the time. Some
disease states (with marked oedema) result in water oozing out through the
skin but it is not common.

Seawater is much more concentrated than plasma- from memory about 5-6 times-
which is why one cannot drink seawater and survive. If it were only slightly
different to plasma then drinking seawater to survive would be possible.

Thus the Ancient Mariner was correct- Water, water everywhere, nor any drop
to drink.

Peter
(Physician)