One of the biggest hazards of deep sea
diving is something called the ‘bends’. The air was breath is 80% nitrogen. Put
the human body under pressure, and the nitrogen is transformed into tiny
bubbles that migrate into the blood and tissues. If the pressure is changed too
rapidly, as with a too quick ascent by a diver; the bubbles trapped within the
body begin to fizz like a freshly opened soda bottle, clogging tiny blood
vessels and depriving cells of oxygen and causing so excruciating pain that
sufferers are prone to bend in agony. A great deal of what we know about
surviving at extremes is owed to extraordinary father and son team of John
Scott and J.B.S. Haldane. Haldane’s gift to diving was to work the rest
intervals necessary to manage an ascent from the depths without getting the
bends. With Admiralty funding, JBS acquired a decompression chamber that he
called the ‘pressure pot.’ This was a metal cylinder in which three people
could sit at a time and could be sealed and subjected to tests of various
types. Volunteers were required to sit in ice water while breathing ‘aberrant
atmosphere’ or subjected to rapid changes or pressure. In one experiment,
Haldane simulated a dangerously hasty ascent and the dental fillings in his
teeth exploded. It is said that every experiment ended with someone having
seizures, vomiting or bleeding. The chamber was virtually soundproof, so the
only way for occupants to signal distress was to tap insistently on the chamber
wall or to hold up notes on the small window. Once while poisoning himself with
elevated levels of oxygen, Haldane had a fit so severe that he crushed several
vertebrae. Collapsed lungs were a routine hazard. Perforated eardrums were
quite common. Haldane in one of his essays writes “ the drum generally heals
up; and if the hole remains in it, although one is somewhat deaf, on can blow
tobacco smoke out of the ear in question, which is a social accomplishment.” It
was not just Haldane, but even his colleagues and family were subjects of his
experiments. Sent on a simulated descent, his wife had a fit that lasted 13
minutes. When at last she stopped bouncing across the floor, she was helped on
her feet and sent home to cook dinner. Haldane happily employed anyone who
happened to be around and on one occasion a former prime minister of Spain ,
Juan Negrin. Dr Negrin complained afterward of minor tingling and ‘curious
velvety sensation on the lips’ Dr Negrin was lucky, a similar experiment with
oxygen deprivation left Haldane without feeling his buttocks and lower spine
for six years.
Adapted from Bill Bryson’s “A short history
of nearly everything”